2D/2D heterostructures of nickel molybdate and MXene with strong coupled synergistic effect towards enhanced supercapacitor performance

Nickel molybdate is emerged as a promising electrode material in supercapacitors for its rich redox chemistry. However, its limited electrical and ionic conductivities keep it from achieving its full capacitance potential. Here, a facile pathway is reported to synthesize NiMoO₄/Ti₃C₂T_x nanosheets with interconnected porous construction, which may promote the electrolyte ion diffusion during reversible insertion/deinsertion processes, further improve its capacity. The fabricated NiMoO₄/Ti₃C₂T_x electrode exhibits a high specific capacity of 545.5 C g⁻¹ (1364 F g⁻¹) at a current density of 0.5 A g⁻¹ alongside with attractive cycling stability, contributed to the strong synergistic effects between NiMoO₄ and Ti₃C₂T_x. Furthermore, an asymmetric supercapacitor is fabricated by coupling NiMoO₄/Ti₃C₂T_x positive electrode with reduced graphene oxide hydrogel negative electrode, which demonstrates a broad potential window of 1.6 V, and an energy density of 33.76 W h kg⁻¹.