A facile synthesis of RGO/HfO2 nanocomposite for high-performance supercapacitor

Abstract

Reduced graphene oxide (RGO) anchored hafnium oxides (HfO2) synthesized by using teflon-lined autoclave for hydothermal method. Supercapacitor application of as synthesized nanomaterial was analyzed by using cyclic voltammetry (CV). Different physical and electrochemical methods, such as XRD, XPS, Raman and HRTEM, were used to examine the prepared sample. The CV curves illustrated a quasi-rectangular with a redox peak, indicating the pseudocapacitance existence of the HfO2 and RGO/HfO2 electrode products, according to the electrochemical characterization. Owing to its large surface area, the HfO2 electrode material has a high specific capacitance (118 Fg−1) at a low scan rate (5 mVs−1). The specific capacitance values of the RGO/HfO2 electrode material are two times higher than those of pure HfO2 electrode material (354 Fg−1 at 5 mVs−1). The excellent electrochemical activity of RGO/HfO2 has assisted a high-performance supercapacitor by allowing higher electron transfer and providing elevated surface sites.