Magnetite Nanoparticles Decorated Graphene Oxide Composite as an Efficient and Recoverable Adsorbent for Removing Aqueous Ni(Ⅱ), Pb(Ⅱ)

Abstract

Massive disposal of various heavy metals by industrial activities gives rise to serious environmental contamination. Herein, a magnetite nanoparticles decorated graphene oxide composite (MNGO) was facilely prepared via simple co-precipitation. The as fabricated MNGO was characterized and used as adsorbent to remove aqueous Ni(Π) and Pb(Π) with high efficiency. The removal performance was investigated, and the interaction mechanism between adsorbent and adsorbate was analyzed. Control experiment presents, MNGO outperforms either single Fe3O4 or graphene oxide (GO), which is owing to the mutual positive effects between the two phases. Concretely, MNGO efficiently adsorbs 391.63 mg·g–1, 373.59 mg·g–1 of Ni(Π), Pb(Π) in 5 min, respectively. In addition, Fe3O4 introduction brings magnetic separability, which make MNGO recoverable. Adsorptions are spontaneous, exothermic and randomness decreasing, which conform well to the Freundlich and pseudo second order models. The interaction mechanism is clarified as: oxygen atoms in C=O, C–O related groups chemically interact with Ni(Ⅱ), Pb(Ⅱ). The high efficiency performance of MNGO entails inspiring application in heavy metal scavenging.