Metal Doped Metal–Organic Frameworks ( MOFs ) Enable Highly Efficient Adsorption of Ibuprofen From Water

ABSTRACT

Emerging organic pollutants (EOCs), such as pharmaceutical compounds, are giving rise to growing environmental concern, necessitating the formulation of novel materials and technologies to achieve their effective removal. Herein, a novel cerium‐doped MIL‐101(Fe) was synthesized via a one‐step solvothermal process and showed high adsorption capacity for ibuprofen (IBP) (506.22 mg/g) in aqueous solutions. Through batch experiments, the adsorption behavior of cerium‐doped MIL‐101(Fe) towards IBP was investigated, encompassing adsorption kinetics and adsorption isotherms, whilst examining the influence of various factors such as pH and ionic strength. The adsorption process follows pseudo‐second‐order kinetics ( R ²  = 0.984), with the calculated equilibrium capacity (qe = 31.87 mg/g) in good agreement with the experimental value (31.68 mg/g), suggesting that chemisorption is the rate‐limiting step. Microscopic characterization results show that complexation, π‐π interaction and hydrogen bonds worked together to IBP adsorption. And complexation was identified as the prevailing driving factor, accounting for 11.26%–40.21% of IBP adsorption at pH 3.0–10.0. Based on the results of two‐dimensional Fourier transform infrared correlation spectroscopy, the interaction sequence of 0.1Ce/Fe‐MIL‐101‐1 adsorbing different concentrations of IBP was hydrogen bonding > complexation > π‐π interaction. Additionally, 0.1Ce/Fe‐MIL‐101‐1 still showed high adsorption efficiency (> 80%) after five adsorption–desorption cycles. This work not only advances the design of multifunctional materials for the removal of emerging organic pollutants, but also provides quantitative perspectives into the interplay mechanisms between high‐performance adsorbents and pollutions.