Synergy of copper doping and oxygen vacancies in porous CoOOH nanoplates for efficient water oxidation

Abstract

The development of highly active and low-cost oxygen evolution reaction (OER) electrocatalysts is pivotal for the efficient generation of renewable hydrogen but still challenging. Heteroatom doping and oxygen vacancy (Ov) engineering are effective strategies to regulate the physical and chemical properties of the catalysts and thus facilitating the intermediates absorption/desorption. Herein, the rational design of Cu doping CoOOH porous nanoplates with rich Ov grown on carbon fiber paper (Cu-CoOOH/CFP) is performed to enhance the OER performance. Experiment results and density functional theory (DFT) calculations uncovered that the synergistic effect of Cu doping with Ov exceptionally modulated the electronic structure of Cu-CoOOH/CFP so that enormously facilitates the (O–H)* bond cleavage and optimize the Gibbs free energies of OER intermediates, thus contributing to fast kinetics and outstanding OER activity. As expected, the optimized three-dimensional (3D) self-supported Cu-CoOOH/CFP with unique porous structure shows unprecedented OER activity with a low overpotential of 234 mV to attain a current density of 10 mA cm−2, as well as superior stability in 1.0 M KOH. This work provides an effective electronic engineering approach for the rational design of nonprecious-metal and efficient electrocatalysts for water oxidation and beyond.