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

Here, we report a synthetic strategy for meso- or macroporous carbon nitride (C₃N₄) using perovskite-type metal fluorides (KMF₃, 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 KMF₃ during the subsequent high-temperature treatment. The subsequent high-temperature treatment then induces further condensation into C₃N₄ while retaining the template-defined structures. After removal of the templates, meso- or macroporous C₃N₄ are successfully obtained, demonstrating that KMF₃ 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 KNiF₃-templated sample (Mel-KNiF₃) shows higher sensitivity and a lower detection limit than bulk C₃N₄ and the macroporous KCoF₃-templated sample (Mel-KCoF₃), 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.