Half-Encapsulated Au Nanorods@CeO2 Core@Shell Nanostructures for Near-Infrared Plasmon-Enhanced Catalysis

The technology of surface plasmon resonance (SPR) is considered to be highly attractive approach to directly harvest optical energy for photocatalytic reactions. However, photocatalytic application is limited mainly by inefficient absorption of catalysts in the visible and infrared range. In this work, an anisotropic Au@CeO2 mushroom-like core@shell nanostructure is designed by controlled hydrolysis of the cerium acetate utilizing the cetyltrimethylammonium bromide (CTAB) as a soft template. Special aspect ratio of the Au nanorods (Au NRs) and the anisotropy of the nanostructures increase the plasmon absorption in the frequency near-infrared range (NIR). Upon 808 nm laser illumination for 7 min, the temperature of the solution containing 75 ppm half-encapsulated Au NRs@CeO2 (h-Au@CeO2) increases up to 53.8 °C. Besides exhibiting plasmon-enhanced photothermal properties, h-Au@CeO2 also has good 4-nitrophenol (4-NP) catalytic reduction activity under near-infrared laser. The anisotropy of h-Au@CeO2 promotes the plasmon produced hot-electron transfer and separation of electron–hole pairs resulting in better photocatalytic effect toward 4-NP reduction compared with totally encapsulated Au NRs@CeO2(t-Au@CeO2) nanostructures.