Phosphate-bridged TiO2-BiVO4 nanocomposites with exceptional visible activities for photocatalytic water splitting

In this work, phosphate-bridged TiO2-BiVO4 is fabricated by a simple wet-chemical method and exploited for water splitting under visible irradiation. By means of ultra-low-temperature electron-spin resonance (ESR) measurements and the designed photoelectrochemical experiments, the spatial transfers of visible-excited energetic electrons from BiVO4 to TiO2 in the fabricated nanocomposites are identified for the first time. Moreover, the phosphate bridges between BiVO4 and TiO2 are successfully built so that the transfers of visible-excited charges in space are greatly improved. This would prolong the lifetime and promote the separation of photogenerated charges. Interestingly, the phosphate-bridged TiO2-BiVO4 nanocomposite exhibits much high photocatalytic activities for water oxidation and H-2 evolution by about three times compared to the un-bridged TiO2-BiVO4 one. This work will provide new ideas to develop visible-response photocatalysts with high visible activities for water splitting. (C) 2015 Elsevier B.V. All rights reserved.