Ultra-thin g-C3N4-Modified Co3V2O8 hollow spheres for enhanced photocatalytic degradation of MB

Abstract

Considering the important role of morphology and interface during the photocatalytic process, the g-C₃N₄@Co₃V₂O₈ Z-scheme heterojunction photocatalyst was successfully prepared by a facile hydrothermal method and subsequent wet-impregnation treatment. The sample synthetic method allowed ultra-thin g-C₃N₄ nanosheets to uniformly adhere on the surface of Co₃V₂O₈ hollow spheres, which not only avoided the aggregation of g-C₃N₄ nanosheets but also benefited from forming a multidirectional contact interface to short the transfer distance of photoelectrons between g-C₃N₄ and Co₃V₂O₈. Benefitting from the unique hollow structure and Z-scheme configuration, g-C₃N₄@Co₃V₂O₈ composite with 10 % g-C₃N₄ showed a better photocatalytic degraded performance, achieving 93.7 % degradation efficiency of methylene blue (MB) in water within 60 min, which was 3.1 and 1.9 times higher than these of pristine Co₃V₂O₈ and g-C₃N₄, respectively. The active species analysis demonstrated that ·O²⁻ and ·OH played a pivotal role in the photocatalytic degradation of MB. Based on the experimental results a comprehensive photocatalytic degradation mechanism was proposed. Our work provided an opportunity to design Z-scheme heterojunction photocatalysts for pollutant degradation in wastewater.