Bimetallic Mo2TiC2Tx-MXene@NiMoO4-Based High-Performance Dual-Mode Electrochemical Platform for Energy Storage and Non-Enzymatic Biomedical Sensors

초록

To meet the growing demands of advanced energy storage and integrated electrochemical sensing technologies, we have presented a bimetallic Mo2TiC2Tx-MXene@NiMoO4-based dual-mode electrochemical platform exhibiting high energy storage and biosensing performance. Electrochemical investigations in a standard three-electrode setup demonstrated the efficient faradaic redox activity and the Cs of 1917.74 C g-1, exhibiting the synergistic charge storage mechanism, combining double-layer capacitance with redox-based energy storage. The present developed Mo2TiC2Tx@NiMoO4//AC asymmetric device exhibited remarkable electrochemical performance, with Cs= 321.44 C g-1, the highest energy density (Ed) of 45 Wh kg-1, and the power density (Pd) of 2467 W/kg. This device can deliver prolonged cycling stability with 80% retention over 5000 continued cycles. The EIS equivalent circuit presents the series resistance (Rs) = 2.45 Omega and charge transfer resistance (Rct) = 11 Omega. The highly stable properties of the present electrode also lead to an effective non-enzymatic uric acid sensor, showing high sensitivity (S) of 0.00468 mu A/mu M, LOD of 0.1323 mu M (at S/N = 3), and LOQ of 0.441 mu M, with a wide linear sub-micromolar detection range (LOR) of 50-1200 mu M, and showed an excellently stable and selective UA detection response. A novel Mo2TiC2Tx-MXene@NiMoO4-based hybrid nanocomposite is developed and integrated a high-capacitance energy storage and sensitive non-enzymatic biosensing into a single multifunctional system.Structural analyses confirmed uniform integration of redox-active NiMoO4 onto conductive Mo2TiC2Tx-MXene sheets, achieving high crystallinity (29.7 nm) and uniform elemental dispersion.A high specific capacity of 1917.74 C g-1 (electrode) and 321.44 C g-1 (device), with energy and power densities of 45 Wh kg-1 and 2467 W kg-1, and 80% retention are achieved after 5000 cycles.BET analysis revealed a surface area of 292 m2 g-1, pore size of 6.6 nm, and total pore volume of 3.2 cm3 g-1, enabling enhanced ion diffusion and reduced charge transfer resistance (Rct = 11 Omega).The platform functioned as a highly selective and stable non-enzymatic uric acid sensor with a sensitivity of 0.00468 mu A mu M-1, LOD of 0.1323 mu M, and broad detection range of 50-1200 mu M.

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