Ultrathin ternary metal oxide Bi2MoO6 nanosheets for high performance asymmetric supercapacitor and gas sensor applications

[Display omitted] •Unstacked, 2-D Bi2MoO6 nanosheets grown on Ni foam via hydrothermal route.•Electrochemical properties via CV, GCD, EIS analysis of Bi2MoO6@Ni foam electrode.•Higher capacitance, power density, long cycle stability of Bi2MoO6@Ni foam electrode.•Fabrication of Bi2MoO6 nanosheets sensor and ethanol sensing for 10–100 ppm.•Sensor exhibits high response, selectivity, transient study, stability at 275 °C. Two dimensional (2-D), unstacked Bi2MoO6 nanosheets are directly grown on nickel foam and prepared as powder via easy, template-free hydrothermal route. The prepared material was systematically characterized using techniques viz XRD, Cs-TEM, HRTEM, FESEM, XPS, elemental mapping, EDS. Bi2MoO6 nanosheets grown on Nickel foam employed for supercapacitor application, whereas powder form was utilized to fabricate ethanol sensor. The electrochemical characteristics viz cyclic voltammetry (CV), galvanic charging-discharging (GCD), and electrochemical impedance spectroscopy (EIS) were investigated for Bi2MoO6 nanosheets grown nickel foam in 1 M KOH aqueous solution within −0.2 to 0.8 V potential window. The areal capacitance of 655.5 mF/cm2 was achieved at 1 mA/cm2 current density with the energy density of 22.76 × 10−3 Wh/cm2 and 347.18 × 10−3 W/cm2 power density. The 5000 charge–discharge cycles were performed with excellent capacitance retention. The Bi2MoO6 sensor was tested for 10–100 ppm ethanol. A high response of 82% was noted for 100 ppm ethanol concentration at 275 °C. The dynamic resistance response, selectivity, and sensor’s stability were tested and analysed.