Control of working wavelength for plasmonic photocatalysts

Abstract

Development of photocatalysts working under visible light is an important topic from a practical point of view. In previous studies, Au nanoparticles supported on metal oxide have been applied as a new type of photocatalysts responding to visible light. In this article, we introduce two methods for control of surface plasmon resonance (SPR) of supported metal nanoparticles by 1) post-calcination of Au/TiO₂ and 2) modification of Au nanoparticles with Ag and Cu. Elevation of calcination temperature induced a red shift of SPR. Modification with Ag and Cu induced blue and red shifts, respectively. These plasmonic photocatalysts were active for mineralization of formic acid and selective oxidation of alcohols to carbonyl compounds under visible-light irradiation and exhibited the best performance when irradiated by light overlapping with their SPR.