Compositing effects of CuBi2O4 on visible-light responsive photocatalysts

The compositing of two kinds of semiconductors is an effective approach for enhancement of the photocatalytic performance. We examined the compositing effects of p-type CuBi2O4 on two kinds of n-type visible-light responsive photocatalysts (WO3 and BiVO4). For the composite photocatalysts of CuBi2O4/WO3 and CuBi2O4/BiVO4, z-scheme type charge transfer would dominantly proceed based on ESR spectroscopy and chemiluminescence photometry. Furthermore, the opposite tendency in the compositing effect of the CuBi2O4 was observed for WO3 and BiVO4. For WO3, the photocatalytic activity decreased after compositing of CuBi2O4. In contrast, for BiVO4, the photocatalytic activity increased after compositing of CuBi2O4. These results would be related to the recombination rate of electrons in the CuBi2O4 with holes in the photocatalysts (WO3 and BiVO4).