TiO2/BiVO4 composite from preformed nanoparticles for heterogeneous photocatalysis.

Heteroaggregation of preformed nanocrystals used as building blocks is an interesting approach for the synthesis of heterostructures since it is possible to retain the main surface characteristics of the materials. In this paper, we studied the synthesis of a heterostructure consisting of monoclinic BiVO4 and anatase TiO2 phase for photocatalytic application. The heterostructures were synthesized using the building blocks technique with different TiO2/BiVO4 molar ratios under hydrothermal treatment. The effectiveness of heteroaggregations formation results in more photoactive catalysts due to the possibility of electron transfer between the materials. Methylene Blue (MB) solutions were decolorized under ultraviolet and visible radiation to evaluate the samples? photocatalytic activity. As a result, the as-synthesized samples presented higher photocatalytic efficiency than pristine anatase TiO2 and m-BiVO4 precursors. The increase of the photocatalytic properties is mainly attributed to the separation of the photogenerated charges, which is the central feature of heterostructures formed due to the collision of the particles during hydrothermal treatment