Supraparamagnetic, Conductive, and Processable Multifunctional Graphene Nanosheets Coated with High-Density Fe₃O₄ Nanoparticles

Abstract

The amazing properties of graphene are triggering extensive interests of both scientists and engineers, whereas how to fully utilize the unique attributes of graphene to construct novel graphene-based composites with tailor-made, integrated functions remains to be a challenge. Here, we report a facile approach to multifunctional iron oxide nanoparticle-attached graphene nanosheets (graphene@Fe(3)O(4)) which show the integrated properties of strong supraparamagnetism, electrical conductivity, highly chemical reactivity, good solubility, and excellent processability. The synthesis method is efficient, scalable, green, and controllable and has the feature of reduction of graphene oxide and formation of Fe(3)O(4) nanoparticles in one step. When the feed ratios are adjusted, the average diameter of Fe(3)O(4) nanoparticles (1.2-6.3 nm), the coverage density of Fe(3)O(4) nanoparticles on graphene nanosheets (5.3-57.9%), and the saturated magnetization of graphene@Fe(3)O(4) (0.5-44.1 emu/g) can be controlled readily. Because of the good solubility of the as-prepared graphene@Fe(3)O(4), highly flexible and multifunctional films composed of polyurethane and a high content of graphene@Fe(3)O(4) (up to 60 wt %) were fabricated by the solution-processing technique. The graphene@Fe(3)O(4) hybrid sheets showed electrical conductivity of 0.7 S/m and can be aligned into a layered-stacking pattern in an external magnetic field. The versatile graphene@Fe(3)O(4) nanosheets hold great promise in a wide range of fields, including magnetic resonance imaging, electromagnetic interference shielding, microwave absorbing, and so forth.

Magnetic Fe3O4-Reduced Graphene Oxide Nanocomposites-Based Electrochemical Biosensing

“…As shown in Fig. 3(B), the magnetic hysteresis loop of the Fe 3 O 4 -RGO hybrid is measured at room temperature with an applied magnetic field sweeping from −5000 to +5000 Oe, exhibiting superparamagnetic property of the magnetic nanocomposite [29]. UV-vis absorption spectra have been carried out to study the effects of Fe 3 O 4 -RGO on the microstructures of immobilized GOx.…”

Synthesis of magnetic crosslinked starch-graft-poly(acrylamide)-co-sodium xanthate and its application in removing heavy metal ions

“…In parts (b) and (c) of Figure 7, the strong and sharp reflection peaks suggest that the prepared samples during ultrasonic radiation were well crystallised. The diffraction peaks at 2 theta values of 31.11, 36.29, 44.08, 53.76, 57.35, and 62.76 can be ascribed to the reflection of (220), (311), (400), (422), (511), and (440) planes of the Fe 3 O 4 , respectively [25]. XRD of the CSAX are shown in Figure 7(d), indicating that no obvious peaks could be observed except for a wide peak at 2 theta = 18.92.…”

“…The mixture was stirred with a mechanical stirrer for 2 h and then dispersed by ultrasonic until it turned saffron yellow. The product (M-CSAX) was cooled to room temperature, precipitated, filtered and washed with 50% aqueous acetone and distilled water, respectively, then dried at 25 C to constant weight.…”

Protein-Directed Synthesis of γ-Fe2O3Nanoparticles and Their Magnetic Properties Investigation

“…In the Fe2p high-resolution XPS spectrum (magnified region), the binding energies around 710 and 723 eV are related to Fe (2p 3/2 ) and Fe (2p 1/2 ), respectively, which are very close to the values of Fe 3 O 4 published in the literature. 21,22 It is remarkable that no charge transfer satellite of Fe (2p 3/2 ) at about 720 eV is detected, indicating the formation of mixed oxides of Fe (II) and Fe (III), such as Fe 3 O 4 .…”