Facile Preparation of Wormlike Graphitic Carbon Nitride for Photocatalytic Degradation of Ustiloxin A.

Natural toxic contaminants have been recognized as threats to human health. Ustiloxins are the toxic secondary metabolites of fungus generated from rice false smut disease, which are harmful to animal/human reproduction and growth. However, there are rare researches on the control and reduction of ustiloxins through physical, chemical and biological ways. Herein, we demonstrated that photocatalysis of semiconductor nanomaterials could be as a potential way to degrade or mitigate the contamination of ustiloxin A. A kind of wormlike graphitic carbon nitride (g-C3N4) was facilely prepared from modified dicyandiamide precursor via pyrolysis method and characterized by X-ray diffraction, high-resolution transmission electron microscope and X-ray photoelectron spectroscopy etc. It was found that g-C3N4 from modified dicyandiamide precursor showed better activity for ustiloxin A degradation under visible light irradiation than that of pristine g-C3N4. This was ascribed to the lager specific surface area, more uniform microstructure, better photogenerated charges separation and transformation of wormlike g-C3N4 compared with pristine g-C3N4. Most important, the structure of degradation intermediates and the possible pathway were proposed based on the results of high-performance liquid chromatography-mass spectrometry after 80 min photoreaction treatment. Our findings may provide a green, efficient way for ustiloxins mitigation and useful information for future study.