ZIF-67 grown onto three-dimensional biomass cotton fibers for efficient adsorption of tetracycline

Abstract

In recent years, Metal-Organic Frameworks (MOFs) have garnered significant attention for their potential in tetracycline (TC) removal. However, pure MOFs typically exist in powdered form and tend to aggregate in water, which greatly limits practical applications. To address this issue, a three-dimensional composite material was prepared by ZIF-67 grown onto cotton fibers (ZIF-670.50@CF). This composite not only enhances adsorption capacity but also reduces the adsorption equilibrium time compared to most other adsorbents. ZIF-670.50@CF boasts a BET specific surface area of 257.74m²·g-1, with pores consisting mainly of mesopores and micropores. Moreover, ZIF-670.50@CF exhibits excellent adsorption capabilities for TC across a broad pH range of 4–9 and displays notable resilience against environmental interference. The adsorption behavior of ZIF-670.50@CF is more consistent with the Langmuir model, with a maximum adsorption capacity of 432.619mg·g-1 for TC. Mechanistic research reveals that adsorption primarily involves chemical interactions (complexation, π-π stacking, and electrostatic interaction) and physical pore filling. Additionally, the favorable plasticity of ZIF-670.50@CF allows it to be fabricated into various shapes for use as filling materials, exhibiting admirable TC removal performance in continuous flow adsorption experiments.