Abstract

The development of robust, affordable, and efficient bifunctional electrocatalysts for practical hydrogen (H2) production remains challenging. In the present study, we propose a facile synthesis strategy using a hydrothermal method followed by sulfurization for the fabrication of Co3O4@FeCo2S4 embedded with the Mo2TiC2TX MXene on Ni foam as a catalyst for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The introduction of the Mo2TiC2TX MXene preserves the Co3O4@FeCo2S4 structure and produces rich catalytic active intermediates to boost the OER and HER. Various characterization tools verify the presence of multiple nanointerfaces between the Co3O4@FeCo2S4 and Mo2TiC2TX, greatly increase the density of active sites and facilitate electron migration, thus reducing the kinetic barriers. As a result, the optimized Co3O4@FeCo2S4/Mo2TiC2TX catalyst displays satisfactory overpotentials of 83.1, 173.3 and 235.1 mV at 10, 50, and 100 mA cm?2, respectively, for the HER and of 221.6, 256.6 and 283.3 mV at 10, 50, and 100 mA cm?2, respectively, for the OER, while also exhibiting excellent durability in a 1 M KOH solution. The Co3O4@FeCo2S4/Mo2TiC2TX catalyst is subsequently used in a water electrolyzer and produces 10, 50, and 100 mA cm?2 at low cell voltages of 1.53, 1.68, and 1.81 V, respectively, which is comparable to the activity of a benchmark Pt/C//RuO2 electrolyzer. These findings verify the potential for constructing precisely engineered electrocatalysts to facilitate H2 generation without the use of noble metals. © 2025 Hydrogen Energy Publications LLC