LAUSR

The acetone gas sensor and electrochemical supercapacitor applications of bismuth oxide (Bi2O3) nanostructures, synthesised using a facile and cost-effective quaternary-beaker mediated successive ion transfer wet chemical method and deposited onto soda-lime-glass (SLG) and Ni-foam substrates, respectively, are explored. The as-deposited Bi2O3 nanostructures on these substrates exhibit polycrystalline nature and a slight change in their surface appearance (i.e. upright-standing nanoplates on SLG and a curvy nanosheet structure on Ni-foam), suggesting the importance of the deposition substrate in developing Bi2O3 morphologies. The Bi2O3 nanoplate gas sensor on the SGL demonstrated a room temperature sensitivity of 41%@100 ppm for acetone gas, whereas the nanosheet structure of Bi2O3 on the Ni-foam elucidated a specific capacitance of 402 F g−1 at 2 mA cm−2, long-term cyclability, and rate capability with moderate chemical and environmental stability in a 6 M KOH electrolyte solution. The Bi2O3//graphite pencil-type asymmetric supercapacitor device revealed a specific capacitance as high as 43 F g−1, and an energy density of 13 W h kg−1 at 793 W kg−1 power density, turning a light emitting diode ON, with considerable full-brightness light intensity, during the process of discharging.