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.