A S-scheme 0D/2D heterojunction formed by decorating Cd0.5Zn0.5S nanoparticles on Cu2MoS4 plates for efficient photocatalytic hydrogen generation

Abstract

Rationally designing a Step-scheme (S-scheme) hetero-structured photocatalyst with high redox capability and separation efficiency of photoinduced carriers is considered as an attractive approach to address the shortcomings of single component and traditional hetero-structured photocatalyst. Herein, enlightened by the predictions of density functional theory (DFT), a unique S-scheme heterojunction photocatalyst was successfully fabricated by incorporating zero-dimensional (0D) Cd0.5Zn0.5S (CZS) on two-dimensional (2D) lamellar Cu2MoS4 (CMS) plates via a facile coprecipitation method, which substantially enhances the photocatalytic activity for hydrogen (H2) generation. CZS nanoparticles deposited on the surface of CMS nanoplates play a crucial role in creating highly intimate heterojunction interfaces and abundant exposed reaction sites, laying the foundation for improved photocatalytic performance. Furthermore, the significant difference in Fermi levels and band structures between CZS and CMS result in the formation of the internal electric field (IEF) and energy band bending at the interface of the heterojunction. This S-scheme charge transfer path enables 0D/2D CZS/CMS heterojunction possesses an exceptional capacity to maintain the robust redox potential and boosts the separation efficiency of light-induced carriers, as verified by DFT calculations and energy band structure analyses. As expected, the optimal heterojunction exhibits a satisfactory H2 generation rate of 13.1 mmol·g-1·h−1, which is nearly 7.7-fold higher than that of individual CZS. This study is expected to inspire the design of morphology-controlled hetero-structured photocatalyst with S-scheme charge transfer route for photocatalytic H2 generation.