Tungsten Carbide‐Enhanced FeNi ₃ /FeNiO x for Efficient Bifunctional Water Splitting

The development of efficient electrocatalytic overall water splitting systems necessitates high‐performance bifunctional catalysts to overcome the sluggish kinetics of both the hydrogen and oxygen evolution reactions (HER and OER). Earth‐abundant transition metal oxides represent promising candidates due to their favorable electronic structure and cost‐effectiveness. However, engineering such materials to simultaneously achieve exceptional activity and robust durability remains a formidable challenge. In this study, a bifunctional non‐noble‐metal electrocatalyst FeNi 3 /FeNiO x ‐WC was prepared by a facile chemical reduction method. Advanced spectroscopic and microscopic analyses revealed that the integration of tungsten carbide (WC) into FeNi 3 /FeNiO x induces significant interfacial charge redistribution. The resulting FeNi 3 /FeNiO x ‐WC catalyst exhibited remarkable performance for overall water splitting in 1 mol L −1 KOH, requiring low overpotentials of 210 mV for the OER and 169 mV for the HER to achieve 10 mA cm −2 , alongside favorable Tafel slopes of 44.9 and 268 mV dec −1 , respectively. Moreover, its turnover frequency (4.23 s −1 for OER, 6.49 s −1 for HER) surpassed that of the WC‐free counterpart, confirming the enhancement of intrinsic activity via WC incorporation. This provides a viable and scalable strategy for designing high‐performance, cost‐effective electrocatalysts for renewable energy conversion.