Fast and efficient adsorption of La(III) on magnetic carbon nitride-based HKUST-1 composites

In this study, using HKUST-1 as the base, g-C₃N₄ and HKUST-1 were mixed by solvothermal method to form graphitic carbon nitride MOF material, and then modified with Fe₃O₄ nanoparticles to form the final composite Fe₃O₄/g-C₃N₄/HKUST-1.The composite Fe₃O₄/g-C₃N₄/HKUST-1 was characterized by XRD, FT-IR, SEM, VSM, BET and XPS. By studying the adsorption properties of g-C₃N₄/HKUST-1 and Fe₃O₄/g-C₃N₄/HKUST-1 on La³⁺ under different conditions, the optimal adsorption conditions were established. Kinetic and isothermal thermodynamic models were used to evaluate the stability and regeneration capacity of the adsorbent. The results show that the composite Fe₃O₄/g-C₃N₄/HKUST-1 has excellent La³⁺ recovery performance and magnetic properties, and has good stability and recovery performance. Through a series of optimization experiments on adsorbents, when pH is 6, the adsorption effect of Fe₃O₄/g-C₃N₄/HKUST-1 is the best, and the adsorption saturation state is reached within 30 min, and the adsorption capacity can reach 225.11 mg/g, which has great potential in environmental management and resource recovery.