Facile Synthesis of 3d Transition-Metal-Doped α-Co(OH) Nanomaterials in Water-Methanol Mediated with Ammonia for Oxygen Evolution Reaction.

Layered cobalt hydroxides are cost-efficient electrocatalysts for oxygen evolution reaction (OER) in the field of energy conversion. Herein, we developed a facile synthesis method of 3d transition-metal-doped α-Co(OH) nanomaterials mediated with ammonia in water-methanol at room temperature. The doping of Cu and Ni leads to flower-like nanostructures similar to pure α-Co(OH), whereas the doping of Fe produces nanoparticles with more than 2 times larger surface area in comparison with the Cu- and Ni-doped nanoflowers. The obtained dispersion with the addition of Nafion can be used directly as an electrocatalyst for OER with excellent catalytic activity, especially that the overpotential of Fe doped is as low as 290 mV at 10 mA cm and the turnover frequency is improved by 3 times as compared with that of α-Co(OH). Furthermore, the catalyst can be loaded onto foam nickel, which presents excellent durability with the current density unchanged under continuous chronoamperometry reaction for as long as 12 h and almost quantitative faradaic efficiency. The superior electrocatalytic properties combined with the simple synthesis without the tedious purification procedure is very promising for OER.