Silica-Templated Covalent Organic Framework-Derived\nFe–N-Doped Mesoporous Carbon as Oxygen Reduction Electrocatalyst

Abstract

The\nrational design and synthesis of mesoporous functional materials\nis of great significance to tackle fundamental challenges in materials\nscience and to yield practical solutions for efficient energy utilization.\nHere, a novel <i>p</i>-toluenesulfonic acid-assisted mechanochemical\napproach is used to prepare a silica-templated bipyridine-containing\ncovalent organic framework (COF), which can be further converted into\nan iron–nitrogen-doped mesoporous carbon (mC-TpBpy-Fe) upon\ncarbonization and template removal. The resulting mC-TpBpy-Fe exhibits\na large pore volume and surface area, which significantly promote\nthe mass transfer efficiency and increase the accessibility of the\nactive sites, yielding a high ORR activity with a competitive half-wave\npotential of 0.845 V and limiting current density of 5.92 mA/cm² (vs 0.852 V and 5.57 mA/cm² for Pt/C). Application\nof this COF derived mesoporous carbon within a Zn–air battery\nrevealed that it can operate in ambient conditions with a competitive\ndischarge performance, showing its potential for practical applications.