TiO₂/Ag₃PO₄ Nanocomposite on Polyurethane Nanofibers: A Dual-Function Filter for Formaldehyde Removal and Antibacterial Action

TiO₂/Ag₃PO₄ Nanocomposite on Polyurethane Nanofibers: A Dual-Function Filter for Formaldehyde Removal and Antibacterial Action | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article TiO₂/Ag₃PO₄ Nanocomposite on Polyurethane Nanofibers: A Dual-Function Filter for Formaldehyde Removal and Antibacterial Action Asghar Hadi, Hamed Akbari, Seyed Mahmood Eshagh Hoseini, Hesam Akbari, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7218349/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Introduction: The industrial use of chemicals, including volatile organic compounds (VOCs), has led to increased air pollution, which poses health risks such as irritation and cancer. The adverse effects of these chemicals have necessitated an efficient control method. One method of mitigating these risks is through effective filtration of VOCs like formaldehyde. Nanofiber-based filtration, especially using nanomaterials, has been shown to improve pollutant removal efficiency. This study aims to add TiO₂/Ag₃PO₄ nano photocatalyst onto polyurethane fibers to increase formaldehyde removal efficiency. Materials and Methods The in situ deposition method was used to synthesize TiO₂/Ag₃PO₄ photocatalyst. The electrospinning method was used to synthesize polyurethane fibers containing photocatalysts. Various characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and BET surface area analysis, were employed to assess the materials. The efficiency of the synthesized substrates for formaldehyde removal was evaluated in a continuous reactor. Also, antibacterial properties were evaluated using the disk diffusion method against Escherichia coli and Staphylococcus aureus. Results XRD results confirmed the crystalline structure of the TiO2/Ag3PO4 composite, indicating a suitable method for its synthesis. SEM revealed that the TiO₂/Ag₃PO₄ nanoparticles had an average size of 102 nm, and the electrospun fiber diameters were around 450 nm. The formaldehyde removal efficiency was highest (86%) for the filter containing 1.5% TiO₂/Ag₃PO₄. Additionally, antibacterial tests showed inhibition zones against both bacterial strains, indicating significant antibacterial activity. Discussion and Conclusion: The TiO₂/Ag₃PO₄ composite exhibited excellent photocatalytic properties due to the presence of the anatase phase of TiO₂. The highest removal efficiency occurred with 1.5% TiO₂/Ag₃PO₄, with a decrease in efficiency at higher nanoparticle concentrations, likely due to particle aggregation and reduced surface area for pollutant interaction. The pure polyurethane substrate showed a 38% removal efficiency, suggesting its potential for VOC absorption. The photocatalytic mechanism involves the interaction between Ag₃PO₄ and TiO₂, which enhances pollutant degradation. The antibacterial properties of the composite were attributed to the generation of silver ions and oxygen radicals. Overall, TiO₂/Ag₃PO₄ nanofiber filters offer a promising solution for both pollutant removal and antimicrobial applications. Physical sciences/Chemistry Earth and environmental sciences/Environmental sciences Physical sciences/Materials science Physical sciences/Nanoscience and technology Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction With the industrialization of societies, the use of various chemicals has become inevitable in continuing production processes, providing medical services, and meeting daily human needs. Many of these chemicals cause air pollution in the workplace or environment, harming human health ( 1 , 2 ). Volatile organic compounds (VOCs) are broadly used in the production of numerous day-to-day products for residential and commercial-based applications. Formaldehyde is one of the best-known volatile organic compounds. Studies have shown that exposure to formaldehyde can irritate the mucous membranes of the eyes and upper respiratory tract and may cause skin sensitization and urticaria ( 3 , 4 ). Chronic exposure to this substance can also lead to the development of cancer, so the International Agency for Research on Cancer (IARC) has classified formaldehyde as a human carcinogen ( 3 , 5 ). Inhalation is one of the most important routes of formaldehyde entry into the human body ( 6 ). Therefore, there is an increasing need for effective control methods to purify inhaled air from toxic gaseous pollutants. Various technologies have been developed to reduce volatile organic contaminants in the air, including photocatalytic oxidation, thermal oxidation, plasma, filtration, and biofiltration( 7 ). Filtration is a standard method for pollutant removal because it is flexible, cost-effective, and requires little energy ( 8 ). The filtration mechanism creates a porous medium in the airflow path that separates pollutants from the airflow. Nanofibers have significant filtration advantages due to their small diameter and high surface-to-volume ratio ( 9 ). In this regard, the use of nanofibers as filtration media has been investigated since the 1980s ( 10 ). Studies have shown that adding nanoparticles to polymer solutions significantly increases the efficiency of the media in removing pollutants ( 11 ). This study aims to add TiO2/Ag3PO4 nano photocatalyst to polyurethane fibers to investigate the formaldehyde removal efficiency and determine its antibacterial properties. Materials and methods Materials Tetrahydrofuran (THF), Dimethylformamide (DMF), Ethanol 99.5%, sodium hydrogen phosphate, and silver nitrate (AgNO₃) were purchased from Merck. For other materials used in this study, polyurethane granules were purchased from ChimoThane, and titanium dioxide (TiO₂) was purchased from US-NANO. Synthesis of TiO₂/Ag₃PO₄ Nanocomposite : The Ag 3 PO 4 /TiO 2 photocatalyst was synthesized using the in situ deposition method. To synthesize TiO 2 /Ag 3 PO 4 with a molar ratio of 25:75, 1.6 g of TiO 2 was sonicated with 50 mL of deionized water for 15 min to form a homogeneous suspension. 3.06 g of AgNO 3 was added to the suspension and stirred for 15 minutes at ambient temperature (22°C). 0.91 g of NaH 2 PO 4 powder was added to 50 ml of distilled water and dropwise to the solution containing TiO 2 and AgNO 3 . Due to the formation of Ag 3 PO 4 at this stage, the color of the solution changed to yellow. After 4 hours of stirring the suspension on a stirrer, TiO 2 /Ag 3 PO 4 particles form. The resulting suspension was then filtered and washed with a solution of equal volume percent ethanol and water. The remaining powder on the filter was placed in an oven at 60°C for 12 hours to dry ( 12 , 13 ). Preparation of Polyurethane Solution Polyurethane granules were placed in an oven at 80°C for 3 hours to prepare a pure polyurethane solution. To prepare a 10% by-weight pure polyurethane solution, 10 grams of polyurethane granules were added to 90 grams of a solution system containing equal weights of dimethylformamide and tetrahydrofuran. Using a magnetic stirrer, the resulting solution was stirred for 6 hours at 30°C. To prepare a polyurethane solution modified with TiO 2 /Ag 3 PO 4 at weight percentages of 1.5, 2, and 2.5, respectively, 1.5, 2, and 2.5 grams of TiO 2 /Ag 3 PO 4 were added to a beaker. Then, pure polyurethane solution was added until the total solution weight reached 10 grams. Electrospinning The polyurethane solution was placed in an ultrasonic bath for 10 minutes at 100% intensity to ensure uniform dispersion of the nano photocatalyst in the polyurethane solution. 4 ml of the solution was transferred into two tanks of the electrospinning machine. The electrospinning device's voltage was set to 18 kV, the needle-to-collector distance was 11 cm, and the solution injection flow rate was 1 ml/h. Product characterization Various analyses were performed to investigate the structural characteristics of the synthesized samples. XRD patterns were performed on the Tongda TD-3700 X-ray diffractometer with a Cu Kα radiation source in the range of 2θ = 10–80◦. BET data determination was calculated by the BET method using the BELSORP MINI II device under nitrogen gas adsorption. SEM images were taken with a FE-SEM, MIRA3 scanning electron microscope. Fourier transform infrared spectroscopy data were obtained using Tensor II. The XRD data was analyzed in HighScore Xpert 3.0 software to identify the phases in the synthesized sample. Also, ImageJ 1.52 software was used to analyze the images obtained from scanning electron microscopy. Formaldehyde Degradation Efficiency Test To test the formaldehyde removal efficiency, pure and Ag 3 PO 4 /TiO 2 modified electrospun substrates, with an area of ​​19.62 cm2, were placed separately in a degradation reactor equipped with one input and one output. As shown in Fig. 1 , 20 mL of formaldehyde was placed in an impinger and allowed to evaporate as airflow passed through it. Before the formaldehyde reached the degradation reactor, the formaldehyde concentration was equilibrated inside a sealed container called a mixing chamber. Another pump supplied pollution-free air to adjust the required concentration and flow rate. A chamber containing silica gel and activated carbon granules was used to remove moisture and other contaminants before the air entered the system. Particle filtration was also performed using a HEPA filter. Finally, the formaldehyde concentration was measured before and after passing through the degradation reactor using Fho Check (USA), and the formaldehyde removal efficiency of the synthesized substrates was determined. A 100-watt lamp was placed in the area adjacent to the degradation reactor, approximately 30 cm from the filter, to provide illumination for the start of the electrospinning process. Antibacterial Activity Test : The disk diffusion test was used to test the substrates' antibacterial properties on two types of bacteria: Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Beef extract agar medium was used to cultivate these bacteria. Bacterial suspension with a standard concentration of 0.5 McFarland was inoculated onto agar plates, and polyurethane filters containing TiO 2 /Ag 3 PO 4 nano photocatalysts with equal diameters were distributed on the surface of the culture medium. After incubation at 37°C for 24 hours, the zones of inhibition and antimicrobial effects were examined. Since it was not possible to use a 100-watt bulb due to the heat it would generate, 10 LED (Light-Emitting Diode) bulbs were used, which were turned on and off alternately every ten minutes using a dimmer. Results Figure 2 shows the XRD pattern of the synthesized nanocomposite. The XRD data were analyzed using HighScore Xpert 3.0 software, which showed that the obtained diffraction peaks showed high similarity with the reference patterns 00-006-0505 and 00-021-1276. These references correspond to silver phosphate (Ag 3 PO 4 ) and anatase titanium dioxide (TiO 2 ). The crystal structure of Ag 3 PO 4 was determined to be cubic with the P-43n space group, while TiO 2 was identified as having a tetragonal structure with the P42/mnm space group. To further investigate the functional groups involved in the structure of the synthesized sample, the nanoparticles of TiO 2 /Ag 3 PO 4 powder were analyzed using FTIR spectroscopy. Figure 3 shows the FTIR spectrum of the TiO 2 /Ag 3 PO 4 powder thin layer. FTIR analysis was performed in the wavenumber range of 400 cm⁻¹ to 4000 cm⁻¹. The broad peak observed in Fig. 3 , ranging from 400 cm⁻¹ to 800 cm⁻¹, is related to the stretching vibration of the Ti-O bond in the Ti-O-Ti network. The broad peak present near 3000 cm⁻¹ is related to the stretching vibration of the O-H bond of water molecules adsorbed in the sample. The peak in the 990 cm⁻¹ range is related to the stretching vibration of the PO 4 ³⁻ group. The SEM images of the TiO 2 /Ag 3 PO 4 sample and particle size distribution are shown in Fig. 4 .a. According to the image, the average size of the synthesized particles is 102 nm, and its standard deviation is 9.5 nm, indicating a relatively close size distribution. However, according to the particle size distribution diagram, the synthesized nanophotocatalysts show some variation in size. According to the diagram, the particle sizes have a normal distribution, and most particles are clustered around the mean value. Figure 4 .c shows SEM images of the polyurethane substrate synthesized with a polyurethane solution containing 1.5 wt% TiO 2 /Ag 3 PO 4 . The average size of nanophotocatalyst particles deposited on polyurethane fibers was about 80 nm. The average diameter of the synthesized polyurethane fibers was 450 nm. The synthesized fibers have a nearly uniform diameter and are free of beads. The BET method was used to determine the specific surface area of ​​the nano photocatalyst and the porosity of the substrates. According to the analysis results, the specific surface area of ​​the synthesized nanophotocatalyst was 12.82 m²/g, and the specific surface area of ​​the synthesized substrate was 2.89 m²/g. This study synthesized polyurethane substrates modified with TiO 2 /Ag 3 PO 4 nanoparticles to remove formaldehyde gas. After establishing and stabilizing a concentration of 2 ppm in the degradation reactor, the degradation efficiency for the filter containing 1.5 wt% TiO 2 /Ag 3 PO 4 was 86%, which brought the concentration to 0.28 ppm. The removal efficiency for filters containing 2 and 2.5 wt% TiO 2 /Ag 3 PO 4 was 72% and 65%, respectively, and for filters containing pure TiO 2 and pure polyurethane, it was 37% and 38%. To investigate the antibacterial properties of the synthesized substrates, a disk diffusion test was performed on two bacteria, Escherichia coli and Staphylococcus aureus. The test results in two states, dark and under visible light irradiation, are shown in Fig. 5 . The diameters of the inhibition zones are 42.5 mm in the plate containing Staphylococcus aureus under visible light irradiation (a), 31.5 mm in the plate containing Staphylococcus aureus in the dark (b), 36.5 mm in the plate containing Escherichia coli under visible light irradiation (c), and 29.5 mm in the plate containing Escherichia coli in the dark (d). Discussion and Conclusion According to the XRD diagram obtained for the synthesized particles and the existing standards, peaks related to the two components TiO 2 and Ag 3 PO 4 were identified, and no unidentified peaks indicating the introduc tio n of impurities into the sample were observed in the diagram. The presence of peaks for both TiO 2 and Ag 3 PO 4 components in the graph indicates that these two components were formed in the composite without chemical reaction during the synthesis process. The sharp and long peaks in the graph indicate the crystalline structure of the synthesized sample. According to a study by Wang et al., among the different polymorphs of TiO 2 , the anatase and brookite polymorphs have more excellent photocatalytic activity than the rutile polymorph. Considering that, according to the results obtained, the dominant phase of the synthesized sample is anatase, this nanocomposite will have significant photocatalytic properties. ( 14 ). According to the FTIR diagram, the peak in the range of 400 cm⁻¹ to 800 cm⁻¹ is related to the vibrations of Ti-O-Ti bonds in the anatase phase, which indicates the stability of TiO 2 during the synthesis process, which is consistent with the study of Barkhade et al. ( 15 ). Also, the peak around 1990 cm⁻¹ is related to the vibrations of the PO 4 3− group, which is consistent with the study by Zhang et al. confirming the formation of the TiO 2 /Ag 3 PO 4 composite ( 16 ). The FTIR results are in good agreement with the XRD analysis, and both tests confirm the formation of the TiO 2 /Ag 3 PO 4 composite. According to studies, one of the factors affecting the efficiency of pollutant removal in photocatalysts is their specific surface area. A higher specific surface area usually results in higher removal efficiency as more active sites are available for pollutant degradation. In this study, the specific surface area of ​​the synthesized photocatalyst was found to be 12.82 m²/g according to BET analysis. According to Formula 1, which is used to approximate the average particle diameter using the specific surface area, the average particle diameter was obtained to be 98.2 nm(Assuming a density of 4.765 grams per cubic centimeter)( 17 ). The calculated value is in good agreement with the particle size observed in scanning electron microscope images. d = 6/SSA⋅ρ Formula 1 d = particle diameter SSA = specific surface area ρ = density of the material In this study, the polyurethane filter synthesized with 1.5 wt% TiO 2 /Ag 3 PO 4 had the highest degradation efficiency. During the experimental process, it was observed that as the concentration of nanoparticles in the electrospinning solution increased, particle aggregation and the formation of larger particles occurred. This accumulation of particles blocked the exit path of the polymer solution and disrupted the synthesis process. Similar studies have shown that the amount of photocatalyst present on the synthesized substrate directly correlates with the pollutant destruction efficiency. However, increasing the amount of photocatalyst present on the substrate beyond a certain value reduces the efficiency of pollutant destruction. This effect may be due to the aggregation of the synthesized photocatalyst structure in dimensions beyond the nanoscale, which, on the one hand, reduces the specific surface area and consequently reduces the active sites for pollutant degradation and, on the other hand, increases the probability of electron and, hole recombination, which in turn further reduces the degradation efficiency. This effect was also observed in the study by Zhou et al., who studied the degradation of Rhodamine B using Ag@AgCl photocatalyst. In that study, the degradation percentage in polyurethane substrates containing 0.075, 0.1, and 0.125 M of Ag@AgCl photocatalyst was lower than that of a 0.05 M concentration. ( 18 ). For the pure polyurethane substrate, a removal efficiency of 38% was observed in this study. This is due to the polyurethane substrate's adsorption properties for volatile organic compounds, which were also observed in the study by Pham et al. Pham et al.'s study focused on removing hexane using a polyurethane substrate containing Ag and V co-doped TiO 2 . The results showed that the concentration of the hexane gas outlet was lower than that entering the reactor. Still, according to CO 2 monitoring, the concentration of CO 2 , which indicates hexane degradation, was zero. This decrease in concentration, despite the lack of hexane degradation, indicates the adsorption properties of the polyurethane substrate for volatile organic gases. In this study, the removal efficiency of the TiO 2 -containing substrate is slightly lower than that of the pure polyurethane substrate. The study by Pham et al. showed that the TiO 2 photocatalyst is not activated by visible light, and the filter containing TiO 2 had the same efficiency in both visible light and dark conditions( 19 ). The probable process of pollutant degradation for the TiO 2 /Ag 3 PO 4 photocatalyst is that the Ag 3 PO 4 photocatalyst is activated by visible light irradiation. As shown in Fig. 6 , according to the position of the valence and conduction bands of Ag 3 PO 4 and TiO 2 , the holes created in the Ag 3 PO 4 valence band are transferred to the TiO 2 valence band to achieve stability ( 20 , 21 ). This displacement causes the electron and hole to separate, which reduces the probability of recombination. The chain reactions carried out to remove formaldehyde are given in reactions 1 to 6( 22 ). Therefore, coupling Ag 3 PO 4 with TiO 2 is a scientific approach to achieving better photocatalytic effects. Reactions taking place in the conduction band of Ag 3 PO 4 e − cb + O 2 + H + → TiO 2 + HO 2 • Reaction 1 e − cb + H 2 O 2 → OH − + OH • Reaction 2 2O 2 − • + 2H 2 O → H 2 O 2 + 2OH − + O 2 Reaction 3 Reactions taking place in the valence band h + vb + H 2 O → OH • + H + Reaction 4 h + vb + OH − → OH • Reaction 5 Formaldehyde removal reaction OH • + O 2 + CO 2 H → CO 2 + H 2 O Reaction 6 According to the disk diffusion test performed on two bacteria, Escherichia coli and Staphylococcus aureus, filters containing nanoparticles under visible light irradiation showed significant antibacterial activity, which was also observed in the study by Mejía et al. ( 23 ). However, the synthesized filters also had antibacterial properties in the absence of visible light and in the dark. According to a study by Zhu et al., in composite materials, Ag + diffusion is one of the important factors affecting the antibacterial properties of the composite ( 24 ). According to Fig. 6 , Under visible light irradiation, holes by producing Ag + ions and electrons by producing active radicals O 2 − • are the active antibacterial species of the TiO 2 /Ag 3 PO 4 photocatalyst( 25 ). Our study showed that Ag 3 PO 4 /TiO 2 nanocomposite can be efficiently synthesized using in situ precipitation and polyurethane filters containing nanocomposite by electrospinning. Also, according to the results obtained, polyurethane filters containing 1.5% by weight of Ag 3 PO 4 /TiO 2 can effectively remove volatile organic pollutants and combat microbial agents in ventilation systems in environments such as pathology laboratories, hospitals, or other industries where there is simultaneous exposure to volatile organic pollutants and microbial agents. Declarations Funding This research was supported by Baqiyatallah University of Medical Sciences under Grant No. [402000116]. Author Contribution In this study, the contributions of the authors are as follows: A.H. conceived and developed the research idea. hamed.A. and A.H. performed the experiments. S. E., Hesam.A., A.M., and M.A. supervised the experiments and provided technical guidance. All authors contributed to writing, reviewing, and editing the manuscript, and approved the final version. Data Availability The datasets generated and/or analyzed during the present study are publicly available in the PicoFile repository via the following link: [https://s34.picofile.com/file/8486488034/Data.rar.html](https:/s34.picofile.com/file/8486488034/Data.rar.html) References Maroni, M., Seifert, B. & Lindvall, T. (eds) Indoor air quality: a comprehensive reference book (1995). Sabirova, A., Wang, S., Falca, G., Hong, P-Y. & Nunes, S. P. Flexible isoporous air filters for high-efficiency particle capture. Polymer 213 , 123278 (2021). Sakamoto, T., Doi, S. & Torii, S. 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Highly effective antibacterial activity and synergistic effect of Ag-MgO nanocomposite against Escherichia coli. J. Alloys Compd. 684 , 282–290 (2016). Lyu, Y. et al. Different antibacterial effect of Ag3PO4/TiO2 heterojunctions and the TiO2 polymorphs. J. Alloys Compd. 876 , 160016 (2021). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7218349","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":512979521,"identity":"b410911b-08b8-4965-8821-1c5d119b393e","order_by":0,"name":"Asghar Hadi","email":"","orcid":"","institution":"Baqiyatallah University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Asghar","middleName":"","lastName":"Hadi","suffix":""},{"id":512979522,"identity":"55bec21d-4580-4b16-bc44-4cfba305a730","order_by":1,"name":"Hamed 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Sciences","correspondingAuthor":false,"prefix":"","firstName":"Seyed","middleName":"Mahmood Eshagh","lastName":"Hoseini","suffix":""},{"id":512979524,"identity":"08e6f40f-5ff0-4431-832e-2d857d45992e","order_by":3,"name":"Hesam Akbari","email":"","orcid":"","institution":"Baqiyatallah University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Hesam","middleName":"","lastName":"Akbari","suffix":""},{"id":512979525,"identity":"ee11f4b7-9314-46d1-87e9-958bf6363811","order_by":4,"name":"Amir Mirshafiee","email":"","orcid":"","institution":"Baqiyatallah University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Amir","middleName":"","lastName":"Mirshafiee","suffix":""},{"id":512979526,"identity":"b58f0741-e770-47cf-adde-c7534fbe22aa","order_by":5,"name":"Mohammad Ali Amani","email":"","orcid":"","institution":"Baqiyatallah University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Mohammad","middleName":"Ali","lastName":"Amani","suffix":""}],"badges":[],"createdAt":"2025-07-26 04:23:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7218349/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7218349/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":91161020,"identity":"85fc06d0-1b5c-4f59-b971-6c9b04fdc8be","added_by":"auto","created_at":"2025-09-12 09:11:47","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":66013,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic of the formaldehyde destruction efficiency testing system\u003c/p\u003e","description":"","filename":"image1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7218349/v1/d4843bcdf89e1df11bc90dc2.jpg"},{"id":91161312,"identity":"2a522746-584c-4945-8d4f-7df77a6c0da0","added_by":"auto","created_at":"2025-09-12 09:19:47","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":132819,"visible":true,"origin":"","legend":"\u003cp\u003eXRD Pattern of Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e/TiO\u003csub\u003e2\u003c/sub\u003e Nanocomposite\u003c/p\u003e","description":"","filename":"image2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7218349/v1/fb27c1607a8e2be987f92924.jpeg"},{"id":91161022,"identity":"27c91fea-c58f-411a-80cf-41b5c9d81215","added_by":"auto","created_at":"2025-09-12 09:11:47","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":104236,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of Ag₃PO₄/TiO₂ samples\u003c/p\u003e","description":"","filename":"image3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7218349/v1/13bb7b4cc7fcb97d7eb38d06.jpeg"},{"id":91161311,"identity":"452f5ce0-9ada-4e69-98e1-7b7844b3395a","added_by":"auto","created_at":"2025-09-12 09:19:47","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":607414,"visible":true,"origin":"","legend":"\u003cp\u003ea) Scanning electron microscope image of Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e/TiO\u003csub\u003e2\u003c/sub\u003e. b) Particle size distribution diagram. c) Scanning electron microscope image of polyurethane filter containing Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e/TiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-7218349/v1/0cd3b4378d4ca8784ce7df58.png"},{"id":91161030,"identity":"4d2fd855-2638-4aa0-b4f5-fdd40da219b0","added_by":"auto","created_at":"2025-09-12 09:11:47","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":261359,"visible":true,"origin":"","legend":"\u003cp\u003eDisk diffusion analysis results: a) Filter with light irradiation on Staphylococcus aureus bacteria. b) Filter without light irradiation on Staphylococcus aureus bacteria. c) Filter with light irradiation on Escherichia coli bacteria. d) Filter without light irradiation on Escherichia coli bacteria.\u003c/p\u003e","description":"","filename":"image5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7218349/v1/5791e7cdd9b1c96a0cac18b0.jpeg"},{"id":91161029,"identity":"9e05f0f4-e7da-4794-ae1c-c1164473d7df","added_by":"auto","created_at":"2025-09-12 09:11:47","extension":"jpeg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":105833,"visible":true,"origin":"","legend":"\u003cp\u003eDegradation process in Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e/TiO\u003csub\u003e2\u003c/sub\u003e photocatalyst\u003c/p\u003e","description":"","filename":"image6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7218349/v1/eda219d4d96999b30888e1c0.jpeg"},{"id":91321840,"identity":"b0af985b-591a-470b-9dca-25aad531fcb7","added_by":"auto","created_at":"2025-09-15 09:16:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1966290,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7218349/v1/1057ebef-347c-433f-af05-87dbff76fe9e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eTiO₂/Ag₃PO₄ Nanocomposite on Polyurethane Nanofibers: A Dual-Function Filter for Formaldehyde Removal and Antibacterial Action\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eWith the industrialization of societies, the use of various chemicals has become inevitable in continuing production processes, providing medical services, and meeting daily human needs. Many of these chemicals cause air pollution in the workplace or environment, harming human health (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Volatile organic compounds (VOCs) are broadly used in the production of numerous day-to-day products for residential and commercial-based applications. Formaldehyde is one of the best-known volatile organic compounds. Studies have shown that exposure to formaldehyde can irritate the mucous membranes of the eyes and upper respiratory tract and may cause skin sensitization and urticaria (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Chronic exposure to this substance can also lead to the development of cancer, so the International Agency for Research on Cancer (IARC) has classified formaldehyde as a human carcinogen (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eInhalation is one of the most important routes of formaldehyde entry into the human body (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Therefore, there is an increasing need for effective control methods to purify inhaled air from toxic gaseous pollutants. Various technologies have been developed to reduce volatile organic contaminants in the air, including photocatalytic oxidation, thermal oxidation, plasma, filtration, and biofiltration(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eFiltration is a standard method for pollutant removal because it is flexible, cost-effective, and requires little energy (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). The filtration mechanism creates a porous medium in the airflow path that separates pollutants from the airflow. Nanofibers have significant filtration advantages due to their small diameter and high surface-to-volume ratio (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). In this regard, the use of nanofibers as filtration media has been investigated since the 1980s (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Studies have shown that adding nanoparticles to polymer solutions significantly increases the efficiency of the media in removing pollutants (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). This study aims to add TiO2/Ag3PO4 nano photocatalyst to polyurethane fibers to investigate the formaldehyde removal efficiency and determine its antibacterial properties.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003e\u003cstrong\u003eMaterials\u003c/strong\u003e\u003cp\u003eTetrahydrofuran (THF), Dimethylformamide (DMF), Ethanol 99.5%, sodium hydrogen phosphate, and silver nitrate (AgNO₃) were purchased from Merck. For other materials used in this study, polyurethane granules were purchased from ChimoThane, and titanium dioxide (TiO₂) was purchased from US-NANO.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eSynthesis of TiO₂/Ag₃PO₄ Nanocomposite\u003c/b\u003e: The Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e/TiO\u003csub\u003e2\u003c/sub\u003e photocatalyst was synthesized using the in situ deposition method. To synthesize TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e with a molar ratio of 25:75, 1.6 g of TiO\u003csub\u003e2\u003c/sub\u003e was sonicated with 50 mL of deionized water for 15 min to form a homogeneous suspension. 3.06 g of AgNO\u003csub\u003e3\u003c/sub\u003e was added to the suspension and stirred for 15 minutes at ambient temperature (22\u0026deg;C). 0.91 g of NaH\u003csub\u003e2\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e powder was added to 50 ml of distilled water and dropwise to the solution containing TiO\u003csub\u003e2\u003c/sub\u003e and AgNO\u003csub\u003e3\u003c/sub\u003e. Due to the formation of Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e at this stage, the color of the solution changed to yellow. After 4 hours of stirring the suspension on a stirrer, TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e particles form. The resulting suspension was then filtered and washed with a solution of equal volume percent ethanol and water. The remaining powder on the filter was placed in an oven at 60\u0026deg;C for 12 hours to dry (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cstrong\u003ePreparation of Polyurethane Solution\u003c/strong\u003e\u003cp\u003ePolyurethane granules were placed in an oven at 80\u0026deg;C for 3 hours to prepare a pure polyurethane solution. To prepare a 10% by-weight pure polyurethane solution, 10 grams of polyurethane granules were added to 90 grams of a solution system containing equal weights of dimethylformamide and tetrahydrofuran. Using a magnetic stirrer, the resulting solution was stirred for 6 hours at 30\u0026deg;C.\u003c/p\u003e\u003c/p\u003e\u003cp\u003eTo prepare a polyurethane solution modified with TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e at weight percentages of 1.5, 2, and 2.5, respectively, 1.5, 2, and 2.5 grams of TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e were added to a beaker. Then, pure polyurethane solution was added until the total solution weight reached 10 grams.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eElectrospinning\u003c/strong\u003e\u003cp\u003eThe polyurethane solution was placed in an ultrasonic bath for 10 minutes at 100% intensity to ensure uniform dispersion of the nano photocatalyst in the polyurethane solution. 4 ml of the solution was transferred into two tanks of the electrospinning machine. The electrospinning device's voltage was set to 18 kV, the needle-to-collector distance was 11 cm, and the solution injection flow rate was 1 ml/h.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eProduct characterization\u003c/strong\u003e\u003cp\u003eVarious analyses were performed to investigate the structural characteristics of the synthesized samples. XRD patterns were performed on the Tongda TD-3700 X-ray diffractometer with a Cu Kα radiation source in the range of 2θ\u0026thinsp;=\u0026thinsp;10\u0026ndash;80◦. BET data determination was calculated by the BET method using the BELSORP MINI II device under nitrogen gas adsorption. SEM images were taken with a FE-SEM, MIRA3 scanning electron microscope. Fourier transform infrared spectroscopy data were obtained using Tensor II.\u003c/p\u003e\u003c/p\u003e\u003cp\u003eThe XRD data was analyzed in HighScore Xpert 3.0 software to identify the phases in the synthesized sample. Also, ImageJ 1.52 software was used to analyze the images obtained from scanning electron microscopy.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eFormaldehyde Degradation Efficiency Test\u003c/strong\u003e\u003cp\u003eTo test the formaldehyde removal efficiency, pure and Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e/TiO\u003csub\u003e2\u003c/sub\u003e modified electrospun substrates, with an area of ​​19.62 cm2, were placed separately in a degradation reactor equipped with one input and one output. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, 20 mL of formaldehyde was placed in an impinger and allowed to evaporate as airflow passed through it. Before the formaldehyde reached the degradation reactor, the formaldehyde concentration was equilibrated inside a sealed container called a mixing chamber. Another pump supplied pollution-free air to adjust the required concentration and flow rate. A chamber containing silica gel and activated carbon granules was used to remove moisture and other contaminants before the air entered the system. Particle filtration was also performed using a HEPA filter. Finally, the formaldehyde concentration was measured before and after passing through the degradation reactor using Fho Check (USA), and the formaldehyde removal efficiency of the synthesized substrates was determined. A 100-watt lamp was placed in the area adjacent to the degradation reactor, approximately 30 cm from the filter, to provide illumination for the start of the electrospinning process.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eAntibacterial Activity Test\u003c/b\u003e: The disk diffusion test was used to test the substrates' antibacterial properties on two types of bacteria: Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Beef extract agar medium was used to cultivate these bacteria. Bacterial suspension with a standard concentration of 0.5 McFarland was inoculated onto agar plates, and polyurethane filters containing TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e nano photocatalysts with equal diameters were distributed on the surface of the culture medium. After incubation at 37\u0026deg;C for 24 hours, the zones of inhibition and antimicrobial effects were examined. Since it was not possible to use a 100-watt bulb due to the heat it would generate, 10 LED (Light-Emitting Diode) bulbs were used, which were turned on and off alternately every ten minutes using a dimmer.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the XRD pattern of the synthesized nanocomposite. The XRD data were analyzed using HighScore Xpert 3.0 software, which showed that the obtained diffraction peaks showed high similarity with the reference patterns 00-006-0505 and 00-021-1276. These references correspond to silver phosphate (Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e) and anatase titanium dioxide (TiO\u003csub\u003e2\u003c/sub\u003e). The crystal structure of Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e was determined to be cubic with the P-43n space group, while TiO\u003csub\u003e2\u003c/sub\u003e was identified as having a tetragonal structure with the P42/mnm space group.\u003c/p\u003e\u003cp\u003eTo further investigate the functional groups involved in the structure of the synthesized sample, the nanoparticles of TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e powder were analyzed using FTIR spectroscopy. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the FTIR spectrum of the TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e powder thin layer. FTIR analysis was performed in the wavenumber range of 400 cm⁻\u0026sup1; to 4000 cm⁻\u0026sup1;. The broad peak observed in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, ranging from 400 cm⁻\u0026sup1; to 800 cm⁻\u0026sup1;, is related to the stretching vibration of the Ti-O bond in the Ti-O-Ti network. The broad peak present near 3000 cm⁻\u0026sup1; is related to the stretching vibration of the O-H bond of water molecules adsorbed in the sample. The peak in the 990 cm⁻\u0026sup1; range is related to the stretching vibration of the PO\u003csub\u003e4\u003c/sub\u003e\u0026sup3;⁻ group.\u003c/p\u003e\u003cp\u003eThe SEM images of the TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e sample and particle size distribution are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.a. According to the image, the average size of the synthesized particles is 102 nm, and its standard deviation is 9.5 nm, indicating a relatively close size distribution. However, according to the particle size distribution diagram, the synthesized nanophotocatalysts show some variation in size. According to the diagram, the particle sizes have a normal distribution, and most particles are clustered around the mean value.\u003c/p\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.c shows SEM images of the polyurethane substrate synthesized with a polyurethane solution containing 1.5 wt% TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e. The average size of nanophotocatalyst particles deposited on polyurethane fibers was about 80 nm. The average diameter of the synthesized polyurethane fibers was 450 nm. The synthesized fibers have a nearly uniform diameter and are free of beads.\u003c/p\u003e\u003cp\u003eThe BET method was used to determine the specific surface area of ​​the nano photocatalyst and the porosity of the substrates. According to the analysis results, the specific surface area of ​​the synthesized nanophotocatalyst was 12.82 m\u0026sup2;/g, and the specific surface area of ​​the synthesized substrate was 2.89 m\u0026sup2;/g.\u003c/p\u003e\u003cp\u003eThis study synthesized polyurethane substrates modified with TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e nanoparticles to remove formaldehyde gas. After establishing and stabilizing a concentration of 2 ppm in the degradation reactor, the degradation efficiency for the filter containing 1.5 wt% TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e was 86%, which brought the concentration to 0.28 ppm. The removal efficiency for filters containing 2 and 2.5 wt% TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e was 72% and 65%, respectively, and for filters containing pure TiO\u003csub\u003e2\u003c/sub\u003e and pure polyurethane, it was 37% and 38%.\u003c/p\u003e\u003cp\u003eTo investigate the antibacterial properties of the synthesized substrates, a disk diffusion test was performed on two bacteria, Escherichia coli and Staphylococcus aureus. The test results in two states, dark and under visible light irradiation, are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. The diameters of the inhibition zones are 42.5 mm in the plate containing Staphylococcus aureus under visible light irradiation (a), 31.5 mm in the plate containing Staphylococcus aureus in the dark (b), 36.5 mm in the plate containing Escherichia coli under visible light irradiation (c), and 29.5 mm in the plate containing Escherichia coli in the dark (d).\u003c/p\u003e"},{"header":"Discussion and Conclusion","content":"\u003cp\u003eAccording to the XRD diagram obtained for the synthesized particles and the existing standards, peaks related to the two components TiO\u003csub\u003e2\u003c/sub\u003e and Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e were identified, and no unidentified peaks indicating the introduc\u003csub\u003etio\u003c/sub\u003en of impurities into the sample were observed in the diagram. The presence of peaks for both TiO\u003csub\u003e2\u003c/sub\u003e and Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e components in the graph indicates that these two components were formed in the composite without chemical reaction during the synthesis process. The sharp and long peaks in the graph indicate the crystalline structure of the synthesized sample. According to a study by Wang et al., among the different polymorphs of TiO\u003csub\u003e2\u003c/sub\u003e, the anatase and brookite polymorphs have more excellent photocatalytic activity than the rutile polymorph. Considering that, according to the results obtained, the dominant phase of the synthesized sample is anatase, this nanocomposite will have significant photocatalytic properties. (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eAccording to the FTIR diagram, the peak in the range of 400 cm⁻\u0026sup1; to 800 cm⁻\u0026sup1; is related to the vibrations of Ti-O-Ti bonds in the anatase phase, which indicates the stability of TiO\u003csub\u003e2\u003c/sub\u003e during the synthesis process, which is consistent with the study of Barkhade et al. (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Also, the peak around 1990 cm⁻\u0026sup1; is related to the vibrations of the PO\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e3\u0026minus;\u003c/sup\u003e group, which is consistent with the study by Zhang et al. confirming the formation of the TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e composite (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). The FTIR results are in good agreement with the XRD analysis, and both tests confirm the formation of the TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e composite.\u003c/p\u003e\u003cp\u003eAccording to studies, one of the factors affecting the efficiency of pollutant removal in photocatalysts is their specific surface area. A higher specific surface area usually results in higher removal efficiency as more active sites are available for pollutant degradation. In this study, the specific surface area of ​​the synthesized photocatalyst was found to be 12.82 m\u0026sup2;/g according to BET analysis. According to Formula 1, which is used to approximate the average particle diameter using the specific surface area, the average particle diameter was obtained to be 98.2 nm(Assuming a density of 4.765 grams per cubic centimeter)(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). The calculated value is in good agreement with the particle size observed in scanning electron microscope images.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ed\u0026thinsp;=\u0026thinsp;6/SSA\u0026sdot;ρ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFormula 1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"2\"\u003ed\u0026thinsp;=\u0026thinsp;particle diameter\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"2\"\u003eSSA\u0026thinsp;=\u0026thinsp;specific surface area\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"2\"\u003eρ\u0026thinsp;=\u0026thinsp;density of the material\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eIn this study, the polyurethane filter synthesized with 1.5 wt% TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e had the highest degradation efficiency. During the experimental process, it was observed that as the concentration of nanoparticles in the electrospinning solution increased, particle aggregation and the formation of larger particles occurred. This accumulation of particles blocked the exit path of the polymer solution and disrupted the synthesis process. Similar studies have shown that the amount of photocatalyst present on the synthesized substrate directly correlates with the pollutant destruction efficiency. However, increasing the amount of photocatalyst present on the substrate beyond a certain value reduces the efficiency of pollutant destruction. This effect may be due to the aggregation of the synthesized photocatalyst structure in dimensions beyond the nanoscale, which, on the one hand, reduces the specific surface area and consequently reduces the active sites for pollutant degradation and, on the other hand, increases the probability of electron and, hole recombination, which in turn further reduces the degradation efficiency. This effect was also observed in the study by Zhou et al., who studied the degradation of Rhodamine B using Ag@AgCl photocatalyst. In that study, the degradation percentage in polyurethane substrates containing 0.075, 0.1, and 0.125 M of Ag@AgCl photocatalyst was lower than that of a 0.05 M concentration. (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eFor the pure polyurethane substrate, a removal efficiency of 38% was observed in this study. This is due to the polyurethane substrate's adsorption properties for volatile organic compounds, which were also observed in the study by Pham et al. Pham et al.'s study focused on removing hexane using a polyurethane substrate containing Ag and V co-doped TiO\u003csub\u003e2\u003c/sub\u003e. The results showed that the concentration of the hexane gas outlet was lower than that entering the reactor. Still, according to CO\u003csub\u003e2\u003c/sub\u003e monitoring, the concentration of CO\u003csub\u003e2\u003c/sub\u003e, which indicates hexane degradation, was zero. This decrease in concentration, despite the lack of hexane degradation, indicates the adsorption properties of the polyurethane substrate for volatile organic gases. In this study, the removal efficiency of the TiO\u003csub\u003e2\u003c/sub\u003e-containing substrate is slightly lower than that of the pure polyurethane substrate. The study by Pham et al. showed that the TiO\u003csub\u003e2\u003c/sub\u003e photocatalyst is not activated by visible light, and the filter containing TiO\u003csub\u003e2\u003c/sub\u003e had the same efficiency in both visible light and dark conditions(\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe probable process of pollutant degradation for the TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e photocatalyst is that the Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e photocatalyst is activated by visible light irradiation. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e, according to the position of the valence and conduction bands of Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e and TiO\u003csub\u003e2\u003c/sub\u003e, the holes created in the Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e valence band are transferred to the TiO\u003csub\u003e2\u003c/sub\u003e valence band to achieve stability (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). This displacement causes the electron and hole to separate, which reduces the probability of recombination. The chain reactions carried out to remove formaldehyde are given in reactions 1 to 6(\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Therefore, coupling Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e with TiO\u003csub\u003e2\u003c/sub\u003e is a scientific approach to achieving better photocatalytic effects.\u003c/p\u003e\u003cp\u003eReactions taking place in the conduction band of Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabb\" border=\"1\"\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003ee\u003csup\u003e\u0026minus;\u003c/sup\u003e\u0026thinsp;\u003csub\u003ecb\u003c/sub\u003e + O\u003csub\u003e2\u003c/sub\u003e + H\u003csup\u003e+\u003c/sup\u003e \u0026rarr; TiO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;HO\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e\u0026bull;\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eReaction 1\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ee\u003csup\u003e\u0026minus;\u003c/sup\u003e\u0026thinsp;\u003csub\u003ecb\u003c/sub\u003e + H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e \u0026rarr; OH\u003csup\u003e\u0026minus;\u003c/sup\u003e + OH\u003csup\u003e\u0026bull;\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eReaction 2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2O\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e\u0026minus; \u0026bull;\u003c/sup\u003e + 2H\u003csub\u003e2\u003c/sub\u003eO \u0026rarr; H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;2OH\u003csup\u003e\u0026minus;\u003c/sup\u003e + O\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eReaction 3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"2\"\u003eReactions taking place in the valence band\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabc\" border=\"1\"\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eh\u003csup\u003e+\u003c/sup\u003e\u0026thinsp;\u003csub\u003evb\u003c/sub\u003e + H\u003csub\u003e2\u003c/sub\u003eO \u0026rarr; OH\u003csup\u003e\u0026bull;\u003c/sup\u003e + H\u003csup\u003e+\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eReaction 4\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eh\u003csup\u003e+\u003c/sup\u003e\u0026thinsp;\u003csub\u003evb\u003c/sub\u003e + OH\u003csup\u003e\u0026minus;\u003c/sup\u003e \u0026rarr; OH\u003csup\u003e\u0026bull;\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eReaction 5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"2\"\u003eFormaldehyde removal reaction\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabd\" border=\"1\"\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOH\u003csup\u003e\u0026bull;\u003c/sup\u003e + O\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;CO\u003csub\u003e2\u003c/sub\u003eH \u0026rarr; CO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;+\u0026thinsp;H\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eReaction 6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eAccording to the disk diffusion test performed on two bacteria, Escherichia coli and Staphylococcus aureus, filters containing nanoparticles under visible light irradiation showed significant antibacterial activity, which was also observed in the study by Mej\u0026iacute;a et al. (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e). However, the synthesized filters also had antibacterial properties in the absence of visible light and in the dark. According to a study by Zhu et al., in composite materials, Ag\u003csup\u003e+\u003c/sup\u003e diffusion is one of the important factors affecting the antibacterial properties of the composite (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). According to Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e, Under visible light irradiation, holes by producing Ag\u003csup\u003e+\u003c/sup\u003e ions and electrons by producing active radicals O\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e\u0026minus; \u0026bull;\u003c/sup\u003e are the active antibacterial species of the TiO\u003csub\u003e2\u003c/sub\u003e/Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e photocatalyst(\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eOur study showed that Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e/TiO\u003csub\u003e2\u003c/sub\u003e nanocomposite can be efficiently synthesized using in situ precipitation and polyurethane filters containing nanocomposite by electrospinning. Also, according to the results obtained, polyurethane filters containing 1.5% by weight of Ag\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e/TiO\u003csub\u003e2\u003c/sub\u003e can effectively remove volatile organic pollutants and combat microbial agents in ventilation systems in environments such as pathology laboratories, hospitals, or other industries where there is simultaneous exposure to volatile organic pollutants and microbial agents.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFunding\u003c/h2\u003e\u003cp\u003eThis research was supported by Baqiyatallah University of Medical Sciences under Grant No. [402000116].\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eIn this study, the contributions of the authors are as follows: A.H. conceived and developed the research idea. hamed.A. and A.H. performed the experiments. S. E., Hesam.A., A.M., and M.A. supervised the experiments and provided technical guidance. All authors contributed to writing, reviewing, and editing the manuscript, and approved the final version.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated and/or analyzed during the present study are publicly available in the PicoFile repository via the following link: [https://s34.picofile.com/file/8486488034/Data.rar.html](https:/s34.picofile.com/file/8486488034/Data.rar.html)\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMaroni, M., Seifert, B. \u0026amp; Lindvall, T. (eds) Indoor air quality: a comprehensive reference book (1995).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSabirova, A., Wang, S., Falca, G., Hong, P-Y. \u0026amp; Nunes, S. P. Flexible isoporous air filters for high-efficiency particle capture. \u003cem\u003ePolymer\u003c/em\u003e \u003cb\u003e213\u003c/b\u003e, 123278 (2021).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSakamoto, T., Doi, S. \u0026amp; Torii, S. Effects of formaldehyde, as an indoor air pollutant, on the airway. \u003cem\u003eAllergology Int.\u003c/em\u003e \u003cb\u003e48\u003c/b\u003e (3), 151\u0026ndash;160 (1999).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, W-X. et al. A review of plants formaldehyde metabolism: Implications for hazardous emissions and phytoremediation. \u003cem\u003eJ. Hazard. Mater.\u003c/em\u003e \u003cb\u003e436\u003c/b\u003e, 129304 (2022).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eProtano, C. et al. The Carcinogenic Effects of Formaldehyde Occupational Exposure: A Systematic Review. \u003cem\u003eCancers (Basel)\u003c/em\u003e ;\u003cb\u003e14\u003c/b\u003e(1). 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Alloys Compd.\u003c/em\u003e \u003cb\u003e876\u003c/b\u003e, 160016 (2021).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-7218349/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7218349/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction:\u003c/h2\u003e\u003cp\u003eThe industrial use of chemicals, including volatile organic compounds (VOCs), has led to increased air pollution, which poses health risks such as irritation and cancer. The adverse effects of these chemicals have necessitated an efficient control method. One method of mitigating these risks is through effective filtration of VOCs like formaldehyde. Nanofiber-based filtration, especially using nanomaterials, has been shown to improve pollutant removal efficiency. This study aims to add TiO₂/Ag₃PO₄ nano photocatalyst onto polyurethane fibers to increase formaldehyde removal efficiency.\u003c/p\u003e\u003ch2\u003eMaterials and Methods\u003c/h2\u003e\u003cp\u003eThe in situ deposition method was used to synthesize TiO₂/Ag₃PO₄ photocatalyst. The electrospinning method was used to synthesize polyurethane fibers containing photocatalysts. Various characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and BET surface area analysis, were employed to assess the materials. The efficiency of the synthesized substrates for formaldehyde removal was evaluated in a continuous reactor. Also, antibacterial properties were evaluated using the disk diffusion method against Escherichia coli and Staphylococcus aureus.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eXRD results confirmed the crystalline structure of the TiO2/Ag3PO4 composite, indicating a suitable method for its synthesis. SEM revealed that the TiO₂/Ag₃PO₄ nanoparticles had an average size of 102 nm, and the electrospun fiber diameters were around 450 nm. The formaldehyde removal efficiency was highest (86%) for the filter containing 1.5% TiO₂/Ag₃PO₄. Additionally, antibacterial tests showed inhibition zones against both bacterial strains, indicating significant antibacterial activity.\u003c/p\u003e\u003ch2\u003eDiscussion and Conclusion:\u003c/h2\u003e\u003cp\u003eThe TiO₂/Ag₃PO₄ composite exhibited excellent photocatalytic properties due to the presence of the anatase phase of TiO₂. The highest removal efficiency occurred with 1.5% TiO₂/Ag₃PO₄, with a decrease in efficiency at higher nanoparticle concentrations, likely due to particle aggregation and reduced surface area for pollutant interaction. The pure polyurethane substrate showed a 38% removal efficiency, suggesting its potential for VOC absorption. The photocatalytic mechanism involves the interaction between Ag₃PO₄ and TiO₂, which enhances pollutant degradation. The antibacterial properties of the composite were attributed to the generation of silver ions and oxygen radicals. Overall, TiO₂/Ag₃PO₄ nanofiber filters offer a promising solution for both pollutant removal and antimicrobial applications.\u003c/p\u003e","manuscriptTitle":"TiO₂/Ag₃PO₄ Nanocomposite on Polyurethane Nanofibers: A Dual-Function Filter for Formaldehyde Removal and Antibacterial Action","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-12 09:11:43","doi":"10.21203/rs.3.rs-7218349/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"edf7566d-6fa6-4198-897a-30074afa16c1","owner":[],"postedDate":"September 12th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":54615560,"name":"Physical sciences/Chemistry"},{"id":54615561,"name":"Earth and environmental sciences/Environmental sciences"},{"id":54615562,"name":"Physical sciences/Materials science"},{"id":54615563,"name":"Physical sciences/Nanoscience and technology"}],"tags":[],"updatedAt":"2025-09-15T09:08:15+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-12 09:11:43","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7218349","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7218349","identity":"rs-7218349","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}