Magnetic graphene oxide prepared via ammonia coprecipitation method: The effects of preserved functional groups on adsorption property

Chromium (Cr) has become one of the main pollutants in tannery wastewater, which causes great harm to human health and environment, especially after being oxidized. Herein, the magnetic graphene oxide composite (GO/ Fe3O4) is synthesized via coprecipitation method with NH3.H2O. In this way, the self-functional group of graphene oxide (GO) are greatly reserved when Fe3O4 nanoparticles grown on GO sheets, confirming by characterizations, including Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Raman. Up to 90% Cr3+ could be adsorbed by resulted GO/Fe3O4 within 140 min, and the maximum adsorption capacity is 279.62 mg g-1. Furthermore, Cr3+ is mainly absorbed by chemical adsorption, according with quasi-secondorder kinetic model and Langmuir isotherm. Most importantly, the external magnetic field can effectively recycle the adsorbents from the aqueous solution, facilitating its application in large-scale treatment of tannery wastewater.

Automated summary

The study focuses on the synthesis of magnetic graphene oxide composite to effectively adsorb chromium in wastewater, with up to 90% of Cr3+ being adsorbed within 140 minutes. The removal of chromium is mainly through chemical adsorption, and the external magnetic field enables the efficient recovery of the adsorbents.