Waveband-dependent photochemical processing of graphene oxide in fabricating reduced graphene oxide film and graphene oxide-Ag nanoparticles film

Waveband-dependent photochemical reduction properties of graphene oxide (GO) were investigated. The ratio of oxygenated carbon to graphitic carbon of the GO film was reduced to 39% and 28% by 400-800 nm and 350-800 nm irradiation, respectively from the initial value of 47%, while this ratio changed negligibly by 520-800 nm irradiation. This waveband-dependent photoreduction is closely related to the wide size distribution of sp(2) carbon clusters with different band gaps within the GO sheet, which play the role of the photochemical reacting centers. In addition, the photochemical activity of GO was also demonstrated by photoreduction of Ag+ in water. Our research suggests the possibilities of tuning the microstructure of GO by careful selection of irradiation conditions and of preparing noble metal nanoparticles with a neat surface on GO sheets.