Nickel-Doped Zn-MOF for Efficient Adsorption of Norfloxacin Antibiotic: Adsorption Behaviors and Mechanisms

In this study, a bimetallic nickel-doped Zn-MOF (Ni@Zn-MOF) was successfully fabricated by the hydrothermal method for the removal of norfloxacin (NOR) in pharmaceutical wastewater. The structural and surface characteristics of Ni@Zn-MOF were systematically characterized using SEM-EDS, BET, XRD, FT-IR, XPS, and Zeta potential analyses. The experimental results demonstrated that NOR could be effectively removed within a wide pH range from 3 to 11, achieving a maximum removal efficiency of approximately 94% under optimal adsorption conditions. The adsorption behaviors of NOR were in good accordance with the pseudo-second-order kinetic model and the Freundlich isotherm model. The adsorption mechanism study revealed that the good adsorption performance originated from the synergistic effects of multiple interactions, including pore filling, metal coordination, electrostatic attraction, hydrogen bond, and π-π stacking interactions. Notably, the adsorption-saturated Ni@Zn-MOF demonstrated exceptional regeneration capability and stability, maintaining removal efficiencies above 60% for NOR after five consecutive adsorption-desorption cycles. The current study suggests that the engineered Ni@Zn-MOF nanocomposite can be as a promising functional material for sustainable removal of residual antibiotic contaminants in practical wastewater treatment applications.