Biogenic synthesis of SnO2 quantum dots encapsulated carbon nanoflakes: An efficient integrated photocatalytic adsorbent for the removal of bisphenol A from aqueous solution

摘要

The present study investigated the decontamination of bisphenol A (BPA) from water through the coupled adsorption-photodegradation process. A biogenic synthetic route for the fabrication of novel SnO2 quantum dot encapsulated carbon nanoflake (SnO2-CNF) as an integrated photocatalytic adsorbent (IPCA) has been proposed and characterized with sophisticated analytical techniques. The synergistic effect of SnO2-CNF nanocomposite for the removal of BPA has been established through detailed study of integrated adsorption-photodegradation process. The Langmuir adsorption capacity was found to be 250 mg/g which is similar to 1.7 and similar to 5.3 times higher than that of bare CNF and bare SnO2 respectively. The overall removal efficiency through the coupled adsorption-photodegradation process has also been found to be synergistically superior (similar to 98%) to CNF (similar to 72%) and SnO2 (similar to 46%). The removal process of BPA has been extensively studied using adsorption kinetics model, adsorption isotherm models, and photodegradation kinetics studies. The effect of pH and multiple cycles of utilization on the overall removal efficiency have also been investigated. Both hydrogen bonding and pi-pi interaction might be responsible for the efficient adsorption of bisphenol A over SnO2-CNF adsorbent. The electron-hole generation of SnO2 under UV illumination coupled with electron sinking ability of CNF might as well facilitate superior photocatalytic efficiency. (C) 2020 Elsevier B.V. All rights reserved.