Synthesis of bismuth oxybromochloroiodide/graphitic carbon nitride quaternary composites (BiOxCly/BiOmBrn/BiOpIq/g-C3N4) enhances visible-light-driven photocatalytic activity

BiOxCly/BiOmBrn/BiOpIq/g-C3N4 was prepared by using the hydrothermal synthesis. The composition and morphologies of the composites were controlled by adjusting the reaction pH value, temperature, and molar ratio. The optimized BiOxCly/BiOmBrn/BiOpIq/g-C3N4 photocatalyst increased the rate of photocatalytic conversion from CO2 to CH4 to 0.036 μmol g−1 h−1 and these samples were subjected to photocatalytic degradation with CV. The enhanced photocatalytic activity can be attributed to the effective separation of photogenerated carriers driven by the photoinduced potential difference generated at these heterostructure interfaces, the transfer of photogenerated electrons through the g-C3N4 skeleton, and the favorable alignment of the straddling band structure from BiOxCly/BiOmBrn/BiOpIq/g-C3N4.