Hierarchical porous ACNF/MIL-68(In)–NH2 composites for rapid and efficient removal of losartan from water: Unveiling adsorption mechanisms and superior performance

Abstract

Losartan (LP), a medication commonly used to treat hypertension, has emerged as a potential environmental pollutant. Despite its widespread use, research on the efficient and rapid removal of LP from the environment remains very scarce. The limited studies on LP adsorption indicate that the adsorption capacity and rate of LP need improvement. In this study, we successfully prepared a hierarchical porous nitric acid-treated carbon nanofiber (ACNF)/MIL-68(In)–NH composite with a robust three-dimensional support structure using a simple hydrothermal method for the first time to adsorb LP. The resulting ACNF/MIL-68(In)–NH composite demonstrated exceptional adsorption capabilities, achieving an equilibrium absorption capacity of 259.87 mg/g within just 64 min, significantly outperforming previously reported results. Langmuir fitting indicated a maximum theoretical adsorption capacity exceeding 630 mg/g at 55 °C. For actual wastewater with low LP concentrations, complete removal was achieved with a minimal dose of the ACNF/MIL-68(In)–NH adsorbent. DFT calculations and Multiwfn wavefunction analysis revealed that the adsorption behavior of LP onto ACNF/MIL-68(In)–NH is primarily driven by electrostatic interactions, multiple hydrogen bonds, π-π stacking interactions, and van der Waals forces. This work presents an innovative strategy for the efficient and rapid removal of residual LP from water environments.