High-Valence Transition Metal Modified FeNiV Oxides Anchored on Carbon Fiber Cloth for Efficient Oxygen Evolution Catalysis

Developing efficient and durable non-noble metal-based oxygen evolution catalysts is of great importance for electrochemical water splitting. Here, we report a new and facile strategy for controllable synthesis of high-valence Mo modified FeNiV oxides as efficient OER catalysts. The Mo-dopant displays a significant influence on the valence state of Fe species in the catalysts, which lead to tunable OER performance. When the feed ratio of Mo-dopant is 5%, the Mo-modified FeNiV oxide shows the best OER performance in terms of low overpotential (237 mV at the current density of 10 mA cm−2), Tafel slope (38 mV per decade), and high mass activity, which exceeds its counterparts and most reported OER catalysts. Furthermore, by assembling the catalyst with a carbon fiber cloth, the fabricated water-splitting device exhibits excellent activity and long-term durability in alkaline electrolyte compared with commercial catalysts equipped device. This work not only provides a series of Mo-modified FeNiV-based oxides as high-performance OER catalysts but also offers a new pathway to tune the charge states of OER active centers.