scholarly journals Catalytic activity of CuxMnxFe3-2xO4/multi-walled carbon nanotubes (0 ≤ x ≤ 0.1) nanocomposites for p-nitrophenol degradation in catalyst/H2O2 system

2019 ◽  
Vol 79 (12) ◽  
pp. 2345-2356
Author(s):  
Jiye Yu ◽  
Xiaojun Tian ◽  
Mingwang Liu ◽  
Zhenzhen Jia ◽  
Hongqin Fang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Cod Removal ◽  
Precipitation Method ◽  
Heterogeneous Fenton ◽  
Removal Rates ◽  
X Ray ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Mn Doped

Abstract Heterogeneous Fenton oxidation has become a very important wastewater-treatment method and its catalyst is crucial for good treatment effect. In order to improve the catalytic properties, the Cu and Mn elements were doped for CuxMnxFe3-2xO4/multi-walled carbon nanotubes (CuxMnxFe3-2xO4/MWCNTs) nanocomposites (0 ≤ x ≤ 0.1) by co-precipitation method. The structure, morphology and surface properties of the nanocomposites were characterized by X-ray powder diffractometer (XRD), N2-physisorption analysis, transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). The CuxMnxFe3-2xO4/MWCNTs nanocomposites were used as heterogeneous Fenton catalysts for p-nitrophenol (p-NP) degradation. The catalytic performances of the Cu and/or Mn doped nanocomposites have remarkable improvement compared with Fe3O4/MWCNTs nanocomposite, especially for both Cu and Mn doped catalyst. For CuxMnxFe3-2xO4/MWCNTs nanocomposites, the catalytic performance increases with increasing x value and reaches a maximum at 0.075 of x value. At optimal condition, the p-NP conversion rate reaches 96.4% in 10 min for Cu0.075Mn0.075Fe2.85O4/MWCNTs nanocomposite. However, the mentioned rate for Fe3O4/MWCNTs catalyst is only 14.5%. The chemical oxygen demand (COD) removal rates in 120 min for Cu0.075Mn0.075Fe2.85O4/MWCNTs and Fe3O4/MWCNTs catalysts are 82.7% and 67.3%, respectively. Furthermore, the p-NP conversion and COD removal rates of Cu0.075Mn0.075Fe2.85O4/MWCNTs nanocomposite still keep at 94.4% and 70.3% after five-time reuse, respectively. This catalyst shows good reusability for p-NP degradation and is very easy to recover from the treated water.

Synthesis and Characteristics of Hierarchical Nanostructure Fe3O4 Coated Multi-Walled Carbon Nanotubes

2014 ◽  
Vol 926-930 ◽  
pp. 258-261
Author(s):  
Jing Heng Deng ◽  
Kan Ping Yu ◽  
Jian Guo Xie
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Solvothermal Process ◽  
X Ray ◽  
Hierarchical Nanostructure ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Hierarchical nanostructure Fe3O4/multi-walled carbon nanotubes (Fe3O4/MWCNTs) were prepared by solvothermal process using acid treated MWCNTs and iron acetylacetonate in ethylene glycol as reduction reagent. The materials were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET). The results showed that petal-like hierarchical Fe3O4 grew on MWCNTs and the Fe3O4 nanoparticles had diameters in the range of 55-110 nm. It was a facile approach to grow hierarchical nanoFe3O4.

scholarly journals Combining Carbon Nanotubes and Chitosan for the Vectorization of Methotrexate to Lung Cancer Cells

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2889 ◽  
Author(s):  
Giuseppe Cirillo ◽  
Orazio Vittorio ◽  
David Kunhardt ◽  
Emanuele Valli ◽  
Florida Voli ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Ph Responsive ◽  
Carbon Nanostructure ◽  
X Ray ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Responsive Behavior ◽  
Walled Carbon Nanotubes

A hybrid system composed of multi-walled carbon nanotubes coated with chitosan was proposed as a pH-responsive carrier for the vectorization of methotrexate to lung cancer. The effective coating of the carbon nanostructure by chitosan, quantified (20% by weight) by thermogravimetric analysis, was assessed by combined scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy (N1s signal), respectively. Furthermore, Raman spectroscopy was used to characterize the interaction between polysaccharide and carbon counterparts. Methotrexate was physically loaded onto the nanohybrid and the release profiles showed a pH-responsive behavior with higher and faster release in acidic (pH 5.0) vs. neutral (pH 7.4) environments. Empty nanoparticles were found to be highly biocompatible in either healthy (MRC-5) or cancerous (H1299) cells, with the nanocarrier being effective in reducing the drug toxicity on MRC-5 while enhancing the anticancer activity on H1299.

Deposition of Titania Nanoparticles on the Surface of Acid Treated Multiwalled Carbon Nanotubes

2010 ◽  
Vol 117 ◽  
pp. 27-32
Author(s):  
Sabita Shrestha ◽  
Chong Yun Park
Keyword(s):  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Decomposition Temperature ◽  
Titania Nanoparticles ◽  
Multiwalled Carbon ◽  
Chemical Route ◽  
X Ray ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Titanium dioxide (Titania, TiO2) nanoparticles have been deposited on the surface of acid treated multi-walled carbon nanotubes (MWCNTs) by simple chemical route. The resultant TiO2/MWCNTs composites were characterized by different techniques. The oxidation of MWCNTs and presence of titania nanoparticles on the surface of MWCNTs is confirmed by transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. TEM image shows the size of titania nanoparticles are around 5 nm. Raman spectroscopy showed the oxidation and functionalization of nanotubes. The TGA curve showed decrease in thermal decomposition temperature of MWCNTs after oxidation and attachment with titania nanoparticles.

scholarly journals Selective Oxidation of Cinnamyl Alcohol to Cinnamaldehyde over Functionalized Multi-Walled Carbon Nanotubes Supported Silver-Cobalt Nanoparticles

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 863
Author(s):  
Zahoor Iqbal ◽  
Muhammad Sufaid Khan ◽  
Rozina Khattak ◽  
Tausif Iqbal ◽  
Ivar Zekker ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Selective Oxidation ◽  
Bimetallic Catalyst ◽  
Precipitation Method ◽  
Cinnamyl Alcohol ◽  
X Ray ◽  
Multi Walled Carbon Nanotubes ◽  
Co Precipitation ◽  
Traditional Approaches ◽  
Walled Carbon Nanotubes

The selective oxidation of alcohols to aldehydes has attracted a lot of attention because of its potential use in agrochemicals, fragrances, and fine chemicals. However, due to homogenous catalysis, low yield, low selectivity, and hazardous oxidants, traditional approaches have lost their efficiency. The co-precipitation method was used to synthesize the silver-cobalt bimetallic catalyst supported on functionalized multi-walled carbon nanotubes (Ag-Co/S). Brunauer Emmet Teller (BET), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and X-ray diffraction (XRD) were used to characterize the catalyst. For the oxidation of cinnamyl alcohol (CA) with O2 as an oxidant, the catalyst’s selectivity and activity were investigated. The impacts of several parameters on catalyst’s selectivity and activity, such as time, temperature, solvents, catalyst dosage, and stirring speed, were comprehensively studied. The results revealed that in the presence of Ag-Co/S as a catalyst, O2 could be employed as an effective oxidant for the catalytic oxidation of cinnamyl alcohol to cinnamaldehyde (CD) with 99% selectivity and 90% conversion. In terms of cost effectiveness, catalytic activity, selectivity, and recyclability, Ag-Co/S outperforms the competition. As a result, under the green chemistry methodology, it can be utilized as an effective catalyst for the conversion of CA to CD.

scholarly journals Polycondensation of Hexamethylenetetramine in Anhydrous Acid Media as a New Approach to Carbyne-Like Materials and Its Application as Dispersant of Carbon Materials

2019 ◽  
Vol 5 (3) ◽  
pp. 54
Author(s):  
Alyona V. Gerasimova ◽  
Olga V. Alekhina ◽  
Leticia García-Cruz ◽  
Jesús Iniesta ◽  
Alexander V. Melezhik ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Spectral Properties ◽  
High Performance ◽  
Carbon Materials ◽  
Acid Media ◽  
New Approach ◽  
X Ray ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Aminocumulene (AC), a technical name that results from the hexamethylenetetramine polycondensation in anhydrous sulfuric acid, was successfully performed toward the synthesis of oligomeric cumulenic compounds made up of carbyne-like (=C=C)x fragments as a main moiety together with amino endcapping groups. The tentative mechanism for the synthesis of the soluble and insoluble AC likely included the participation of carbene species as an intermediate. Spectral properties obtained from UV-Vis, infrared, and Raman spectroscopies, and surface chemistry analysis through X-ray photoelectron spectroscopy of the soluble AC confirmed the presence of a mixture of linear and branched aminocumulene-based oligomers. AC displayed high performance as a dispersant and stabilizer agent of both multi-walled carbon nanotubes and graphene in aqueous solutions after powerful insonation treatment under controlled temperature compared to the most commonly used dispersant agents. Thereby, AC is vitally important for the preparation of carbonaceous materials based on nanoinks in a wide variety of fields.

Role of chemical funcionalization of carbon nanoparticles in epoxy matrices

2017 ◽  
Vol 52 (4) ◽  
pp. 449-464 ◽  
Author(s):  
Roger H Bello ◽  
Luiz AF Coelho ◽  
Daniela Becker
Keyword(s):  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Modulus Of Elasticity ◽  
Graphene Nanoplatelets ◽  
Neat Resin ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The effects of the silanization of multi-walled carbon nanotubes and graphene nanoplatelets with 3-APTES on thermal, mechanical and electrical properties of epoxy nanocomposites were investigated. Nanocomposites containing pristine, oxidized and silanized nanoparticles of multi-walled carbon nanotubes or graphene nanoplatelets at two different concentrations (0.15 and 0.50 vol.%) were prepared by in situ polymerization without using solvents. The functionalized nanoparticles were characterized by Fourier-transform infrared, X-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscope techniques. The oxidation and the silanization on the surface of both nanoparticles were confirmed by Fourier-transform infrared, X-ray photoelectron spectroscopy, Raman and transmission electron microscope analysis. The thermal properties of all studied materials were analyzed by differential scanning calorimetry and the mechanical properties by nanoindentation. The addition of both nanoparticles (pristine and functionalized) into the matrix did not show significant variations on thermal properties, but decreased values for glass transition temperature (Tg) compared to the neat resin. Higher values for modulus of elasticity and hardness of epoxy/nanocomposites were obtained when silanized multi-walled carbon nanotubes or oxidized graphene nanoplatelets were added into the matrix. Adding 0.15 vol.% of silanized multi-walled carbon nanotubes the modulus of elasticity increased in approximately 60%, whereas 0.50 vol.% this increase was greater than 90% compared to the neat resin. While adding 0.15 vol.% of oxidized graphene nanoplatelets, the modulus of elasticity increased approximately 83%, whereas 0.50 vol.% this increase was greater than 88% compared to the neat resin. The formation of percolating networks has been achieved only by pristine multi-walled carbon nanotubes addition at a concentration of 0.50 vol.% and by silanized graphene nanoplatelets at a concentration of 0.15 vol.%. However, for both carbon-based nanoparticles conductivities on the order of 10−7 S/m for frequencies near 100 Hz were observed.

scholarly journals X-ray Photoelectron Spectroscopy Study of Cobalt Supported Multi-walled Carbon Nanotubes Prepared by Different Precursors

2007 ◽  
Vol 8 (2) ◽  
pp. 120-126 ◽  
Author(s):  
Jeong-Min Lee ◽  
Ju-Wan Kim ◽  
Ji-Sun Lim ◽  
Tae-Jin Kim ◽  
Shin-Dong Kim ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Spectroscopy Study ◽  
X Ray ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Removal of Pb(II) and Cu(II) from aqueous solution using multiwalled carbon nanotubes/iron oxide magnetic composites

2011 ◽  
Vol 63 (5) ◽  
pp. 917-923 ◽  
Author(s):  
Jun Hu ◽  
Donglin Zhao ◽  
Xiangke Wang
Keyword(s):  
Carbon Nanotubes ◽  
Iron Oxide ◽  
Multiwalled Carbon Nanotubes ◽  
Sorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Precipitation Method ◽  
Multiwalled Carbon ◽  
Magnetic Composites ◽  
X Ray

Multiwalled carbon nanotubes (MWCNTs)/iron oxide magnetic composites (named as MCs) were prepared by co-precipitation method, and were characterised by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) in detail. The prepared MCs were employed as an adsorbent for the removal of Pb(II) and Cu(II) ions from wastewater in heavy metal ion pollution cleanup. The results demonstrated that the sorption of Pb(II) and Cu(II) ions was strongly dependent on pH and temperature. The experimental data were well described by Langmuir model, and the monolayer sorption capacity of MCs was found to vary from 10.02 to 31.25 mg/g for Pb(II) and from 3.11 to 8.92 mg/g for Cu(II) at temperature increasing from 293.15 to 353.15 K at pH 5.50. The sorption capacity of Pb(II) on MCs was higher than that of Cu(II), which was attributed to their ionic radius, hydration energies and hydrolysis of their hydroxides. The thermodynamic parameters (i.e., ΔH0, ΔS0 and ΔG0) were calculated from temperature dependent sorption isotherms, and the results indicated that the sorption of Pb(II) and Cu(II) ions on MCs were spontaneous and endothermic processes.

scholarly journals Synthesis and Cytotoxicity of POSS Modified Single Walled Carbon Nanotubes

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yuhua Xue ◽  
Hao Chen
Keyword(s):  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Single Walled Carbon Nanotubes ◽  
X Ray ◽  
Single Walled Carbon ◽  
Amine Functionalized ◽  
Low Toxicity ◽  
Organic Solutions ◽  
Oligomeric Silsesquioxane ◽  
Walled Carbon Nanotubes

Single walled carbon nanotubes (SWNTs) decorated with polyhedral oligomeric silsesquioxane (POSS) were synthesized via the amide linkages between the acid treated SWNTs and amine-functionalized POSS. The successful modification of SWNTs with POSS was confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and UV-Vis spectra. The resulting SWNTs-POSS can be dispersed in both water and organic solutions. The biocompatibility and cytotoxicity of the SWNTs and SWNTs-POSS were evaluated by CCK-8 viability assays, which indicated that SWNTs-POSS exhibit very extremely low toxicity. The low toxicity of the POSS modified SWNTs leads to more opportunities for using carbon nanotubes in biomedical fields.

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