Facile synthesis of CeO2-decorated Co4N nanoparticles as a highly active and durable electrocatalyst for the oxygen evolution reaction

In this study, Co– and Ce-based bimetal organic frameworks are employed as self-templates for the synthesis of CeO2-decorated Co4N (Co4N/CeO2) nanoparticles with strongly coupled heterointerfaces. The rough surface and well-developed mesoporous structure of Co4N/CeO2 can enhance the exposure of electrochemically active sites. In addition, the lattice mismatch at the heterointerface between Co4N and CeO2 introduces abundant oxygen vacancies, which moderately controls the electronic structure and provides efficient active sites for an alkaline OER. Consequently, the as-prepared Co4N/CeO2 electrocatalyst exhibits superior OER activity: a small overpotential of 297 mV to acquire a current density of 10 mA cm−2, low Tafel slope of 81 mV dec−1, and a turnover frequency of 4.75 s−1 at an overpotential of 420 mV. Additionally, the Co4N/CeO2 nanoparticles show an excellent long-term durability of more than 80 h of continuous electrocatalytic operation in an alkaline solution.