Enhancing the Visible Light Photoelectrochemical Water Splitting of TiO2 Photoanode via a p–n Heterojunction and the Plasmonic Effect

• Published in: Journal of physical chemistry. C Vol. 126; no. 28; pp. 11510 - 11517
• Main Authors: Cheng, Zhengwang, Hu, Zhilong, Ma, Xinguo, Wang, Mei, Gan, Neng, Pan, Minghu
• Format: Journal Article
• Language: English
• Published: American Chemical Society 21.07.2022
• Subjects: C: Energy Conversion and Storage
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.2c02798

Developing visible light-responding photoelectrocatalysts with higher efficiency is highly demanded and broadly concerned in terms of photoelectrochemical (PEC) water splitting. Here, we report that by constructing a TiO2/CuInS2 p–n junction and further decorating it with plasmonic Cu nanoparticles, the synthesized TiO2/CuInS2/Cu photoanodes show significantly enhanced visible light absorption and higher photoelectrocatalysis efficiency, benefiting from the joint influence of the built-in electric field and surface plasmonic resonance (SPR). Under >420 nm light irradiation, the photocurrent density is 2.36 mA/cm2 at 1.23 V vs reversible hydrogen electrode (RHE), enhanced by about 10 times than that of pure TiO2. Furthermore, the hydrogen production rate was enhanced from an undetectable level to 4.552 μmol/cm2/h. Our results exhibit that the strategy of a double-layer co-catalyst has promising applications in water splitting and other solar energy-conversion areas.