Photocatalytic Remote Oxidation Induced by Visible Light

Photocatalytic remote oxidation was examined under visible light by using WO 3 -based photocatalysts: WO 3, WO 3 modified with Pt nanoparticles (Pt–WO 3 ), and WO 3 modified with Cu(II) ions (Cu(II)–WO 3 ). Alkyl chains on a glass plate separated from the photocatalyst by 7.5 μm thick air were removed in 40 min under visible light (≥420 nm, ∼100 mW cm –2 ). Among the photocatalysts examined, Pt–WO 3 exhibits the highest remote oxidation activity. Its activity is higher than that of TiO 2 modified with Pt nanoparticles in the wavelength range 360–460 nm. It is likely that Pt–WO 3 emits • OH under visible light, which diffuses in air and attacks alkyl chains, whereas the major path of the remote oxidation induced by UV light involves emission of H 2 O 2 and its photocleavage into • OH. Remote storage of oxidative energy in Ni(OH) 2 is also possible by using visible light-irradiated Pt–WO 3 .