Enhanced Photocatalysis of Black TiO2/Graphene Composites Synthesized by a Facile Sol-Gel Method Combined with Hydrogenation Process

Zhaoqing Li; Zhufeng Liu; Xiao Yang; Annan Chen; Peng Chen; Lei Yang; Chunze Yan; Yusheng Shi

doi:10.3390/ma15093336

Enhanced Photocatalysis of Black TiO₂/Graphene Composites Synthesized by a Facile Sol-Gel Method Combined with Hydrogenation Process

Materials (Basel). 2022 May 6;15(9):3336. doi: 10.3390/ma15093336.

Authors

Zhaoqing Li¹, Zhufeng Liu¹, Xiao Yang¹, Annan Chen¹, Peng Chen¹, Lei Yang¹, Chunze Yan¹, Yusheng Shi¹

Affiliation

¹ State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.

Abstract

In this study, in situ TiO₂ was grown on the surface of graphene by a facile sol-gel method to form black TiO₂/graphene composites with highly improved photocatalytic activity. The combination of graphene and TiO₂ was beneficial to eliminate the recombination of photogenerated electron holes. The self-doping Ti³⁺ was introduced, accompanied by the crystallization of amorphous TiO₂, during the hydrogenation process. Consequently, the narrowed bandgap caused by self-doping Ti³⁺ enhanced the visible light absorption and thus made the composites appear black. Both of them improved the photocatalytic performance of the synthesized black TiO₂/graphene composites. The band structure of the composite was analyzed by valence band XPS, revealing the reason for the high visible light catalytic performance of the composite. The results proved that the black TiO₂/graphene composites synthesized show attractive potential for applications in environmental and energy issues.

Keywords: Ti3+ self-doping; graphene; hydrogenation; photocatalysis; titanium dioxide.

Grants and funding

This research was funded by the National Natural Science Foundation of China (No. 51805185), the Hubei Provincial technical innovation major program (No. 2017AAA109), the Wuhan Science and Technique Foundation (No. 2018010401011281), and Shenzhen Knowledge Innovation Program (No. 20180213102634650).