Efficient photocatalysis with graphene oxide/Ag/Ag2S-TiO2 nanocomposites under visible light irradiation

Shuang Shuang; Ruitao Lv; Xiaoyang Cui; Zheng Xie; Jian Zheng; Zhengjun Zhang

doi:10.1039/c7ra13501g

Efficient photocatalysis with graphene oxide/Ag/Ag₂S-TiO₂ nanocomposites under visible light irradiation

RSC Adv. 2018 Feb 5;8(11):5784-5791. doi: 10.1039/c7ra13501g. eCollection 2018 Feb 2.

Authors

Shuang Shuang¹, Ruitao Lv², Xiaoyang Cui¹, Zheng Xie^{1

3}, Jian Zheng⁴, Zhengjun Zhang²

Affiliations

¹ State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University Beijing 100084 China.
² Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University Beijing 100084 China zjzhang@tsinghua.edu.cn.
³ High-Tech Institute of Xi'an Xi'an 710025 China.
⁴ Department of Chemistry, University of Oslo Sem Sælands Vei 26 0371 Oslo Norway.

Abstract

Lack of visible light response and low quantum yield hinder the practical application of TiO₂ as a high-performance photocatalyst. Herein, we present a rational design of TiO₂ nanorod arrays (NRAs) decorated with Ag/Ag₂S nanoparticles (NPs) synthesized through successive ion layer adsorption and reaction (SILAR) and covered by graphene oxide (GO) at room temperature. Ag/Ag₂S NPs with uniform sizes are well-dispersed on the TiO₂ nanorods (NRs) as evidenced by electron microscopic analyses. The photocatalyst GO/Ag/Ag₂S decorated TiO₂ NRAs shows much higher visible light absorption response, which leads to remarkably enhanced photocatalytic activities on both dye degradation and photoelectrochemical (PEC) performance. Its photocatalytic reaction efficiency is 600% higher than that of pure TiO₂ sample under visible light. This remarkable enhancement can be attributed to a synergy of electron-sink function and surface plasmon resonance (SPR) of Ag NPs, band matching of Ag₂S NPs, and rapid charge carrier transport by GO, which significantly improves charge separation of the photoexcited TiO₂. The photocurrent density of GO/Ag/Ag₂S-TiO₂ NRAs reached to maximum (i.e. 6.77 mA cm^-2 vs. 0 V). Our study proves that the rational design of composite nanostructures enhances the photocatalytic activity under visible light, and efficiently utilizes the complete solar spectrum for pollutant degradation.