Improved hydrogen evolution and interesting luminescence properties of rare Earth ion-doped ZnS nanoparticles

Rare Earth-doped nanocrystalline semiconductor compounds can create novel pathways to enhance the hydrogen evolution reaction. In this study, terbium-doped zinc sulfide (ZnS) nanoparticles (NPs) were fabricated using an economical and facile co-precipitation method. STEM results revealed that the synthesized samples were composed of NPs with a uniform size distribution. The spatial distribution images showed that terbium ions were randomly distributed in the ZnS matrix with the anticipated stoichiometry. Transmission electron microscopy confirmed the presence of NPs. Terbium doping decreased the optical band gap of the ZnS NPs. Terbium-induced emission peaks were recognized at 465, 490, 545, 587, and 621 nm, demonstrating that the dopant ions were included in the parent matrix. The terbium (2 at%)-doped ZnS NPs exhibited an enhanced hydrogen evolution capability under simulated solar light. Therefore, the results of this study heavily suggest that the terbium-doped ZnS NPs are beneficial candidates for hydrogen gas generation. This study is the first to investigate the evolution of H₂ using the ZnS:Tb system.