Electron Tandem Transport Channel in a Cu<sub>3</sub>P/Sv-ZnIn<sub>2</sub>S<sub>4</sub> p–n Heterojunction for Photothermal-Photocatalytic Benzyl Alcohol Oxidation and H<sub>2</sub> Production
Haopeng Jiang, Jinghang Xu, Lijuan Sun, Jinhe Li, Lele Wang, Weikang Wang, Qinqin Liu, Juan Yang
Abstract
The development of photocatalytic systems with an electron tandem transport channel represents a promising avenue for improving the utilization of photogenerated electrons and holes despite encountering significant challenges. In this study, ZnIn 2 S 4 (Sv-ZIS) with sulfur vacancies was fabricated using a solvothermal technique to create defect energy levels. Subsequently, Cu 3 P nanoparticles were coupled onto the surface of Sv-ZIS, forming a Cu 3 P/Sv-ZIS p–n heterojunction with an electron tandem transport channel. Experimental findings demonstrated that this tandem transport channel enhanced the carrier lifetime and separation efficiency. In addition, mechanistic investigations unveiled the formation of a robust built-in electric field (BEF) at the interface between Cu 3 P and Sv-ZIS, providing a driving force for electron migration. The combined consequences of the transport channel, the strong BEF, and photothermal effect led to a surface carrier separation efficiency of 65.85%. Consequently, Cu 3 P/Sv-ZIS achieved simultaneous H 2 yield and benzaldehyde production rates of 18,101.4 and 15,012.6 μmol·g –1 ·h –1, which were 2.31 and 2.62 times higher than those of ZnIn 2 S 4, respectively. This work exemplifies the design of the p–n heterojunction for the efficient utilization of photogenerated electrons and holes.