Novel supercapacitor electrodes based semiconductor nanoheterostructure of CdS/rGO/CeO2 as efficient candidates

Abstract

In this study, we have synthesized metal oxide/metal sulphide based nanoheterostuctures mediated with graphene nanosheets. The synthesized nanoheterostructures were characterized via different techniques such as XRD, XPS, and TEM. The electrochemical characteristics of the investigated nanoheterostucture (CdS/rGO/CeO2) were investigated through electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge-discharge. The specific capacitance of the single rGO, binary CdS/CeO2 and ternary CdS/rGO/CeO2 heterostructures were measured. The CdS/rGO/CeO2 nanoheterostucture showed the most excellent cycling stability with high specific capacitance of 407 F g−1 achieved at a charge-discharge rate of 1 A/g. The investigated supercapacitor retained about 96% of the initial energy density after charge-discharge at a 10 A/g for 5000 cycles. The ternary CdS/rGO/CeO2 nanoheterostucture revealed the best specific capacitance as the graphene nanosheets increased interfacial electron transfer. The results revealed that the investigated novel nanoheterostucture is among the best reported ones in the literature. Keywords: Nanoheterostucture, Semiconductors, Galvanostatic charge-discharge, Specific capacitance