Disposable Planar Reference Electrode Based on Carbon Nanotubes and Polyacrylate Membrane

2011 ◽  
Vol 83 (14) ◽  
pp. 5783-5788 ◽  
Author(s):  
F. Xavier Rius-Ruiz ◽  
Diego Bejarano-Nosas ◽  
Pascal Blondeau ◽  
Jordi Riu ◽  
F. Xavier Rius
Keyword(s):  
Carbon Nanotubes ◽  
Reference Electrode ◽  
Polyacrylate Membrane

scholarly journals Fully Transparent Gas Sensor Based on Carbon Nanotubes

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4591 ◽  
Author(s):  
Florin C. Loghin ◽  
Aniello Falco ◽  
Jose F. Salmeron ◽  
Paolo Lugli ◽  
Alaa Abdellah ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensor ◽  
Active Layer ◽  
Gas Sensors ◽  
Spray Deposition ◽  
Reference Electrode ◽  
Gold Electrodes ◽  
Integrated Sensors ◽  
Reference Sensor ◽  
Higher Sensitivity

In this paper, we demonstrate the feasibility of realization of transparent gas sensors based on carbon nanotubes (CNTs). Both sensing layer and electrodes consist of CNTs deposited by spray deposition. The transparent sensor—with a transmittance higher than 60% in both sensing layer and electrodes—is characterized towards NH3 and CO2 and compared with a reference sensor with the same active layer but evaporated Au electrodes. In particular, the sensitivity towards NH3 is virtually identical for both reference and transparent sensors, whereas the transparent device exhibits higher sensitivity to CO2 than the reference electrode. The effect of the spacing among consecutive electrodes is also studied, demonstrating that a wider spacing in fully CNT based sensors results in a higher sensitivity because of the higher sensing resistance, whereas this effect was not observed in gold electrodes, as their resistance can be neglected with respect to the resistance of the CNT sensing layer. Overall, the transparent sensors show performance comparable—if not superior—to the traditionally realized ones, opening the way for seamlessly integrated sensors, which do not compromise on quality.

Experimental and theoretical study of the electrochemical behavior of N-protonated dopamine at Nafion multiwalled carbon nanotubes (MWNTs) modified glassy carbon (GCE) electrode

2006 ◽  
Vol 84 (8) ◽  
pp. 1084-1092 ◽  
Author(s):  
Yuanzhi Song ◽  
Yang Song
Keyword(s):  
Carbon Nanotubes ◽  
Cyclic Voltammetry ◽  
Multiwalled Carbon Nanotubes ◽  
Glassy Carbon ◽  
Electrode Potential ◽  
Reference Electrode ◽  
Weighted Average ◽  
Standard Electrode Potential ◽  
Free Energies ◽  
Multiwalled Carbon

The electrochemistry of N-protonated dopamine (DAH+) was studied by cyclic voltammetry (CV) at a glassy carbon electrode modified by Nafion multiwalled carbon nanotubes (MWNTs) in phosphate buffers (pH 5.50) and the results show that the standard electrode potential of half reaction for DAH+(O),H+/ DAH+(R) is 0.74 V. Calculations are performed using DFT B3LY/6-31G(d,p) for nine conformers of N-protonated dopamine (DAH+(R)) and three conformers of oxidized N-protonated dopamine (DAH+(O)). The energies of solvation and sum of electronic and thermal free energies of DAH+(R), DAH+(O), p-benzoquinone (p-BQ), and p-hydroquinone (p-HQ) are calculated at same level. The theoretical weighted average of the standard electrode potential (0.732 V) for DAH+(O),H+/ DAH+(R), using the transformed Gibbs free energies of the stable DAH+(R) and DAH+(O) with a p-BQ, H+/p-HQ reference electrode, is consistent with the experimental one of 0.74 V.Key words: dopamine, DFT, cyclic voltammetry, standard electrode potential.

Nickel-Cobalt Double Hydroxide Decorated Carbon Nanotubes via Aqueous Electrophoretic Deposition towards Catalytic Glucose Detection

2015 ◽  
Vol 654 ◽  
pp. 70-75 ◽  
Author(s):  
Anirudh Balram ◽  
Jie Chao Jiang ◽  
Moisés Hernández Fernández ◽  
Dennis De Sheng Meng
Keyword(s):  
Carbon Nanotubes ◽  
Electrophoretic Deposition ◽  
Reference Electrode ◽  
Glucose Detection ◽  
Electrochemical Testing ◽  
Nickel Cobalt ◽  
The Individual ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Cobalt Hydroxides

In this work, we present a facile technique based on electrophoretic deposition (EPD) to produce transition metal hydroxide decorated carbon nanotubes (CNT) for electrochemical applications. We specifically explore the performance of nickel-cobalt hydroxides given their high activity, conductivity and stability as compared to the individual hydroxides. We exploit the high local pH at the negative electrodes during water-based EPD to form nanoparticles of nickel-cobalt hydroxides in situ on the CNT surface. We focus our work here on obtaining functional and conductive deposits on CNTs. The hydrophilic binderless deposits of Ni-Co double hydroxide decorated CNTs obtained here are used for non-enzymatic glucose detection. XPS data and electrochemical testing reveal difference in the deposited double hydroxide based on chronology of charging salt addition even at the same ratio. When cobalt and nickel salts are sequentially added at a ratio of 1:1, the deposited double hydroxides show excellent glucose sensitivity of ~3300μA/mM.cm2 at applied potential of 0.55V vs. Ag/AgCl reference electrode.

scholarly journals Utilization of carbon nanotubes in hydrogen electrosynthesis from tropical fruit fermentation

2020 ◽  
Vol 25 (3) ◽  
Author(s):  
Adriana Carla de Oliveira Lopes ◽  
Fabiane Caxico de Abreu
Keyword(s):  
Carbon Nanotubes ◽  
Hydrogen Production ◽  
Fossil Fuels ◽  
Oil And Gas ◽  
Reference Electrode ◽  
Hydrogen Gas ◽  
Household Waste ◽  
Vitreous Carbon ◽  
Tropical Fruit ◽  
Working Electrode

ABSTRACT The use of fossil fuels, especially oil and gas, has accelerated in recent years, resulting in the global energy crisis. The fermentative biological process is a sustainable way to produce hydrogen, as it can use as a substrate various types of carbohydrate-rich industrial and household waste such as fruit, minimizing but not completely eliminating the problems caused by improper disposal of this material. From a perspective of energy conservation and use of renewable sources for energy generation, this work aims to contribute to the identification of the use of a currently unused portion of energy, optimizing hydrogen production from a fuel cell. microbial. The main nanomaterial used in electrolysis was carbon nanotubes (CNT) incorporated into carbon felt (CF). Cyclic voltammetry studies were also performed on three electrode systems: vitreous carbon electrode as working electrode, platinum electrode as auxiliary electrode and Ag / AgCl / Cl- as reference electrode. An electrochemical cell formed by two separate compartments was constructed. Before starting the electrolysis experiment, an experimental design was performed using the complete factorial design technique to analyze the influence of the variables selected for this study. The independent variables selected were: Tropical fruit liquor concentration in %v/v, type of working electrode, electrolysis time and pH of the electrolyte medium. The observed variable was the concentration in% v / v of the hydrogen gas obtained in the electrolysis. After the results of the tests, it was concluded that carbon nanotubes can be used as working electrode, presenting success in the hydrogen production process and that the pH of the electrolytic medium has a strong influence on this process. The present work was concluded presenting an alternative way in the production of a renewable energy source.

scholarly journals Polyaniline Enhanced Supercapacitance of Cobalt Hydroxide Nanowires/Carbon Nanotube Containing Polymer Sponge Layered Composite

2018 ◽  
Vol 778 ◽  
pp. 175-180
Author(s):  
Syed Hashim Shah ◽  
Muhammad Imran Khan ◽  
Rida Sarfraz ◽  
Rozeen Nazir ◽  
Ashraf Ali
Keyword(s):  
Carbon Nanotubes ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Reference Electrode ◽  
Layered Composite ◽  
Cobalt Hydroxide ◽  
Flow Surface ◽  
Metal Oxide Nanostructures ◽  
Carbon Based Nanomaterials

Transition metal oxide nanostructures and conducting polymers like polyaniline have specific capacitance orders of magnitude higher than those of carbon based nanomaterials. In the present study nanoflowers of Cobalt Hydroxide, Polyaniline and Carbon Nanotubes were combined on a conventional Polymeric sponge to develop by using facile wet chemical techniques. High surface area of Cobalt Hydroxide nanoflowers when combined with Polyaniline showed enhanced capacitance values and stability. The carbon nanotubes enhanced the conductivity of the composite while the double porous structure of polyurethane sponge enhances the electrolyte flow, surface area, and reduces current density which leads to good reversibility and greater capacitance. Samples were characterized by cyclic voltammetry technique against Ag/AgCl reference electrode in three electrode setup.

Electric Double Layer Capacitor of Multiwall Carbon Nanotubes under Different Degree of Acid Oxidations

2014 ◽  
Vol 802 ◽  
pp. 186-191
Author(s):  
Eduardo Saito ◽  
Vagner Eduardo Caetano ◽  
Erica Freire Antunes ◽  
Anderson Oliveira Lobo ◽  
Fernanda Roberto Marciano ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Double Layer ◽  
Multiwall Carbon Nanotubes ◽  
Reference Electrode ◽  
Chemical Vapor ◽  
Specific Area ◽  
Double Layer Capacitor ◽  
Acid Washing ◽  
Chemical Vapor Depostion ◽  
High Specific Area

Carbon nanotubes (CNT) are a material with unique properties (mechanical, electrical, electrochemical, etc) allied with low density and high specific area. The present paper studied the electrochemical properties of carbon nanotubes growth by Chemical Vapor Depostion (CVD) technique. The samples were characterized by SEM, Raman Spectroscopy and the double layer capacitance of the powders was evaluated in a Teflon capacitor system with a Ag/AgCl (3M) as reference electrode. The catalyst remotion is provided in Hydrochloric acid washing and the wet oxidative treatments promotes the CNT oxidation and increase the pseudocapacitive response.

Structural phenomena in the growth of carbon nanotubes

1993 ◽  
Vol 51 ◽  
pp. 750-751
Author(s):  
Jun Jiao
Keyword(s):  
Carbon Nanotubes ◽  
Growth Mechanism ◽  
Carbonaceous Material ◽  
Cluster Growth ◽  
Structural Elements ◽  
Rich Variety ◽  
Different Shapes ◽  
Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

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