Efficient water oxidation using an Fe-doped nickel telluride–nickel phosphide electrocatalyst by partial phosphating

Abstract

Developing transition-metal-based electrocatalysts for the oxygen evolution reaction (OER) with enhanced activities is a feasible strategy to enable the renewable energy conversion. We report here an Fe-doped nickel telluride–nickel phosphide composite (Fe-NiTe–Ni₁₂P₅) in situ grown on a nickel foam (NF) substrate. Using a partial phosphating treatment of an Fe-doped NiTe nanosheet array precursor, the as-prepared Fe-NiTe–Ni₁₂P₅ composite demonstrates superior OER electrocatalytic performance with a lower overpotential, smaller Tafel slope, and satisfactory long-term stability in comparison to the benchmark RuO₂ and recently reported transition-metal-based catalysts. The physical characterization studies suggest that a dense γ-NiOOH nanosheet layer is formed on the surface of Fe-NiTe–Ni₁₂P₅ after the OER. Due to the synergistic effects among Fe-doping, NiTe, Ni₁₂P₅, and the newly formed γ-NiOOH species, a high proportion of the accessible active sites are exposed, and the electronic structure of the catalyst is well modulated to optimize the binding strengths of OER intermediates, while the mass/charge transfer can also be promoted, thereby contributing to enhanced OER results. This work provides a simple and effective strategy for the design of highly active and stable OER electrocatalysts with multi-components by partial phosphating.