Photocatalytic hydrogen production from aqueous solutions over novel Bi0.5Na0.5TiO3 microspheres

Metal oxide compounds containing bismuth are considered as potential candidates for photocatalysis in both contaminant degradation and H-2 generation, due to the interesting lone electron pairs and the band gap narrowing effect of Bi3+. Quaternary perovskite oxide Bi0.5Na0.5TiO3 was thus synthesized at low temperature via a soft chemical route. The influence of alkaline concentrations on the structure, morphology, and optical properties of the samples has been systematically investigated. All samples existed as hierarchical microspheres, which are consisted of cubic nanocrystallines. For the first time, the photocatalytic water splitting for H-2 evolution over Bi0.5Na0.5TiO3 has been studied. A high H-2 evolution rate of 325.4 mu mol h(-1) g cat(-1) under the irradiation of a 500 W xenon lamp was obtained. More importantly, no decrease in the catalytic performance was observed after three consecutive runs of 15 h, suggesting new possibility in designing multi-component photocatalysts for future applications. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.