Molybdenene for Energy Storage Applications

Abstract

Molybdenene, a full-fledged metallene has been sensational among all Xenes. Apart from metallicity with excellent carrier concentration, it is anticorrosive, rendering it a superioor electrode material for electrochemical energy storage. As evident from atomic force microscopy, microwave-synthesized molybdenene constitutes of monolayers (each layer ≈0.4 nm) and lateral dimensions extended to millimeters. Cris-cross intertwinned crystals with close to square (0.20, 0.21 nm) lattice with fourfold symmetry were observed in electron imaging. Characteristic metallic signal (Mo–Mo vibration) in Raman peak at ≈405 cm⁻¹ proves chemical phase purity. The electrochemical performance of synthesized molybdenene sheets is evaluated for supercapacitor applications in a 2 m KOH electrolyte. The as-synthesized molybdenene demonstrates a specific capacitance of 327.78 F g⁻¹ at a scan rate of 10 mV s⁻¹ and 118.6 F g⁻¹ at a current rate of 0.50 A g⁻¹ in a three-electrode configuration, with a capacitance retention of 81.0% over 5000 cycles. Furthermore, an asymmetric supercapacitor employing molybdenene as the positive electrode and activated carbon as the negative electrode exhibits an energy density of 15.94 Wh kg⁻¹ at a power density of 399.72 W kg⁻¹. These findings highlight molybdenene as a promising candidate for high-performance electrochemical energy storage devices.