Magnetic Carbon Nanocomposite Research Articles

Magnetic porous carbon nanocomposite derived from cobalt based-metal-organic framework for extraction and determination of homo and hetero-polycyclic aromatic hydrocarbons

Herein, a novel magnetic porous carbon nanocomposite derived from a cobalt based-metal-organic framework was synthesized and evaluated for simultaneous preconcentration of homo and hetero-polycyclic aromatic hydrocarbons. Briefly, magnetite nanoparticles (MNPs) were synthesized and then were coated with a metal-organic framework layer. Finally, the magnetic nanocomposite was carbonized under an inert atmosphere to obtain the magnetic porous carbon (MPC). Various characterization techniques such as FT-IR spectroscopy, transmission and scanning electron microcopies, vibrating sample magnetometry, and X-ray diffraction were employed. Applicability of the MPC was explored using benzothiophene, dibenzothiophene, 9,10-dimethylanthracene, and benz[α]anthracene as the model analytes. Limits of detection and linearities were achieved in the range of 0.06–0.18 μg L−1 and 0.25–500 μg L−1, respectively. Precision of the method as RSDs was evaluated which was in the range of 4.2–7.0% (within-day, n = 5) and 8.2–11.3% (between-day, n = 3). Ultimately, the method was applied to analyze two seawater samples and satisfactory results (RSDs%, 5.0–9.0%; relative recoveries, 89–104%) were obtained.

Thermal, mechanical, rheological, electrical and electromagnetic interference shielding performance of polypropylene/magnetic carbon nanocomposites

Novel magnetic bio-nanocomposites were fabricated using polypropylene (PP) as polymer matrix and graphene supported magnetic carbon nanocomposite (MCNC, produced by solvothermal carbonization co-precipitation route integrating low-cost graphene, renewable biomass and iron oxide nanoparticles) serving as filler by incorporating nano-fillers of loading 5%, 10% and 15% with PP using a convenient and time efficient route melt processing. Utilizing waste biomass as integral part of MCNC offers cost effective solution for hybrid nanocomposite synthesis and its application in advance field as electromagnetic interference (EMI) shielding material. The study provides comprehensive analysis for its upgradation in rheological properties that have exclusive impact on its final application. Furthermore, the behaviour for thermal, structural, mechanical, chemical, magnetic, and electrical features using various characterization techniques. Field emission scanning electron micrographs revealed good dispersion of MCNC in PP matrix and formation of network for 15% loading of the filler facilitated 800% higher shielding effectiveness as compared to that of neat PP. It was revealed that functionalization with graphene supported magnetic nanocomposite and polymer matrix have improved the overall conductivity for the composites. Rheological studies indicated the upgradation in viscoelastic properties as solid like behaviour was seen with the increment of filler concentration. X-ray diffractometer demonstrated that MCNC had a substantial impact on the crystallinity of nanocomposite that is validated with modulated differential scanning calorimetry analysis.

Dual-application of novel magnetic carbon nanocomposites as catalytic liquefaction for bio-oil synthesis and multi-heavy metal adsorption

The objective of this study is the applications of hybrid magnetic nanocomposites as catalyst as well as an adsorbent. Four magnetic nanocomposites (graphene and chitosan based) were fabricated using single pot solvothermal carbonization co-precipitation (STCC) route by integrating biomass functionalized with iron oxide nanoparticles. All hybrid nanocomposites were characterized for their magnetic, thermal, chemical and structural properties. Adsorption isotherms and kinetics studies were performed for adsorption of multi-heavy metals including Cd, Ni, Cu and Cr. Finally, the hybrid magnetic carbon nanocomposites were tested as catalysts to produce bio-oil through catalytic liquefaction of rice husk in supercritical ethanol. It was found that the bio-oil yield and overall conversion was enhanced significantly from 29.5% and 48.11% without catalyst, to 36.8% and 60.81% respectively with the presence of magnetic carbon nanocomposites as catalyst. Furthermore, the bio-oil energy quality was enhanced in energy content from 21.72 to 23.21 MJ/kg with the presence of catalyst and H/C and O/C ratios were reduced. Finally, GCMS revealed that the bio-oil produced using catalysts showed higher mass fraction of esters, hydrocarbons and reduced acid groups as compared to bio-oil. This study provides insights to the understanding of the role of hybrid magnetic nanocomposites for its expansion for future applications.

Catalytic conversion of plastic wastes using cost-effective bauxite residue as catalyst into H2-rich syngas and magnetic nanocomposites for chrome(VI) detoxification

Red mud (RM) as bauxite residue from aluminum plant was investigated as cost-effective catalyst for pyrolysis and ex-situ catalytic conversion of plastic wastes into H2-rich syngas and magnetic carbon nanocomposites. The results showed that the introduction of RM catalyst elevated gas yield from 23.8 to 60.3 wt% as a rise of catalytic temperature (700–850 °C), due to its high iron activity for scission of polymer chains. Furthermore, the endothermic nature of cracking reactions of hydrocarbons led to the maximum H2 production of 28.8 mmol gfeed−1 and 63 vol% at 850 °C. The carbon/RM nanocomposites were comprehensively evaluated by multiple characterizations. High-resolution TEM indicated considerable carbon nanotubes(CNTs) depositing on the RM surface that modified iron sites dispersion and diminished nanoparticle size of iron at higher temperature of ≥800 °C. XRD and XPS results confirmed that higher temperature provided carbon components surrounding iron species to form metallic iron. The carbon/RMs were initially applied to chromium(VI) removal in sewage. RM-800 delivered high-profile adsorption capacity of 193.8 mg g−1, mainly attributed to the synergistic effect of chemical reduction by sufficient Fe0 exposure and CNTs growth promoting electrostatic attraction and electron transfer capacity. Furthermore, the correlation mechanism between catalytic temperature and the evolution of products and was discussed.

Effective removal of tetracycline from water by batch method using activated carbon, magnetic carbon nanocomposite, and membrane hybrid technology

Abstract In this study two adsorbents (activated carbon; AC and magnetic activated carbon; MCN) were prepared from Dalbergia sissoo sawdust and used as potential adsorbents for the removal of tetracycline (TC) from water. Both the adsorbents were characterized by instrumental techniques like energy dispersive x-ray (EDX), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), x-ray diffraction (XRD), surface area analyzer and thermal gravimetric/Differential thermal analysis (TG/DTA). The effect of antibiotic initial concentration, contact-time, pH, adsorbent-dose, and temperature were evaluated to determine optimum adsorption conditions. The optimum TC concentration for both AC and MCN was 120 mg/L while optimum time of saturation for both adsorbents was 120 min. The optimum pH determined was five while optimum adsorbent dose was 0.1 g. The adsorption isothermal data of both sets of experiments was best explained by Langmuir model. The kinetic data was well explained by pseudo-second order kinetics model. The ΔH° (enthalpy change) and ΔSo (entropy change) were; −14.989 and 25.174 kJ/mol for AC and −11.628 and 51.302 kJ/mol for MCN respectively. The values of Gibbs free energy (ΔG°) calculated for AC were 7.36, −7.99, −7.36, −7.61, and −8.12 kJ/mol while for MCN these were −15.02, −15.53, −16.05, −16.56, and −17.07 kJ/mol corresponding to temperatures; 298, 303, 313, 323, and 333 K. To control fouling in ultra-filtration, nano-filtration, and reverse osmosis membranes caused by TC, and both adsorbents, a continuous stirred reactor was connected in series with membrane pilot plant. The improvement brought about by both adsorbent in parameters like % retention and permeate flux was also evaluated. Comparatively, better improvement was brought about in % retention and permeates flux by MCN.

Controllable preparation of magnetic carbon nanocomposites by pyrolysis of organometallic precursors, similar molecular structure but very different morphology, composition and properties

Organometallic compounds were synthesized for solid-state pyrolysis to research the structure–property relationship between the precursors and the as-generated magnetic carbon nanocomposites.

Determination of sulfonamide residues in animal foodstuffs by magnetic dispersive solid-phase extraction using magnetic carbon nanocomposites coupled with ion pair-dispersive liquid\u2013liquid micro-extraction combined with HPLC-DAD

In this study, magnetic-dispersive solid-phase extraction coupled with ion pair-dispersive liquid–liquid micro-extraction (MSPE-i-DLLME) was used to the pre-concentration and extraction of five sulfonamides residues (sulfadiazine, sulfathiazole, sulfacetamide, sulfamethazine and sulfamethoxazole) in animal foodstuffs. The sulfonamides are extracted using magnetic carbon nanocomposite and then eluted with acetonitrile. In the DLLME step, the target analytes are collected in 1-octanol containing 10% Aliquat-336 (as extraction solvent). Finally, the compounds are quantified by HPLC with DAD detection. The extraction parameters optimized using the one at the time and central composite design methods. Under the optimized conditions: sample solution volume was 100 mL; initial pH: 12, amounts of MCNs: 30 mg; desorption solvent (ACN) volume, 1 mL; desorption condition, 10 min sonication at two step; extraction solvent (1-octanol + 10% aliquat) volume, 115 µL; pH of DLLME step, 3; salt effect, 24.6%, (w/v) NaCl; centrifuge, 5 min, 4000 rpm. In these extraction conditions, the proposed procedure represented good pre-concentration factors between 130 and 490; detection limits in the range from 0.01 to 5 μg kg−1 (at S/N = 3), and linear response in the 0.1–400 μg kg−1 concentration range. The method is successfully applied to the determination of sulfonamides residues in animal foodstuffs.

A magnetic palladium nickel carbon nanocomposite as a heterogeneous catalyst for the synthesis of distyrylbenzene and biphenyl derivatives

Distyrylbenzene and 9,10-distyrylanthracene derivatives were synthesized using an Fe3O4@Pd@Ni/C nanocomposite as a recyclable catalyst. The catalyst was recycled up to eight times.

A novel polymer coated magnetic porous carbon nanocomposite derived from a metal-organic framework for multi-target environmental pollutants preconcentration

This study describes the synthesis of a novel polymer (polypyrrole-polythiophene) coated magnetic porous carbon (MPC) composite derived from magnetic metal-organic framework (MOF) and its utilization in multi-target environmental pollutants preconcentration. In this regards, Fe3O4 nanoparticles (NPs) was used as magnetic core and Co-MOF-71 was coated on the surface of the NPs. Afterwards, magnetic MOF (MMOF) was carbonized under nitrogen atmosphere and finally MNC was coated with a polymer layer of the type polypyrrole-polythiophene to obtain the nanocomposite (MPC@PPy-PTh). Magnetic property, structure and morphology of MPC@PPy-PTh were explored via various characterization techniques. Applicability of MPC@PPy-PTh nanoadsorbent was investigated in multi-target environmental pollutants preconcentration using 4-chlorophenol 2-naphtol, 1-amino-2-naphthol, 2,4-dichloroaniline, 3,4-dichloroaniline, benzothiophene and naphthalene as the model analytes. Effect of experimental factors on the preconcentration of target pollutants was explored and optimized systematically. Under the optimized condition, LODs were obtained in the range of 0.06-0.18 µg L−1. The proposed method exhibited linearity within the range of 0.25-500 µg L−1. Repeatability of the new method based on the relative standard deviations (n = 5) was in the range of 3.4-9.0%. Finally, the analytical applicability of the optimized method was investigated in seawater and wastewater samples and satisfactory results were achieved.

Magnetic nanoparticles incorporation into different substrates for dyes and heavy metals removal-A Review.

Substantial discharge of hazardous substances, especially dyes and heavy metal ions to the environment, has become a globalconcern due to many industries neglecting the environmentalprotocols in waste management. A massive discharge of contaminantsfrom different anthropogenic activities, can pose alarming threats to living species and adverse effect to the ecosystem stability. In the process of treating the polluted water, various methods and materials are used.Hybrid nanocomposites have attained numerous interest due to the combination of remarkable features of the organic and inorganic elements in a single material. In this regards, carbon and polymer basednanocomposites have gained particular interest because of their tremendous magnetic properties and stability. These nanocomposites can be fabricated using several approaches that include filling, template, hydrothermal, pulsed-laser irradiation, electro-spinning, detonation induced reaction, pyrolysis, ball milling, melt-blending, and many more. Moreover, carbon-based and polymer-based magnetic nanocomposites have been utilized for an extensive number of applications such as removal ofheavy metal and dye adsorbents, magnetic resonance imaging, and drug delivery. This review emphasized mainly on the production of magnetic carbon and polymer nanocomposites employing various approaches and their applications in water and wastewater treatment. Furthermore, the future opportunities and challenges in applying magnetic nanocomposites for heavy metal ion and dye removal from water and wastewater treatment plant.

The Study on Material Preparation and Adsorption Properties of Magnetic Smaller Sized Fe<sub>3</sub>O<sub>4</sub> Load on Multi-Walled Carbon Nanotubes

On the one hand, accordingly to remove the surface impurities, we purified the prepared Multi-walled carbon nanotubes (MWCNTs) in our advance experiment; ferrous ions and iron ions in lye through the action of micro-filtration membrane to form smaller size Fe3O4 magnetic particles on the other hand. The prepared magnetic Fe3O4 with small particle size was loaded on the adorption point of the multi-walled carban nanotubes(MWCNTs) to form magnetic carbon nanocomposites. In order to achieve the best adsorption effect, the preparation temperature was improved in the experiment, and the influence of the ratio of ferrous ions to iron ions on the properties of the material was adjusted. The best adsorption properties of the composites were confirmed by X-ray diffraction and Fourier infrared spectrometer phase analysis. In addition, the application of this experiment to water treatment has a good effect on the copper ion removal.

Application of heterogeneous catalytic ozonation process for treatment of high toxic effluent from a pesticide manufacturing plant

Background: The discharge of untreated wastewater containing toxic and resistant compounds into the environment is a serious threat for ecosystems. Therefore, this study was conducted to evaluate the treatment of poison production factory wastewater using heterogeneous catalytic ozonation process (COP). Methods: Magnetic carbon nanocomposite was used as a catalyst at concentrations of 1, 2, and 4 g/L. Its effect on improving the treatment process was evaluated at reaction time of 30, 60, 90, and 120 minutes. At the end of each experiment, parameters including total organic carbon (TOC), chemical oxygen demand (COD), biological oxygen demand (BOD5 ), pH, electrical conductivity (EC), and turbidity were measured. Results: It was revealed that in single ozonation process (SOP), the maximum removal efficiencies of TOC, COD, and BOD5 were achieved at reaction time of 120 minutes as 56%, 40%, and 11.7%, respectively. By adding the catalyst to the wastewater, the treatment process was improved, so that the maximum removal efficiencies of COD (91%), TOC (73%), and BOD5 (74%) were obtained at catalyst concentration of 4 g/L. Under this condition, BOD5 /COD ratio increased from 0.22 to 0.64. Also, the results of analysis of ozone consumption per each mg of reduced COD showed that its amount sharply decreased from 2.1 mgO3 / mg COD removal in the SOP, to 0.34 mgO3 /mg COD removal in the COP. The results of kinetic reaction analysis also revealed that the rate constant increased from 0.007 to 0.02 min-1. Conclusion: According to the results, it can be concluded that the COP at a catalyst concentration of 4 g/L, by decomposing resistant compounds and increasing the biodegradability, can be used as a suitable pretreatment method for biological processes.

Isolation of Quercetin from Rubus fruticosus, Their Concentration through NF/RO Membranes, and Recovery through Carbon Nanocomposite. A Pilot Plant Study.

In this study, an attempt has been made to devise a method for a large-scale production of quercetin from a medicinal plant. The natural products are first isolated from plants and then synthesized commercially. During their synthesis, a number of impurities or side products are also formed, most of which are carcinogenic. Plant products have limited side effects. Therefore, they are considered safe to be used for systemic uses. In the Rubus fruticosus fruit, the ethyl acetate extract was loaded to 50 optimized silica gel columns. The effluents of columns were passed through the membrane system for concentration. A 100% recovery was achieved from the drain pipe in case of reverse osmosis membrane when the specified rely of the pilot plant was set on 25% rejection. About 95% recovery was achieved through the NF membrane while the 5% loss in permeate was recovered through magnetic carbon nanocomposite (characterized through a bar magnet, SEM, XRD, and EDX). The equilibrium time of adsorption was 83 min and followed by pseudo-first-order kinetics. The adsorption equilibrium data fitted well to the Langmuir isotherm model. Through the devised method, quercetin was successfully concentrated with high efficiencies; however, further studies are needed to validate the method.

Correction: Cr(vi) removal by magnetic carbon nanocomposites derived from cellulose at different carbonization temperatures

Correction for ‘Cr(vi) removal by magnetic carbon nanocomposites derived from cellulose at different carbonization temperatures’ by Bin Qiu et al., J. Mater. Chem. A, 2015, 3, 9817–9825, DOI: 10.1039/C5TA01227A.

Synthesis of novel magnetic carbon nano-composite from waste biomass: A comparative study of industrially adoptable hydro/solvothermal co-precipitation route

Development of advanced magnetic carbon nano-materials has provided new dimensions in numerous research areas due to their multiple applications. In this study, novel magnetic carbon nano-composites were synthesised by integration of magnetic nanoparticle on novel graphene and renewable carbon materials from rice husk. Magnetic carbon nano-composites were fabricated by hydrothermal carbonization-coprecipitation (HTCC) and solvothermal carbonization-coprecipitation (STCC) routes that are easily scalable. The objective of this work is a comparative study of HTCC and STCC processed and their products. The experiments were conducted using different process variables including process temperatures (180,220 and 260 °C), process time (0.5,1 and 2 h) and solvents (water and ethanol). Chemical interaction of well-dispersed magnetic nano-particles of 5–20 nm size with carbonaceous material was confirmed. Magnetically recoverable nano-composite is highly suitable for use in multiple applications including catalysis, super-capacitance, biosensing devices, environmental remediation and enzymes immobilization and can establish various opportunities for industry in future.

Removal of Enrofloxacin from Water through Magnetic Nanocomposites Prepared from Pineapple Waste Biomass

In this study, a novel approach was adopted to determine the drug resistance developed due to the presence of antibiotics in industrial effluents. As a remedy, magnetic carbon nano-composites (MCNs) were prepared from waste biomass and characterized by a surface area analyzer, by SEM, EDX, XRD, FTIR, and TG/DTA. Langmuir, Freundlich and Temkin isotherms were used for the determination of adsorption parameters. The Langmuir adsorption isotherm was found to fit better the data of the equilibrium adsorption of enrofloxacin (ENR) on MCN (R2 = 0.99). The effect of pH on the adsorption process was evaluated and a decline in percentage of adsorption was noted at both highly acidic and alkaline pH. The maximum percentage of adsorption was observed at pH 6–8. The effect of ionic strength and humic acid was also tested for the removal of ENR by MCNs. Various kinetic models were used to analyze the kinetics data. The best fit was obtained with a pseudo 2nd order kinetic equation. The thermodynamic parameters were also determined: ΔS° was positive (80 J mol–1K –1) while ΔH° (23.57 kJ mol–1) and ΔG° were negative with numerical values of –0.27, –1.47, and –3.07 kJ mol–1 corresponding to temperatures 25, 40, and 60°C, respectively. MCNs were regenerated with 3% NaOH solution, methanol, and distilled water.

Comparative study of microwave and conventional solvothermal synthesis for magnetic carbon nanocomposites and bio-oil from rice husk

This article provides a comparative study of advanced single pot microwave versus conventional solvothermal co-precipitation synthesis for producing magnetic carbon nanocomposites and bio-oil from rice husk. The aim was to produce nanocomposites composed of magnetic nanoparticles and novel graphene on the surface of hydrochar improving the reaction efficiency. The experiments were conducted at two different temperatures (140 °C and 180 °C). The processing time was varied from 0.5 to 2 h. The main focus of the study was to investigate the effect of process parameters on the yield, thermal stability and morphology. Microwave-assisted solvothermal carbonisation (MSTC) provided a higher yield of bio-oil compared to solvothermal carbonisation (STC) due to more effective heat transfer to the core of the material. Microwave processing also resulted in less CC and C–H vibrations as measured by FTIR. Transmission electron microscopy confirmed the presence of well-dispersed nanoparticles, ranging in size from 5 to 20 nm in both MSTC and STC. Thermal stability of the nanocomposite materials was significantly higher for conventional solvothermal synthesis compared to the microwave system.

Separation of Levofloxacin from Industry Effluents Using Novel Magnetic Nanocomposite and Membranes Hybrid Processes.

Magnetic carbon nanocomposite (MCN) was synthesized from waste biomass precursor, pineapple. The prepared adsorbent was characterized using different instrumental techniques and was used to remove levofloxacin (LEV) from effluents. The maximum sorption of LEV was observed at pH 7. Pseudo-2nd-order (PSO) kinetic was found to be the best model that fits well the adsorption kinetics data. For Langmuir adsorption isotherm, the R2 value was higher as compared with other isotherms. The Van't Hoff equation was used for thermodynamic parameters determinations. ΔS° (standard entropy) was positive and ΔG° (standard Gibb's free energy) was negative: -0.37, -1.81, and -3.73 kJmol−1 corresponding to 25, 40, and 60°C. The negative values of ΔG° at different temperatures stipulate that the adsorption of LEV was spontaneous in nature and adsorbent has a considerable affinity for LEV molecules. The MCN was then utilized in hybrid way by connecting with ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) membranes in series and as a result enhanced permeate fluxes were observed. The percent retention of LEV molecules was lower with UF membrane and with NF it was 96%, while it was 100% with RO. For MCN/UF and MCN/NF systems, improvement in % retention was recorded.

Simultaneous extraction of 32 polychlorinated biphenyls by using magnetic carbon nanocomposite based dispersive microextraction, subsequent dispersive liquid-liquid microextraction with two miscible stripping solvents, and quantitation by GC-μECD.

A highly sensitive new method is described for performing dispersive microextractions. It is making use of a magnetic carbon nanocomposite and two miscible organic solvents. The method was applied to simultaneous extraction of 32 polychlorinated biphenyls (PCBs) prior to their quantitation by gas chromatography with electron capture detection. The effects of pH value of sample for both micro solid phase extraction and dispersive liquid-liquid microextraction, of the amount of sorbent, extraction time, type and volume of the miscible organic solvents and of salt addition were optimized. Figures of merit obtained under optimized conditions (sample solution: 500ml, volume of disperser solvent, ACN, 1.5mL; volume of extraction solvent, TCB, 30μL; extraction time: 50min, 20mg magnetic sorbent, centrifuge, 5min, 4000rpm), include (a) preconcentration factors between 10,880 and 34,000; (b) repeatabilities of ≤14.9%, (c) detection limits between 0.01 and 0.2ngkg-1, and (d) linear dynamic ranges from 0.05 to 100ngkg - 1. The method was applied to the simultaneous analysis of residues in (spiked) real samples of fish, milk, packing sheet, and tap waters. Some of the analytes were found to be present in fish samples. The method is simple, rapid, and more sensitive than any of the previously reported ones. Graphical abstract Schematic presentation of simultaneous extraction of 32 polychlorinated biphenyls (PCBs) by using magnetic carbon nanocomposites (MCNs) based dispersive microextraction (M-SPE), subsequent dispersive liquid-liquid microextraction (DLLME) with two miscible stripping solvents, and quantitation by GC-μECD.

Application of EDTA modified Fe3O4/sawdust carbon nanocomposites to ameliorate methylene blue and brilliant green dye laden water

This work explored the potential of magnetic sawdust carbon nanocomposites for cationic dyes removal from aqueous medium. EDTA modified magnetic sawdust carbon nanocomposites (EDTA@Fe3O4/SC ncs) were prepared by biogenic green reduction and precipitation approach. The surface properties, structure and composition of nanocomposites were characterized by HRTEM, FESEM, XRD, EDX, BET, FTIR etc. The Fe3O4 nanoparticles were 10–20 nm in diameters and having 14 m2/g surface area. Removal of Methylene blue (MB) and Brilliant green (BG) dyes from aqueous medium was studied in batch mode experiments. The maximum removal was achieved at neutral pH 7.0 with in 30 min. Adsorption capacity of EDTA@Fe3O4/SC for MB and BG dyes was 227.3 mg/g and 285.7 mg/g, respectively. Dye adsorption behaviour is well explained by Freundlich model. The rate of cationic dye adsorption is explained by pseudo-second order model. The value of thermodynamic parameters confirmed that adsorption process was spontaneous and favourable. Desorption and reusable efficiency of nanocomposites was also evaluated.