Novel noble-metal-free Co2P/CdIn2S4 heterojunction photocatalysts for elevated photocatalytic H2 production: Light absorption, charge separation and active site

Xiaohui Ma; Wenjun Li; Hongda Li; Mei Dong; Liang Geng; Tianyu Wang; Hualei Zhou; Yanyan Li; Mengchao Li

doi:10.1016/j.jcis.2023.02.062

Novel noble-metal-free Co₂P/CdIn₂S₄ heterojunction photocatalysts for elevated photocatalytic H₂ production: Light absorption, charge separation and active site

J Colloid Interface Sci. 2023 Jun:639:87-95. doi: 10.1016/j.jcis.2023.02.062. Epub 2023 Feb 15.

Authors

Xiaohui Ma¹, Wenjun Li², Hongda Li³, Mei Dong¹, Liang Geng¹, Tianyu Wang¹, Hualei Zhou⁴, Yanyan Li¹, Mengchao Li¹

Affiliations

¹ Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, University of Science and Technology Beijing, Beijing 100083, China.
² Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, University of Science and Technology Beijing, Beijing 100083, China. Electronic address: wjli_ustb@163.com.
³ School of Microelectronics and Materials Engineering, Guangxi University of Science and Technology, Liuzhou 545006, China.
⁴ Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, University of Science and Technology Beijing, Beijing 100083, China. Electronic address: hlzhou@ustb.edu.cn.

PMID: 36804796
DOI: 10.1016/j.jcis.2023.02.062

Abstract

Constructing heterojunctions is an effective and controllable approach that can boost the activity of photocatalysts. Inspiringly, this study explored a simple method that can be used to construct novel noble-metal-free Co₂P/CdIn₂S₄ (CPCIS) heterojunction photocatalysts for photocatalytic hydrogen production. The heterojunction was formed by loading CdIn₂S₄ (CIS) nanoparticles on the surface of Co₂P (CP). The structure, morphology, and optical property of the as-prepared samples were characterized by a series of tests. The DRS results showed that, the light absorption range of CPCIS was extended to the full visible light range and its light absorption intensity obviously was enhanced at 500-800 nm. The PL and photoelectrochemical tests manifested that the formed heterojunction promoted the separation of charges. The LSV results indicated that CP reduced the H₂ evolution overpotential of the composites. Besides, CP could serve as active sites of H₂ evolution in heterojunction composites. Interestingly, the H₂-evolution rate for the optimum CPCIS (471.87 μmol h^-1 g^-1) was around 3.6 times than CIS-Pt. The elevated activity of CPCIS may mainly attribute to the following aspects: its enhanced light absorption, elevated charge separation and increased active site. More importantly, the photocatalytic activity of heterojunction composites didn't almost decrease after three cycles. This article delivers an idea that can be applied to form heterojunctions between CP and other sulfides for photocatalytic H₂ production, easily extending to other transition metal phosphides.