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 (10) 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. (C) 2015 Elsevier Ltd. All rights reserved.