Effect of air-annealing on the structure, surface morphology, and supercapacitive properties of the 2D-BiOCl nanosheets

Upright-standing nanosheets of bismuth oxychloride (BiOCl), synthesized via a facile chemical synthesis method and air-annealed from 50 to 600 ℃ temperatures (named BOC-50–600), are envisaged as electrochemical supercapacitor electrodes. These electrodes are initially screened for their surface morphology, elemental configuration, phase purity, and binding energy by various means. Due to changes in the surface morphology, phase, charge transfer resistance, and binding energy, the one annealed at 150 ℃ i.e., BOC-150 has offered targeted supercapacitive performance due to quasi-faradaic redox reactions in 6 M KOH electrolyte solution. The specific capacitance of the BOC-150 electrode, measured at 1.40–5.0 A/g current densities, varies from 264.6 to 95 F/g. The as-assembled BOC-150//BOC-150 symmetric supercapacitor device (SSD) demonstrates an efficient supercapacitive performance with a maximum 86.87 Wh/kg energy density and 3735 W/kg power density. Additionally, the as-designed SSD endows an admirable capacity retention of 81.6% for 5000 charge-discharge cycles, approving moderate chemical stability and considerable mechanical robustness for use in commercial electronic items. [Display omitted]