Construction of Covalent Triazine Frameworks (CTFs) Based on Imine Bonds for Efficient Adsorption of Hg2+ from Water

In this study, a novel imine bond-based covalent triazine framework (CTF) with triazine groups as its backbone, designated as SWFU-CTFs-101 CTFs, was synthesized and utilized for the adsorption of Hg 2+ in an aqueous solution. The quasi-secondary kinetic model and Langmuir model indicate that the capture of Hg 2+ by the SWFU-CTFs-101 is a chemisorption process in a monomolecular layer. The maximum adsorption capacity of the material was determined to be 148.33 mg/g at a solid-liquid ratio of 1 mg/mL, an initial concentration of Hg 2+ of 400 mg/L, a pH of 6.0 and a temperature of 25°C. The adsorption mechanism of SWFU-CTFs-101 was elucidated by integrating experimental results, spectroscopic properties (SEM and XPS, etc.), and density functional theory (DFT) calculations. Notably, the adsorption capacity of SWFU-CTFs-101 in water remained largely stable after four cycles of recycling, indicating its promising potential for future practical applications.