Investigation of Adsorption of Heavy Metal Ions on C3N4 Nanosheets by Batch and Microscopic Methods

This paper mainly studies the adsorption of C3N4 on a series of heavy metals and focuses on the adsorption performance of C3N4 on Nd and Th. The main conclusions are as follows: Through the use of the thermal stripping method and melamine as the raw material, C3N4 was obtained at a lower cost, with superior adsorption performance. Through SEM-EDS, TEM, and other characterization analyses, the results show that C3N4 has a clear multilayer sheet structure, and the surface of the material is more uniformly dispersed. The maximum adsorption capacity of C3N4 for Th is 86.6 mg.g-1, and the maximum adsorption capacity for Nd is 60.1 mg.g-1. The kinetic model is also used for fitting, and the results showed that the kinetic of the adsorption was in line with the pseudo-second-order model, indicating that the adsorption was chemical interaction. After C3N4 adsorbed heavy metal elements, it was characterized by SEM-EDS, TEM, UHRTEM, and AFM. The results showed that a variety of heavy metal ions can be adsorbed by C3N4, which proved that C3N4 has good adsorption performance. Due to factors such as metal particle size, the adsorption of C3N4 on heavy metal elements is different.