Salt-Mediated Structural Transformation in Carbon Nitride: From Regulated Atomic Configurations to Enhanced Photocatalysis

Molten salts-assisted synthesis is widely used in the construction of high efficiency graphitic carbon nitride (g-C3N4) photocatalysts, and two isotypes g-C3N4 have been synthesized by such method, namely poly (heptazine imide) (PHI) (triazine (PTI). However, understanding structural changes taking place during molten salt process structure–activity relationship polymorphs remain blurred. Herein, regulating treatment duration nanosheets (melon) salts, we successfully with phases PHI, PHI/PTI PTI. A continuous transformation induced ions, which melon transforms to a stable phase PTI via an intermediate state, was unveiled for first time. In addition, results reveal that atomic configurations play vital role photo absorption, charge carrier transfer surface reaction, leading significant differences photocatalytic degradation. Among them, PHI K+ cyan groups modification, as well crystallinity, exhibits remarkable degradation efficiency, 90% removal tetracycline 10 min 80% phenol 60 min. This study sheds light on deeper salt-assisted provides new ideas preparing efficient organic semiconductor photocatalysts.