Quintinite: A Mg–Al-layered double hydroxide as an efficient amido black dye adsorbent

Abstract

Through this work, we show the potency of Quintinite (Mg–Al-Layered Double Hydroxide with Mg/Al ratio ∼2) as an efficient toxic dye (Amido Black 10B) adsorbent. Our strategy involves a facile, scalable synthesis of Layered Double Hydroxide (LDH) with magnesium as divalent and aluminium as trivalent ions in Mg/Al ratio ∼2 that forms a layered structure of metal hydroxides balanced by anions which develops a net positive charge on the surface in an aqueous medium. Adsorption behaviour examined via UV–Visible Spectrometry showed rapid dye adsorption for low dye concentrations (∼99% in 2 min) and displayed a high adsorption capacity of 207 mg/g at higher dye concentrations. These adsorption results were one of the highest reported ever to date with quintinite or any pristine Mg–Al-LDH processed below 100 °C. The mesoporous adsorbent surface together with a net positive charge in an aqueous medium provided an additional advantage in possessing more active adsorbing sites on the adsorbent (Mg–Al-LDH). We attempt to unravel the fact that, the LDH with appropriate preparation conditions can deliver maximum efficiency without any additional modification.