Synergistic MoS2@MWCNT nanocomposites for high-efficiency catalysis and energy applications

The MoS₂-MWCNT composite heterojunction for its potential as an electrocatalyst and energy storage material. The composite demonstrated remarkable electrochemical performance, achieving a specific capacitance of 263 F/g, an energy density of 16.89 Wh/kg, and a power density of 478 W/kg. Using CV profiles, we analyzed the charge storage mechanism and found that the anodic and cathodic processes had b values of 0.48 and 0.45, respectively, indicating diffusion-controlled behavior. Diffusion coefficients of 6.44 × 10⁻⁷ cm²/s (anodic) and 11.32 × 10⁻⁷ cm²/s (cathodic) confirmed this mechanism. In the constructed device using MoS₂-MWCNT and activated carbon (AC), we observed a specific capacitance of 18.71 F/g, an energy density of 5.09 Wh/kg, and a power density of 833 W/kg. After stability, testing, electrochemical impedance spectroscopy (EIS) revealed a slight increase in series resistance, rising from 2.33 Ω to 2.49 Ω. The MoS₂-MWCNT composite also exhibited excellent electro catalytic performance. For the hydrogen evolution reaction (HER), it achieved an over potential of 0.221 V and a Tafel slope of 0.321 V/dec. After stability testing, we measured R_s and R_ct values of 4.86 Ω and 2.57 Ω, respectively. For the oxygen evolution reaction (OER), the composite showed an over potential of 597 mV and a Tafel slope of 0.285 V/dec, with post-stability R_s and R_ct values of 5.63 Ω and 5.57 Ω, respectively. These findings highlight the versatility of the MoS₂-MWCNT composite for applications in energy storage and water splitting.