Effective removal of heavy metals from aqueous solution by porous activated carbon/thiol functionalized graphene oxide composite

As a result of need to develop effective adsorbents for water pollution treatment, in present study, a novel composites from thiolated graphene oxide (TGO) and activated carbon (AC) was prepared from sugar cane molasses using a one-step chemical activation process by KOH and ZnCl2. KAC/TGO and ZAC/TGO, were successfully synthesized and characterized by Brunauer-Emmett-Teller (BET) surface area analysis, iodine adsorption, Fourier transform infrared (FTIR)spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Among produced ACs and composites, KAC/TGO possesses higher specific surface area of 1044 m(2)/g, a total pore volume of 0.998 m(3)/g and iodine number of 920 mg/g. Results of heavy metals removal experiments with KAC/TGO in aqueous solution showed that the Langmuir model fitted better than Freundlich model with a maximum adsorption capacity of 204.08 and 196.07 mg/g for Pb(II) and Cu(II) respectively which is higher than many other adsorbents. Also the pseudo-second order kinetic model was found to agree well with the experimental data for both Pb(II) and Cu(II) adsorption. It is expected that this novel and low cost adsorbent can be effectively used for removal of heavy metals from the aqueous polluted environment.