Graphene oxide/PVC composite papers functionalized with p-Phenylenediamine as high-performance sorbent for the removal of heavy metal ions

Due to the rapid industrialization, heavy metals contamination in the aquatic environment has become more serious. Thus, it is urgent to develop enhanced removal technology for heavy metals. Graphene oxide (GO) based composite paper-like materials have been widely applied for adsorption of heavy metals from wastewater. Herein, we fabricated for the first time an advanced, highly-ordered and homogenous PVC/PPD/GO paper-like material using a resin-infiltration technique. This process is complimentary to layer-by-layer assembly, where the assembling components are required to interact strongly (e.g., via hydrogen bonding or electrostatic attraction). The results showed that the composite papers could achieve high removal efficiency of the heavy metals from water. The amount of Pb(II) adsorbed at equilibrium as achieved by GO, PVC/GO-0.05, PVC/GO-0.08, PVC/ PPD/GO-0.05 and PVC/PPD/GO-0.08 buckypapers were 17.61, 22.17, 25.41, 33.57 and 44.80 mg g(-1), respectively. In addition, the effects of experimental factors (e.g. GO content, ionic strength of heavy metal ions, temperature and solution pH) on heavy metal adsorption were discussed. Furthermore, the as-prepared PVC/ PPD/GO-0.08 composite papers exhibited superior stability and could be recycled more than 900 h based on their 15 regeneration cycles. The improved heavy metal removal efficiency was attributed to the enhanced morphology and the formation of micro- and nano-channels created by the entangled PPD/GO. The findings indicated that the PVC/PPD/GO composite buckypapers could be used as promising materials for the adsorption of heavy metals from wastewater.