Low Dimension f-MWCNT/Ti₃C₂ MXene Nanocomposite for Alkaline Hydrogen Evolution Reaction

The development of an efficient, cost-effective, and earth-abundant electrocatalyst for hydrogen production is essential for sustainable energy conversion. In this study, we report a f-MWCNT/Ti₃C₂ MXene nanocomposite synthesized by the hydrothermal method to evaluate the electrocatalytic activity of hydrogen evolution reaction (HER) in alkaline media. The acid-functionalized MWCNT was introduced onto Ti₃C₂ MXene sheets to prevent agglomeration and restacking and to improve charge-transfer kinetics, thereby enhancing active-site exposure and electrochemical performance. A hybrid nanostructure demonstrates a synergistic effect in facilitating HER, exhibiting a low overpotential of 415 mV at a current density of 10 mA cm⁻² and a small Tafel slope of 197 mV dec⁻¹, compared with the individual f-MWCNT and Ti₃C₂ MXene components. The high double-layer capacitance (8.03 mF cm⁻²), which directly indicates a high ECSA (200.83 cm²) and is supported by a small charge-transfer resistance (9.76 Ω), indicates the nanocomposite's role in enhancing active surface area and interfacial charge transfer to improve HER activity. The durability test results also show the nanocomposite's efficient stability for 9000 s with no significant change in overpotential before and after chronoamperometry. These findings highlight the potential of f-MWCNT/Ti₃C₂ MXene to improve the efficiency of renewable energy conversion.