Cerium-Doped WS ₂ /ZnO Heterostructure with Engineered Interfacial Defects for Enhanced Photocatalytic/Electrocatalytic Hydrogen Evolution and Antimicrobial Applications

Developing efficient and durable photocatalysts for solar-driven hydrogen production remains a key challenge for sustainable energy conversion. Herein, we report a Ce-doped WS2/ZnO heterostructure with an engineered electronic structure and defect states for enhanced photocatalytic performance. The incorporation of Ce induces lattice strain and defect formation, as evidenced by the increased Urbach energy (Eu), indicating a higher density of localized states associated with oxygen vacancies and Ce3+/Ce4+ redox behavior. This electronic modulation promotes efficient charge separation and interfacial charge transfer across the heterojunction. As a result, the optimized catalyst exhibits a high hydrogen evolution rate of 6.70 mmol h–1 g–1 and a cumulative H2 production of 26.81 mmol g–1 under visible-light irradiation (λ > 420 nm) in the presence of sacrificial agents. Electrochemical analyses further confirm improved HER kinetics and excellent durability over 18,000 s of continuous operation. The enhanced activity is attributed to the synergistic interaction between WS2, ZnO, and Ce dopants, which facilitates charge transport and suppresses recombination. These findings highlight the critical role of defect-engineered heterostructures in achieving efficient and stable solar hydrogen production.