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.