Construction of binary BiVO 4 /g-C 3 N 4 photocatalyst and their photocatalytic performance for reactive blue 19 reduction from aqueous solution coupling with H 2 O 2

A highly efficient binary composite consisting of ripple-like sheet g-C 3 N 4 doped with paramecium-shape BiVO 4 has been successfully fabricated in a mild method and was further characterized by X-ray diffraction, Transmission electron microscopy, Fourier-transform infrared spectroscopy, UV–Vis diffuse reflectance spectrum, and photoluminescence. Their photocatalytic performances were estimated by monitoring the degradation process of reactive blue 19 (RB19) in the aqueous phase under visible light irradiation. The results showed that when the mass ratio of BiVO 4 and g-C 3 N 4 was 1:5, the binary composite presented the best catalytic activities during the photocatalytic degradation of RB19, and the synthesized composite with H 2 O 2 addition could further promote the photocatalytic activities. It is worth mentioning that H 2 O 2 acted only as a electron acceptor for accelerating the separation of electron–hole pairs. The trapping experiments showed that ·O 2 − was main active species in photocatalytic degradation of RB19. The improving of photocatalytic performance can be put down to the synergistic effect of g-C 3 N 4 , BiVO 4 , and H 2 O 2 in Z-scheme mechanism, which give rise to enlarge optical absorption range and suppress the recombination of photo-generated charge carrier.