Au nanoparticles decorated brookite-anatase nanowires for efficient photo-oxidation of aqueous resorcinol

Abstract

A simple photoreduction method was used to deposit Au nanoparticles (Au NPs) at different loadings (0.1–2 Au%) into mixed phase brookite-anatase titanium dioxide (TiO2) nanowires (NWs). X-ray diffraction (XRD) verified that the Au/TiO2 NWs were composed of a mixture of brookite (84.24%) and anatase (15.76%); while transmission electron microscopy (TEM) showed a uniform dispersion of 5- to 10-nm Au NPs over the TiO2 NWs. The photocatalytic performance of the synthesized Au/TiO2 NWs was evaluated for the degradation of resorcinol under UVA illumination. The 0.1% Au/TiO2 NWs photocatalyst offered the best photocatalytic efficiency for resorcinol degradation among the synthesized samples, with the rate, constantly increasing from 0.0014 to 0.003 min−1 after adding 0.1% Au into TiO2 NWs. At Au higher loadings, the rate decreased (0.0005 min−1 for 2% Au/TiO2 photocatalyst. The enhanced activity of the 0.1% Au/TiO2 NWs sample could be ascribed to the effective electron–hole separation at brookite/anatase phase junctions. The Au/TiO2 NWs has maintained good activity over five catalytic test cycles.