Synergistic effects of Co/CoO nanoparticles on imine-based covalent organic frameworks for enhanced OER performance

The development of non-noble metal electrocatalysts toward the oxygen evolution reaction (OER) is a key challenge in advancing electrocatalytic water splitting, which is essential for the commercialization of clean and renewable energy. A covalent organic framework (COF) has a precise and controllable structure, high pi-pi conjugation, large surface area, and porosity and shows great potential as an OER electrocatalyst. However, the relative conductivity and inherent instability greatly limit the further improvement of its performance. Herein, imine-based COF-supported Co/CoO nanoparticles (Co/CoO@COF) were developed for the high-performance electrocatalytic OER. For the Co/CoO@COF catalyst, Co/CoO could form a conjugation effect with the COF, which can increase the electron cloud density of the delocalized large pi bond, then improve the conductivity. The combination of Co/CoO and COF effectively enhances the structural stability of the catalyst and enriches the catalytic active sites. Under alkaline conditions, the Co/CoO@COF shows a very low overpotential of 278 mV at a current density of 10 mA cm(-2), and a Tafel slope of 80.11 mV dec(-1) which is better than that of commercial RuO2.

Automated summary

A covalent organic framework (COF) with precise structure and high pi-pi conjugation shows great potential as an OER electrocatalyst, but its relative conductivity and instability limit further improvement. Co/CoO@COF catalyst combines Co/CoO nanoparticles with COF to enhance conductivity and structural stability, achieving a low overpotential and better performance than commercial RuO2.