Trace Cu+-dominated band structure engineering in CuxIn0.25ZnSy for promoting photocatalytic H2 evolution

Kun Li; Lingling Ding; Jinghan Li; Shuaishuai Liu; Fan Fang; Donglei Guo; Kun Chang

doi:10.1016/j.jcis.2023.03.004

Trace Cu⁺-dominated band structure engineering in Cu_xIn_0.25ZnS_y for promoting photocatalytic H₂ evolution

J Colloid Interface Sci. 2023 Jul:641:239-250. doi: 10.1016/j.jcis.2023.03.004. Epub 2023 Mar 6.

Authors

Kun Li¹, Lingling Ding¹, Jinghan Li¹, Shuaishuai Liu¹, Fan Fang¹, Donglei Guo², Kun Chang³

Affiliations

¹ Centre for Hydrogenergy, College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, PR China.
² Key Laboratory of Function-Oriented Porous Materials, College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang, 471934, PR China.
³ Centre for Hydrogenergy, College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, PR China. Electronic address: changkun@nuaa.edu.cn.

PMID: 36933470
DOI: 10.1016/j.jcis.2023.03.004

Abstract

As an attractive semiconductor photocatalyst, (CuInS₂)_x-(ZnS)_y has been intensively studied in photocatalysis, due to its unique layered structure and stability. Here, we synthesized a series of Cu_xIn_0.25ZnS_y photocatalysts with different trace Cu⁺-dominated ratios. The results show that doping with Cu⁺ ions leads to an increase in the valence state of In and the formation of a distorted S structure, simultaneously inducing a decrease in the semiconductor bandgap. When the doping amount of Cu⁺ ions is 0.04 atomic ratio to Zn, the optimized Cu_0.04In_0.25ZnS_y photocatalyst with a bandgap of 2.16 eV shows the highest catalytic hydrogen evolution activity (191.4 μmol.h^-1). Subsequently, among the common cocatalysts, Rh loaded Cu_0.04In_0.25ZnS_y gives the highest activity of 1189.8 μmol·h^-1, corresponding to an apparent quantum efficiency of 49.11 % at 420 nm. Moreover, the internal mechanism of photogenerated carrier transfer between semiconductors and different cocatalysts is analyzed by the band bending phenomenon.

Keywords: Cu(x)In(0.25)ZnS(y); Photocatalyst; Photocatalytic hydrogen evolution; trace Cu(+) domination.