NiCoO2 nanowires grown on carbon fiber paper for highly efficient water oxidation

Water oxidation is a critical step in water splitting to make hydrogen fuel. We report a hybrid material consisting of NiCoO2 nanowires grown on carbon fiber paper (denoted as NiCoO2@CFP) as a highly efficient oxygen evolution reaction (OER) electrocatalyst. In 0.1 M KOH, the highly nanostructured NiCoO2 catalyst presents a small overpotential of ∼0.303 V at a current density of 10 mA cm−2 and a low Tafel slope of ∼57 mV dec−1, comparable to the commercial precious RuO2 catalyst. Such a good performance for OER may be attributed to the NaCl-type structure of the NiCoO2 nanowires and CFP substrate, which can boost the formation of active Ni-Co layered hydroxide/oxyhydroxide species during the catalysis process. Additionally, the aligned 3D structure of NiCoO2@CFP plays an important role in the high catalytic activity for OER. These merits combined with the satisfactory stability of the hybrid material indicate that it is a promising material for water oxidation.