In situ confined construction of BiVO₄/pg-C₃N₄ direct Z-heterostructures and its efficient degradation and photodynamic sterilization of rhodamine under visible light

Abstract Photocatalytic degradation is increasingly recognized as a highly effective approach for the removal of organic pollutants and pathogenic microorganisms from wastewater. Nevertheless, conventional unit catalysts often fall short of practical requirements, primarily due to their limited efficiency in photoinduced electron-hole transfer and the scarcity of active sites. In this work, three-dimensional porous material pg-C₃N₄ was synthesized utilizing the hard template method, employing dendritic mesoporous silica as the templating agent. And the nanoparticles of BiVO₄/pg-C₃N₄ direct Z-heterojunction composite (BCN) were successfully constructed by using pg-C₃N₄ as growth template and BiVO₄ in situ directed growth. The heterogeneous surface morphology of pg-C₃N₄ markedly enhances its capacity for visible light absorption and increases the availability of catalytic active sites. BCN demonstrates the ability to degrade 98% of Rhodamine B under simulated solar irradiation within 120 min and effectively inactivates 2 × 10⁷ cfu ml⁻¹ of E. coli under similar conditions within 60 min. Notably, after five cycles of use, the structural integrity and functional properties of the material remain largely unaltered. The superior photocatalytic degradation and photodynamic sterilization performance of BCN can be primarily attributed to its narrower band gap width of 2.34 eV, reduced electrochemical impedance, and enhanced separation and transfer rate of photogenerated carriers. Collectively, these properties facilitate the effective degradation of organic pollutants and the robust inactivation of bacteria by BCN under visible light irradiation. The successful implementation of this research offers a theoretical foundation and experimental insights for the future development of advanced Z-type photocatalysts.