MORPHOLOGY EFFECT OF Ni–Ag/CARBON NANOMATERIALS ON THEIR ELECTROCATALYTIC ACTIVITY FOR GLUCOSE OXIDATION

2016 ◽  
Vol 23 (06) ◽  
pp. 1650059 ◽  
Author(s):  
RUIZHUO OUYANG ◽  
WEIWEI LI ◽  
YANG YANG ◽  
WANGYAO ZHANG ◽  
KAI FENG ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Surface Morphology ◽  
Active Sites ◽  
Carbon Nanomaterials ◽  
Modified Electrodes ◽  
Single Wall Carbon Nanotubes ◽  
Composite Electrodes ◽  
Ag Nps ◽  
Multi Wall Carbon Nanotubes ◽  
Ag Deposition

We presented here three carbon-nanomaterials-based modified glassy carbon electrodes (GCE) with Ni–Ag nanohybrid nanoparticles (NPs) deposited upon, including single-wall carbon nanotubes (SWCNTs), multi-wall carbon nanotubes (MWCNTs) and the mesoporous carbons (MPCs), and compared their morphology effects on both Ni–Ag deposition quality and electrocatalytic performances toward Glu oxidation. After being deposited with Ni–Ag NPs, a homogenous surface with very small Ni–Ag NPs was obtained for Ni–Ag/SWCNTs/GCE, while heterogeneous, coarse surfaces with obvious embedment with large Ni–Ag particles were observed for both Ni–Ag/MWCNTs/GCE and Ni–Ag/MPC/GCE. All three modified electrodes were well characterized in terms of surface morphology, electron transfer rate, hydrophilicity, interference resistance, stability, electrocatalytic behaviors as well as practicability in real samples, based on which Ni–Ag/SWCNTs/GCE was always proved to be more advantageous over other two composite electrodes. Such advantage of Ni–Ag/SWCNTs/GCE was attributed to its desirable surface morphology good for Ni–Ag deposition and exposure of as many active sites as possible to Glu oxidation, leading to the extraordinary electrocatalytic performance.

Fabrication of Polyaniline/Carbon Nanotubes Composites Using Carbon Nanotubes Films Obtained by Electrophoretic Deposition

2012 ◽  
Vol 507 ◽  
pp. 113-117 ◽  
Author(s):  
Luisa Pilan ◽  
Matei Raicopol ◽  
Mariana Ioniţă
Keyword(s):  
Carbon Nanotubes ◽  
Electrode Materials ◽  
Diazonium Salt ◽  
Modified Electrodes ◽  
Single Wall Carbon Nanotubes ◽  
Composite Electrodes ◽  
Electrochemically Deposited ◽  
Aniline Oxidation ◽  
Storage Properties ◽  
Diphenyl Amine

In this study, we report a facile electrochemical method to obtain polyaniline/single-wall carbon nanotubes (PANI/SWCNTs) composite electrodes by combining the electroreduction of diazonium salts and electropolymerization of conductive polymers. In a first step, the SWCNTs are covalently functionalized with diphenyl amine through the electrochemical reduction of the 4-aminodiphenylamine diazonium salt in order to provide anchors for the subsequent polymer electrodepostion. The aniline oxidation remains possible on this grafted layer and PANI can easily be deposited on the diphenyl amine-modified electrodes. The electrochemically deposited PANI/SWCNTs composites exhibit excellent electrochemical charge storage properties making them promising electrode materials for high power supercapacitors.

Environmental implications and applications of carbon nanomaterials in water treatment

2013 ◽  
Vol 67 (11) ◽  
pp. 2582-2586 ◽  
Author(s):  
S. R. Chae ◽  
E. M. Hotze ◽  
A. R. Badireddy ◽  
S. Lin ◽  
J. O. Kim ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Membrane Filtration ◽  
Photocatalytic Oxidation ◽  
Carbon Nanomaterials ◽  
New Technologies ◽  
Microbial Inactivation ◽  
Single Wall Carbon Nanotubes ◽  
Environmental Implications ◽  
Multi Wall Carbon Nanotubes ◽  
Biofilm Development

Carbon nanomaterials have been proposed as a basis for developing new technologies for photocatalytic oxidation and disinfection, improved membrane processes, adsorbents, and biofilm-resistant surfaces. This study details recent progress towards the development of these proposed applications. We explored the use of carbon nanomaterials such as fullerene C60, single-wall carbon nanotubes (SWCNTs), and multi-wall carbon nanotubes (MWCNTs) for a range of new technologies including, degradation of a probe organic compound by in situ generation of reactive oxygen species (ROS), new strategies for microbial disinfection, and the inhibition of biofilm development on membrane surfaces. The results show that the degradation of 2-chlorophenol by ROS produced microbial inactivation, and the mobility of the nanoparticle aggregates of the carbon nanomaterials all increased as suspensions were fractionated to enrich with smaller aggregates with sonication followed by successive membrane filtration.

Transient Free Convective Flow of CNT Water Nanofluid with Heat Transfer from a Moving Cylinder

2020 ◽  
Vol 10 ◽  
Author(s):  
C. Sridevi ◽  
A. Sailakumari
Keyword(s):  
Carbon Nanotubes ◽  
Heat Generation ◽  
Convective Flow ◽  
Volume Fraction ◽  
Vertical Cylinder ◽  
Single Wall Carbon Nanotubes ◽  
Free Convective Flow ◽  
Multi Wall Carbon Nanotubes ◽  
Moving Cylinder ◽  
Variable Surface

Background: In this paper, transient two-dimensional laminar boundary layer viscous incompressible free convective flow of water based nanofluid with carbon nanotubes (CNTs) past a moving vertical cylinder with variable surface temperature is studied numerically in the presence of thermal radiation and heat generation. Methods: The prevailing partial differential equations which model the flow with initial and boundary conditions are solved by implicit finite difference method of Crank Nicolson type which is unconditionally stable and convergent. Results: Influence of Grashof number (Gr), nanoparticle volume fraction ( ), heat generation parameter (Q), temperature exponent (m), radiation parameter (N) and time (t) on velocity and temperature profiles are sketched graphically and elaborated comprehensively. Conclusion: Analysis of Nusselt number and Skin friction coefficient are also discussed numerically for both single wall carbon nanotubes (SWCNTs) and multi wall carbon nanotubes (MWCNTs).

scholarly journals Application of Fractional Derivative Without Singular and Local Kernel to Enhanced Heat Transfer in CNTs Nanofluid Over an Inclined Plate

2020 ◽  
Author(s):  
Muhammad Saqib ◽  
Abdul Rahman Mohd Kasim ◽  
Nurul Farahain Mohammad ◽  
Dennis Ling Chuan Ching ◽  
Sharidan Shafie
Keyword(s):  
Heat Transfer ◽  
Carbon Nanotubes ◽  
Fractional Derivatives ◽  
Saturated Porous Medium ◽  
Convection Heat Transfer ◽  
Heat Transfer Fluid ◽  
Single Wall Carbon Nanotubes ◽  
Inclined Plate ◽  
Multi Wall Carbon Nanotubes ◽  
Laplace Transform Technique

Nanofluids are a novel class of heat transfer fluid that plays a vital role in industries. In mathematical investigations, these fluids are modeled in terms of traditional integer-order partial differential equations (PDEs). It is recognized that traditional PDEs cannot decode the complex behavior of physical flow parameters and memory effects. Therefore, this article intends to study the mixed convection heat transfer in nanofluid over an inclined vertical plate via fractional derivatives approach. The problem in hand is modeled in connection with Atangana-Baleanu fractional derivatives without singular and local kernel having strong memory. The human blood is considered as base fluid dispersing carbon nanotube (CNTs) (single-wall carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes(MWCNTs )) into it to form blood-CNTs nanofluid. The nanofluids are considered to flow in a saturated porous medium under the influence of an applied magnetic field. The exact analytical expressions for velocity and temperature profiles are acquired using the Laplace transform technique and plotted in various graphs. The empirical results indicate that the memory effect decreases with increasing fractional parameters in the case of both temperature and velocity profiles. Moreover, the temperature profile is higher for blood-SWCNTs by reason of higher thermal conductivity whereas, this trend is opposite in case of velocity profile due densities difference.

scholarly journals A Stability Analysis of Solutions in Boundary Layer Flow and Heat Transfer of Carbon Nanotubes over a Moving Plate with Slip Effect

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3243 ◽  
Author(s):  
Nur Anuar ◽  
Norfifah Bachok ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Carbon Nanotubes ◽  
Stability Analysis ◽  
Skin Friction ◽  
Single Wall Carbon Nanotubes ◽  
Slip Effect ◽  
Slip Parameter ◽  
Moving Plate ◽  
Multi Wall Carbon Nanotubes ◽  
Flow And Heat Transfer

The flow and heat transfer characteristics of both single-wall and multi-wall carbon nanotubes (CNTs) with water and kerosene as base fluid on a moving plate with slip effect are studied numerically. By employing similarity transformation, governing equations are transformed into a set of nonlinear ordinary equations. These equations are solved numerically using the bvp4c solver in Matlab which is a very efficient finite difference method. The influence of numerous parameters such as nanoparticle volume fraction, velocity ratio parameter and first order slip parameter on velocity, temperature, skin friction and heat transfer rate are further explored and discussed in the form of graphical and tabular forms. The results reveal that dual solutions exist when the plate and free stream move in the opposite direction and slip parameter was found to widen the range of the possible solutions. However, skin friction coefficients decrease, whereas the heat transfer increases in the presence of slip parameter. Single-wall carbon nanotubes (SWCNTs) give higher skin friction and heat transfer compared to multi-wall carbon nanotubes (MWCNTs) due to the fact that they have higher density and thermal conductivity. A stability analysis is carried out to determine the stability of the solutions obtained.

scholarly journals Application of Fractional Derivative Without Singular and Local Kernel to Enhanced Heat Transfer in CNTs Nanofluid Over an Inclined Plate

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 768 ◽  
Author(s):  
Muhammad Saqib ◽  
Abdul Rahman Mohd Kasim ◽  
Nurul Farahain Mohammad ◽  
Dennis Ling Chuan Ching ◽  
Sharidan Shafie
Keyword(s):  
Heat Transfer ◽  
Carbon Nanotubes ◽  
Fractional Derivatives ◽  
Saturated Porous Medium ◽  
Convection Heat Transfer ◽  
Heat Transfer Fluid ◽  
Single Wall Carbon Nanotubes ◽  
Inclined Plate ◽  
Multi Wall Carbon Nanotubes ◽  
Laplace Transform Technique

Nanofluids are a novel class of heat transfer fluid that plays a vital role in industries. In mathematical investigations, these fluids are modeled in terms of traditional integer-order partial differential equations (PDEs). It is recognized that traditional PDEs cannot decode the complex behavior of physical flow parameters and memory effects. Therefore, this article intends to study the mixed convection heat transfer in nanofluid over an inclined vertical plate via fractional derivatives approach. The problem in hand is modeled in connection with Atangana–Baleanu fractional derivatives without singular and local kernel with a strong memory. Human blood is considered as base fluid and carbon nanotube (CNTs) (single-wall carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs)) are dispersed into it to form blood-CNTs nanofluid. The nanofluid is considered to flow in a saturated porous medium under the influence of an applied magnetic field. The exact analytical expressions for velocity and temperature profiles are acquired using the Laplace transform technique and plotted in various graphs. The empirical results indicate that the memory effect decreases with increasing fractional parameters in the case of both temperature and velocity profiles. Moreover, the temperature profile is higher for blood SWCNTs because of higher thermal conductivity whereas this trend is found opposite in the case of velocity profile due to densities difference.

Facile Synthesis of Cobalt Oxide Uniformly Coated on Multi-Wall Carbon Nanotubes for Supercapacitors

2011 ◽  
Vol 306-307 ◽  
pp. 1148-1152 ◽  
Author(s):  
Liang Yu Gong ◽  
Ling Hao Su
Keyword(s):  
Carbon Nanotubes ◽  
Cobalt Oxide ◽  
Solid Phase ◽  
Synthesis Method ◽  
Electrochemical Performances ◽  
Composite Electrodes ◽  
Phase Synthesis ◽  
Multi Wall Carbon Nanotubes ◽  
Electrochemical Tests ◽  
Transmission Electron

The composite electrodes of cobalt oxide and multi-wall carbon nanotubes (MWCNTs) are prepared by a simple low-temperature solid-phase synthesis method with the assistance of polyethylene glycol and their pseudocapacitive performances are investigated in alkaline solution by cyclic voltammetry and galvanostatic charge/discharge tests, respectively. Transmission electron microscope images show that cobalt oxide is uniformly coated on multi-wall carbon nanotubes and the homogeneous hybrid nanostructure are considered to be responsible for their preferable electrochemical performances. The electrochemical tests further reveal that the composite can deliver a maximum specific capacitance of 217 F/g with a biggest utilization of Co element when the content of MWCNTs increases to 50 wt.%.

scholarly journals Flow Analysis of Hybridized Nanomaterial Liquid Flow in the Existence of Multiple Slips and Hall Current Effect over a Slendering Stretching Surface

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1546
Author(s):  
Enran Hou ◽  
Fuzhang Wang ◽  
Muhammad Naveed Khan ◽  
Shafiq Ahmad ◽  
Aysha Rehman ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fluid Velocity ◽  
Continuation Method ◽  
Flow Analysis ◽  
Heat Rate ◽  
Single Wall Carbon Nanotubes ◽  
Local Skin ◽  
Flow Equations ◽  
Multi Wall Carbon Nanotubes ◽  
The Impact

Carbon nanotubes (CNTs) are favored materials in the manufacture of electrochemical devices because of their mechanical and chemical stability, good thermal and electrical conductivities, physiochemical consistency, and featherweight. With such intriguing carbon nanotubes properties in mind, the current research aims to investigate the flow of hybridized nano liquid containing MWCNTs (multi-wall carbon nanotubes) and SWCNTs (single-wall carbon nanotubes) across a slendering surface in the presence of a gyrotactic-microorganism. The temperature and solutal energy equation are modified with the impact of the modified Fourier and Fick’s law, binary chemical reaction, viscous dissipation, and joule heating. The slip conditions are imposed on the surface boundaries. The flow equations are converted into ODEs by applying similarity variables. The bvp4c approach is applied to tackle the coupled and extremely nonlinear boundary value problem. The outputs are compared with the PCM (Parametric continuation method) to ensure that the results are accurate. The influence of involved characteristics on energy distribution, velocity profiles, concentration, and microorganism field are presented graphically. It is noted that the stronger values of the wall thickness parameter and the Hartmann number produce a retardation effect; as a result, the fluid velocity declines for MWCNT and SWCNT hybrid nano liquid. Furthermore, the transport of the mass and heat rate improves with a higher amount of both the hybrid and simple nanofluids. The amount of local skin friction and the motile density of microorganisms are discussed and tabulated. Furthermore, the findings are validated by comparing them to the published literature, which is a notable feature of the present results. In this aspect, venerable stability has been accomplished.

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