LAUSR

Abstract Bismuth oxide incorporated reduced graphene oxide (Bi2O3@rGO) nanocomposite containing different bismuth nitrate Bi(NO3)3 concentrations were synthesized via facile in-situ chemical reduction technique. The SEM image of Bi2O3@rGO nanocomposite revealed a flower-shaped morphology with Bi2O3 nanoparticles over rGO sheets with an average particle size ranging within 103 nm–326 nm. The crystallite size of Bi2O3@rGO nanocomposite varied from 10.42 nm to 25.62 nm with the increasing amount of Bi(NO3)3 content into it. The vibration signatures of Bi–O, Bi–O–Bi, C–O, C C, C O, C–H2, and O–H bonds were obtained at 446 cm−1, 846 cm−1, 1034 cm−1, 1558 cm−1, 1729 cm−1, 2901 cm−1 and (3205–3261) cm−1 respectively from the FTIR analysis of Bi2O3@rGO nanocomposite. The bandgap of Bi2O3@rGO nanocomposite decreased from 3.63 eV to 2.32 eV with the variation of Bi(NO3)3 content from 5 mM to 25 mM respectively. The atomic percentage of O (1s), N (1s), C (1s), Bi (4d), Bi (4f) and Bi (5d) were varied as 13.64–13.06 at.%, 1.81–1.22 at.%, 64.46–43.14 at.%, 12.96–27.72 at.%, 3.59–7.35 at.% and 3.55–7.51 at.% respectively with increasing the Bi(NO3)3 conc. from 5 mM to 25 mM. The maximum specific capacitances of 690.88 F/g and 1248.355 F/g were exhibited by 25 mM Bi2O3@rGO nanocomposite at 5 mV/s scan rate and 1 A/g current density respectively, also besides achieving the highest Ecorr value of 0.107 V from the corrosion analysis. Moreover, I–V characteristics for Bi2O3@rGO nanocomposites exhibit diode characteristic curves.