Wrinkled Ultrathin Graphitic C₃N₄ Nanosheets for Photocatalytic Degradation of Organic Wastewater

Wrinkled ultrathin graphitic C3N4 nanosheets (U-g-C3N4) have been successfully synthesized via a thermal condensation process and subsequent rapid cooling treatment in liquid nitrogen. The layer contraction force caused by the rapid cooling process can break the van der Waals forces between the interlayers, thus successfully exfoliating the bulk g-C3N4. The U-g-C3N4 exhibits large specific surface area, effective separation of the photogenerated carriers, and increased visible-light absorbance, which can promote the quantity and lifetime of the photoexcited electrons, resulting in a high photodegradation efficiency of 99.82%. These results show that the interlayer contraction force is a viable option for exfoliating layered materials into a thin-layer structure. This is an interesting and easy method for obtaining thin-layer materials.