Facile, eco-friendly, ultrasonic-assisted synthesis of functionalized Co₅₀Ni₅₀-LDH for enhanced pharmaceutical adsorption: Mechanistic insights using carprofen as a model drug.

BACKGROUND

The efficient removal of pharmaceutical contaminants like carprofen (CPF) from aqueous systems is crucial due to their persistence and environmental risks. This investigation sought to create an eco-friendly adsorbent with a simplified preparation process with high CPF removal efficiency, addressing the need for cost-effective materials in pharmaceutical wastewater treatment.

METHODS

A Ni50Co50-layered double hydroxide (LDH) was fabricated and surface-modified with AEAMP-TMS, a silane coupling agent bearing amine and phenyl groups, via a facile, scalable, and eco-friendly route. The AEAMP-LDH adsorbent (functionalized LDH) was structurally characterized using XRD and FTIR, and its morphology and porosity were examined by FESEM/FESEM mapping and N2 adsorption-desorption isotherms. The resulting AEAMPS-LDH exhibited a well-defined macroporous-mesoporous structure, as confirmed by N₂ adsorption-desorption analysis, with a surface area of 65.2 m² g⁻¹ . Adsorption experiments were carried out to evaluate the capacity, pH dependence, and reusability of the material.

SIGNIFICANT FINDINGS: AEAMPS-LDH achieved a Langmuir maximum adsorption capacity of 742 mg g⁻¹ for CPF, driven by π-π interactions, hydrogen bonding, electrostatic attraction, and interlayer anion exchange. Optimal removal occurred at pH 5-8, where CPF exists in an anionic form. The material retained over 90 % efficiency after eight reuse cycles. Compared to Fe3O4@ZIF-67@Co-Ni LDH, the only previously reported LDH-based adsorbent for CPF removal from water, AEAMPS-LDH demonstrated comparable performance with a simpler, more sustainable synthesis process.