scholarly journals Three-dimensional Co 3 O 4 @MWNTs nanocomposite with enhanced electrochemical performance for nonenzymatic glucose biosensors and biofuel cells

2017 ◽  
Vol 4 (12) ◽  
pp. 170991 ◽  
Author(s):  
Kailong Jiao ◽  
Yu Jiang ◽  
Zepeng Kang ◽  
Ruiyun Peng ◽  
Shuqiang Jiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Glucose Oxidation ◽  
Low Cost ◽  
Three Dimensional ◽  
Open Circuit ◽  
Strongly Coupled ◽  
X Ray ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Three-dimensional nanoarchitectures of Co 3 O 4 @multi-walled carbon nanotubes (Co 3 O 4 @MWNTs) were synthesized via a one-step process with hydrothermal growth of Co 3 O 4 nanoparticles onto MWNTs. The structure and morphology of the Co 3 O 4 @MWNTs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, scanning electron microscopy and transmission electron microscopy. The electrocatalytic mechanism of the Co 3 O 4 @MWNTs was studied by X-ray photoelectron spectroscopy and cyclic voltammetry. Co 3 O 4 @MWNTs exhibited high electrocatalytic activity towards glucose oxidation in alkaline medium and could be used in nonenzymatic electrochemical devices for glucose oxidation. The open circuit voltage of the nonenzymatic glucose/O 2 fuel cell was 0.68 V, with a maximum power density of 0.22 mW cm −2 at 0.30 V. The excellent electrochemical properties, low cost, and facile preparation of Co 3 O 4 @MWNTs demonstrate the potential of strongly coupled oxide/nanocarbon hybrid as effective electrocatalyst in glucose fuel cells and biosensors.

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 Synthesis of Three-Dimensional Fe3O4/Graphene Aerogels for the Removal of Arsenic Ions from Water

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Ye ◽  
Da Yin ◽  
Bin Wang ◽  
Qingwen Zhang
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
3D Structure ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Aerogels ◽  
Transmission Electron ◽  
Potential Applications ◽  
Removal Of Arsenic

We report the synthesis of three-dimensional Fe3O4/graphene aerogels (GAs) and their application for the removal of arsenic (As) ions from water. The morphology and properties of Fe3O4/GAs have been characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and superconducting quantum inference device. The 3D nanostructure shows that iron oxide nanoparticles are decorated on graphene with an interconnected network structure. It is found that Fe3O4/GAs own a capacity of As(V) ions adsorption up to 40.048 mg/g due to their remarkable 3D structure and existence of magnetic Fe3O4nanoparticles for separation. The adsorption isotherm matches well with the Langmuir model and kinetic analysis suggests that the adsorption process is pseudo-second-ordered. In addition to the excellent adsorption capability, Fe3O4/GAs can be easily and effectively separated from water, indicating potential applications in water treatment.

Ni/MWCNT-Supported Palladium Nanoparticles as Magnetic Catalysts for Selective Oxidation of Benzyl Alcohol

2013 ◽  
Vol 66 (5) ◽  
pp. 564 ◽  
Author(s):  
Mingmei Zhang ◽  
Qian Sun ◽  
Zaoxue Yan ◽  
Junjie Jing ◽  
Wei Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Benzyl Alcohol ◽  
Bimetallic Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Oxidation Of Benzyl Alcohol ◽  
Uniform Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Well dispersed Pd@Ni bimetallic nanoparticles on multi-walled carbon nanotubes (Pd@Ni/MWCNT) are prepared and used as catalysts for the oxidation of benzyl alcohol. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy analysis, and X-ray diffraction were performed to characterise the synthesised catalyst. The results show a uniform dispersion of Pd@Ni nanoparticles on MWCNT with an average particle size of 4.0 nm. The as synthesised catalyst was applied to the oxidation of benzyl alcohol. A 99 % conversion of benzyl alcohol and a 98 % selectivity of benzaldehyde were achieved by using the Pd@Ni/MWCNT (Pd: 0.2 mmol) catalyst with water as a solvent and H2O2 as oxidant at 80°C. The catalytic activity of Pd@Ni/MWCNT towards benzyl alcohol is higher than that of a Pd/MWCNT catalyst at the same Pd loadings. The catalyst can be easily separated due to its magnetic properties.

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.

scholarly journals Incorporating N Atoms into SnO2 Nanostructure as an Approach to Enhance Gas Sensing Property for Acetone

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 445 ◽  
Author(s):  
Xiangfeng Guan ◽  
Yongjing Wang ◽  
Peihui Luo ◽  
Yunlong Yu ◽  
Dagui Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Gas Sensing ◽  
Diffuse Reflectance Spectroscopy ◽  
Limit Of Detection ◽  
Low Cost ◽  
X Ray ◽  
Sno2 Nanostructure

The development of high-performance acetone gas sensor is of great significance for environmental protection and personal safety. SnO2 has been intensively applied in chemical sensing areas, because of its low cost, high mobility of electrons, and good chemical stability. Herein, we incorporated nitrogen atoms into the SnO2 nanostructure by simple solvothermal and subsequent calcination to improve gas sensing property for acetone. The crystallization, morphology, element composition, and microstructure of as-prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Electron paramagnetic resonance (EPR), Raman spectroscopy, UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and the Brunauer–Emmett–Teller (BET) method. It has been found that N-incorporating resulted in decreased crystallite size, reduced band-gap width, increased surface oxygen vacancies, enlarged surface area, and narrowed pore size distribution. When evaluated as gas sensor, nitrogen-incorporated SnO2 nanostructure exhibited excellent sensitivity for acetone gas at the optimal operating temperature of 300 °C with high sensor response (Rair/Rgas − 1 = 357) and low limit of detection (7 ppb). The nitrogen-incorporated SnO2 gas sensor shows a good selectivity to acetone in the interfering gases of benzene, toluene, ethylbenzene, hydrogen, and methane. Furthermore, the possible gas-sensing mechanism of N-incorporated SnO2 toward acetone has been carefully discussed.

scholarly journals LignoPhot: Photoactive Hybrid lignin/Bi4O5Br2/BiOBr Composite for Complex Pollutants Removal

2021 ◽  
Author(s):  
Tetyana Budnyak ◽  
Joy Onwumere ◽  
Ievgen V. Pylypchuk ◽  
Aleksander Jaworski ◽  
Jianhong Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Dye Degradation ◽  
Low Cost ◽  
Resonance Spectroscopy ◽  
Hydrolysis Lignin ◽  
X Ray ◽  
Main Component

Valorization of lignin is still an open question and lignin has therefore remained an underutilized biomaterial. This situation is even more pronounced for hydrolysis lignin, which is characterized by a highly condensed and excessively cross-linked structure. We report on photoactive lignin/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr bio-inorganic composites consisting of a lignin substrate that is coated by Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr nanosheet photocatalysts. The structure of the hybrid material was investigated by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy including energy dispersive X-ray (EDX) spectroscopy, and solid state <sup>1</sup>H−<sup>13</sup>C nuclear magnetic resonance spectroscopy (<sup>1</sup>H−<sup>13</sup>C NMR). The material contains 18.9% of Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr and was found to be effective for the photocatalytic degradation of cationic methylene blue (MB) and zwitterionic rhodamine B (RhB) dyes under irradiation with 405 nm light. Lignin/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr was able to decrease the dye concentration from 80 mg·L<sup>–1</sup> to 12.3 mg·L<sup>–1</sup> for RhB (85%) and from 80 mg·L<sup>–1</sup> to 4.4 mg·L<sup>–1</sup> for MB (95%). Complementary to the dye degradation, the lignin as a main component of the composite, was found to be efficient and rapid biosorbent for metal ions in aqueous solutions. The highest adsorption capacity was found after 2 hours of phases contact and reached 0.45 mmol·g<sup>–1 </sup>for Ni(II) ions (neutral media). The low cost, simplicity of the synthesis, good stability and ability to simultaneously photooxidize organic dyes and to adsorb metal ions, make the developed photoactive lignin/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr composite a prospective material for textile wastewaters remediation

Carbon nanotubes and metalloporphyrins and metallophthalocyanines-based materials for electroanalysis

2012 ◽  
Vol 16 (07n08) ◽  
pp. 713-740 ◽  
Author(s):  
José H. Zagal ◽  
Sophie Griveau ◽  
Mireya Santander-Nelli ◽  
Silvia Gutierrez Granados ◽  
Fethi Bedioui
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Hybrid Materials ◽  
Photoelectron Spectroscopy ◽  
State Of The Art ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Walled Carbon Nanotubes

We discuss here the state of the art on hybrid materials made from single (SWCNT) or multi (MWCNT) walled carbon nanotubes and MN4complexes such as metalloporphyrins and metallophthalocyanines. The hybrid materials have been characterized by several methods such as cyclic voltammetry (CV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electrochemical microscropy (SECM). The materials are employed for electrocatalysis of reactions such as oxygen and hydrogen peroxide reduction, nitric oxide oxidation, oxidation of thiols and other pollutants.

Microstructural of Cr/MWCNT Composites and its Catalysis in Synthesis of Biodiesel

2012 ◽  
Vol 455-456 ◽  
pp. 1053-1059
Author(s):  
Xue Hai Fan ◽  
Guo Min Xiao
Keyword(s):  
Electron Microscopy ◽  
Potassium Dichromate ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Ft Ir ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWCNTs), potassium dichromate (K2Cr2O7) and sulphuric acid were used for the preparation of Cr/MWCNT composite by impregnation method. The composites were comprehensively characterized by transmission electron microscopy （TEM），energy dispersive X-ray analysis (EDX), infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermal gravity analysis (TGA). Due to its unique electrical and structural properties, this composite was applied to the synthesis of biodiesel (FAME) as a catalyst, showing effectively catalytic performance.

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.

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