Construction of a Z-scheme CdIn2S4/ZnS heterojunction for the enhanced photocatalytic hydrogen evolution

In this paper, CdIn2S4/ZnS (CIS/ZnS) nanocomposites were prepared by a one-step hydrothermal method. The structures and physicochemical properties of the nanocomposites were characterized by XRD, SEM, TEM, XPS, UV-Vis, TPR, EIS, PL, and ESR. The photocatalytic activity of CdIn2S4/xZnS composites for water splitting hydrogen evolution (the molar ratio of CdIn2S4 and ZnS is 1: x) is much better than that of the pristine ZnS and CdIn2S4. The optimal catalyst CdIn2S4/12ZnS exhibits the best performance. The hydrogen production rate reaches 3743 mu mol center dot g-1 center dot h-1, which is about 59.1 and 14.4 times that of pure CdIn2S4 and ZnS. The reasons for the better performance of CdIn2S4/xZnS are the strong interaction between CdIn2S4 and ZnS, the formation of Z-scheme heterojunction, the more efficient charge separation, the extension light re-sponse in comparison with the single component, and the stronger redox properties. Moreover, the possible hydrogen production mechanism is proposed by the study of VB-XPS, Mott-Schottky, and EPR, which im-plies it is a Z-scheme photosystem. This work provides an effective method for the modification of ZnS catalysts for the application in photocatalytic hydrogen evolution. (c) 2023 Elsevier B.V. All rights reserved.

Automated summary

CdIn2S4/ZnS (CIS/ZnS) nanocomposites were prepared using a one-step hydrothermal method and characterized by various techniques. The CdIn2S4/xZnS composites showed superior photocatalytic activity compared to pure ZnS and CdIn2S4, with the CdIn2S4/12ZnS catalyst exhibiting the best performance. The enhanced performance of CdIn2S4/xZnS can be attributed to the strong interaction, Z-scheme heterojunction formation, efficient charge separation, extended light response, and stronger redox properties. Additionally, the proposed hydrogen production mechanism suggests a Z-scheme photosystem. This study provides an effective method for modifying ZnS catalysts for photocatalytic hydrogen evolution.