Solar water splitting over Rh(0.5)Cr(1.5)O(3)-loaded AgTaO(3) of a valence-band-controlled metal oxide photocatalyst

Improvement of water splitting performance of AgTaO(3) (BG 3.4 eV) of a valence-band-controlled photocatalyst was examined. Survey of cocatalysts revealed that a Rh(0.5)Cr(1.5)O(3) cocatalyst was much more effective than Cr(2)O(3), RuO(2), NiO and Pt for water splitting into H(2) and O(2) in a stoichiometric amount. The optimum loading amount of the Rh(0.5)Cr(1.5)O(3) cocatalyst was 0.2 wt%. The apparent quantum yield (AQY) at 340 nm of the optimized Rh(0.5)Cr(1.5)O(3)(0.2 wt%)/AgTaO(3) photocatalyst reached to about 40%. Rh(0.5)Cr(1.5)O(3)(0.2 wt%)/AgTaO(3) gave a solar to hydrogen conversion efficiency (STH) of 0.13% for photocatalytic water splitting under simulated sunlight irradiation. Bubbles of gasses evolved by the solar water splitting were visually observed under atmospheric pressure at room temperature.