Optimization of plasmon-induced photocatalysis in electrospun Au/CeO2 hybrid nanofibers for selective oxidation of benzyl alcohol

Abstract

Exploiting photocatalysts with improved properties for solar-driven chemical reactions is of great significance in developing green chemistry. Here, a series of Au/CeO2 hybrid nanofibers with different Au loadings have been fabricated by a simple method of electrospinning followed by calcination in air. The particle size and plasmonic absorption of Au nanoparticles (NPs) loaded in the nanofibers were analyzed and found to vary with the dosage of chloroauric acid in the precursor solution. The Au/CeO2 hybrid nanofibers were used as photocatalysts for selective oxidation of benzyl alcohol to benzaldehyde with O2 under simulated sunlight and visible light (>420nm), respectively. The results showed that introducing Au NPs into CeO2 nanofibers induced a great improvement in photocatalysis. The degree of improvement increased first and then decreased with the increase in Au loading, reaching an optimal level over 0.5wt.% Au-loaded CeO2 nanofibers. The photocatalytic reaction presents a very high selectivity of 100% for benzaldehyde, which is important for organic synthesis. The transient photocurrent responses of the Au/CeO2 catalysts were also tested for corroborative evidence. After detailed discussion of various factors including plasmonic absorption, charge transfer, and surface activity of the photocatalyst, a possible mechanism for the photocatalytic oxidation of benzyl alcohol occurring at the Au–CeO2 interface was proposed.