Exquisitely regulated CeO2/Co(OH)2 electrocatalysts for enhanced oxygen evolution reaction

Abstract

The development of advanced transition metal catalysts for efficient electrocatalytic oxygen evolution has been widely studied, and these catalysts have the potential to replace precious metals and achieve widespread commercial application. The rare earth element cerium with a flexible 4f state can strongly regulate the electronic structure and charge transfer rate of the transition metal catalysts and obviously improves the activity and stability of the catalysts. Herein, we fabricated advanced electrocatalysts consisting of CeO₂ nanorods anchored on Co(OH)₂ nanosheets based on a facile co-deposition protocol. The CeO₂/Co(OH)₂ nanocomposite exhibits obviously enhanced OER activity with an overpotential of only 322 mV at a current density of 10 mA cm⁻² and a Tafel slope of 55 mV dec⁻¹, which are greater than those of pristine CeO₂ and Co(OH)₂, respectively. These results were ascribed to the tight interfacial contact and the populations of surface oxygen vacancies, which efficiently increased the electrochemical specific surface area and promoted the transfer/separation of interfacial charge carriers. Overall, the successful synthesis and characterization of the CeO₂/Co(OH)₂ nanocomposite, along with its exceptional electrocatalytic performance, offer valuable insight into the development of advanced electrocatalysts with applications in green chemistry and environmental remediation.