Tetrazole-functionalized two-dimensional covalent organic frameworks coordinated with metal ions for electrocatalytic oxygen evolution reaction

The search for functionalized covalent organic framework  (COF) materials is significant on account of their great promise for frontline applications in various fields. Herein, a novel and convenient tactic is developed to design and fabricate the tetrazole-functionalized COF materials with abundant nitrogen atoms, which can provide active sites, facilitating the incorporation of COFs with metal ions. In particular, a β -ketoenamine-linked COF named COF-TpDb is selected as precursor for postsynthetic modification to introduce the tetrazole moieties to coordinate with metal ions cobalt (Co 2+ ) and palladium (Pd 2+ ), giving two functional metal-coordinated COFs complexes COF-TpDb-TZ-Co and COF-TpDb-TZ-Pd. The resultant COF-TpDb-TZ-Co displays a higher oxygen evolution reaction activity with a lower overpotential of 390 mV at a current density of 10 mA cm −2 , which is much enhanced compared with COF-TpDb-TZ. The tactic for the fabrication of tetrazole-functionalized COFs with abundant nitrogen atoms implements rational design for the construction of functional COFs and expands the promising application of metal-coordinated COF materials in electrocatalysis .