Facile construction of Cd0.3Zn0.7S/Ti3C2 MXene catalyst for efficient visible-light photocatalytic hydrogen evolution

Hydrogen production via photocatalytic water splitting is an essential technology for renewable energy conversion, but its real-world application is restricted by insufficient carrier separation efficiency and compromised stability of semiconductor-based catalytic materials. In this study, we address these challenges by designing a sandwich-like Cd 0.3 Zn 0.7 S@Ti 3 C 2 MXene Schottky junction catalyst. First, we precisely tuned the molar ratio of Zn/Cd precursors to synthesize Cd x Zn 1-x S solid solutions, and found that Cd 0.3 Zn 0.7 S nanosheets exhibited the optimal photocatalytic hydrogen evolution rate, due to its harmonious absorption of visible light and optimized band structure. Next, multilayer Ti 3 C 2 MXene nanosheets were prepared via hydrofluoric acid (HF)-assisted etching of Ti 3 AlC 2 MAX phase, and then composited with Cd x Zn 1-x S precursor to form the Cd 0.3 Zn 0.7 S@Ti 3 C 2 heterojunction. When the loading capacity of Ti 3 C 2 MXene is optimized, the composite exhibits a maximum hydrogen production rate of 9.4 mmol·h −1 ·g −1 , representing a 2.5-fold enhancement compared to pristine Cd 0.3 Zn 0.7 S and a 7.5-fold enhancement compared to pristine Ti 3 C 2 MXene. The Cd 0.3 Zn 0.7 S@Ti 3 C 2 exhibits excellent photocatalytic performance, primarily attributed to its unique sandwich structure and the Schottky junction. Which significantly enhances charge separation efficiency, and effectively suppresses the photocorrosion of Cd 0.3 Zn 0.7 S and ensures superior photochemical stability.This study provides a novel approach for the development of high-performance photocatalysts for water splitting.