Photoelectrolysis of water in cells with SrTiO3 anodes

The photoelectrolysis of water in cells with SrTiO3 anodes has been confirmed. The maximum external quantum efficiency at zero bias voltage is 10% (at hν=3.8 eV), about an order of magnitude higher than the maximum value obtained with anodes of TiO2, the only other material so far known to catalyze photoelectrolysis. In agreement with the energy-level model proposed previously, the efficiency is increased because the band bending at the anode surface is about 0.2 eV larger for SrTiO3 than for TiO2, as a result of the smaller electron affinity of SrTiO3.