Preparation of ZnO/graphene heterojunction via high temperature and its photocatalytic property
This paper introduces a novel electrochemical route for preparing the ZnO/graphene heterojunction composite via high temperature. This process includes: (1) depositing the electrochemically reduced graphene oxide (ERGO) on ITO glass via cyclic voltammetry; (2) pulse plating a zinc (Zn) layer on the ERGO; (3) thermally treating the Zn/ERGO composite and “in situ” to obtain the ZnO/ERGO composite. SEM characterizations revealed that the Zinc Oxide (ZnO) particles were homogenously distributed on the surface of graphene sheets. XRD and Raman spectra found a ZnCO3 phase in the ZnO/ERGO composite, which demonstrated that when the Zn film transformed into ZnO particles during thermal treatment, Zn also reacted with graphene and formed a ZnCO3 intermediate layer at the interface between ZnO and ERGO via short-range diffusion. Compared with the heterojunction formed from regular chemical route, the present process provided a tight contact and combination between ZnO and ERGO, which eventually led to a heterojunction between ZnO and graphene sheets. This heterojunction exhibited great improvement for separation efficiency of photo-generate electron–hole pairs. Experimental results of ultraviolet–visible (UV–Vis) light catalysis demonstrated that the photocatalytic activity of the ZnO/ERGO composite had been greatly improved, and exhibited a value of three times higher than that of pure ZnO.
KeywordsGraphene Oxide Photocatalytic Activity Graphene Sheet Photocatalytic Property Terephthalic Acid
This research was supported by the National Natural Science Foundation of China (Nos. 11174227, 51209023, J1210061), and the Fundamental Research Funds for the Central Universities.
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