Iron-induced electron modulation of nickel hydroxide/carbon nanotubes composite to effectively boost the oxygen evolution activity

The practical potential of nickel hydroxide for oxygen evolution reaction (OER) is hindered by its low electron transport efficiency and weak coupling between hydroxyl groups and active sites. Here, we introduce iron into the nickel hydroxide to effectively adjust the local coordination environment and electron structure. This conception is realized by a facile surface-redox-etching method to grow Fe-decorated nickel hydroxide nanoparticles on the three-dimensional (3D) carbon nanotube networks (Fe-Ni(OH)2/CNT). It is surprising that the Fe-Ni(OH)2/CNT catalyst displays extraordinary OER performance with a low overpotential of 63 mV and 228 mV at 10 mA cm−2 and 100 mA cm−2, respectively, outstripping most OER electrocatalysts. The superior OER performance is ascribed to the 3D CNT networks and synergistic interaction between Ni and Fe in the lattice, which not only accelerate electron transfer but also induce strong electron coupling with OH*, boosting the reaction kinetics of OER.