Synthesis Of Magnetic Graphene Oxide Research Articles

Magnetic graphene oxide/Mg-Al layered double hydroxide nanocomposite as an efficient adsorbent for removal of methylene blue: A study of equilibrium isotherms, kinetics, thermodynamic and reusability

Dye pollution, mainly caused from textile industry, has become a global environmental problem. Methylene blue (MB) is a cationic dye commonly used in textile industry and needs to be removed from textile effluents. This work reports the synthesis of magnetic graphene oxide and Mg-Al layered double hydroxide (MGO/LDH) nanocomposite as an efficient adsorbent for the removal of MB from wastewater. The influence of different parameters including, pH, adsorbent amount, contact time, temperature, and initial concentration of MB were evaluated and optimized. Thermodynamic studies showed that the reaction was spontaneous and exothermic. The data were more compatible with the pseudo-second-order kinetic model with a high correlation coefficient (R2 = 0.994). Equilibrium isotherms demonstrated that the data were fitted well by a Langmuir model. Due to the synergistic effects of MGO and LDH in the nanocomposite, the removal efficiency was improved to 93.8 % for MB from wastewater by MGO/LDH.

Highly furosemide uptake employing magnetic graphene oxide: DFT modeling combined to experimental approach

Furosemide (FUR) is a diuretic employed in hypertension treatment, this drug is excreted in unchanged form by human body which contributes to water contamination and toxic effects for humans and the environment. Due to the ineffective removal of this pollutant by conventional water treatment methods, this work reports a synthesis of magnetic graphene oxide (GO‧Fe3O4) with different amounts of iron nanoparticles for FUR adsorption. The nanomaterials were characterized by FTIR, XRD, SEM, Raman, and VSM techniques. DFT modeling and thermodynamic parameters show that the FUR adsorption is exothermic, favorable, and predominantly occurs in chemical interactions. The experimental study demonstrated that the best adsorbent was GO‧Fe3O4 1:1 showing a removal percentage and adsorption capacity of 96.15% and 96.91 mg g−1, respectively, at pH 3.0 and 293.15 K. The process was dependent on initial concentration, adsorbent dosage, and pH. ionic strength doesn’t significantly affect the adsorbent performance of GO‧Fe3O4 1:1. Sips and PSO model presented the best adjustment for experimental data, suggesting that the process occurs in a heterogeneous surface. Finally, GO‧Fe3O4 1:1 exhibited a high removal percentage after several cycles of adsorption/desorption.

Study from the influence of magnetite onto removal of hydrochlorothiazide from aqueous solutions applying magnetic graphene oxide

In this work, we report a straightforward synthesis of magnetic graphene oxide (GO·Fe3O4) in very mild conditions. This methodology proved to be effective in obtain graphene oxide (GO) decorated with different amounts of incorporated magnetite. The characterizations reveal the presence of magnetic nanoparticles (MNPs) in analyzed nanomaterial. Despite several methods shown in the literature, this protocol enables the amount control of incorporated magnetite on the surface of GO. Experimental data shows that GO·Fe3O4 1:10 (mass:mass) demonstrates the highest adsorption capacity on the hydrochlorothiazide with a 67.86% removal of the contaminant and pH 7.0 as the favorable condition. The removal rate and adsorption capacity are dependent on the initial concentration of the HCTZ, amount and type of the adsorbent. Temperature, ionic strength, and solution pH in the adsorption were also studied. The pseudo-second-order and Freundlich models showed better adjustment of the experiment. Thermodynamic parameters indicated that the adsorption process is exothermic and occurred spontaneously. Magnetic nanoadsorbent proves to be an efficient alternative nanomaterial for removing hydrochlorothiazide from aqueous solutions, avoiding filtration and centrifugation steps.

Synthesis of magnetic graphene oxide modified with dodecylamine and its application for the determination of seven endocrine-disrupting chemicals in environmental water samples

Magnetic graphene oxide (MGO) modified with dodecylamine (DDA) was synthesized in this work. The as-prepared MGO-DDA was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometer measurements. The material was used as the absorbent in magnetic solid-phase extraction (MSPE) for seven environmental endocrine-disrupting chemicals (EDCs):estrone (E1), β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2), hexoestrol (HEX), androstendione (AND), and bisphenol A (BPA). MSPE combined with HPLC-UV was developed for the determination of EDCs in environmental water samples. The effects of the amount of adsorbent, adsorbing time, and the type and volume of eluents on the recoveries of the EDCs were investigated. Under the optimal conditions, good linear relationships between the UV signals and the EDC concentrations were obtained, with R2 greater than 0.999. The limits of detection for all the EDCs were between 0.10 and 0.23 nmol/L. The MSPE-HPLC-UV method was successfully applied to the analysis of the seven EDCs in environmental water samples such as lake water and sewage water samples. The recoveries of all the EDCs in spiked lake water and sewage water samples were between 73.9% and 114.7%, and the RSDs ranged from 0.7% to 11.8%. Thus, the proposed MSPE-HPLC-UV method is simple, reliable, sensitive, and low-cost.

Solid-phase extraction of phytosterols from rapeseed oil deodorizer distillates with magnetic graphene oxide nanocomposite

A fast and facile method was employed for the synthesis of magnetic graphene oxide (MGO). The synthesized MGO is characterized by different techniques and used as a solid-phase adsorbent for the extraction of β-sitosterol from rapeseed oil deodorizer distillates (RODD) followed by gas chromatography-mass spectrometry analysis. Several parameters affecting the extraction efficiency, including the amount of adsorbent, extraction time and temperature, desorption solvent and desorption time, were investigated. The procedure exhibited desirable extraction efficiency within 30 min at 35 °C. Recoveries higher than 80% were obtained with acetone as eluent and the method was successfully applied to concentrate the β-sitosterol in RODD CO2-supercritical extract. Compared to C18-silica and graphitic carbon, the composite showed satisfactory results for the extraction of β-sitosterol from oil samples.

Application of Magnetic Graphene Oxide for Water Purification: Heavy Metals Removal and Disinfection

Water pollutant like heavy metals is one of the major hazards due to rapid urbanization and industrialization. In this study, a simple, fast and facile method was applied for the synthesis of magnetic graphene oxide (MGO) by fabricating the surface of graphene oxide (GO) with iron particles (Fe3+). Characterization of MGO was done by UV-VIS, FT-IR, SEM, XRD and VSM. Efficient removal of toxic heavy metal ions (Pb+2, Cr+3, Cu+2, Zn+2 and Ni+2) were studied using Atomic Absorption Spectroscopy (AAS). The adsorption performance of MGO was evaluated by investigating the effect of different parameters such as pH (3-9), temperature (25-55 °C), contact time (10-65 mins) and adsorbent dose (0.002 – 0.016 g). The maximum adsorption capacities at pH 5.0 for Pb (II), pH 6 for Cr (III), pH 6 for Cu (II), pH 7 for Zn (II) and pH 8 for Ni (II), ions were 200, 24.330, 62.893, 63.694 and 51.020 mg/g respectively. The adsorption processes was spontaneous and endothermic, followed the Langmuir adsorption isotherm and pseudo-second-order kinetics model. MGO action against microbial activity of E-Coli, Yersina Ruckeri and Antobacter Agglomerans was also studied. The results exhibited that MGO is a competent adsorbent and disinfectant for safe drinking water.

Synthesis of Magnetic Graphene Oxide (MGO) and Auxiliary Microwaves To Enhance Oil Recovery

Currently, thermal oil recovery methods are commonly applied to heavy oil development. Microwave heating is an effective recovery method and has the advantages of rapid heat transfer, volumetric he...

One-pot synthesis of magnetic graphene oxide composites as an efficient and recoverable adsorbent for Cd(II) and Pb(II) removal from aqueous solution

It is extremely desirable but challenging to develop a facile synthesis method to directly prepare reusable and longtime stable magnetic graphene oxide (GO) adsorbent. Here, a new approach to prepare a magnetic GO for removing the heavy metal ions is reported by using n-Propyltrimethoxysilane (NPTS) as a cross-coupling agent to connect Fe3O4/SiO2 and GO. The as-prepared magnetic GO can be separated quickly from their aqueous solution by the permanent magnet and also exhibited excellent adsorption performance for Cd(II) and Pb(II) with maximum adsorption capacities for Cd(II) and Pb(II) to 128.2 and 385.1 mg/g under neutral conditions, respectively. The presence of other ions such as Na(I) and K(I), had little influence on the Cd(II) and Pb(II) removal efficiency. Moreover, the as-prepared Fe3O4/SiO2-GO adsorbents can be recycled and exhibited good reproducibility. Thus, the magnetic GO adsorbents are effective materials for the removal of heavy metal ions and thus could offer a new platform for water cleanup.

Adsorption of Trace Estrogens in Ultrapure and Wastewater Treatment Plant Effluent by Magnetic Graphene Oxide.

In the current study, graphene oxide, Fe3+, and Fe2+ were used for the synthesis of magnetic graphene oxide (MGO) by an in situ chemical coprecipitation method. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction were used to characterize the well-prepared MGO. The prepared MGO was used as an adsorbent to remove five typical estrogens (estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (17α-E2), estriol (E3), and synthetic estrogen (EE2)) at the ppb level from spiked ultrapure water and wastewater treatment plant effluent. The results indicated that the MGO can efficiently remove estrogens from both spiked ultrapure water and wastewater treatment plant effluent in 30 min at wide pH ranges from 3 to 11. The temperature could significantly affect removal performance. A removal efficiency of more than 90% was obtained at 35 °C in just 5 min, but at least 60 min was needed to get the same removal efficiency at 5 °C. In addition, an average of almost 80% of the estrogens can still be removed after 5 cycles of MGO regeneration but less than 40% can be reached after 10 cycles. These results indicate that MGO has potential for practical applications to remove lower levels of estrogens from real water matrixes and merits further evaluation.

Synthesis of magnetic graphene oxide grafted polymaleicamide dendrimer nanohybrids for adsorption of Pb(II) in aqueous solution

In this paper, using maleic anhydride and ethylenediamine as functional monomers, graphene oxide (GO) loaded magnetic Fe3O4 nanoparticles modified by (3-Aminopropyl) triethoxysilane as support, magnetic graphene oxide grafted polymaleicamide dendrimer (GO/Fe3O4-g-PMAAM) nanohybrids were fabricated by divergent method and magnetic separation technology. The obtained samples were characterized by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, elementary analyzer and vibrating sample magnetometer. The effects of PMAAM generations, solution pH, Pb(II) initial concentration, temperature and contact time on the adsorption property of the samples for Pb(II) in aqueous solution were studied. The results demonstrated that nitrogen content and adsorption capacity of the as-synthesized samples with amino terminal groups were all higher than their adjacent generations PMAAM with carboxyl terminal groups. Moreover, with increasing generations of PMAAM grafted on to the GO/Fe3O4, the nitrogen content and the adsorption capacity of the samples with the same terminal groups gradually increased. The maximum adsorption capacity of GO/Fe3O4-g-G3.0 for Pb(II) was 181.4mgg−1 at 298K. The rising of temperature was beneficial for the adsorption. The adsorption kinetics had a better agreement with pseudo-second-order equation, and equilibrium data followed the Langmuir model.

Synthesis of magnetic graphene oxide doped with strontium titanium trioxide nanoparticles as a nanocomposite for the removal of antibiotics from aqueous media

In this study, strontium titanium trioxide (SrTiO3) nanoparticles were synthesized and doped onto graphene oxide (GO) based magnetic nanoparticles (MNPs) simply via ultrasound.