Improved electrocatalytic performance of delaminated-MXene and cobalt ferrite nanocomposite for hydrogen evolution in acidic medium

Abstract

Recently, the electrochemical hydrogen evolution reaction (HER) for hydrogen generation has garnered research attention due to growing environmental concerns over fossil fuels usage. This paper discusses HER activity of cobalt ferrite and delaminated-MXene (D-MX) nanocomposites at different mass ratios. The electrochemical performance of the nanocomposites was evaluated based on their structural, microstructural, and spectroscopic features. D-MX was successfully synthesized from the MAX phase by the chemical etching route, followed by a chemical delamination process. CoFe<inf>2</inf>O<inf>4</inf> nanoparticles (CF) were synthesized using the sol-gel auto-combustion method. It has been observed that the D-MX and CF nanocomposite with the mass ratio of 5:1 (CMX51) exhibits superior electrocatalytic behavior for HER. When compared to other mass ratios, the composite CMX51 has the lowest overpotential of 681 mV in a 0.5 M acidic solution. The CMX51 composite demonstrated a Tafel slope of 112 mV/dec for the hydrogen evolution reaction (HER), which is lower compared to that of CF. This indicates that the presence of D-MX in the nanocomposite improved the sluggish kinetic behavior of the CF nanoparticles. This may be attributed to the enhancement in ionic conductivity of CF with improved charge transfer kinetics resulting from the addition of D-MX. The Electrochemical impedance spectroscopy analysis reveals that the nanocomposite CMX51 shows improved ionic conductivity with a low charge transfer resistance. © 2025