2D Ti3C2 MXene/WO3 Hybrid Architectures for High-Rate Supercapacitors

Abstract

Energy storage capabilities of transition metal oxides (TMOs) have expanded beyond the realm of ruthenium and manganese oxides to a versatile TMO like tungsten trioxide (WO3). The phase-determined nature, such as intrinsic formation of hollow tunnels in the hexagonal polymorph of WO3 (Hexa WO3) and highly crystalline features in the monoclinic phase (Mono WO3), makes WO3 an attractive candidate for energy storage applications like supercapacitors. The development of superior WO3 supercapacitor electrode demands developing synergetic architectures with a variety of 2D materials like graphene, titanium carbide (Ti3C2) MXenes, etc. that can complement conductivity and stability. Here, the hybrids of Mono WO3-Ti3C2 and Hexa WO3-Ti3C2 are synthesized hydrothermally in one step by meticulously controlling the phase of WO3. The comparison of electrochemical performance reveals that the electrodes of 2D synergetic hybrid architectures almost double the specific capacitance (C-sp) with respect to Mono WO3- and Hexa WO3-only electrodes, exhibiting the highest C-sp (566 F g(-1)) for Hexa WO3-Ti3C2, while retaining excellent life cycle (approximate to 92%) of the initial C-sp after 5000 cycles.