Magnetic Carbon Composites Research Articles

Facile fabrication of magnetic carbon composites from hydrochar via simultaneous activation and magnetization for triclosan adsorption.

Advanced magnetic carbon composites with high specific surface area and high microporosity are required for both environmentally and agriculturally related applications. However, more research is needed for the development of a facile and highly efficient synthesis process. In the present work, a novel approach of simultaneous activation and magnetization is proposed for the fabrication of magnetic carbon composites via the thermal pyrolysis of hydrochar (i.e., a solid residue from a hydrothermal carbonization process) that has been pretreated with mixtures of ferric chloride (FeCl3) and zinc chloride (ZnCl2). The main objective of this study is the investigation of the variation of characteristics of magnetic carbon composites produced at various conditions, as well as triclosan (TCS) adsorption behavior on such composites. This presented simple one-step synthesis method has the following advantages: (a) the hydrochar is activated with high surface area and pore volume (up to 1351 m(2)/g and 0.549 cm(3)/g, respectively), (b) activation and magnetization are simultaneously achieved without further modification, (c) the magnetic particles (γ-Fe2O3) are stable under an acidic medium (pH of 3.0 and 4.0), and (d) the products have the potential to remove TCS from aqueous solutions with a maximum adsorption capacity of 892.9 mg/g. The results indicate the effectiveness of this facile synthesis strategy in converting low-value biowaste into a functional material with high performance for pollutant removal from aqueous solutions.

Novel and High-Performance Magnetic Carbon Composite Prepared from Waste Hydrochar for Dye Removal

In recent years, more and more attention has been paid to the hydrothermal liquefaction (HTL) of waste biomass for the production of bio-oil and hydrochar (a solid residue from HTL process). However, hydrochar possesses limited porosity and surface area, hindering its environmental application. In the present work, to promote the development of a sustainable application of waste biomass, waste hydrochar was activated and modified to a novel magnetic carbon composite, which exhibited high performance for dye removal from aqueous solutions. The composite possessed a saturation magnetization of 38.5 emu g–1 at room temperature and could be facilely attracted from an aqueous solution by an external magnet. The as-prepared composite exhibited a superior malachite green (MG) adsorption capacity (476 mg g–1), which was much higher than the known magnetic adsorbents. Our results suggested that the waste hydrochar could be efficiently transformed to a high-performance sustainable material for dye removal.

Metal organic framework derived magnetic porous carbon composite supported gold and palladium nanoparticles as highly efficient and recyclable catalysts for reduction of 4-nitrophenol and hydrodechlorination of 4-chlorophenol

A magnetic porous carbon composite which has been synthesized from MOF is used as a catalyst support to fabricate Au and Pd NP based nanocatalysts.

Facile Low Temperature Hydrothermal Synthesis of Magnetic Mesoporous Carbon Nanocomposite for Adsorption Removal of Ciprofloxacin Antibiotics

A new magnetic mesoporous carbon composite (Fe3O4/C) was synthesized and characterized by XRD, nitrogen adsorption–desorption isotherms, FT-IR, TG, ζ potential, SEM, and TEM. The performance of using Fe3O4/C composite as an adsorbent for removal of antibiotics using ciprofloxacin (CIP) as a model was investigated. The Langmuir adsorption isotherm was applicable to fit the removal process. Kinetics of the CIP removal was found to follow a pseudo-second-order rate equation. The solution pH is critical for the adsorption of CIP on Fe3O4/C, and the maximum adsorption of CIP could be reached under neutral conditions. In addition, the Fe3O4/C adsorbent showed high magnetization and operational stability, and it could be readily separated from solution by applying an external magnetic field. After 10 recycle runs, over 85% of the adsorption capacity was retained. The high performance, low cost, and easily recyclable Fe3O4/C composite may become a promising adsorbent for water treatment.

A facile co-gelation route to synthesize FeCo/carbon nanocomposites and their application as magnetically separable adsorber

A new kind of magnetic porous FeCo/carbon nanocomposites was successfully synthesized by using a facile co-gelation sol–gel route. The sol–gel process of this route started from an ethanol solution containing teraethylorthosilicate (TEOS), furfuryl alcohol (FA), and metal nitrates. With the evaporation of solvent, the weak acidity produced from hydrolysis of metal nitrates simultaneously catalyzed the polymerization of FA and the hydrolysis of TEOS, which led to the inorganic/organic hybrid xerogel, accompanying metal salts spontaneously captured in the xerogel. The composites obtained have high surface areas, pore volumes and strong magnetic strengths, which make them exhibit excellent performance of adsorption for bulk dyes and easily separated from solution by external field after adsorption. Compared to the previous methods, this route is very simple and operable for the preparation of magnetic porous carbon composites. Such facile co-gelation route also provides a common path to the synthesis of nanoscale metal or alloy embedded in the porous carbon materials.

An easy co-casting method to synthesize mesostructured carbon composites with high magnetic separability and acid resistance

Magnetic mesoporous carbon composites with high surface areas and narrow mesopore size distributions were directly replicated from SBA-15 by a simple co-casting method and the amount of incorporated magnetic particles and saturation magnetization value can be easily tuned by changing the added amount of iron source during synthesis. Furthermore, the magnetic mesoporous carbon composites show good acid resistance due to a carbon shell coating structure around the magnetic particles, which is spontaneously formed during the replication process of the mesoporous carbon composites. The characteristics of the as-synthesized magnetic mesoporous carbon composites were examined by X-ray diffraction, N2 sorption, transmission electron microscopy (TEM), Mossbauer spectroscopy and vibrating-sample magnetometry.