Fabrication of bentonite nanosheets from natural bentonite using ultrasonic-assisted liquid phase exfoliation method and its application for adsorptive removal of Methylene Blue from water

Abstract

Clays (especially bentonite) are widely used as barriers in landfills to prevent contamination of subsoil and groundwater by leachate containing heavy metals or toxic organics. However, the future application of bentonite nanomaterials is still limited due to complicated and expensive preparation process requiring several steps, toxic chemical agents, or additional surfactants. In this study, a green approach was proposed to produce bentonite nanoplatelets by an ultrasound-assisted liquid-phase exfoliation method using natural clay minerals containing bentonite as a precursor. The materials were then characterized by SEM, BET, AFM and XRD. The produced material was used to remove methylene blue (MB) from aqueous solution by batch adsorption. Results showed that the bentonite nanoplatelets gave high adsorption ability with Langmuir maximum adsorption capacity of 312.50 mg/g, which could be a good adsorbent for removing dyes and other toxic organics in wastewater.