The development of bifunctional electrocatalysts with efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is still a key challenge at the current stage. Herein, FeNi LDH/V₂CT_x/nickel foam (NF) self-supported bifunctional electrode was prepared via deposition of FeNi LDH on V₂CT_x/NF substrate by hydrothermal method. Strong interfacial interaction between V₂CT_x/NF and FeNi LDH effectively prevented the aggregation of FeNi LDH, thus exposing more catalytic active sites, which improved electrical conductivity of the nanohybrids and structural stability. The results indicated that the prepared FeNi LDH/V₂CT_x/NF required 222 mV and 151 mV overpotential for OER and HER in 1 M KOH to provide 10 mA cm⁻², respectively. Besides, the FeNi LDH/V₂CT_x/NF electrocatalysts were applied to overall water splitting, which achieved a current density of 10 mA cm⁻² at 1.74 V. This work provides ideas for improving the electrocatalytic performance of electrocatalysts through simple synthesis strategies, structural adjustment, use of conductive substrates and formation of hierarchical structures.

Water electrolysis represents a viable and scalable green hydrogen production technology, which mitigates carbon emissions and contributes to environmental sustainability. Transition metal-based layered double hydroxides (LDHs) exhibit excellent oxygen evolution reaction (OER) efficiency, attributed to their adjustable interlayer spacing combined with abundant active sites. Here, we report a uniform multimetallic catalyst, demonstrating robust and efficient OER performance for high-performance water splitting. SEM and TEM confirmed its ultrathin hierarchical nanosheet structure. The characteristic peaks of LDH in XRD and Raman spectra further verified the successful synthesis of the LDH material. Fe-CoZn LDH delivers exceptional OER performance in 1 M KOH, requiring overpotentials of just 209, 238, and 267 mV to reach 10, 100, and 400 mA cm⁻², respectively. The catalyst also demonstrates exceptional hydrogen evolution reaction (HER) performance, achieving 10 mA cm⁻² at 119 mV. It also has excellent stability, with stable operation for up to 100 h under 100 mA cm⁻² in 1 M KOH electrolyte solution.