Au-Mediated Composite In2S3-Au-BiVO4 with Enhanced Photocatalytic Activity for Organic Pollutant Degradation

A ternary composite photocatalyst In2S3-Au-BiVO4 was fabricated by stepwise photo-reduction and deposition-precipitation methods. It was found that the Au nanoparticles (NPs) were selectively anchored on the {010} facets of decahedral BiVO4 crystals due to the oriented accumulation of electrons during the photo-reduction stage. Based on the strong interaction between S-Au, In2S3 was loaded on the surface of Au NPs on BiVO4 {010} facets. Photocatalytic degradations of organic contaminants Rhodamine B and phenol indicated that In2S3-Au-BiVO4 showed evidently improved visible light photocatalytic activity than BiVO4, Au-BiVO4, and In2S3-BiVO4. On the basis of the photoelectrochemical and photoluminescence (PL) analyses, it can be inferred that the facet hetero-juction and Au-mediated composite structures of In2S3-Au-BiVO4 can improve the separation efficiency of photo-generated carriers as well as make the carriers keep higher redox ability. The radical trapping experiments indicated that for In2S3-Au-BiVO4, .OH, h(+), and .O-2(-) are the main reactive species which take part in the organic contaminant degradation.