Design of Well‐Defined Meso‐ or Macroporous Carbon Nitride with an Amorphous Framework via Perovskite Fluoride Templating

ABSTRACT Here, we report a synthetic strategy for meso‐ or macroporous carbon nitride (C 3 N 4 ) using perovskite‐type metal fluorides (K M F 3 , M = Co, Ni) as hard templates. The synthesis involves a two‐step thermal treatment. An initial low‐temperature polycondensation of melamine generates polymeric intermediates that stabilize the template/precursor composites, thereby suppressing aggregation and/or sintering of K M F 3 during the subsequent high‐temperature treatment. The subsequent high‐temperature treatment then induces further condensation into C 3 N 4 while retaining the template‐defined structures. After removal of the templates, meso‐ or macroporous C 3 N 4 are successfully obtained, demonstrating that K M F 3 can serve as effective templates even under high‐temperature polycondensation conditions through appropriate reaction stage control. As a representative demonstration of functionality, electrochemical glucose sensing was used to evaluate the porous materials. The mesoporous KNiF 3 ‐templated sample (Mel‐KNiF 3 ) shows higher sensitivity and a lower detection limit than bulk C 3 N 4 and the macroporous KCoF 3 ‐templated sample (Mel‐KCoF 3 ), suggesting an important role of pore architecture in determining the accessibility of active sites. This study establishes a practical route to porous carbon nitride under thermal conditions and provides a simple strategy for structural control in high‐temperature polymeric systems.