title: Multi-electron oxygen reduction by a hybrid visible-light-photocatalyst consisting of metal-oxide semiconductor and self-assembled biomimetic complex.
abstract: Adsorption experiments and density functional theory (DFT) simulations indicated that Cu(acac)2 is chemisorbed on the monoclinic sheelite (ms)-BiVO4 surface to form an O2-bridged binuclear complex (OBBC/BiVO4) like hemocyanin. Multi-electron reduction of O2 is induced by the visible-light irradiation of the OBBC/BiVO4 in the same manner as a blue Cu enzyme. The drastic enhancement of the O2 reduction renders ms-BiVO4 to work as a good visible-light photocatalyst without any sacrificial reagents. As a model reaction, we show that this biomimetic hybrid photocatalyst exhibits a high level of activity for the aerobic oxidation of amines to aldehydes in aqueous solution and imines in THF solution at 25 °C giving selectivities above 99% under visible-light irradiation.
authors.affiliation: Environmental Research Laboratory, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan).
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Naya
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Niwa
authors.forename: Ryo
authors.initials: R
authors.lastname: Negishi
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tada
mesh_terms: D032701:Biomimetics; D002384:Catalysis; D004583:Electrons; D008027:Light; D008670:Metals / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D012666:Semiconductors
chemical_list: D008670:Metals; D010100:Oxygen
keywords: biomimetic complex; oxidation; oxygen reduction; photocatalysis; visible light