Synthesis of Ag-AgBr nanoparticles modified BiOCl_1-xBr_x composites with enhanced photocatalytic activity under visible light

The morphology and band gap of BiOCl1-xBrx micromaterials were controlled by adjusting the molar ratio of Br and Cl (x = 1, 0.68, 0.51, 0.35) by simple glycerol-hydrothermal method. With the increase of doping amount of Cl, the morphology of BiOCl1-xBrx changes from microsphere structure composed of nanosheets to flower structure. On this basis, Ag-AgBr was successfully loaded onto BiOCl1-xBrx micromaterials by precipitation conversion method to optimize the photocatalytic performance. When 2 %Ag-AgBr/BiOCl0.49Br0.51 composite was used as photocatalyst, the degradation rate of RhB reached 98.77 % after 6 min of light exposure, which was 1.33 times that of BiOCl0.49Br0.51 and 8.83 times that of BiOBr. After 5 cycles, the degradation rate of RhB was still above 93 %. The main active substance in the degradation of RhB was determined to be center dot O-2 by radical capture experiments. After a series of characterization and photoelectrochemical tests, the possible photocatalytic mechanism of a new Z-scheme heterojunction Ag-AgBr/BiOCl0.49Br0.51 photocatalyst was proposed.