Synthesis and enhanced photocatalytic activity of NaNbO3 prepared by hydrothermal and polymerized complex methods

We prepared NaNbO3 by several methods, namely solid-state reaction (SSR), hydrothermal (HT) and polymerized complex (PC) methods, and investigated the relationships between the photocatalytic activity and the particle size and morphology. The photocatalytic activity was evaluated by H-2 evolution from an aqueous methanol solution and pure water splitting in the presence of the Pt(0.5 wt%)/NaNbO3 and RuO2(1.25 wt%)/NaNbO3, respectively. It is found that the sample prepared by PC with smallest particles exhibits the highest photocatalytic activity in both reactions. Moreover, the HT sample with the cubic and rectangular shape also shows the enhanced photocatalytic activity for H2 evolution from an aqueous methanol solution in comparison with that of the sample prepared by SSR. (C) 2008 Elsevier Ltd. All rights reserved.