ZnTiO3/BiOCl Nanostructures for UV-DrivenHydrogen Production and Degradation of Rhodamine B

Advanced nanomaterials must be developed for hydrogen production and wastewater treatment to enhance green energy generation and remove environmental contaminants via photocatalytic processes. In this study, the effect of BiOCl concentration in ZnTiO3/BiOCl (ZTBi) nanostructures on photocatalytic hydrogen (H2) evolution and rhodamine B (RhB) degradation under UV irradiation was systematically investigated. ZnTiO3 was synthesized via a molten-salt method, and BiOCl was prepared via coprecipitation. Various ZTBi nanostructures (ZTBi_1, ZTBi_2, and ZTBi_3) with varying BiOCl contents were characterized to evaluate their physicochemical properties. Among all the nanostructures, ZTBi_2 with an optimal BiOCl concentration (∼45 wt %) exhibited the highest hydrogen evolution activity, achieving a rate of 241.9 μmol g–1h–1 after 3 h of UV irradiation in pure water without using scavenger agents. ZTBi_3, with the highest BiOCl content, showed the highest photocatalytic efficiency and adsorption capacity for RhB molecules, achieving 94.8% of RhB photodegradation after 1 h. The improved photocatalytic performance of the ZTBi nanostructures was attributed to the synergistic effect of Ti3+ impurity levels in ZnTiO3 and the formation of metallic Bi nanoparticles that act as electron-trapping sites on the BiOCl surface, thereby enhancing charge-carrier separation. The conduction band positions of ZnTiO3 and BiOCl were estimated from Mott–Schottky curves, based on which a photocatalytic mechanism for hydrogen generation and RhB photodegradation was proposed.