Nickel-based composites with Mo2C and TiC for improved electrocatalytic performance of HER

Abstract

The development of efficient and sustainable catalysts for hydrogen evolution reaction (HER) is critical to the development of renewable energy technologies. Nickel-based catalysts, particularly those derived from Ni-Watts electrodeposition baths have shown significant potential due to their cost effectiveness and catalytic activity. This study investigates the effects of incorporating transition metal carbides, specifically molybdenum carbide (Mo₂C) and titanium carbide (TiC), into nickel electroplating baths to improve electrochemical performance. By systematically varying the concentrations of Mo₂C and TiC, we are evaluating their effect on the structural and catalytic properties of the resulting nickel-based composites. Characterization techniques including X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy and confocal microscopy show that the addition of these carbides alters the crystallographic orientation of nickel matrix, increases the surface roughness and improves the active surface area of the catalysts. Electrochemical tests including cyclic voltammetry, electrochemical impedance spectroscopy and differential electrochemical mass spectrometry show that the modified composites exhibit enhanced HER activity compared to conventional Ni-Watts catalysts. Differential electrochemical mass spectrometry (DEMS) was used to accurately determine the onset potential and Tafel slopes for the materials in NaOH 0.1 M media, showing the lowest onset potentials and most favored kinetics for the composites containing TiC. These findings provide valuable insights into the design of durable, efficient electrocatalysts for HER applications, which are prepared by the one-step electrodeposition technique. This fact means that this procedure simplifies electrode fabrication, offering practical advantages for large-scale hydrogen production