Surface morphology and interface electronic structure tailoring of cobalt carbonate hydroxide via Ce doping for enhanced oxygen evolution reaction

Abstract

As a high-quality green and clean energy source, hydrogen is produced from electrochemical water splitting. The superior activity is significant for the non-precious-metal electrocatalyst in water electrolysis process. Herein, cerium-doped cobalt carbonate hydroxide nanohybrids on nickel foam (Co2CexCH/NF) have been synthesized by a one-step hydrothermal method. The cobalt carbonate hydroxide (CoCH)/cerium fluoride (CeF3) heterostructure preparation was achieved and characterized by physical and chemical characterization. The doping of cerium facilitates nucleation, resulting in a unique hierarchical morphology that exposes more active sites. And the mechanism of catalyst formation was investigated. Tailoring the electronic structure of the cobalt active center and producing the layered nanowire array/flower-like ball structure is favorable to enhance the oxygen evolution activity of the Co2Ce0.06CH/NF electrocatalyst. In 1.0 M KOH, the Co2Ce0.06CH/NF electrocatalyst presents efficient OER activity with a lower onset potential of 1.48 V vs. RHE during the electrochemical water splitting and an overpotential of only 304 mV at a current density of 100 mA cm−2. Besides, the Co2Ce0.06CH/NF electrocatalyst exhibits a Tafel slope of 81 mV dec−1 as well as good stability and durability. This research offers a possible method for the design and synthesis of OER catalysts.