Exploring the role of semi-crystalline carbon nitride as exciton transition accelerator in enhancing energy transfer during photodegradation of imidacloprid

Exciton utilization offers a non-radical pathway for pollutant removal, yet efficient triplet-state population and oxygen activation remain challenging. Here, a semi-crystalline melon carbon nitride (Mel-Salt-Th100, 100 mg thiourea) is fabricated via a one-step molten-salt route. Under visible-light irradiation (300 W Xe, λ > 420 nm), the material eliminates 80% of imidacloprid within 60 min, with a rate constant 17.3 and 8.1 times those of Mel-Th and Mel-Salt, respectively. Cyano/sulfur doping and K + intercalation introduce exciton trap levels and optimize intersystem crossing, facilitating rapid triplet-state population and energy transfer to adsorbed O 2 for selective 1 O 2 generation. HPLC-MS/MS (high-performance liquid chromatography-tandem mass spectrometry) and toxicological tests further confirm efficient imidacloprid degradation and detoxification. This exciton-engineering strategy is readily extendable to other refractory organics and to triplet-sensitized energy-conversion reactions, providing a general blueprint for designing high-performance polymer photocatalysts.