3D spongy porous g-C3N4 material synthesized by supramolecular self-assembly for efficient degradation of tetracycline

In recent years, g-C 3 N 4 has shown excellent advantages as a metal-free visible light-responsive catalyst in the field of environmental remediation. However, the pristine g-C 3 N 4 still has drawbacks such as small specific surface area, low visible light utilization and severe photogenerated carrier recombination. In this paper, a 3D spongy g-C 3 N 4 material (SC x ) was prepared using melamine and oxalamide based on the supramolecular self-assembly strategy. The role of oxalamide in the supramolecular self-assembly process and the effect on the morphology of g-C 3 N 4 were investigated and analyzed. The optical and photoelectrochemical properties of materials were studied using UV vis DRS, PL, EIS, etc., and the results indicate that porous structure, the increase of specific surface area and decrease of bandgap are the main reasons for enhanced degradation performance of 3D spongy g-C 3 N 4 . The results show that SC1 exhibits the best degradation rate (reaching 88.8 % within 60 min) and the reaction rate constant (0.0740 min −1 ). In addition, the SC1 has broad applicability to organic pollutants, excellent anti-interference ability and long-term stability. Furthermore, the degradation pathways were proposed using LC-MS and practical aquatic ecosystems experiments evaluated the toxicity of degradation products. Finally, the photocatalytic degradation mechanism was proposed based on free radical capture experiments and ESR spectra.