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BiVO4/Bi2MoO6 composites have been fabricated via the one-step hydrothermal method. The properties of composites were tailored by altering the V/Mo molar ratios. Photocatalytic activities were evaluated by measuring degradation of RhB under visible-light irradiation. BiVO4/Bi2MoO6 composites with V/Mo molar ratio of 8:1 possessing the optimal photocatalytic performance. The enhanced photocatalytic activity was attributed to the efficient charge carrier separation of composite heterostructures. In addition, the study of adsorption and photocatalytic activity suggested that a moderate amount of adsorption has a positive effect on photocatalytic reaction.

Hierarchical heterostructure of rutile TiO2 nanoflower array on anatase TiO2 sheet was fabricated by a two-step method. Anatase TiO2 sheet was synthesized by a modified dip coating method, followed by the formation of rutile TiO2 nanoflower array via a wet chemical route. Studies by X-ray diffraction and scanning electron microscopy indicated the formation of hierarchical heterostructure. Tests on degradation of methylene blue under UV light illumination showed that the hierarchical TiO2 film exhibited superior photocatalytic performance to those with monophased anatase and rutile TiO2 films and commercial P25 film. It was attributed to efficient separation of photogenerated charge carriers and prevention of the unfavorable multiple electron transfer on biphase interface. Investigation on the influence of addition of scavengers on photocatalysis suggested that hydroxy radicals and superoxide anion radicals dominated the photocatalytic degradation of MB. The hierarchical TiO2 film exhibited excellent photocatalytic stability in cycling tests.

Biphase bismuth vanadate (BiVO4) particles have been synthesized using a surfactant-free hydrothermal strategy. Biphase BiVO4 were formed at [Formula: see text], 5 and 7 with a bandgap between 2.28[Formula: see text]eV and 2.86[Formula: see text]eV, which are those of monoclinic and tetragonal phases, respectively. Photocatalytic tests on the degradation of rhodamine B (RhB) under visible-light irradiation showed that biphase BiVO4 with both monoclinic and tetragonal structures synthesized at [Formula: see text] achieved enhanced photocatalytic performance in comparison with pure monoclinic and tetragonal phases, which was attributed to the heterostructures leading to low recombination rate of electron–hole pairs.