Effect of electrodeposition time on the super-capacitive performance of electrodeposited MnO2 on g-C3N4 nanosheets

Abstract

Herein, the effect of electrodeposition time on the super-capacitive performance of three-dimensional (3D) MnO2/g-C3N4 heterostructured electrodes was investigated. MnO2 nanoparticles were electrodeposited on the g-C3N4 nanosheets drop-casted on the Ni foam substrate. The microstructural analysis, carried out by FE-SEM and TEM, confirmed the homogeneous distribution of MnO2 nanoparticles on g-C3N4 nano-sheet layers. The electrochemical capacitive performances of the MnO2/g-C3N4 electrodes were evaluated by cyclic voltammetry (CV), galvanostatic charge/discharge tests, and electrochemical impedance spectra (EIS). The obtained results suggested that the supercapacitor (SC) performance of all prepared g-C3N4/MnO2 composite electrodes is higher than pure MnO2 and pure g-C3N4 electrodes. The effect of electrochemical deposition time on the electrochemical performances of the fabricated electrodes was investigated as well. The specific capacitance of synthesized g-C3N4/MnO2 electrodes was measured as 87.6, 67, and 49.5 Fg-1 for 1, 2, and 3 min deposition time respectively at the current density of 0.5 Ag-1, indicating the electrode obtained with shorter deposition time delivers maximum specific capacity. Therefore, this deposition time has been validated as the optimum time for electrochemical energy storage application.