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 NiCoO 2 nanowires grown on carbon fiber paper (denoted as NiCoO 2 @CFP) as a highly efficient oxygen evolution reaction (OER) electrocatalyst. In 0.1   M KOH, the highly nanostructured NiCoO 2 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 RuO 2 catalyst. Such a good performance for OER may be attributed to the NaCl-type structure of the NiCoO 2 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 NiCoO 2 @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.