| Abstract
| - New photocatalysts MIn0.5Nb0.5O3 (M = Ca, Sr, and Ba) with the ABO3 type perovskite structure in whichB sites are occupied by In3+ or Nb5+ ions randomly in a charge-balanced manner were synthesized. Theywere characterized by structural analysis, diffuse reflectance spectroscopy, and photocatalytic activitymeasurement in evolving H2 and O2 from pure water with cocatalysts Pt and NiOx under UV and visible lightirradiation (λ > 420 nm), respectively. It is suggested that the conduction bands of these photocatalysts arecomposed of In 5s and Nb 4d levels, and the valence bands are composed of O 2p levels. With the decreaseof the ionic radius in the A site, the CaIn0.5Nb0.5O3, SrIn0.5Nb0.5O3, and BaIn0.5Nb0.5O3 photocatalysts showdifferent photocatalytic activities. Under UV light irradiation, the BaIn0.5Nb0.5O3 photocatalyst powder withcocatalyst NiOx split pure water into H2 and O2 in a nearly stoichiometric ratio. Under visible irradiation, allof these photocatalysts show obvious photocatalytic activity in evolving H2 from pure water with cocatalystNiOx.
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