Synthesis of novel visible light responding vanadate/TiO2 heterostructure photocatalysts for application of organic pollutants

A series of vanadate grafted TiO2 heterostructure photocatalyst were synthesized to enhance the visible light activity of TiO2 using a rapid and efficient ion impregnate method with simultaneous formation of vanadate combined with TiO2. Crafted vanadate with narrow band gap can absorb light at significantly lower energies in the visible range (>500 nm), resulting in charge transfer to TiO2, hence improving the visible light response of TiO2. Moreover, the BiVO4 grafted TiO2 heterostructure photocatalysts revealed highest visible light response for degradation of non-sensitized dye due to especial atom orbit energy of BiVO4. facilitating charge transfer from BiVO4 to TiO2 at the interface. However, the InVO4/TiO2 had best photocatalytic performance for photosensitized dye due to the gradient charge transfer for minimizing the energy-wasteful electron-hole recombination. The synthesis of vanadate grafted TiO2 heterostructure photocatalysts described here electron/hole transfer in junction interface of vanadate and TiO2, leading to sensitization of TiO2 for absorption in the visible region and provide a systematic study for controlling and understanding the energy levels of conduction band and valence band relevant to charge-transfer phenomena for the photocatalytic and optoelectronic properties of TiO2. (C) 2011 Elsevier B.V. All rights reserved.