Hydrothermally synthesized porous Mn3O4 nanoparticles with enhanced electrochemical performance for supercapacitors

摘要

Porous like nanostructures are significant electrodes for electrochemical capacitors owing to their high surface area and variable pore sizes. In this study, an attempt was made to synthesize porous like Mn3O4 structure using H2O2 at different concentrations via solvent assisted hydrothermal method. The concentration of H2O2 during synthesis played critical role in controlling microstructure, morphology and hence supercapacitive performance. The XRD pattern shows, there is no much change in the diffraction peaks but peak broadening with addition of H2O2 was notified, which indicates decrease in crystallite size. The Raman studies also support the XRD result and the main Raman peak at 658 cm(-1) shifted with increase in solvent concentration which is due to grain size effect. The SEM micrographs confirmed that the samples synthesized at 3 M H2O2 concentration are of porous like structure with variable pore sizes which is positive sign for supercapacitor applications. The electrical conductivity of the sample increased with temperature. The electrochemical properties of porous Mn3O4 were studied using CV, CP and EIS. The Mn3O4 exhibited a specific capacitance of 435 F g(-1) at a scan rate of 1 mV s(-1) with good rate capability and excellent capacitive retention.