Novel ZIF-67/BC/β-CD bio-based nanocomposite for sustainable removal of tetracycline from polluted water

Abstract

Antibiotic pollution poses significant ecological and human health risks in aquatic environments, making their removal an urgent environmental challenge. This study presents the development of an eco-friendly and efficient adsorbent fabricated from Hyphaene thebaicaplant biochar along with Zeolitic imidazolate framework and Beta-cyclodextrin (ZIF-67/BC-β-CD). The fabricated ZIF-67/BC-β-CD nanocomposite demonstrates remarkable mechanical, thermal, and chemical stability as confirmed via different characterization techniques, including Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, zeta potential, and X-ray photoelectron spectroscopy. To examine the adsorption ability and optimize the performance of ZIF-67/BC-β-CD nanocomposite, a series of adsorption experiments of tetracycline (TC) were conducted. Results revealed that the maximum adsorption capacity of ZIF-67/BC-β-CD nanocomposite for TC is 294.11 mg.g^− 1 at 25 ℃ and pH 5. The findings clarified that the process followed a pseudo-second-order kinetics model with a good fit to the Freundlich isotherm, rather than the Langmuir isotherm, suggesting a combination of physical and chemical adsorption. The adsorption of TC onto ZIF-67/BC-β-CD was found to be governed by a combination of physisorption (electrostatic, hydrophobic, and π–π interactions) and chemisorption (hydrogen bonding and n–π electron donor–acceptor interactions). Furthermore, the adsorbent demonstrated significant regeneration potential after five successive cycles, proving its potential to be used as a sustainable and efficient adsorbent for treating water contaminated with antibiotics.