Green room-temperature fabrication of phosphotungstic acid functionalized MOF-808 for efficient removal of cationic antibiotics

[Display omitted] •Green, one-pot synthesis of PTA-modified MOF-808 was achieved at room temperature.•The introduction of PTA enhanced the electronegativity of the modified MOF-808.•PTA addition could fine-tune the pore size and surface area of PTA@ MOF-808.•The composite showed high cationic antibiotics adsorption capacity and reusability. ZrⅣ-based metal–organic frameworks (MOFs)–featuring exceptional water stability, large surface area, and structural tunability–hold promise for efficient antibiotics adsorption from water. However, their inherent positive charge in neutral environments and the harsh conditions required for their synthesis hinder their effective removal of cationic antibiotics. To address this challenge, a green one-pot synthesis approach was proposed to fabricate phosphotungstic acid-functionalized MOF-808 (termed as PTA@MOF-808) at room temperature for elevated antibiotic adsorption. This approach not only leverages the strong electronegativity of PTA to improve electrostatic interactions and π-π stacking but also finely tailors the pore size of MOF-808, resulting in enhanced adsorption capacity of PTA@MOF-808. The influence of PTA loading, solution pH, and absorbent dosage on the performance of PTA@MOF-808 were studied in detail. Adsorption experiments demonstrated that PTA@MOF-808 outperformed unmodified MOF-808 in removing various positively charged antibiotics, with 5 % PTA@MOF-808 exhibiting maximum adsorption capacities of 548.1 mg g−1 and 482.9 mg g−1, for DOX and TCHC, respectively. The adsorption process followed the Langmuir isothermal model and the pseudo-second-order kinetic equation. Furthermore, the composite PTA@MOF-808 displayed excellent reusability after multiple adsorption–desorption cycles. These findings highlight the potential of PTA@MOF-808 as a promising absorbent for removing specific antibiotics from water, with significant implications for wastewater treatment.