The large-area preparation and photoelectrochemical properties of graphene/ZnO nanorod composite film

We proposed a new method for preparing a single-crystalline (002)-oriented ZnO nanorod (ZnONR) array and graphene/ZnO nanorod (GZN) composite film on quartz plates using double glow plasma surface alloying (DGPSA) technology. The effects of graphene film on the photoelectrochemical properties of ZnO thin film were investigated. Ultraviolet (UV)-visible spectroscopy showed that the total transmittance of the GZN composite film was maintained at nearly 75% and the addition of graphene caused an increase in the absorption intensity at wavelengths greater than 375 nm. The contact angle (51 degrees) of the GZN film after UV irradiation was lower than that (82.4 degrees) of the film before UV irradiation. A comparison of the photoelectrochemical properties of graphene, ZnO and GZN films indicated that the synergistic effects of graphene and the ZnONR array enhanced charge transfer on the surface and reduced impedance in the solid state interface layer. In other words, the introduction of graphene has an obvious influence on the photoelectrochemical properties of GZN composite film. Therefore, our study suggests for the first time that double-glow plasma surface treatment can be considered as a new potential technology for the large-area preparation of graphene and GZN composite film.