Photocatalytic Hydrogen or Oxygen Evolution from Water over S‐ or N‐Doped TiO 2 under Visible Light

Abstract

S‐ or N‐doping of TiO 2 powder having an anatase or rutile phase extended the photocatalytic activity for water oxidation and reduction under UV light and visible light irradiation. For the reduction of water, anatase‐doped TiO 2 showed higher level of activity than that of doped TiO 2 having a rutile phase using ethanol as an electron donor. Furthermore, the activity level of S‐doped TiO 2 for hydrogen evolution was higher than that of N‐doped TiO 2 photocatalysts under visible light. Photocatalytic oxidation of water on doped TiO 2 having a rutile phase proceeded with fairly high efficiency when Fe 3+ ions were used as electron acceptors compared to that on doped TiO 2 having an anatase phase. In addition, water splitting under visible light irradiation was achieved by construction of a Z‐scheme photocatalysis system employing the doped TiO 2 having anatase and rutile phases for H 2 and O 2 evolution and the redox couple as an electron relay.