Anatase TiO2 nanobelts with plasmonic Au decoration exhibiting efficient charge separation and enhanced activity

The impact of Au particle size on photoactivity of anatase TiO2 nanobelts (TNBs) has been studied. Anatase TNBs were obtained via a stirring-assisted hydrothermal synthesis and then decorated with Au nanoparticles. The aspect ratio of the TNBs was tailored by the stirring speed and the size of the Au nanoparticles was adjusted by sintering temperature. Evaluation of photoactivity via methylene blue degradation revealed superior activity of the Au-decorated TNBs than commercial P25 under both UV and visible light. 3-D finite difference time domain simulation was performed to investigate the electric-field amplification at the interface between the Au nanoparticles and TNBs as a result of local surface plasmon resonance effect. It was found that the TiO2/Au interface acted as a plasmonic enhancement center and was responsible for the photoactivity enhancement.