In Situ Induced Visible-Light Photoeletrocatalytic Activity from Molecular Oxygen on Carbon Aerogel-Supported TiO2

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• 作者：Yuning Jin ; Guohua Zhao ; Meifen Wu ; Yanzhu Lei ; Mingfang Li ; Xueping Jin
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：May 26, 2011
• 年：2011
• 卷：115
• 期：20
• 页码：9917-9925
• 全文大小：1075K
• 年卷期：v.115,no.20(May 26, 2011)
• ISSN：1932-7455

文摘

This study presents a stable, efficient visible-light photoelectrocatalytic method induced by molecular-oxygen assistance on a carbon aerogel-supported TiO₂ (TiO₂/CA) electrode, which combines the in situ surface synthesis of H₂O₂ and Ti-peroxide photocatalysis under visible light. Results reveal that the optical absorption edge for TiO₂/CA, which is cathodic polarized under aerobic conditions, is red-shifted to 530 nm. Under visible light (位 > 420 nm) irradiation, the increment from dark current to photocurrent density obtained on TiO₂/CA is 315 times that on TiO₂/ITO. The mechanism of the molecular-oxygen-induced visible light photoeletrocatalytic activity is proposed and further verified through investigating the hydroxyl radical evolution and monitoring the surface changes of photocatalyst by Raman spectra and diffuse reflection spectra (DRS). This method is further applied in the degradation of the Rhodamine 6G (Rh-6G) wastewater. The result shows that Rh-6G molecules are almost totally decomposed with high TOC removal by the in situ induced photoelectrocatalytic process on TiO₂/CA (TiO₂/CA,PE-O₂), which is closely related to the degradation mechanism and pathway of the pollutant. It is found that the intermediate products detected in the TiO₂/CA,PE-O₂ process are less than those in the traditional photocatalytic degradation on TiO₂/ITO.