Performance of Xanthate-Modified Multi-Walled Carbon Nanotubes on Adsorption of Lead Ions

Abstract

A novel adsorbent was prepared by introducing xanthate group onto pristine multi-walled carbon nanotubes (MWCNTs) for removing Pb (II) from aqueous solution. The structure and property of xanthate-modified MWCNT (MWCNT-X) were detected by the technologies of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET). The investigation of various parameters, such as initial metal concentration, pH, contact time, and temperature, was taken to illustrate the adsorption behaviors of Pb (II) on MWCNT-X. Based on experimental data, Langmuir isotherm and pseudo-second-order kinetic provided a better correspondence to the adsorption process. The negative values of ΔG ^θ and ΔH ^θ indicated that the adsorption process is exothermic and spontaneous. Besides, the maximum uptake of MWCNT-X reached to 83.01 mg/g, which was much higher than that of pristine MWCNT and hydroxylated MWCNT (MWCNT-OH). Thus, the MWCNT-X can be potentially applied in heavy metal treatment.

http://ift.tt/2pfRm1t