Cr2O3/rGO nanocomposite with excellent electrochemical capacitive properties

Abstract

Herein, we have reported the excellent electrochemical capacitive properties of the Cr2O3/rGO nanocomposite synthesized by hydrothermal. After the structural authentication by Raman spectroscopy and XRD studies, the Cr2O3/rGO nanocomposite was probed under different physicochemical techniques. It is found that due to good structural congruity between Cr2O3 nanoplates and rGO, the electrochemical properties of Cr2O3/rGO nanocomposite have strong synergistic effects. As a result, an unprecedented pseudocapacitance of Cr2O3/rGO nanocomposite is revealed at extremely small scan rate (0.1–1.1 mV s−1). At higher scan rate (10–50 mV s−1), the charge/discharge behavior (in CV) of the Cr2O3/rGO nanocomposite is found to be oriented towards the ordinary known properties of the commercial Cr2O3 however, the charge storage capacity is still very high. Furthermore, very high theoretical charge storage capacity (93% at 50 mV s−1), high specific capacitance (556 F g−1/310 F g−1 at 0.75 A g−1/1.75 A g−1 (GCD) and 635 F g−1 at 1.1 mV s−1 (CV) respectively) and excellent cyclic retention (92% of the initial value after 3500 cycles) was obtained for the Cr2O3/rGO nanocomposite. The EIS test (Nyquist plot) is in good agreement with the aforementioned results.