Metal-carbon Nanocomposites Research Articles

Role of nanocomposites and nano adsorbents for heavy metals removal and dyes. An overview

Water scarcity and wastewater treatment are major concerns due to increased urbanization, industrialization, and anthropogenic practices. Various toxic heavy metals, dyes, pollutants, and chemicals are a matter of concern as they have severe environmental and ecological damage and health effects. Various advancements are being introduced in the field of adsorption using nano adsorbents and composites to deal with wastewater treatment problems. Nanocomposites are intelligent to eliminate bacteria, viruses, and inorganic and organic pollutants from wastewater due to precise binding action (chelation, absorption, ion exchange). Nanocomposite materials, such as metal nanocomposite, metal oxide nanocomposite, carbon nanocomposite, polymer nanocomposite, and membrane nanocomposite, are active in water purification. Nanoparticles (N.P.s) are important for remediation because of their large surface area, size, reactivity, and active sites. For high adsorption of pollutants, N.P.s were treated by increasing the electron density and surface area and adding functional groups. They are more capable of eliminating hazardous organic-inorganic pollutants, pathogens, and heavy metals from wastewater. This nanotechnology treatment technique has no hazardous by-products; these techniques have various regenerative efficiencies. Among various treatment methods, the adsorption process is considered one of the most highly effective treatments of heavy metals, and the functionalization of adsorbents can fully enhance the adsorption process. Therefore, four adsorbent sources are highlighted: polymeric, natural mineral, industrial by-product, and carbon nanomaterial adsorbent. The major purpose of this review is to gather up-to-date information on research and development on various adsorbents in the treatment of heavy metal and dyes from water by emphasizing the adsorption capability, the effect of pH, isotherm and kinetic model, removal efficiency, and the contact of time of every adsorbent.

Synthesis of Microdispersed Ni1–xRux Alloys for Obtaining Metal-Carbon Nanocomposites in the Mode of Carbon Erosion

Synthesis of Microdispersed Ni1–xRux Alloys for Obtaining Metal-Carbon Nanocomposites in the Mode of Carbon Erosion

Plasma-Treated Cobalt-Doped Nanoporous Graphene for Advanced Electrochemical Applications

Metal–carbon nanocomposites are identified as key contenders for enhancing water splitting through the oxygen evolution reaction and boosting supercapacitor energy storage capacitances. This study utilizes plasma treatment to transform natural graphite into nanoporous few-layer graphene, followed by additional milling and plasma steps to synthesize a cobalt–graphene nanocomposite. Comprehensive structural characterization was conducted using scanning and transmission electron microscopy, X-ray diffraction, Raman spectroscopy, gas sorption analysis and X-ray photoelectron spectroscopy. Electrochemical evaluations further assessed the materials’ oxygen evolution reaction and supercapacitor performance. Although the specific surface area of the nanoporous carbon decreases from 780 to 480 m2/g in the transition to the resulting nanocomposite, it maintains its nanoporous structure and delivers a competitive electrochemical performance, as evidenced by an overpotential of 290 mV and a Tafel slope of 110 mV/dec. This demonstrates the efficacy of plasma treatment in the surface functionalization of carbon-based materials, highlighting its potential for large-scale chemical-free application due to its environmental friendliness and scalability, paving the way toward future applications.

Short-Time Magnetron Sputtering for the Development of Carbon-Palladium Nanocomposites.

In recent nanomaterials research, combining nanoporous carbons with metallic nanoparticles, like palladium (Pd), has emerged as a focus due to their potential in energy, environmental and biomedical fields. This study presents a novel approach for synthesizing Pd-decorated carbons using magnetron sputter deposition. This method allows for the functionalization of nanoporous carbon surfaces with Pd nano-sized islands, creating metal-carbon nanocomposites through brief deposition times of up to 15 s. The present research utilized direct current magnetron sputtering to deposit Pd islands on a flexible activated carbon cloth substrate. The surface chemistry, microstructure, morphology and pore structure were analyzed using a variety of material characterization techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy, gas sorption analysis and scanning electron microscopy. The results showed Pd islands of varying sizes distributed across the cloth's carbon fibers, achieving high-purity surface modifications without the use of chemicals. The synthesis method preserves the nanoporous structure of the carbon cloth substrate while adding functional Pd islands, which could be potentially useful in emerging fields like hydrogen storage, fuel cells and biosensors. This approach demonstrates the possibility of creating high-quality metal-carbon composites using a simple, clean and economical method, expanding the possibilities for future nanomaterial-based applications.

Sustainability in magnetic metal-carbon nanocomposites: A comprehensive review of manufacturing, characterization, and applications

Magnetic metal-carbon nanocomposites (MMCN) are emerging as sustainable materials, consisting of magnetic metals or alloys and carbon-based materials like CNT, graphene (Gr), carbon fiber (CF), and activated carbon. These materials possess unique magnetic properties that depend on various factors, such as preparation conditions, metal content, and phase composition. Incorporating carbon-based materials into magnetic metals has been observed to enhance their magnetic properties, including magnetic strength and moment. Researchers employ a range of tests to characterize these materials, such as FTIR, XRD, FESEM, TEM, BET, and VSM. Carbon-based materials such as CNT, graphene, etc., have been used as filler materials to reinforce the metal matrix because of their sustainability, tendency to integrate, and low cost. Further, they enhance the tribological performance and mechanical strength, provide corrosion resistance and improve electrical and thermal properties. Additionally, the addition of filler magnetic material in single or hybrid form into the carbon matrix increases the scope of application of MMCN. These composites are widely used in the application of biomedical, semiconductors, tribology, fuel cells, etc. In the present study, a comprehensive review has been carried out to provide a view of the fabrication aspect of the MMNC and to understand the role of the reinforcement method used to fabricate the composites. Finally, it covers different uses of the MMCN, which can lead to an eco-friendly environment.

Transient and scalable synthesis of metal-carbon nanocomposites by thermal plasma with self-coordinated mechanism

In this work, an in situ strategy was developed to construct various metal-carbon heterostructures with high yield. Notably, the multi-step reactions and structural regulation were completed in milliseconds due to the greatly enhanced kinetic driving force originated from the ultra-high temperature and ionized reactive atmosphere in thermal plasma, resulting in ultrasmall metal nanocrystals with size about several nanometers embedded in high-crystalline and nitrogen-doped porous carbon nanolayer. Based on controlled experiments, a self-coordinated mechanism involved the catalytic effect of metal species and the confined growth function of C was proposed to clarify the formation of heterogeneous nanocomposites. Furthermore, the advantage of synthesized heterostructure was illustrated by its superior performance of electrocatalytic hydrogen evolution from water splitting. The obtained dual CoNi@NC presents a competitive overpotential of 149 mV to deliver a current density of 10 mA cm−2, together with 98 % preservation of initial capacity after 20 h test, highlighting the universality of this work to construct well-designed metal/C nanocomposites with potential engineering application in electrocatalytic field.

Synthesis, structure and electromagnetic properties of FeCoCu/C nanocomposites

FeCoCu ternary nanoparticles distributed and stabilized in the carbon matrix of FeCoCu/C metal-carbon nanocomposites have been synthesized using controlled IR pyrolysis of precursors consisting of the “polymer / iron acetylacetate / cobalt and copper acetates” type system obtained by joint dissolution of components followed by solvent removal. The effect of the synthesis temperature on the structure, composition and electromagnetic properties of the nanocomposites has been studied. By XRD was shown that the formation of the FeCoCu ternary nanoparticles occurs due to the interaction of Fe3С with the nanoparticles of the CoCu solid solution. An increase in the synthesis temperature leads to an increase in the size of the metal nanoparticles due to their agglomeration and coalescence as a result of matrix reconstruction. Furthermore, ternary alloy nanoparticles having a variable composition may form depending on the synthesis temperature and the content ratio of the metals. Raman spectroscopy has shown that the crystallinity of the carbon matrix of the nanocomposites increases with the synthesis temperature. The frequency responses of the relative permittivity and permeability of the nanocomposites have been studied at 3–13 GHz. It has been shown that a change in the content ratio of the metals noticeably increases both the dielectric and the magnetic losses. The former loss is caused by the formation of a complex nanostructure of the nanocomposite carbon matrix while the latter one originates from an increase in the size of the nanoparticles and a shift of the natural ferromagnetic resonance frequency to the low-frequency region. The reflection loss has been calculated using a standard method from the experimental data on the frequency responses of the relative permittivity and permeability. It has been shown that the frequency range and the absorption of electromagnetic waves (from –20 to –52 dB) can be controlled by varying the content ratio of the metals in the precursor. The nanocomposites obtained as a result of the experiment deliver better results in comparison with FeCo/C nanocomposites synthesized under similar conditions.

A novel MOF-derived binary metal oxides and carbon nanocomposite for high-performance symmetric supercapacitor application

A novel MOF-derived binary metal oxides and carbon nanocomposite for high-performance symmetric supercapacitor application

Synthesis, structure and electromagnetic properties of FeCoCu/C nanocomposites

FeCoCu ternary nanoparticles distributed and stabilized in the carbon matrix of FeCoCu/C metal-carbon nanocomposites have been synthesized using controlled IR pyrolysis of precursors consisting of the “polymer / iron acetylacetate / cobalt and copper acetates” type system obtained by joint dissolution of components followed by solvent removal. The effect of the synthesis temperature on the structure, composition and electromagnetic properties of the nanocomposites has been studied. By XRD was shown that the formation of the FeCoCu ternary nanoparticles occurs due to the interaction of Fe3С with the nanoparticles of the CoCu solid solution. An increase in the synthesis temperature leads to an increase in the size of the metal nanoparticles due to their agglomeration and coalescence as a result of matrix reconstruction. Furthermore, ternary alloy nanoparticles having a variable composition may form depending on the synthesis temperature and the content ratio of the metals. Raman spectroscopy has shown that the crystallinity of the carbon matrix of the nanocomposites increases with the synthesis temperature. The frequency responses of the relative permittivity and permeability of the nanocomposites have been studied at 3–13 GHz. It has been shown that a change in the content ratio of the metals noticeably increases both the dielectric and the magnetic losses. The former loss is caused by the formation of a complex nanostructure of the nanocomposite carbon matrix while the latter one originates from an increase in the size of the nanoparticles and a shift of the natural ferromagnetic resonance frequency to the low-frequency region. The reflection loss has been calculated using a standard method from the experimental data on the frequency responses of the relative permittivity and permeability. It has been shown that the frequency range and the absorption of electromagnetic waves (from –20 to –52 dB) can be controlled by varying the content ratio of the metals in the precursor. The nanocomposites obtained as a result of the experiment deliver better results in comparison with FeCo/C nanocomposites synthesized under similar conditions.

Study of the radar absorption of metal-carbon nanocomposites (review)

Development of the technology for the synthesis of magnetic nanoparticles of metals and alloys has opened up the possibility of their use in the field of radar-absorbing materials (RAM). The results of studying the properties of nanocomposites, method for the synthesis of metal-carbon nanocomposites by pyrolysis using infrared heating are reviewed. The magnetic, electromagnetic, and radar-absorbing properties of the obtained nanocomposites depending on the synthesis temperature and metal concentration were studied. It is shown that the chosen metals, alloys (FeCo) and carbon material are effective for isolating magnetic nanoparticles when developing hybrid radar-absorbing composites. Moreover, methods for controlling the radar-absorbing properties of hybrid composites and the prospects for improving the impedance matching are considered. An analysis of the efficiency of absorption of electromagnetic radiation by FeCo/C nanocomposites synthesized by different methods is presented. The possibility of controlling the morphology and properties of metal-carbon nanocomposites using certain approaches to synthesis, varying the compositions of precursors, and the orientation of FeCo nanoparticles synthesized in the form of flakes in the composite has been revealed. The results of the study can be used to improve the technique of using FeCo/C nanocomposites obtained by pyrolysis of organometallic precursors based on polyacrylonitrile in the field of radar-absorbing materials.

Effect of alkaline activation on the structural characteristics of nanocomposites based on carbonized chitosan and Fe-Co bimetallic nanoparticles

Metal-carbon nanocomposites consisting of Fe-Co bimetallic nanoparticles uniformly dispersed in the carbon matrix were synthesized by pyrolysis of a precursor based on chitosan and metal salts in the temperature range 500-800°C. The change in the structural characteristics of the samples after activation in the presence of potassium hydroxide was studied. It was found that alkaline activation leads to an increase in the specific surface area of the nanocomposites up to 700 m2/g and in the size of metal nanoparticles, whereas the phase composition and morphology of the carbon support remain unchanged.

Conversion of polyethylene terephthalate waste in the presence of cobalt compound into highly-porous metal-carbon nanocomposite (c-PET-Co)

A method for conversion of polyethylene terephthalate (PET) waste into cobalt-carbon nanocomposites is proposed. The main feature of the procedure is the simultaneous formation of highly porous PET-derived carbon support and cobalt nanoparticles. Pyrolysis of a joint precursor obtained by mixing the three main components (PET, cobalt nitrate and KOH) in dimethyl sulfoxide results in the formation of a metal-carbon nanocomposite. The effect of the amount of KOH introduced on the structural properties of nanocomposites has been studied. It was shown that the weight ratio of PET:KOH affects both the porous characteristics of the material and the size of the cobalt nanoparticles. Also, the amount of alkali affects the yield of nanocomposite, both the yield of carbon residue, increasing it from 11.6 to 20.7 wt%, and the content of metal in the composite, which was in the range of 18.5–28.4 wt%.

Cobalt phthalocyanine-derived Co–C@C porous composites for tunable electromagnetic absorption

The metal-carbon nanocomposites are widely applied to electromagnetic wave (EMW) absorption due to their good impedance matching characteristics and multiple attenuation mechanisms. Here, the cobalt@carbon (Co–C@C) composites with the porous tubular structure were prepared by calcining the polydopamine (PDA) coated porphyrin derivative cobalt phthalocyanine (CoPc). The heating temperature has a significant effect on the morphology, porosity, magnetization intensity, and EMW absorption performance. These results show that Co–C@C composites after heat treatment temperature at 800 °C have the best EMW absorption performance because of their large specific surface area, abundant mesopores and macropores, and high magnetization. Meanwhile, the Co–N bond could generate at the surface of cobalt nanoparticles, resulting in an interfacial effect and enhancing polarization loss. The minimum reflection loss (RLmin) is −47.36 dB at 12.76 GHz and the effective absorption bandwidth (EAB) is 5 GHz. In addition, Co–C@C composites can be used as tunable EMW absorbers with superior performance.

Mesoporous Ce–Fe–Ni nanocomposites encapsulated in carbon-nanofibers: Synthesis, characterization and catalytic behavior in oxygen evolution reaction

Ceria-iron oxide mesoporous materials with Fe:Ce molar ratio of 5:5 and 9:1 were synthesized by hydrothermal method using CTAB as a template and subsequently modified with NiO (molar ratio Ni:Fe = 1:2) by incipient wetness impregnation technique. In order to increase the electro-capacitive properties and reduce the intrinsic impedance of the metal oxides, the samples were consecutively modified by reduction in hydrogen to obtain highly dispersed Ni–Fe alloys into ceria matrix. By exploiting the high permeability of carbon inside ferrous alloys, the metal phase has been further modified into ferrous carbides and metal alloys encapsulated within carbon nanofibers. For this purpose, a reaction, already widely studied for the production of hydrogen, was used, that is the decomposition of methanol vapors. In fact, this decomposition, in addition to producing syn-gas and methane, changes the catalysts in use through a chemical vapor deposition-carbon coating process. This fact, has been used by us to demonstrate how the newly obtained metal-carbon nanocomposites can be used for electro-catalytic purposes. The modified phases of the two molar ratios of the Fe–Ni–Ce catalysts were tested in the Oxygen Evolution Reaction (OER) in an alkaline environment (1 M KOH), showing a satisfactory and progressive increase in activity and a surprising decrease in the overpotential at 10 mA/cm2 of current density. The morphological, textural and physicochemical properties of the samples were characterized in details by XRD, N2-physisorption, TG-TPO, TEM, EDX, FTIR, XPS, Raman and Moessbauer spectroscopies.

Metal-organic aerogel derived hierarchical porous metal-carbon nanocomposites as efficient bifunctional electrocatalysts for overall water splitting

An efficient strategy to construct non-noble metal-base electrocatalysts for water splitting is the direct carbonization of metal–organic aerogel composites. Herein for the first time, a novel tube-like metal–carbon nanocomposite with encapsulated small-size individual Fe, Cr and Ni nanoparticles, is prepared by the carbonization of a FeCr-doped Ni-benzenetricarboxylate aerogel. The slender skeleton of the aerogel, supercritical drying and Cr doping alleviates metal aggregation and facilitates the in-situ growth of carbon tubes. This nanocomposite exhibits remarkably low overpotential of the hydrogen evolution reaction (137 mV) and oxygen evolution reaction (220 mV). Further, the cell voltage could be as low as 1.54 V with the current density of 10 mA cm−2 and illustrates excellent stability under a continuous operation for 50 h. This non-noble metal-base electrocatalyst is comparable to noble metal-based electrocatalysts and the impressive performance is ascribed to the abundant active catalytic sites and short reactant diffusion pathways. This work demonstrates great capability of aerogel derivation in the highly active electrocatalyst design for promising electrochemical applications.

Novel synthesis of Cu-HAP/SiO2@carbon nanocomposites as heterogeneous catalysts for Fenton-like oxidation of 2,4-DCP

Hydroxyapatite (HAP) has stable ion exchange capacity and is a potential environmental catalyst carrier. In this paper, a novel metal–carbon nanocomposite (Cu-HAP/SiO2@carbon) was synthesized as a catalyst to remove 2,4-DCP. The SEM, XRD, FT-IR, XPS and BET were used to characterize the synthesized catalyst materials, the results showed that Cu-HAP/SiO2@carbon has a rich pore structure and a high specific surface area, and the copper element is well dispersed on the surface of the carrier. The results of 2,4-DCP removal effect showed that almost 100 % of 2,4-DCP was removed under the optimal reaction conditions. In addition, the Cu-HAP/SiO2@carbon broaden the applicable pH range and has excellent performance in terms of reusability (93.73 % of removal rate after 5 cycles). Finally, based on the intermediate products identify by HPLC, the degradation mechanism and possible degradation pathway of 2,4-DCP was investigated, EPR was employed to confirm the effects of ·OH.

Synthesis, structure and electromagnetic properties of FeCoAl/C nanocomposites

Magnetic nanoparticles play an important role in rapidly developing advanced branches of science and industry, e.g. fabrication of magnetic storage media, synthesis of ferromagnetic liquids, medicine and chemistry. One problem faced in the usage of magnetic nanoparticles is their high chemical activity leading to oxidation in air and agglomeration. The chemical activity of magnetic nanoparticles stems from the contribution of their large specific surface to volume ratio. Carbon coating of nanoparticles reduces the interaction between nanoparticles. FeCoAl/C metal-carbon nanocomposites have been synthesized using IR pyrolysis of polymer / metal salt precursors. The effect of synthesis temperature (IR heating) in the range from 500 to 700 °C on the structure and composition of the nanomaterials has been studied. We show that the forming particles are the FeCoAl ternary solid solution with a FeCo based bcc lattice. An increase in the synthesis temperature from 500 to 700 °C leads to an increase in the coherent scattering region of three-component nanoparticles from 5 to 19 nm. An increase in the aluminum content from 20 to 30 % relative to Fe and Co results in an increase in the size of the nanoparticles to 15 nm but this also entails the formation of a Co based solid solution having an fcc lattice. An increase in the nanocomposite synthesis temperature and a growth of the relative Al content as a result of a more complete carbonization and the structure-building effect of metals reduce the degree of amorphousness of the nanocomposite carbon matrix and lead to the formation of graphite-like phase crystallites having an ordered structure. The effect of synthesis temperature and relative content of metals on the electromagnetic properties (complex dielectric and magnetic permeability) of the synthesized nanocomposites has been studied. Synthesis conditions affect the radio absorption properties of the nanocomposites, e.g. reflection loss (RL) in the 3—13 GHz range.

Synthesis, structure and electromagnetic properties of FeCoAl/C nanocomposites

Magnetic nanoparticles play an important role in rapidly developing advanced branches of science and industry, e.g. fabrication of magnetic storage media, synthesis of ferromagnetic liquids, medicine and chemistry. One problem faced in the usage of magnetic nanoparticles is their high chemical activity leading to oxidation in air and agglomeration. The chemical activity of magnetic nanoparticles stems from the contribution of their large specific surface to volume ratio. Carbon coating of nanoparticles reduces the interaction between nanoparticles. FeCoAl/C metal-carbon nanocomposites have been synthesized using IR pyrolysis of polymer/metal salt precursors. The effect of synthesis temperature (IR heating) in the range from 500 to 700 °C on the structure and composition of the nanomaterials has been studied. We show that the forming particles are the FeCoAl ternary solid solution with a FeCo based bcc lattice. An increase in the synthesis temperature from 500 to 700 °C leads to an increase in the coherent scattering region of three-component nanoparticles from 5 to 19 nm. An increase in the aluminum content from 20 to 30% relative to Fe and Co results in an increase in the size of the nanoparticles to 15 nm but this also entails the formation of a Co based solid solution having an fcc lattice. An increase in the nanocomposite synthesis temperature and a growth of the relative Al content as a result of a more complete carbonization and the structure-building effect of metals reduce the degree of amorphousness of the nanocomposite carbon matrix and lead to the formation of graphite-like phase crystallites having an ordered structure. The effect of synthesis temperature and relative content of metals on the electromagnetic properties (complex permittivity and permeability) of the synthesized nanocomposites has been studied. Synthesis conditions affect the radio absorption properties of the nanocomposites, e.g. reflection loss (RL) in the 3–13 GHz range.

Nanocomposites FeCoNi/C based on polyvinyl alcohol: synthesis and electromagnetic properties

Triple FeCoNi nanoparticles distributed and stabilized in the carbon matrix of FeCoNi/C metal-carbon nanocomposites were synthesized. The synthesis of nanocomposites was carried out by controlled IR pyrolysis of precursors of the "polymer-metal nitrates" type, obtained by joint dissolution of the components with subsequent removal of the solvent. The effect of the synthesis temperature on the structure, composition, and electromagnetic properties of nanocomposites has been studied. It was shown by XRD that the formation of ternary FeCoNi nanoparticles occurs through the dissolution of Fe in the nanoparticles of the NiCo solid solution. With an increase in the synthesis temperature, the size of metal nanoparticles increases, which is determined by the processes of their agglomeration and coalescence during matrix rearrangement. Also, depending on the synthesis temperature, nanoparticles of a ternary alloy with different compositions can be formed, and the ratio of metals specified in the precursor is achieved at 700 °C. By Raman spectroscopy was shown that, with an increase in the synthesis temperature, the degree of crystallinity of the carbon matrix of nanocomposites increases, and graphene structures consisting of several layers can be formed. The frequency dependences of the relative complex dielectric and magnetic permeabilities of nanocomposites in the range of 3–13 GHz were studied. It is shown that an increase in the synthesis temperature causes a significant increase in both dielectric and magnetic losses (~ 2 times). The former are associated with the formation of a complex nanostructure of the carbon matrix of the nanocomposite, while the latter are determined by an increase in the size of nanoparticles and a shift of the EFMR frequency to the low-frequency region. Reflection loss (RL) calculations were performed according to the standard procedure based on experimental data of the frequency dependences of the complex magnetic and dielectric permittivity. It was shown that control of the frequency range and absorption value of electromagnetic waves (from 50 to 94%) can be carried out by changing the temperature of synthesis of nanocomposites.

Effect of the Temperature of Preliminary Treatment on the Structural Characteristics of Highly Porous Iron-Containing Metal–Carbon Nanocomposites during Their Production

An approach to the synthesis of metal-carbon nanocomposites, comprising iron-containing nanoparticles distributed in a highly porous carbon support based on pyrolyzed polyacrylonitrile, has been developed. It is shown that metal nanoparticles form in situ during pyrolysis of the polymer and the formation of a porous carbon matrix. Features of the formation of iron-containing particles are investigated, depending on the temperature of preliminary treatment (200, 500, and 800°C) and on the final temperature of synthesis, which varied from 500 to 900°C. The change in the specific surface area of the carbon support is shown, depending on the conditions of preparation. The formation of phases α-Fe, γ-Fe, and KFeO2 is observed in addition to that of iron carbide nanoparticles.