Z-scheme g-C3N4/BiVO4 photocatalysts with RGO as electron transport accelerator

BiVO 4 is known for its ability to decompose water under visible light irradiation. However, BiVO 4 overall suffers from rapid recombination of photogenerated carriers, low photochemical conversion efficiency, low specific surface area, poor conductivity, and weak adsorption capacity of dye. These features limited its application in photocatalysis. In this work, ternary Z-scheme g-C 3 N 4 /RGO/BiVO 4 nanocomposites were successfully fabricated by in situ electrostatic adsorption of g-C 3 N 4 sheets on RGO/BiVO 4 surface using hydrothermal and thermal oxidations processes. The ternary Z-scheme g-C 3 N 4 /RGO/BiVO 4 nanocomposites were then tested for photodegradation of Rhodamine B. The introduction of graphene into direct Z-scheme g-C 3 N 4 /BiVO 4 nanocomposites as an electronic accelerator efficiently enhanced the photocatalytic properties. The as-prepared g-C 3 N 4 /RGO/BiVO 4 composites exhibited optimal visible light responses with significantly improved photocatalytic performances toward degradation of Rhodamine B. The degradation efficiency using ternary photocatalyst reached 100% after 20 min of irradiation time. The reaction rate constant was estimated to 1.537, which was almost 29- and 20-folds higher than those of pure g-C 3 N 4 and binary g-C 3 N 4 /BiVO 4 , respectively. The synergistic effect between BiVO 4 , RGO and g-C 3 N 4 yielded g-C 3 N 4 /RGO/BiVO 4 composites with Z-scheme charge transfer mechanism, promoting rapid separation and slow recombination of photogenerated electron–hole pairs with strong photocatalytic activity. Overall, these findings look promising for design of future Z-scheme photocatalysts for environmental degradation of organic dyes.