title: Control of Surface Plasmon Resonance of Au/SnO2 by Modification with Ag and Cu for Photoinduced Reactions under Visible-Light Irradiation over a Wide Range.
abstract: Gold particles supported on tin(IV) oxide (0.2 wt% Au/SnO2) were modified with copper and silver by the multistep photodeposition method. Absorption around λ=550 nm, attributed to surface plasmon resonance (SPR) of Au, gradually shifted to longer wavelengths on modification with Cu and finally reached λ=620 nm at 0.8 wt% Cu. On the other hand, the absorption shifted to shorter wavelength with increasing amount of Ag and reached λ=450 nm at 0.8 wt% Ag. These Cu- and Ag-modified 0.2 wt% Au/SnO2 materials (Cu-Au/SnO2 and Ag-Au/SnO2) and 1.0 wt% Au/SnO2 were used for mineralization of formic acid to carbon dioxide in aqueous suspension under irradiation with visible light from a xenon lamp and three kinds of light-emitting diodes with different wavelengths. The reaction rates for the mineralization of formic acid over these materials depend on the wavelength of light. Apparent quantum efficiencies of Cu-Au/SnO2, Au/SnO2, and Ag-Au/SnO2 reached 5.5% at 625 nm, 5.8% at 525 nm, and 5.1% at 450 nm, respectively. These photocatalysts can also be used for selective oxidation of alcohols to corresponding carbonyl compounds in aqueous solution under visible-light irradiation. Broad responses to visible light in formic acid mineralization and selective alcohol oxidation were achieved when the three materials were used simultaneously.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, Kowakae, Higashiosaka, Osaka, 577-8502, Japan.|Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Tanaka
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, Kowakae, Higashiosaka, Osaka, 577-8502, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Hashimoto
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, Kowakae, Higashiosaka, Osaka, 577-8502, Japan. hiro@apch.kindai.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kominami
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D017971:Tin Compounds; D012834:Silver; D006046:Gold; D003300:Copper; C045358:stannic oxide
keywords: gold; nanoparticles; photochemistry; supported catalysts; surface plasmon resonance