Kinetic and isotherm studies on adsorption of methylene blue using polyacrylonitrile/hydroxyl group functionalized multiwall carbon nanotube multilayered nanofibrous composite

Abstract

Nanofibrous composite mat was prepared using polyacrylonitrile hard yarn waste and hydroxyl group functionalized multiwall carbon nanotubes (MWCNTs-OH) by electrospinning technique and exploit for methylene blue dye adsorption from aqueous solution. The nanofibrous composite mat was characterized by Fourier transform (FT) infrared spectroscopy, FT-Raman, scanning electron microscopy, X-ray diffractometer and thermogravimetric analyser. The adsorption experiments were studied to investigate the effect of MWCNT-OH weight percentage, initial solution pH, contact time and initial dye concentration on the adsorption. The higher percentage of methylene blue adsorption was found to be 80.05% under optimal condition. The adsorption equilibrium data were studied with Langmuir and Freundlich isotherm models. The R 2 value was found to be higher in the Freundlich isotherm model which was clearly indicated that the Freundlich isotherm model is most suitable for the adsorption of methylene blue on nanofibrous composite mat. The kinetic study was carried out to explain the adsorption rate of methylene blue on nanofibrous composite. The kinetic study of methylene blue adsorption was favourable to the pseudo second-order equation.