The mechanism of enhanced charge separation and photocatalytic activity for Au@TiO2 core-shell nanocomposite

The core-shell nanoparticles of Au@TiO2 were synthesised via a simple and flexible hydrothermal route. The structure and properties were characterised by X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, ultraviolet/visible diffuse reflectance spectra, photoluminescence spectra and Raman spectra. The photocatalytic activity and the photoelectrochemical behaviours were investigated. Compared to TiO2, Au@TiO2 exhibits superior photocatalytic activity and photoelectrochemical property. The enhanced properties of Au@TiO2 attributed to the Au core as electron trap to promote the separation of photogenerated charge carriers in the photocatalytic process, which was also confirmed by the results of electrochemical impedance spectra and photoluminescence