TiO2/graphene/CuSbS2 mixed-dimensional array with high-performance photoelectrochemical properties

Qianyuan Chen; Zhongchi Wang; Keqiang Chen; Qiang Fu; Yueli Liu; Yupeng Zhang; Delong Li; Chunxu Pan

doi:10.1039/c9ra07237c

TiO₂/graphene/CuSbS₂ mixed-dimensional array with high-performance photoelectrochemical properties

RSC Adv. 2019 Oct 21;9(58):33747-33754. doi: 10.1039/c9ra07237c. eCollection 2019 Oct 18.

Authors

Qianyuan Chen^{1

2}, Zhongchi Wang¹, Keqiang Chen², Qiang Fu³, Yueli Liu⁴, Yupeng Zhang², Delong Li², Chunxu Pan^{1

3}

Affiliations

¹ School of Physics and Technology, MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University Wuhan 430072 China cxpan@whu.edu.cn.
² Institute of Microscale Optoelectronics, College of Electronic Science and Technology, Shenzhen Key Laboratory of Flexible Memory Materials and Devices, Shenzhen University Shenzhen 518060 China ypzhang@szu.edu.cn ldlong19890809@163.com.
³ Center for Electron Microscopy, Wuhan University Wuhan 430072 China.
⁴ State Key Laboratory of Silicate Materials for Architectures, School of Materials Science and Engineering, Wuhan University of Technology Wuhan 430070 China.

Abstract

The growing demands for reproducible and clean sources of power has prompted the exploitation of novel materials for solar-energy conversion; in any case, the improvement of their conversion efficiency remains a big challenge. We report a mixed-dimensional heterostructure to synchronously enhance charge separation and light-absorption of the photoanodes via the introduction of two-dimensional reduced graphene oxide and zero-dimensional CuSbS₂ quantum dots on one-dimensional TiO₂ arrays. The experimental results show that the graphene sheets with a low Fermi level and a superior electron mobility accept photo-excited electrons from TiO₂ and enable fast electron transportation; while the CuSbS₂ quantum dots promote the visible light-absorption of the photoanode. The synergistic effects in this mixed-dimensional (1D-2D-0D) heterostructure photoanode induce a markedly raised photoconversion efficiency of 1.2% at 0.3 V and a photocurrent density of 5.5 mA cm^-2 at 0.4 V. Furthermore, the photocurrent density of the mixed-dimensional heterostructure exceeds previously reported TiO₂-based photoanodes in neutral media. The improved photoelectrochemical properties are attributed to the synergistic-effect-induced highly organized, mixed-dimensional architectures. It is expected that the mixed-dimensional heterostructure photoanode will be a potential candidate for applications in environmental remediation and energy fields.