2D Ti 3 C 2 MXene/WO 3 Hybrid Architectures for High‐Rate Supercapacitors

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 (WO 3 ). The phase‐determined nature, such as intrinsic formation of hollow tunnels in the hexagonal polymorph of WO 3 (Hexa WO 3 ) and highly crystalline features in the monoclinic phase (Mono WO 3 ), makes WO 3 an attractive candidate for energy storage applications like supercapacitors. The development of superior WO 3 supercapacitor electrode demands developing synergetic architectures with a variety of 2D materials like graphene, titanium carbide (Ti 3 C 2 ) MXenes, etc. that can complement conductivity and stability. Here, the hybrids of Mono WO 3 –Ti 3 C 2 and Hexa WO 3 –Ti 3 C 2 are synthesized hydrothermally in one step by meticulously controlling the phase of WO 3 . 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 WO 3 ‐ and Hexa WO 3 ‐only electrodes, exhibiting the highest C sp (566 F g −1 ) for Hexa WO 3 –Ti 3 C 2 , while retaining excellent life cycle (≈92%) of the initial C sp after 5000 cycles.