Study on Preparation and Photocatalytic Performance of Two-Dimensional Carbon Nitride Nanosheet Materials

Abstract The thin g-C3N4 nanosheets were prepared by simple second-time etching approach with melamine as raw material. The microstructure, composition, thickness, specific surface area, and optical properties of the obtained materials were investigated by XRD, XPS, SEM, TEM, AFM, and BET. The results show that the specific surface area of the two-dimension ultrathin g-C3N4 nanosheets was as high as 139.42 m2/g, and the thickness was around 5nm, which improved the response range to visible light and promoted the separation of photogenerated electron-hole pairs. The photocatalytic degradation performance of g-C3N4 nanosheets for organic pollutants was studied with dye wastewater as model pollutant, the removal efficiency of RhB solution (20 mg/L) reached 91.8% with 20mg catalyst after 30min reaction. The content of total organic carbon in the solution decreased by 58.7%, and the first-order kinetic rate constant was 10 times than that of bulk-C3N4, indicating the high catalytic activity. The stability was excellent since the activity of catalyst was not significantly reduced after used for four times.