In situ synthesis of covalent cobalt porphyrin framework/CNTs composites for efficient oxygen evolution reaction

Covalent organic framework materials (COFs) are a new class of crystalline porous polymers with high porosity, robust frame structure, and uniform dispersion atoms, but lower conductivity normally. Given this, we in situ prepared a cobalt-porphyrin-based COF modified with CNTs via Schiff base condensation reaction for the oxygen evolution reaction, without a high-temperature pyrolysis process. The electrocatalysts exhibit outstanding oxygen evolution reaction activity because of the uniform distribution of active centers and the synergistic effects between Co-COF and CNTs. The results show that Co-COF/3 mg CNT electrocatalyst exhibits an overpotential of 376 mV and a low Tafel slope of 61 mV dec at a current density of 10 mA cm in the alkaline solution with pH = 13.6. Moreover, the chronopotentiometry measurements manifest that the as-prepared electrocatalysts are superior superiorly stable during the long-term OER process, retaining 93% of their initial current density after 7 h of continuous measurement. Thus, this work proposes a convenient method for fabricating effective OER electrocatalysts directly using COF-based material in energy conversion.