Journal of the American Ceramic Society, Vol.101, No.12, 5469-5476, 2018
Enhanced photoresponse and photocatalytic activities of graphene quantum dots sensitized Ag/TiO2 thin film
TiO2 thin films were fabricated through hydrothermal method. Silver nanoparticles were loaded on TiO2 thin films via photoreduction technique. Subsequently, the graphene quantum dots (GQDs) were spin-coated on the Ag/TiO2 nanocomposites thin films. The crystal structure, surface morphology and UV-vis absorbance were tested by XRD, SEM and ultraviolet-visible spectrophotometer. These results indicated that Ag nanoparticles and GQDs are anchored on the TiO2 nanorods. Absorbance of Ag/TiO2 and GQDs/Ag/TiO2 nanocomposite thin films have been extended into the visible region. Visible-light response of the samples were investigated by electrochemical workstation. The photoresponse of the sample can be enhanced by sensitization of the Ag nanoparticles and GQDs. The enhanced visible-light response may be due to the surface plasmon resonance of silver nanoparticles and visible absorbance of GQDs. The highest photocatalytic activity has been observed in the 9-GQDs/Ag/TiO2 composite thin film. The efficient charge separation and transportation can be achieved by introducing the Ag nanoparticles and GQDs in the TiO2 thin film.