Synthesis and photocatalytic characterization of a new photocatalyst BaZrO3

A new photocatalyst BaZrO3 with a cubic perovskite structure was synthesized via a Pechini-type process and characterized by powder X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy, photoluminescence (PL) spectroscopy, and photocatalytic activity, respectively. Hydrogen was produced from pure water over BaZrO3 photocatalyst without the assistance of any cocatalysts under ultraviolet light irradiation. The highest H-2 evolution rate was up to 0.5 mmol . (h g)(-1), corresponding to 3.7% of apparent quantum efficiency, for the BaZrO3 sample calcined at 1273 K for 6 h. The density functional theory calculation indicated that the top of the valence band is dominated by the contributions of O 2p orbitals while the bottom of the conduction band is predominantly contributed by Zr 4d orbitals. The largely dispersed conduction band, 180 degrees Zr-C-Zr bond angle, and highly negative flat-band potential are responsible for the high photocatalytic activity of BaZrO3 for water splitting. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.