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 H2 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 H2 evolution over Bi0.5Na0.5TiO3 has been studied. A high H2 evolution rate of 325.4 μmol 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.

► Quaternary Bi0.5Na0.5TiO3 has been successfully prepared via soft chemical route. ► The samples exhibited superior photocatalytic activity for H2 evolution. ► High stability of Bi0.5Na0.5TiO3 was achieved for H2 evolution. ► The effect of alkaline concentrations has been systematically investigated.