Feasibility of Fe3O4 nanoparticles decorated reduced graphene oxide heterostructure as photocatalyst and chemical sensors / Teo Peik See

In this study, iron oxide/reduced graphene oxide (Fe3O4/rGO) nanocomposite materials were successfully synthesized via a simple, eco-friendly and cost-effective approach at room temperature. The XRD spectra indicated peaks that attributed to the face-centre-cubic phase Fe3O4, while the absence peak of GO in nanocomposite provides evidence for the reduction of GO. The field emission scanning electron microscopic (FESEM) images showed Fe3O4 nanoparticles were uniformly deposited on the rGO sheets with a narrow size distribution for all the nanocomposites. Besides, the synthesized Fe3O4/rGO nanocomposites were found to be superparamagnetic in nature at room temperature. In the photocatalysis application, methylene blue (MB) solution was used as a model organic pollutant; the Fe3O4/rGO nanocomposite materials showed better adsorption and excellent photocatalytic activity towards the degradation of MB under natural sunlight irradiation due to the synergistic effect that arises between rGO and Fe3O4 nanoparticles. Interestingly, a maximum photodegradation of almost 100% MB were achieved at 1 h light irradiation. Moreover, the magnetically separable Fe3O4/rGO nanocomposite exhibit good sustainability and photocatalytically stable morphology even after eight cycles of photocatalytic treatment. Thus, this newly prepared Fe3O4/rGO nanocomposite could serve as potential candidate in variety environmental remediation. The electrochemical studies were carried out with the iron oxide/graphene modified glassy carbon electrode (Fe3O4/rGO/GCE) for the simultaneous detection of dopamine (DA) and ascorbic acid (AA). The detection limit (S/N=3) was found to be 0.42 μM and 0.12 μM for AA and DA, respectively. The Fe3O4/rGO/GCE displayed not only excellent electrocatalytic activity and remarkable electron transfer kinetics towards the oxidation of DA but also portrayed capability of high sensitivity and selectivity toward simultaneous detection of AA and DA. In a nutshell, the Fe3O4/rGO/GCE has iv been proved as a promising candidate and applicable for electrocatalysis and chemical sensor application

Simultaneous Electrochemical Detection of Dopamine and Ascorbic Acid Using an Iron Oxide/Reduced Graphene Oxide Modified Glassy Carbon Electrode

The fabrication of an electrochemical sensor based on an iron oxide/graphene modified glassy carbon electrode (Fe3O4/rGO/GCE) and its simultaneous detection of dopamine (DA) and ascorbic acid (AA) is described here. The Fe3O4/rGO nanocomposite was synthesized via a simple, one step in-situ wet chemical method and characterized by different techniques. The presence of Fe3O4 nanoparticles on the surface of rGO sheets was confirmed by FESEM and TEM images. The electrochemical behavior of Fe3O4/rGO/GCE towards electrocatalytic oxidation of DA was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) analysis. The electrochemical studies revealed that the Fe3O4/rGO/GCE dramatically increased the current response against the DA, due to the synergistic effect emerged between Fe3O4 and rGO. This implies that Fe3O4/rGO/GCE could exhibit excellent electrocatalytic activity and remarkable electron transfer kinetics towards the oxidation of DA. Moreover, the modified sensor electrode portrayed sensitivity and selectivity for simultaneous determination of AA and DA. The observed DPVs response linearly depends on AA and DA concentration in the range of 1–9 mM and 0.5–100 µM, with correlation coefficients of 0.995 and 0.996, respectively. The detection limit of (S/N = 3) was found to be 0.42 and 0.12 µM for AA and DA, respectively

Magnetically separable reduced graphene oxide/iron oxide nanocomposite materials for environmental remediation

Magnetically separable reduced graphene oxide/iron oxide (rGO/Fe3O4) nanocomposite materials were synthesized at room temperature through a facile, eco-friendly and cost-effective approach. The prepared nanocomposite materials were characterized by different techniques. X-ray diffraction analysis revealed the formation of the rGO/Fe3O4 nanocomposites, while transmission electron microscope images showed that the Fe3O4 nanoparticles with an average size of 10 nm were embedded uniformly on the surface of rGO sheets. The synthesized rGO/Fe3O4 nanocomposite materials were found to be super-paramagnetic in nature at room temperature. The photocatalytic performance of the rGO/Fe3O4 nanocomposite materials was investigated under natural sunlight irradiation using methylene blue (MB) as a model target organic pollutant. The rGO/Fe3O4 showed better adsorption behaviour and excellent photocatalytic activity towards the degradation of MB, when compared to other samples such as rGO and pristine Fe3O4 nanoparticles. This enhanced photocatalytic activity could be attributed to the synergistic effect that arises between the rGO and Fe3O4, which significantly reduces charge recombination. Moreover, the rGO/Fe3O4 nanocomposite materials exhibited good sustainability, which was evidenced by their consistent photocatalytic performance and the absence of any observable changes in morphology, even after eight cycles of operation during photocatalytic experiments. The overall results of the study indicate that these newly prepared photocatalytically stable and magnetically separable rGO/Fe3O4 nanocomposites could be potentially utilized for many environmental remediation applications