Cost-effective pure and Fe-doped amorphous and composite Ni-P alloys as efficient electrocatalysts for alkaline oxygen evolution reaction

Amorphous and nanocrystalline Ni-P alloys are suitable for different applications in various fields of modern technology, including the catalytic ones. In this work, several amorphous/nanocrystalline Ni-P and Ni-Fe-P alloys were prepared in powder form by simple chemical reduction method, using different reactants ratios, and studied in terms of electrocatalytic activity for oxygen evolution reaction (OER) in alkaline environment (0.1 M KOH). The prepared samples were thoroughly characterized regarding their microstructural properties and electrochemical behavior. Their OER performance considerably outperformed that of pure Ni (fcc) powder, and was strongly influenced by their composition and microstructure. Due to its specific electronic structure, mostly amorphous Fe-containing Ni-P-based alloy demonstrated OER activity superior to all other samples, according to low Tafel slope of 72 mV dec-1 and overpotential at 10 mA cm-2 of 0.35 V, and relatively good durability. Quantum chemical calculations additionally confirmed the beneficial effect of Fe addition on the OER performance of Ni-P materials. The findings arising from this study contribute to further development of cost-effective, efficient and durable non-noble metal-based electrocatalysts for OER, with a view to future progress in the field of clean energy.