Nature of Conduction Band Tailing in Hydrogenated Titanium Dioxide for Photocatalytic Hydrogen Evolution

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• 作者：Jiawei Xue ; Xiaodi Zhu ; Dr. Yi Zhang ; Dr. Wendong Wang ; Wei Xie ; Jilong Zhou ; Prof. Dr. Jun Bao ; Ying Luo ; Xiang Gao ; Dr. Yong Wang ; Dr. Ling-yun Jang ; Prof. Dr. Song Sun and Prof. Dr. Chen Gao
• 刊名：ChemCatChem
• 出版年：2016
• 出版时间：June 21, 2016
• 年：2016
• 卷：8
• 期：12
• 页码：2010-2014
• 全文大小：1555K
• ISSN：1867-3899

文摘

The involvement of oxygen vacancies in the electronic and structural properties and photocatalytic activity of hydrogenated TiO₂ (H-TiO₂) for water splitting are currently under debate. Herein, the process for the formation of oxygen vacancies in H-TiO₂ is illustrated for the first time to verify the role of these vacancies on the surface and in the bulk of H-TiO₂ by using surface-sensitive soft X-ray techniques and bulk-information-included hard X-ray techniques for the O K-edges and Ti K-edges, respectively. We find that oxygen vacancies on the surface and in the bulk contribute differently to tailing of the conduction band of H-TiO₂. By controlling the degree of hydrogenation to restrict tailing of the conduction band to just above the H⁺/H₂ redox potential, the most favorable disordered structure for photocatalytic H₂ evolution is developed. This work promotes a better understanding of the possible negative consequence of hydrogenated semiconductors in H₂ evolution apart from the positive effect on visible-light response.