The Study Of Preparation And Properties Of ZnO-graphene Composite Films

Zinc oxide/graphene composite film has application value in optical devices,sensors,photocatalysis and other aspects.However,there are limitations in the methods for preparing composite films.In most cases,the composite with ZnO is performed by coating a graphene film on an electrode or adding a buffer layer on the graphene.Moreover,the direct deposition of ZnO on graphene also has some problems such as weak bonding strength and poor crystallinity.This paper uses two-step method to prepare zinc oxide graphene composite film,in the first step,an ITO-based reduced graphene oxide film（ErGO）was prepared by electrochemical reduction,in the second step,a ZnO-ErGO composite film was obtained by direct electrodeposition on a thin film substrate.The effects of deposition voltage,concentration of graphene oxide solution and deposition time on the structure and electrical properties of the ErGO film were studied during the preparation of the ErGO film.The deposition voltage,deposition time,electrolyte concentration,deposition sequence and other factors were studied during the preparation of ZnO-ErGO composite films.After X-ray diffraction（XRD）,scanning electron microscopy（SEM）,infrared spectroscopy,ultraviolet-visible spectroscopy,atomic force microscopy,Raman and other test methods,the optimal conditions for the preparation of ErGO film is 2 mg/mL GO solution.,deposition time of 300 s and deposition voltage of-1.1 V.The best deposition sequence for preparing ZnO-ErGO composite films is to deposit ZnO directly after deposition of ErGO film.The optimum electrolyte concentration,deposition voltage and deposition time are 0.1 M,-1.1 V and 10 min,respectively.The R_ctt value of the ErGO/ZnO composite film reached 3.728 kΩ·cm^-2and the photocurrent reached 20.12×10^-6A·cm^-2（voltage-1V）,which was higher than that of a single film.The large increase shows that ZnO-ErGO composite films have good potential for electrochemical and optoelectronic applications.