Ti3C2Tx MXene coupled Co(OH)2: a stable electrocatalyst for the hydrogen evolution reaction in alkaline media

Abstract

Green hydrogen (H₂) production via water electrolysis is a promising technique. Within this domain, two dimensional (2D) materials are gaining more attention throughout the world particularly in energy conversion/storage devices due to their unique features. Herein, this study focuses on the development of sustainable, durable, and economical electrocatalysts based on titanium carbide (Ti₃C₂T_x) MXene and cobalt hydroxide (Co(OH)₂) as a composite. Ti₃C₂T_x has been doped into Co(OH)₂ (CT nanostructure) with varying concentrations by the aqueous chemical growth method. The as-prepared electrocatalysts (CT-15 and CT-30) have been investigated through different physicochemical characterization studies including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and electrochemical analysis in order to access their morphology, crystalline phase homogeneity, surface functionalization, and electrochemical behaviour for the HER. It is observed that the as-prepared material (CT-30) exhibits superior hydrogen evolution reaction (HER) activity in 1.0 M potassium hydroxide (KOH). The optimised electrocatalyst CT-30 demonstrates an overpotential of 380 mV at a current density of 10 mA cm⁻² with a 99 mV dec⁻¹ Tafel slope value, showing fast reaction kinetics. Moreover, it offers a low charge transfer resistance (R_ct) accompanied by good stability, high electrochemical active surface area (ECSA), and durability for 30 h, as evident for efficient HER activity. This novel electrocatalyst can contribute to the replacement of noble metal-based electrocatalysts for practical usage in energy conversion/storage systems.