Robust Organic Radical Cations with Near-Unity Absorption across Solar Spectrum

Robust Organic Radical Cations with Near-Unity Absorption across Solar Spectrum | 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 Robust Organic Radical Cations with Near-Unity Absorption across Solar Spectrum Zikai He, Shuai Zhang, Wenbin Huang, Yuxin Zhu, Jian Wang, Feng Cao, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5905584/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Developing low energy-gap materials for efficient photothermal conversion provides promising candidates for solar energy utilization. Herein, we explore the feasibility of employing robust organic radical cations as near-unity solar absorbers for practical seawater evaporation. Gram-scale organic radical cations are straightforwardly synthesized through single-electron oxidation. The open-shell structure and intervalence charge transfer (IVCT) characteristics of radicals enable near-unity absorption of full solar spectral irradiance. Femtosecond transient absorption spectroscopy reveals that the IVCT electron relaxes nonradiatively in femtoseconds, with a rapid rate of 5.26 × 1012 s. Notably, the radical cations exhibit exceptional stability, attributed to para-position protection, spin delocalization, and frontier orbitals inversion. By simply soaking cellulose paper, a highly efficient interfacial evaporation system is established. Under one sunlight irradiation, the system achieves a remarkable solar-to-vapor conversion efficiency of 110% and a high evaporation rate of 1.60 kg·m·h. This work opens a new avenue for applying robust radical cations as a cutting-edge candidate for photothermal materials. Physical sciences/Materials science/Materials for optics Physical sciences/Chemistry/Materials chemistry/Optical materials Physical sciences/Optics and photonics/Other photonics Full Text Additional Declarations There is NO Competing Interest. Supplementary Files OrganicradicacationphotothermalSI20250126.pdf ESI Cite Share Download PDF Status: Under Review 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. 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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-5905584","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":425165410,"identity":"d676e60d-33ff-4cf4-a8fa-f7b2cfb9affd","order_by":0,"name":"Zikai 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Herein, we explore the feasibility of employing robust organic radical cations as near-unity solar absorbers for practical seawater evaporation. Gram-scale organic radical cations are straightforwardly synthesized through single-electron oxidation. The open-shell structure and intervalence charge transfer (IVCT) characteristics of radicals enable near-unity absorption of full solar spectral irradiance. Femtosecond transient absorption spectroscopy reveals that the IVCT electron relaxes nonradiatively in femtoseconds, with a rapid rate of 5.26 × 10\u003c12/sup\u003e12 s\u003c-1/sup\u003e. Notably, the radical cations exhibit exceptional stability, attributed to para-position protection, spin delocalization, and frontier orbitals inversion. By simply soaking cellulose paper, a highly efficient interfacial evaporation system is established. 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