Engineering the WTe2/NiFe2O4 hybrid catalyst for bifunctional water splitting kinetics

초록

Renewable-energy-driven water electrolysis offers a sustainable pathway to carbon–neutral hydrogen production, addressing pressing energy and environmental challenges. Rare-earth metal-based catalysts remain benchmarks for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), but their scarcity and high cost impede large-scale implementation. NiFe-based catalysts show high OER activity due to optimized intermediate adsorption energetics but exhibit inferior HER performance because of low conductivity and particle aggregation. To address these limitations, we designed a bifunctional WTe2@NiFe2O4 electrocatalyst via solid-state reaction, leveraging synergistic effects between the heterointerfaces. The hybrid system combines the metallic conductivity and topological surface states of WTe2 for efficient charge transfer, along with multivalent Ni/Fe redox couples and defect-rich sites in NiFe2O4 for enhanced catalytic activity. The catalyst achieves overpotentials of 55 mV (HER) and 247 mV (OER) in alkaline media to reach the 10 mA cm−2 current density, which is highly competitive with various literature electrocatalysts. When configured in a symmetric WTe2@NiFe2O4||WTe2@NiFe2O4 electrolyzer, the system requires only 1.51 V at 10 mA cm−2, comparable to noble-metal benchmarks (RuO2||Pt/C, 1.52 V) while maintaining stable performance over 24 h. Interfacial engineering combined with topological material integration provides an effective route toward efficient, durable bifunctional catalysts for scalable water splitting. © 2026 The Korean Society of Industrial and Engineering Chemistry.

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