Bandgap-adjusted bismuth tungstate-titanium dioxide S-scheme heterojunctions: Optimizing interfacial electronic structure for rapid VOC mineralization

Bandgap-adjusted bismuth tungstate-titanium dioxide S-scheme heterojunctions: Optimizing interfacial electronic structure for rapid VOC mineralization | 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 Research Article Bandgap-adjusted bismuth tungstate-titanium dioxide S-scheme heterojunctions: Optimizing interfacial electronic structure for rapid VOC mineralization Qian Yin, Hubdar Ali Maitlo, Ki-Hyun Kim This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9277031/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 8 You are reading this latest preprint version Graphical Abstract Abstract To strategically overcome the shortcomings of conventional photocatalysts, particularly inadequate redox potentials, a series of precisely engineered TiO-BiWO heterojunction photocatalysts, coded as TB-x (x presents the molar ratio% of Bi:Ti), has been designed through deliberate bandgap adjustment. An optimal interfacial electronic structure, formed by coupling wide-bandgap TiO (3.0–3.2 eV) with narrower-bandgap BiWO (2.6–2.9 eV), enables efficient charge dynamics under low-intensity UV irradiation (~ 1 W). The optimized TB-5 demonstrates complete removal of 5 ppm formaldehyde (FA: 100% X) within 600 seconds, achieving a clean air delivery rate of 10.37 L min and apparent quantum yield of 2.68E-01%. The exceptional activity is supported by the formation of a robust S-scheme heterojunction, as confirmed both experimentally and theoretically via density functional theory calculations. This charge preservation mechanism demonstrates remarkable robustness, achieving an 81.6% conversion of FA to CO in 2 hours even at a FA concentration of 100 ppm. DRIFTS analysis further suggests that FA oxidation proceeds sequentially through dioxymethylene and formate intermediates. This work thus establishes a foundational strategy for practical indoor air purification by integrating advanced S-scheme design with atomic-level mechanistic insight, charting a clear path from lab-scale discovery to real-world application Formaldehyde Photocatalytic air purification TiO2-Bi2WO6 S-scheme Charge transfer and reaction mechanism Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 07 May, 2026 Reviews received at journal 07 May, 2026 Reviews received at journal 03 May, 2026 Reviewers agreed at journal 30 Apr, 2026 Reviewers agreed at journal 26 Apr, 2026 Reviewers invited by journal 21 Apr, 2026 Submission checks completed at journal 21 Apr, 2026 First submitted to journal 20 Apr, 2026 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. 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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-9277031","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":629965761,"identity":"efc4e9ac-3c63-4911-9498-7004422bab8f","order_by":0,"name":"Qian Yin","email":"","orcid":"","institution":"Hanyang University","correspondingAuthor":false,"prefix":"","firstName":"Qian","middleName":"","lastName":"Yin","suffix":""},{"id":629965762,"identity":"1f4b2557-7525-47c0-b953-8df8be08cf66","order_by":1,"name":"Hubdar Ali Maitlo","email":"","orcid":"","institution":"Hanyang University","correspondingAuthor":false,"prefix":"","firstName":"Hubdar","middleName":"Ali","lastName":"Maitlo","suffix":""},{"id":629965763,"identity":"e762621b-feea-4096-b86e-409f53cca792","order_by":2,"name":"Ki-Hyun Kim","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA80lEQVRIiWNgGAWjYBACCR7GBoYPBjYJSGJshLUwzihII0kLAwMzx4fDJGiR7DncupnB4Hwe/+wew88Fvxjk+RvY0j7g0yLN29h2u8DgdrHEnTPG0jP7GAxnHGA7PAOfFjl+xrbbMwxuJzbcyDGQ5u1hYNzAwN6M12FgLTwG5xLn38gx/g3UYk9QC9hhPAYHEjfcyDGT5vnBkLiBge0wXi2SPQfbbs4wSE7ceCOtzJq3QSJ5xmG2ZLxaJM6kP7vx4Y9d4rwbyZtv8/yxse1vbzPGqwUJcBgwMLZJAKOJWA0MDOwPGBj+EK98FIyCUTAKRg4AAO9wS/5Qu0ZaAAAAAElFTkSuQmCC","orcid":"","institution":"Hanyang University","correspondingAuthor":true,"prefix":"","firstName":"Ki-Hyun","middleName":"","lastName":"Kim","suffix":""}],"badges":[],"createdAt":"2026-03-31 08:42:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9277031/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9277031/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108167660,"identity":"57f1069b-a1fc-40d7-9206-f0c503b23192","added_by":"auto","created_at":"2026-04-30 06:22:54","extension":"png","order_by":16,"title":"","display":"","copyAsset":false,"role":"graphical-abstract","size":589436,"visible":true,"origin":"","legend":"To strategically overcome the shortcomings of conventional photocatalysts, particularly inadequate redox potentials, a series of precisely engineered TiO-BiWO heterojunction photocatalysts, coded as TB-x (x presents the molar ratio% of Bi:Ti), has been designed through deliberate bandgap adjustment. 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