Construction and photocatalytic performance of dual Z-scheme BiVO4/AgBr/Ag2MoO4 heterojunction for enhanced photocatalytic degradation of rhodamine B

Photocatalysis is a green and efficient technology for degrading organic pollutants. However, its development is restricted by the high recombination rate of photogenerated electron-hole pairs. In this study, double-Z-type BiVO 4 /AgBr/Ag 2 MoO 4 ternary photocatalysts were successfully synthesized by a one-step precipitation method at room temperature, and their photocatalytic performance for degrading rhodamine B (RhB) was investigated. The composition and microstructure of the photocatalysts were characterized by X-ray diffraction (XRD), cold field scanning electron microscopy (FE-SEM), X-ray energy dispersive spectroscopy (EDS), specific surface area testing, and X-ray photoelectron spectroscopy (XPS). The results of ultraviolet-visible diffuse reflectance spectroscopy (UV–Vis DRS), photoluminescence (PL), and electrochemical impedance spectroscopy (EIS) indicate that the optical properties of the photocatalysts are good. Under visible light irradiation, the BiVO 4 /AgBr/Ag 2 MoO 4 photocatalyst with Ag 2 MoO 4 mass fraction of 12% achieved a degradation rate > 99% within 12 min, with degradation rates 260.5, 6.1, and 161.7 times that of pure BiVO 4 , AgBr, and Ag 2 MoO 4 , respectively. In addition, holes (h + ) and superoxide radicals (·O 2− ) are the main active species, and hydroxyl radicals (·OH) also have a certain influence during the photocatalysis process, according to the active species capture experiments. This study demonstrates that the ternary photocatalyst has the potential to efficiently degrade organic pollutants under sunlight.