One dimensionally spinel NiCo₂O₄ nanowire arrays: facile synthesis, water oxidation, and magnetic properties

Development of efficient, affordable, non-precious metal oxides catalysts is critical for the oxygen evolution reaction (OER). Herein, we present a spinel NiCo₂O₄ nanowire arrays (NWAs), synthesized by a simple solution route, as an inexpensive, efficient anode electrocatalyst for water electrolysis. The as-prepared NiCo₂O₄ NWAs contains Ni²⁺/Ni³⁺ which replace Co in octahedral sites of the spinel Co₃O₄, exhibiting higher catalytic activity than that of Co₃O₄ and NiO. The enhanced catalytic activity of NiCo₂O₄ NWAs is correlated with a large surface area, one-dimensional (1D) architecture, high conductivity and synergistic behavior of Ni/Co bifunctional catalyst. Besides, oxygen vacancies, which favor efficient electrons transport, supply more active sites, and assist in the adsorption of OH⁻, can be conducive to make high utilization of catalytic materials in the OER. Moreover, the magnetic properties of NiCo₂O₄ NWAs are also investigated in detail. The results indicate that NiCo₂O₄ NWAs could be a promising economical and environmentally benign bifunctional electrocatalyst for water splitting and other applications