Electrochemical Response of Clay/Polyelectrolyte Composite Barrier Coatings

Composite materials made of polymer and clay are effective at blocking mass transport. In this study, the blocking efficacy of layer-by-layer (LbL) coatings of exfoliated montmorillonite (MMT) and polyethylenimine (PEI) was studied using cyclic voltammetry and a redox couple, indigo carmine (IC). The pH of the MMT solution was varied from 4 to 10 to prepare LbL coatings of different surface roughness on metal substrates. It was found that the coated electrode had a lower redox peak current value than without the coating, demonstrating the reduction of the mass transport of IC to the metal surface. The peak values decreased with decreasing the coating’s roughness and increasing the number of layers, indicating that the blocking capability can be controlled by changing the deposition conditions. Smooth LbL coatings deposited with MMT at pH 4 showed the highest blocking efficacy up to 97.5%. The IC adsorbed at the interface between the coating and the metal substrate was found to cause the peak current measured for the coated electrode. It was also confirmed that the same coating on the copper substrate reduced the corrosion of the copper during the electrochemical potential cycling.

Effect of magnetic field on the performance of a deep eutectic solvent-based redox flow battery from polarization perspective

In recent years, with the promotion of global renewable energy, the introduction of energy storage batteries has become more and more important. Redox flow battery has attracted more and more attention due to their environmental friendliness, safe and reliable operation. This work studies the effect of different magnetic field intensities and the duration of magnetic field addition on the mass transfer and electrochemical reaction process of iron-vanadium ions in deep eutectic solvent (DES). At the same time, the effect of magnetic field on the polarization performance of DES-based redox flow battery is also studied. The experimental results show that the iron and vanadium DES electrolytes increase their redox peak current density under the action of adding magnetic field. The test of the polarization performance of the DES-based redox flow battery shows that the addition of magnetic field can reduce the area specific resistance (ASR) of the battery and improve the polarization performance of the battery.

Gold Nanocage-Based Electrochemical Sensing Platform for Sensitive Detection of Luteolin

A simple and sensitive electrochemical sensor was developed for the detection of tracelevels of luteolin. The sensoris based on a novel type of chemically modified electrode: gold nanocage (AuNCs)-modified carbon ionic liquid electrode (CILE). To construct this electrochemical sensing platform for luteolin, CILE is initially prepared by using 1-hexylpyridinium hexafluorophosphate as the binder and then AuNCs are coated on the surface of CILE to fabricate AuNCs-modified CILE (AuNCs/CILE). Electrochemical studies have shown that AuNCs/CILE can exhibit enhanced electrocatalytic activity toward the redox reaction of luteolin, therefore, the redox peak current of luteolin can be greatly improved, resulting in the high sensitivity of the developed sensor. Under the optimal conditions, the oxidation peak currents of the sensor increase linearly with an increase in the luteolin concentration in a range from 1 to 1000 nM with a detection limit of 0.4 nM, which is lower than those of most reported electrochemical luteolin sensors. Moreover, the reproducibility, precision, selectivity, and stability of this sensor are excellent. Finally, the sensing system was applied to the analysis of luteolin-spiked drug samples and the recovery in all cases was 95.0–96.7%, indicating the potential application of this simple, facile, and sensitive sensing system in pharmaceutical analysis.

Preparation and Photoelectronic Properties of Zinc Oxide/Perovskite Nanocomposites/Polypyrrole

La0.3Ca0.7Fe0.7Ni0.3O3 perovskite-type composite was prepared by glycine-nitrate combustion method , Zinc Oxide was prepared by liquid crystal precipitation, then we synthesized ZnO/La0.3Ca0.7Fe0.7Ni0.3O3/Ppy nanocomposites with different content of Ppy in situ method. XRD,SEM,UV-vis were used to characterized the crystal structure and morphology of the nanocomposites and their photocatalytic activity. Cyclic voltammetry of the composites were conducted in 1mol/L KCl solutions to discuss their electrochemical properties.According to the electrochemical properties, we found that with the increase of the zinc oxide content,the redox peak current of the composites becomes larger, also their reversible redox properties was improved.

Effect of Propanetriol on the Electrochemical Behavior of Nano Fumed Silica Gel

The effect of propanetriol on the electrochemical properties of nanofumed silica gel of Valve-regulated lead-acid (VRLA) batteries have been investigated by means of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), transmission electron microscope (TEM) and linear sweep voltammetry (LSV). The results show that with the adding of propanetriol the redox peak current density of the lead electrode greatly increases and the reaction resistance reduces obviously. Additionally, the oxygen reactions take place less easily in the gels containing propanetriol. The content of the additive propanetriol also relates with the gel properties. It is proved that the electrochemical properties of gel contained excessive propanetriol (4wt. %) are not as good as that contain 1wt.%~3wt.%.

Electrochemical detection of non-labeling DNA using electronic array

Our system is the electrochemical approaches include the detection of hybridization from nonlabeling nucleic acids to protein-bound nucleic acids using soluble mediators with K4Fe(CN)6 solutions. In order to generate bio-functional surfaces, the streptavidin(SAv)-biotin system is used. A 50 % change of redox peak current after hybridization measured with 50 μM concentration of target DNA. We suggest that this result comes from the efficient electron transport through the SAv-biotin interaction. Our electrochemical detection system showed good reproducibility on a chip with non-labeling DNA hybridization detection.

Electrochemical detection of non-labeling DNA using electronic array

Our system is the electrochemical approaches include the detection of hybridization from nonlabeling nucleic acids to protein-bound nucleic acids using soluble mediators with K4Fe(CN)6 solutions. In order to generate bio-functional surfaces, the streptavidin(SAv)-biotin system is used. A 50 % change of redox peak current after hybridization measured with 50 ?M concentration of target DNA. We suggest that this result comes from the efficient electron transport through the SAv-biotin interaction. Our electrochemical detection system showed good reproducibility on a chip with non-labeling DNA hybridization detection.

A Novel Conducting Polymer with O-S-S-O Bonds for Positive Material:Poly(2,2′-Diaminobenzyloxydisulfide)

ABSTRACTOrganic disulfide compounds has been proposed as a new class of high-energy storage material. Poly(2,2'-diaminobenzyloxydisulfide), a novel conducting polymer having O-S-S-O bond joined two moieties of anilines, is synthesized both chemically and electrochemically as a new positive storage material. It exhibits conductivity in the region of 10-3 S cm-1 by the fourprobe method and the O-S-S-0 bonds in it are confirmed by Fourie Transform Raman Spectroscopy(FT-RS) and Fourie Transform Infrared Spectroscopy(FT-IR). The poly(2,2'- diaminobenzyloxydisulfide) films are formed by electropolymerization from a AN/THF solution containing 0. IM LiClO4, 0. IM HCl and 0.05 M 2,2'-diaminobenzyloxydisulfide monomer on Pt electrode under continuous cycling between -0.30V and 1.20V vs Ag/AgCl(sat. KCI) at scanning rate 50mv s-1. The cyclic voltammetry shows its electrochemical behaviour is similar to polyaniline. The redox peak current of the cyclic voltammograms increase with increasing of the cyclic numbers.