Magnetic Graphene Composites Research Articles

Adsorption of naphthalene and its derivatives on magnetic graphene composites and the mechanism investigation

Reduced graphene oxide/iron oxide (GO/FeOFe2O3) composites were prepared as super adsorbent to adsorb 1-naphthylamine, 1-naphthol and naphthalene with different polaritiy. The adsorption capacity was found in the order of naphthalene<1-naphthol<1-naphthylamine. Electron-donor–acceptor (EDA) interaction was proposed to be the primary mechanism for the adsorption of aromatic compounds, and the adsorption capacity increased with increasing dipole moment. Compared with multi-walled carbon nanotubes/iron oxide (MWCNTs/FeOFe2O3), we found the morphology of adsorbents played an important role in the adsorption for these aromatic compounds. Thermodynamic experiments further indicated that the adsorption processes were endothermic and spontaneous.

Synthesis of water-soluble magnetic graphene nanocomposites for recyclable removal of heavy metal ions

In this work, graphene oxide/Fe3O4 (GO/Fe3O4) composites were synthesized via a copper catalyzed azide-alkyne cycloaddition reaction for the first time. After further modification with polyacrylic acid (PAA), water-soluble magnetic graphene nanocomposites were obtained. The PAA/GO/Fe3O4nanocomposites were characterized by atomic force microscopy, transmission electron microscopy, X-ray diffraction, Raman, Fourier transform infrared spectroscopy, thermogravimetric analysis and vibrating sample magnetometry. Due to the high surface area, excellent complex ability and superparamagnetism, the PAA/GO/Fe3O4 nanocomposites were used as nanoadsorbents for recyclable removal of Cu2+, Cd2+ and Pb2+ ions from aqueous solution. It is found that the PAA/GO/Fe3O4 nanocomposites show extraordinary removal capacity for Cu2+, Cd2+ and Pb2+ ions. Moreover, the PAA/GO/Fe3O4 nanocomposites are very easy to separate and recycle due to the superparamagnetism of Fe3O4. After five cycles, the removal efficacy of the nanoadsorbents for Cu2+, Cd2+ and Pb2+ ions is over 85%. All of the results demonstrate that the water-soluble magnetic graphene composites are effective adsorbents for removal of heavy metals and thus could provide a new platform for water cleanup.

A novel and simple approach for the synthesis of Fe3O4-graphene composite

High crystalline Fe3O4-graphene composite has been successfully synthesized via one-step thermolysis reaction. The results demonstrated that the attachment of iron-organic complex with graphene oxide sheets can facilely lead to magnetic graphene composites with a time-dependent calcination process. The composite was characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The high efficient removal of methylene blue determined that Fe3O4-graphene is a promising sorbent material for wastewater treatment.

Enrichment and detection of small molecules using magnetic graphene as an adsorbent and a novel matrix of MALDI-TOF-MS

Magnetic graphene composites were synthesized via a simple hydrothermal reaction, and the as-made composites were successfully applied as an adsorbent and a novel matrix in the enrichment and analysis of small molecules by matrix assisted laser desorption/ionization mass spectrometry.

Facile synthesis of magnetic graphene and carbon nanotube composites as a novel matrix and adsorbent for enrichment and detection of small molecules by MALDI-TOF MS

In this work, for the first time, we synthesized magnetic graphene and carbon nanotube (graphene/CNT) composites via a simple solvothermal synthesis of magnetite particles in the presence of CNTs and graphene. The magnetic graphene/CNT composites possess a unique structure in which CNTs are coated by magnetite particles and deposit on graphene sheets, which not only provides strong magnetic responsiveness for separation, but also prevents the self-aggregation of graphene and CNTs. By using their magnetic separability and large surface areas accessible for guest molecules, this novel composite has been successfully employed as a matrix and adsorbent for the analysis and enrichment of small molecule compounds using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). It is found that the graphene/CNT composites have several advantages such as higher sensitivity, facile desorption/ionization process, higher efficiency in analyte desorption/ionization and higher peak intensities for aromatic analytes, which are attributed to the distinct structure of magnetic graphene/CNTs comprised of π-conjugated networks with a highly exposed surface. Additionally, they exhibited very high salt tolerance, which makes them a good candidate for application in analysis and enrichment of small molecules present in complex media, such as urine samples.