The reclaimable hydrogels space-limited Ni-based/CdZnS to overcome photo-oxygen corrosion for efficient hydrogen production from solar energy

Abstract

A hydrogel CZS/NiS@HR for photocatalytic hydrogen production is fabricated through solvothermal synthesis of CdZnS (CZS) composites, followed by physical cross-linking and self-assembly. This material facilitates spatially oriented charge separation via heterojunctions, effectively suppressing electron-hole recombination. The hydrogen evolution rate reaches 65 mmol/g/h, with stable catalytic activity maintained at 45 mmol/g/h after five cycles. The hydrogel structure prevents the release of toxic Cd²⁺ into the environment. Compared to CZS, the UV absorption edge of CZS/NiS@HR is significantly redshifted, confirming successful Ni-based heterojunction surface modification. The three-dimensional network of the hydrogel enhances H⁺ diffusion, thereby improving photocatalytic hydrogen production efficiency while mitigating sulfide photo-oxygen corrosion and reducing catalyst costs. This study underscores the synergistic effects of heterojunctions and hydrogels in promoting sustainable photocatalytic hydrogen production.