Synchronous promotion of ZnIn2S4 sacrificial agent-free photocatalytic hydrogen production by non-metallic doping and construction of heterojunction

A review of previously reported materials for photocatalytic hydrogen production reveals that most of these still require the involvement of hole scavengers. To avoid the consumption of non-essential resources, the development of non-precious metal catalyst materials capable of achieving photocatalytic hydrogen production in a sacrificial agent-free environment is of greater value for practical applications. This study successfully prepared x-CdS/NZIS composites. The hydrogen precipitation rate of the 30-CdS/NZIS samples reached 212.81 μmol/g/h, which is 2.8, 20, and 82.8 times higher than that of NZIS, pristine ZIS, and CdS nanorods, respectively. Notably, this result was achieved without the addition of sacrificial agents. The strategy of replacing part of the sulfur with nitrogen doping increases the concentration of photogenerated carriers, improves the charge transfer rate, and suppresses the formation of electron-hole pairs. Furthermore, incorporating CdS nanorods into the composite structure facilitates the formation of type II heterojunctions, effectively suppressing interband electron-hole recombination. The combined implementation of these modification strategies results in the formation of an electron-rich region at the NZIS conduction band, which is conducive to H₂ generation, even in the absence of sacrificial agents. This study offers a potential avenue for developing cost-effective solar hydrogen production systems that do not require the use of sacrificial agents.