Ultrathin α-Bi2O3 Nanosheets Prepared via Hydrothermal Method for Electrochemical Supercapacitor Applications


 Monoclinic bismuth oxide nanosheets (α-Bi2O3 NSs) of average thickness 28nm were successfully synthesized via hydrothermal method. Various characterization techniques such as powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Ramman spectroscopy, UV-Vis spectroscopy and Field Emission scanning electron microscopy (FE-SEM) coupled with Energy dispersive x-ray spectroscopy (EDXS) were employed to investigate the prepared bismuth oxide nanopowder in terms of its structural, morphological and optical properties. Electrochemical measurements of α-Bi2O3 NSs deposited on nickel foam substrate were carried out in 6 M KOH electrolyte to examine its supercapacitive performance. The α-Bi2O3 NSs based electrode with 90 wt% active material exhibited excellent electrochemical performance with pronounced oxidation and reduction peaks, confirming the pseudocapacitive behaviour with a high specific capacitance of 764.5 Fg-1 at 5 mVs-1 scan rate. The electrode also presented good cycling stability of about 69% capacitive retention after 3000 cycles measured at 10 mAcm-2 current density. This enhanced supercapacitive performance is attributed to the increased effective surface area offered by widely open and ultrathin nanosheet like morphology.