DBSA doped polyaniline/multi-walled carbon nanotubes composite for high efficiency removal of Cr(VI) from aqueous solution

[Display omitted] •DBSA doped polyaniline/MWCNTs composite was synthesized.•DP/MWCNTs showed higher efficiency for Cr(VI) than the pristine and oxidized CNTs.•The removal of Cr(VI) was highly depends on solution pH.•The experimental data was analyzed using isotherm and kinetic models. Dodecyl-benzene-sulfonic-acid (DBSA) doped polyaniline/multi-walled carbon nanotubes (DP/MWCNTs) nanocomposite was prepared by in situ oxidative polymerization. DP/MWCNTs was found to be ideal adsorbent for the removal of Cr(VI) as compared to pristine and oxidized MWCNTs. The adsorption of Cr(VI) onto DP/MWCNTs was found to be strongly dependent on the solution pH. The rate of Cr(VI) adsorption increased with the increase in solution temperature and followed pseudo-second order kinetics. The adsorption isotherm of Cr(VI) onto DP/MWCNTs fitted the Freundlich isotherm model and maximum monolayer adsorption capacity was found to be 55.55mgg−1. The values of thermodynamic parameters suggested that adsorption was spontaneous and endothermic in nature. The desorption of Cr(VI) was found to increase with the increase in solution pH and temperature.