Biomass-Derived Carbon Meets MoS2: A Green Route to High-Performance Supercapacitor Electrodes

The quest for renewable energy storage technologies has fuelled increased interest in supercapacitors, especially those that utilise sophisticated electrode materials of high capacitance and environmental sustainability. Among emerging candidates, biocarbon-based MoS2 composites have garnered attention for their unique combination of conductivity, porosity, and eco-friendliness, making them ideal for next-generation energy storage devices. Molybdenum disulfide (MoS2) is a layered transition metal dichalcogenide with high theoretical specific capacitance but with low conductivity and structural stability. To improve these drawbacks, we herein present a simple synthesis of MoS2/biocarbon (MoBC) composites for the very first time from cowpea pod-derived biocarbon activated through NaOH treatment. Exfoliated MoS2 nanosheets were combined with biocarbon in different proportions (MoBC10, MoBC20, MoBC30) to prepare composite electrodes. Structural and morphological studies (XRD, Raman, FTIR, SEM, TEM, BET) validated successful hybridisation, improved graphitisation, and defective interfaces favourable for charge transport, and porous structure studies. Electrochemical properties by cyclic voltammetry and galvanostatic charge–discharge characterised MoBC20 to be the best composition with a high specific capacitance of 1855.65F/g at 0.1 mA (3-electrode set-up), energy density of 41.930 Wh/kg, power density of 344.678W/kg, and superior cycling stability with 98% retention of capacitance over 2000 cycles. The coulombic efficiency was consistently greater than 91% during the cycling tests. The synergistic effect of MoS2 and biocarbon promotes ion diffusion, inhibits restacking, and enhances conductivity, making MoBC composites scalable, green contenders for high-performance supercapacitor applications.