AgLi1/3Ti2/3O2 and AgLi 1/3Sn2/3O2 with delafossite structures were synthesized by treating the layered compounds Li2TiO3 and Li2SnO3 with molten AgNO3 (573 K for 5 h) through ion exchange of Li+ for Ag+. The band, gaps of both AgLi1/3Ti2/3O2 and AgLi 1/3Sn2/3O2 were estimated to be 2.7 eV from diffuse reflectance spectra. These delafossite-type metal oxides showed activity for O2 evolution from an aqueous silver nitrate solution under visible light irradiation. Moreover, these materials were also active for photocatalytic degradation of methylene blue under irradiation of monochromatic light at 420 nm. The visible light responses of AgLi1/3Ti2/3O 2 and AgLi1/3Sn2/3O2 were due to the band gap excitation between conduction bands consisting of either Ti 3d or Sn 5s5p orbitais and valence bands consisting of Ag 4d orbitais.
ASJC Scopus subject areas
- Materials Chemistry