Ni-CdS/CoFe-PBA Nanoparticles for Enhanced Photocatalytic Hydrogen Evolution by Element Doping and S-Scheme Heterojunction Construction

Traditional photocatalysts are limited in photocatalytic hydrogen evolution applications due to inherent performance constraints. In this work, Ni was incorporated into CdS, substantially improving the material’s electron transfer efficiency due to Ni doping. Subsequently, the S-scheme heterojunction was constructed with a bimetallic Prussian blue analogue, facilitating long-distance migration for more photogenerated electrons. Additionally, the composite catalyst’s inherent electric field efficiently inhibits the recombination of photogenerated electron–hole pairs, increasing the activity of photocatalytic hydrogen evolution. The accumulated evolution of hydrogen during 4 h of light irradiation was 40.4 mmol·g–1. Based on DFT calculations and XPS analysis, the possible mechanism of photocatalytic hydrogen evolution in the composite was elucidated.