Band-engineering-regulated ZnCdS/ReSe2 S-scheme heterojunction for efficient photocatalytic hydrogen production

Photocatalytic hydrogen evolution (PHE) represents a promising approach to generating sustainable hydrogen, offering significant potential for renewable energy applications. However, its efficiency often constrained by the limited solar energy harvesting capability of photocatalyst and the inefficient separation of photoinduced charge carriers. In this study, an efficient non-precious metal-based photocatalyst ZnCdS/ReSe2 was successfully constructed by coupling ReSe2 to ZnCdS nanoparticles. The catalyst showed a dramatically enhanced photocatalytic activity under visible light, with a hydrogen production rate 3.96 times greater (17.93 mmol·h−1·g−1) than that of pristine ZnCdS, along with an apparent quantum efficiency (AQE) of 5.49% at 420 nm. Through Kelvin probe force microscopy (KPFM) combined with in situ/non-in situ XPS analysis, it was confirmed that this system formed a S-scheme heterojunction structure. This unique energy band alignment and built-in interfacial electric field (IEF) effectively enabled anisotropic transport of electron-hole pairs, leading to a marked suppression of carrier recombination. Moreover, this system optimizes the adsorption free energy of the *H intermediate, reducing the reaction energy barrier. This research opens a new avenue for developing high-performance heterojunction photocatalysts, and holds significant importance for advancing artificial photosynthesis technology.