Dual oxygen and sulfur vacancies trigger double Z-scheme rapid charge transport for efficient photocatalysis with electricity generation

Regulating charge separation is crucial for achieving optimal efficiency in any photoelectrode. Engineering vacancies and heterojunctions represent a promising approach in this regard. Herein, sulfur and oxygen vacancies-enriched ZnIn₂S₄/BiVO₄ photoanode (SOV-ZIS/BVO/W) was fabricated through in situ growth on a tungsten substrate, specifically tailored for antibiotic-contaminated water treatment. Under illumination for 2 h, the SOV-ZIS/BVO/W exhibited an enhanced berberine (BBR) degradation rate of 91.2 %, with a corresponding reaction rate constant of 0.03265 min⁻¹. Experimental analyses and density functional theory calculations unveiled that the enhanced charge density at the heterojunction interface of the dual-vacancies-functionalized SOV-ZIS/BVO/W significantly accelerated the charge transfer process. Benefiting from the synergistic effect between the enhanced built-in electric field in dual Z-scheme heterojunction and dual-vacancies, the photocatalytic performance was improved. Subsequently, SOV-ZIS/BVO/W photoanode was integrated with a CoFe₂O₄/C₃N₄ photocathode to construct a photocatalytic fuel cell system. This system demonstrated remarkable performance in degrading BBR and simultaneously generating electricity with a potential of 0.29 V. This work offers a promising avenue to construct effective and stable photoanodes for environmental remediation and energy recovery. © 2025 Elsevier B.V.