Designing CoTb2O4 electrodes integrated with MoTe2 and graphene for high-performance supercapacitors and HER catalysis

초록

Developing multifunctional materials that merge high (Ed) energy density, long cycle life, and outstanding catalytic activity is vital for next-generation energy systems. In this work, we report the synthesis of a CoTb2O4/MoTe2/Gr novel ternary nanocomposite that was prepared via a simple hydrothermal technique. The electrochemical analysis of the composite was assessed using a three-electrode scheme in a 1 M KOH electrolyte. The CoTb2O4/MoTe2/Gr electrode demonstrated an impressive specific capacity of 1080 C/g. Furthermore, an asymmetric supercapacitor (ASC) device was assembled using CoTb2O4/MoTe2/Gr as the positive electrode and commercially available activated carbon as the negative electrode. The device attained a maximum Ed of 56.93 Wh/kg at a power density (Pd) of 1120 W/kg and maintained 89 % of its initial capacity after 4000 charge/discharge cycles, representing exceptional stability. In addition to its exceptional energy storage capability, the CoTb2O4/MoTe2/Gr composite also revealed resourceful electrocatalytic activity toward the hydrogen evolution reaction (HER), with a low overpotential of 186 mV at 10 mA/cm2 and a Tafel slope of 53.6 mV/dec for the CoTb2O4/MoTe2 electrode. These outcomes highlight the strong potential of CoTb2O4/MoTe2/Gr as a multifunctional electrode for both energy storage and HER applications.

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