Metal-Free Covalent Organic Frameworks for Electrocatalytic Oxygen Reduction Reaction.

Exploring efficient and low-cost electrocatalysts for the oxygen reduction reaction (ORR) is important for renewable energy conversion. Covalent organic frameworks (COFs) have recently risen as ideal candidates for catalyzing ORR, but this field is still in its infancy. Herein, a new framework material (named as COF-JLU82) containing bifluorenylidene and benzoselenadiazole units with periodic alternating arrangement is designed and synthesized. The metal-free COF-JLU82 exhibits good electrocatalytic activity with a half-wave potential of 0.68 V, Tafel slope of 72.79 mV dec-1 and the conversion frequency (TOF) of 0.0044 s-1 , which is better than the previously reported COF-JLU23. This study enriches the types of COF-based ORR electrocatalysts and promotes the development of more highly efficient metal-free ORR electrocatalysts.