Synergistic morphology and interface engineering: A dual strategy for ultra-efficient photocatalytic H2 evolution over NiS/ZnxCd1-xS heterostructures

Photocatalytic hydrogen evolution reaction (HER) represents one of the key technologies for realizing renewable energy conversion and storage. However, the precise development of efficient HER photocatalysts remains a critical challenge due to rapid charge recombination. In this study, the NiS/Zn 0.5 Cd 0.5 S (NZCS-X) Schottky junctions were successfully synthesized by hydrothermal deposition of NiS nanoparticles on coral-like Zn 0.5 Cd 0.5 S nanoclusters. Under visible light irradiation, the optimal composite material achieves a hydrogen evolution rate of 104.48 mmol h −1 g −1 —over 41 and 2 times higher than that of pristine CdS (2.52 mmol h −1 g −1 ) and Zn 0.5 Cd 0.5 S (47.92 mmol h −1 g −1 ). Mechanistically, X-ray photoelectron spectroscopy (XPS) confirms the electron transfer from Zn 0.5 Cd 0.5 S to NiS. Femtosecond transient absorption (fs-TA) spectroscopy reveals that the average carrier lifetime decreases to 4.83 ps in the composite, providing direct evidence of ultrafast interfacial electron extraction. Density functional theory (DFT) calculations further demonstrate that metallic NiS acts as an electron sink to optimize the Gibbs free energy (ΔG H∗ ). This work concludes that the synergistic engineering of morphology and Schottky interfaces is a decisive strategy for designing high-performance sulfide photocatalysts.