Photoelectrochemical properties of Nb-doped titanium dioxide

Nb-doped TiO2 (0–15 at% Nb) polycrystalline specimens were prepared by sol–gel method. The materials were used as photoanode in photoelectrochemical cell to water splitting. Based on the photocurrent experiments, the effects of Nb concentration on incident photon-to-current efficiency (IPCE), flat band potential and overall efficiency of solar energy conversion were discussed. It was found that addition of Nb leads to an increase in solar-to-hydrogen energy efficiency. The maximum energy conversion efficiency has been observed for TiO2 doped with 1 at% Nb.