Improved removal of lead(II) from water using a polymer-based graphene oxide nanocomposite

Poly(N-vinylcarbazole) (PVK) was blended with graphene oxide (GO) to form a PVK-GO polymer nanocomposite capable of adsorbing heavy metal from aqueous solutions. The homogenous distribution of GO in the PVK-GO nanocomposite was determined by X-ray photoelectron microscopy (XPS) and attenuated total reflectance -infrared spectroscopy (ATR-IR). The results show that the adsorption capacity of Pb2+ by the nanocomposite increased with increasing amount of GO. This phenomenon was attributed to the increasing concentration of oxygen-containing functional groups available in the nanocomposite. Furthermore, the adsorption of Pb2+ onto PVK-GO nanocomposite was influenced by pH changes. Higher pHs had a better adsorption capacity than lower pHs, due to changes in the nanocomposite surface properties. The highest adsorption capacity of the PVK-GO nanocomposite for Pb2+ was 887.98 mg g(-1) and fits well the Langmuir model. This adsorption capacity was achieved using a 10 : 90 wt% ratio of PVK : GO at pH 7 +/- 0.5 with a 90 min contact time. The high removal efficiency of this nanocomposite suggests that PVK-GO is effective and can be applied to remove heavy metals from water.