电化学法制备部分还原氧化石墨烯薄膜及其光电性能

Photoelectric Properties of Graphene Oxide Film Prepared with the Electrochemical Method Using Varying Levels of Reduction

提供了一种快速制备氧化石墨烯(GO)薄膜的方法,并通过调节GO薄膜的含氧量来调控其能级结构.采用阳极电泳及阴极电化学还原联用的方法在F掺杂Sn O2(FTO)导电玻璃上制备出不同层数及含氧量的GO薄膜,并通过扫描电镜(SEM)、X射线衍射(XRD)、紫外可见(UV-Vis)光谱、X射线光电子能谱(XPS)、拉曼光谱及电化学分析对样品进行表征.用20-350 s不同时间电泳沉积得到层数约为77-570层的GO薄膜.经过不同时间阴极还原的GO薄膜的禁带宽度为1.0-2.7 e V,其导带位置及费米能级也随之改变.GO作为p型半导体,与FTO导电膜之间会形成p-n结,在光强为100 m W·cm-2的模拟太阳光照射下,电泳300 s且电化学还原120 s时GO薄膜阳极光电流密度达到5.25×10-8A·cm-2.

This article details a quick and simple method to prepare graphene oxide（GO） film and tune its energy level by adjusting the oxygen content. GO films with different layers were fabricated on fluorine-doped Sn O2（FTO） conductive glass using the anodic electrophoretic deposition process. The degree of oxidation was regulated by cathodic electrochemical reduction. The as-prepared GO films were characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, ultraviolet-visible absorption（UV-Vis） spectroscopy, X-ray photoelectron spectra（XPS）, Raman spectroscopy and electrochemical analysis. The number of GO layers was varied between 77 and 570 by controlling the electrophoretic deposition time（from 20 to 350 s）. Changing the degree of oxidation caused the optical gap of GO to vary between 1.0 and 2.7 e V, and also impacted the edge of the conduction band and the Fermi energy for the sample. As a p-type semiconductor, a p-n junction can be formed between reduced GO and FTO. Under simulated sunlight irradiance of 100 m W·cm^-2, the GO film with a deposition time of 300 s and reduction time of 120 s produced the highest photocurrent density of5.25×10^-8A·cm^-2.