Affinity of boron nitride nanomaterials towards antibiotics established by exhaustive experimental and theoretical investigations

Abstract

Pharmaceutical pollutants are the emerging class of contaminants due to their prevalence and persistence in the aquatic environment. In this regard, boron nitride (BN) nanomaterials with two different morphologies have been constructed via solid state high temperature annealing approach. Excellent adsorbent properties of as prepared BN nanomaterials have been explored by adsorbing two different antibiotics i.e. ciprofloxacin (CIP) and norfloxacin (NOR) over their surfaces. High surface area consisting negative charge has been revealed by the BET and zeta potential analysis. Effect of various experimental parameters like contact time, pH, adsorbent dosage and initial antibiotic concentration on the adsorption process has been discussed in detail. The adsorption experiments performed at various pH has resulted the maximum adsorption at pH between 4 and 6. Adsorption isotherms have also been incorporated to evaluate the nature of adsorption. Out of Langmuir and Freundlich isotherm models, earlier one offers best fitting into the experimental data suggesting that the adsorption is monolayer. Furthermore, the kinetics studies established that the adsorption process follows pseudo-second-order kinetic model. In addition, theoretical studies have also been included for insight knowledge of nature of interactions between adsorbate and adsorbent using density functional theory formalism. These results demonstrate the great potential of BN nanomaterials for the water purification systems.