Reduction of Graphene Oxide with Ni Powder for the Preparation of Ni(OH)₂/Reduced Graphene Oxide Hybrid Electrodes for Supercapacitors

A green and simple method to reduce graphene oxide (GO) with Ni powder has been developed. The reduction of GO by Ni powder was traced by UV-visible absorption spectroscopy, and the obtained reduced graphene oxide (RGO) was analyzed with some kinds of characterization methods. These results showed that the Ni powder efficiently reduced GO to form RGO. The by-product, Ni²⁺ ions, produced during the reaction between the GO and the Ni powder were chemically transformed to Ni(OH)₂ and formed Ni(OH)₂/RGO hybrid materials. The Ni(OH)₂/RGO hybrid materials were used as electrode materials of supercapacitors and their capacitance was studied by cyclic voltammetry and galvanostatic charge/discharge. The Ni(OH)₂/RGO electrodes showed excellent electrochemical performance with a highest specific capacitance of about 621 F · g^–1 and improved cycling stability.