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

2011 ◽  
Vol 110-116 ◽  
pp. 514-518
Author(s):  
Cheng Fang Sun ◽  
Fa Liang Cheng ◽  
Mei Qiong Chen ◽  
Min Zhang ◽  
Zhi Quan Cai
Keyword(s):  
Electrochemical Properties ◽  
Silica Gel ◽  
Electrochemical Impedance ◽  
Linear Sweep Voltammetry ◽  
Peak Current Density ◽  
Gel Properties ◽  
Redox Peak ◽  
Transmission Electron ◽  
Lead Electrode ◽  
Redox Peak Current

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.%.

scholarly journals Development of one-dimensional titania nanomaterials

2014 ◽  
Author(s):  
Ναούμ Βαενάς
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Impedance ◽  
Linear Sweep Voltammetry ◽  
Linear Sweep ◽  
One Dimensional ◽  
Force Microscopy ◽  
Photocurrent Spectroscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Dye Solar Cells

Σκοπός αυτής της διδακτορικής διατριβής είναι η ανάπτυξη μονοδιάστατων νανοδομών τιτανίας και εν συνεχεία η εφαρμογή τους στην κατασκευή ευαισθητοποιημένων ηλιακών κελιών (Dye Solar Cells - DSCs). Οι νανοσωλήνες τιτανίας αποτελούν την ιδανική επιλογή για τους στόχους αυτής της έρευνας καθώς: α) μπορούν να προετοιμαστούν εύκολα από την ανοδική οξείδωση ενός φύλλου τιτανίου, β) επιτρέπουν τον εύκολο έλεγχο της μορφολογίας τους μέσω της ηλεκτροχημικής νάνο-μηχανικής, γ) εξασφαλίζουν εξαιρετικές ηλεκτρικές ιδιότητες, όπως κατευθυνόμενη κίνηση των ηλεκτρονίων. Οι νανοσωλήνες τιτανίας χρησιμοποιήθηκαν ως ηλεκτρόδια εργασίας (photo-anodes) στα ευαισθητοποιημένα ηλιακά κελιά που κατασκευάστηκαν στη συνέχεια.Τα μορφολογικά και δομικά χαρακτηριστικά των νανοσωλήνων μελετήθηκαν με τις τεχνικές, της μικροσκοπίας ατομικών δυνάμεων (Atomic Force Microscopy - AFM), της μικροσκοπίας ηλεκτρονικής σάρωσης (Scanning Electron Microscopy - SEM), της μικροσκοπίας ηλεκτρονικής διελεύσεως (Transmission Electron Microscopy - TEM), της φασματοσκοπίας υπεριώδους/ορατού (Ultraviolet–Visible - UV-Vis) και της φασματοσκοπίας Ράμαν (Raman spectroscopy). Επιπλέον η αξιολόγηση και ο χαρακτηρισμός των ηλιακών κελιών πραγματοποιήθηκε με τις μεθόδους, της φασματοσκοπίας ηλεκτροχημικής εμπέδησης (Electrochemical Impedance Spectroscopy - EIS), της φασματοσκοπίας φωτοδυναμικού/φωτορεύματος περιοδικά μεταβαλλόμενης έντασης φωτισμού (Intensity Modulated Photovoltage/ Photocurrent Spectroscopy - IMVS/IMPS) και τελικά οι αποδόσεις των φωτοβολταϊκών εξάχθηκαν από την βολταμετρία φωτορεύματος (Linear Sweep Voltammetry - LSV). Κίνητρα για αυτήν την μελέτη αποτέλεσαν η ανάγκη κατανόησης, των βασικών μηχανισμών ανάπτυξης των νανοσωλήνων τιτανίας καθώς και των αρχών λειτουργίας που διέπουν τα ευαισθητοποιημένα ηλιακά κελιά. Στο πρώτο μέρος αυτής της έρευνας πραγματοποιήθηκαν μερικά προκαταρτικά πειράματα, με σκοπό την βελτίωση της μορφολογίας του χρησιμοποιούμενου υποστρώματος τιτανίου, όπως και των νανοσωλήνων τιτανίας που προέκυψαν. Μόλις οι συνθήκες ανοδίωσης σταθεροποιήθηκαν, υψηλής ομοιογένειας και ποιότητας νανοσωλήνες προετοιμάστηκαν και χρησιμοποιήθηκαν σε ευαισθητοποιημένα ηλιακά κελιά με ικανοποιητική απόδοση. Στην δεύτερη φάση αυτού του έργου, οι δομικές ιδιότητες των νανοσωλήνων μελετήθηκαν , με σκοπό να εξασφαλιστεί η ανεμπόδιστη μεταφορά των ηλεκτρονίων. Συγκεκριμένα η επίδραση της διαδικασίας απόπτυσης των νανοσωλήνων διερευνήθηκε συνάρτηση των ηλεκτρικών χαρακτηριστικών των φωτοβολταϊκών συσκευών που τελικά παράχθηκαν. Στο τρίτο στάδιο της διατριβής, προηγμένες δομές νανοσωλήνων προετοιμάσθηκαν μέσω σύνθετων τρόπων ανοδίωσης. Η ποτενσιοστατική και γαλβανοστατική ανοδίωση συνδυάστηκαν για πρώτη φορά στην βιβλιογραφία και οδήγησαν στην εξέλιξη της μεθόδου της ανοδίωσης. Το τελευταίο μέρος της δουλειάς αφιερώθηκε αποκλείστηκα στην αύξηση της απόδοσης των φωτοβολταϊκών που ενσωμάτωναν φωτοηλεκτροδία νανοσωλήνων, μέσω της χρήσης των πιο σύγχρονων ηλεκτρολυτών και χρωστικών. Το οξειδοαναγωγικό ζεύγος κοβαλτίου διαχύθηκε με ευκολία στους πορώδους νανοσωλήνες και σε συνδυασμό με την οργανική χρωστική D35, οδήγησε σε υψηλές φωτοτάσεις και αποδόσεις.

scholarly journals Ex-Situ Electrochemical Characterization of IrO2 Synthesized by a Modified Adams Fusion Method for the Oxygen Evolution Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 318 ◽  
Author(s):  
Cecil Felix ◽  
Bernard Bladergroen ◽  
Vladimir Linkov ◽  
Bruno Pollet ◽  
Sivakumar Pasupathi
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Electrochemical Impedance ◽  
Fusion Reaction ◽  
Linear Sweep Voltammetry ◽  
Ex Situ ◽  
Gravimetric Analysis ◽  
Fusion Method ◽  
Transmission Electron ◽  
Significant Research

The development of highly stable and active electrocatalysts for the oxygen evolution reaction (OER) has attracted significant research interest. IrO2 is known to show good stability during the OER however it is not known to be the most active. Thus, significant research has been dedicated to enhance the activity of IrO2 toward the OER. In this study, IrO2 catalysts were synthesized using a modified Adams fusion method. The Adams fusion method is simple and is shown to directly produce nano-sized metal oxides. The effect of the Ir precursor salt to the NaNO3 ratio and the fusion temperature on the OER activity of the synthesized IrO2 electrocatalysts, was investigated. The OER activity and durability of the IrO2 electrocatalysts were evaluated ex-situ via cyclic voltammetry (CV), chronopotentiometry (CP), electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV). Physical properties of the IrO2 electrocatalysts were evaluated via X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), differential thermal analysis (DTA), and energy dispersive spectroscopy (EDS). The results show that the addition of excess NaNO3 during the modified Adams fusion reaction is not a requirement and that higher synthesis temperatures results in IrO2 electrocatalysts with larger particle sizes and reduced electrocatalytic activity.

scholarly journals Role of Mg(NO3)2 as Defective Agent in Ameliorating the Electrical Conductivity, Structural and Electrochemical Properties of Agarose–Based Polymer Electrolytes

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3357
Author(s):  
N. I. Ali ◽  
S. Z. Z. Abidin ◽  
S. R. Majid ◽  
N. K. Jaafar
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Properties ◽  
Polymer Electrolyte ◽  
Polymer Electrolytes ◽  
Electrochemical Impedance ◽  
Linear Sweep Voltammetry ◽  
Amorphous Nature ◽  
Different Temperatures ◽  
Solution Casting Method

Polymer electrolytes based on agarose dissolved in DMSO solvent complexed with different weight percentages of Mg(NO3)2 ranging from 0 to 35 wt% were prepared using a solution casting method. Electrochemical impedance spectroscopy (EIS) was applied to study the electrical properties of this polymer electrolyte, such as ionic conductivity at room and different temperatures, dielectric and modulus properties. The highest conducting film has been obtained at 1.48 × 10−5 S·cm−1 by doping 30 wt% of Mg(NO3)2 into the polymer matrix at room temperature. This high ionic conductivity value is achieved due to the increase in the amorphous nature of the polymer electrolyte, as proven by X-ray diffractometry (XRD), where broadening of the amorphous peak can be observed. The intermolecular interactions between agarose and Mg(NO3)2 are studied by Fourier transform infrared (FTIR) spectroscopy by observing the presence of –OH, –CH, N–H, CH3, C–O–C, C–OH, C–C and 3,6-anhydrogalactose bridges in the FTIR spectra. The electrochemical properties for the highest conducting agarose–Mg(NO3)2 polymer electrolyte are stable up to 3.57 V, which is determined by using linear sweep voltammetry (LSV) and supported by cyclic voltammetry (CV) that proves the presence of Mg2+ conduction.

scholarly journals Investigation of the Electrochemical Properties of Ni0.5Zn0.5Fe2O4 as Binder-Based and Binder-Free Electrodes of Supercapacitors

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3297
Author(s):  
Bushra Nawaz ◽  
Ghulam Ali ◽  
Muhammad Obaid Ullah ◽  
Sarish Rehman ◽  
Fazal Abbas
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Current Density ◽  
Electrochemical Impedance ◽  
Nickel Foam ◽  
Specific Capacity ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Binder Free ◽  
Interconnected Structure

In this work, Ni0.5Zn0.5Fe2O4 is synthesized as binder-based (NZF) and binder-free electrodes (NZF@NF). The binder-free electrode is directly synthesized on nickel foam via facile hydrothermal techniques. The crystalline phase of both of these electrodes is examined through X-ray diffraction. Their morphology is investigated by scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (TEM), which revealed the well-defined nanostructure with the shape like thin hexagonal platelets. The chemical composition is verified by energy dispersive spectroscopy (EDS). Their electrochemical properties are analyzed by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The NZF@NF electrode has outperformed the binder-based NZF electrode in terms of electrochemical performance owing to the 3D interconnected structure of the nickel foam. The NZF@NF electrode has delivered a high specific capacity of 504 F g−1 at the current density of 1 A g−1, while its counterpart has delivered a specific capacity of 151 F g−1 at the same current density.

scholarly journals Impact of incorporation of chromium on electrochemical properties of LiFePO4/C for Li-ion batteries

2015 ◽  
Vol 33 (4) ◽  
pp. 742-750 ◽  
Author(s):  
Amol Naik ◽  
Jian Zhou ◽  
Chao Gao ◽  
Guizhen Liu ◽  
Lin Wang
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Electrochemical Impedance ◽  
Single Mode ◽  
X Ray Diffraction ◽  
Raman Spectroscopic ◽  
Transmission Electron ◽  
Specific Discharge ◽  
One Step ◽  
Current Densities

AbstractLiFe0.95Cr0.05PO4/C was successfully synthesized by one-step solid-state reaction using a single mode microwave reactor. The effect of incorporation of chromium on LiFePO4 lattice parameters was systematically investigated by X-ray diffraction. Surface analysis was done by scanning electron microscopy and transmission electron microscopy. The ratio of amorphous to graphitic carbon was determined from Raman spectroscopic data. The influence of chromium incorporation on electrochemical properties was studied by recording charge/discharge cycles combined with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. It was found that Cr incorporation significantly enhanced the electrochemical performance of LiFePO4 at all current densities up to 10 C. LiFe0.95Cr0.05PO4/C prepared exhibited the best performance with an initial specific discharge capacity of 157.7, 144.8, 138.3, 131.0, 124.1 and 111.1 mAh·g−1 at 0.1 C, 0.5 C, 1.0 C, 2.0 C, 5 C and 10 C, respectively. The doped sample displayed excellent capacity retention, which was substantially superior than that of pristine LiFePO4/C at a higher current rate.

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

2020 ◽  
Vol 194 ◽  
pp. 02027
Author(s):  
Rong Cheng ◽  
Qiang Ma ◽  
Weiqi Zhang ◽  
Huaneng Su ◽  
Qian Xu
Keyword(s):  
Magnetic Field ◽  
Deep Eutectic Solvent ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Reliable Operation ◽  
Peak Current Density ◽  
Environmental Friendliness ◽  
Redox Peak ◽  
Redox Peak Current ◽  
Storage Batteries

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.

The study of the electrochemical properties of zinc-rich coating on the base of water sodium silicate

2019 ◽  
Vol 24 (4) ◽  
pp. 51-58
Author(s):  
Le Hong Quan ◽  
Nguyen Van Chi ◽  
Mai Van Minh ◽  
Nong Quoc Quang ◽  
Dong Van Kien
Keyword(s):  
Carbon Steel ◽  
Electrochemical Properties ◽  
Sodium Silicate ◽  
Cathodic Protection ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Electrical Contact ◽  
Electrochemical Impedance Spectra ◽  
Pure Zinc ◽  
Electric Circuits

The study examines the electrochemical properties of a coating based on water sodium silicate and pure zinc dust (ZSC, working title - TTL-VN) using the Electrochemical Impedance Spectra (EIS) with AutoLAB PGSTAT204N. The system consists of three electrodes: Ag/AgCl (SCE) reference electrode in 3 M solution of KCl, auxiliary electrode Pt (8x8 mm) and working electrodes (carbon steel with surface treatment up to Sa 2.5) for determination of corrosion potential (Ecorr) and calculation of equivalent electric circuits used for explanation of impedance measurement results. It was shown that electrochemical method is effective for study of corrosion characteristics of ZSC on steel. We proposed an interpretation of the deterioration over time of the ability of zinc particles in paint to provide cathodic protection for carbon steel. The results show that the value of Ecorr is between -0,9 and -1,1 V / SCE for ten days of diving. This means that there is an electrical contact between the zinc particles, which provides good cathodic protection for the steel substrate and most of the zinc particles were involved in the osmosis process. The good characteristics of the TTL-VN coating during immersion in a 3,5% NaCl solution can also be explained by the preservation of corrosive zinc products in the coating, which allows the creation of random barrier properties.

scholarly journals Water Photo-Electrooxidation Using Mats of TiO2 Nanorods, Surface Sensitized by a Metal–Organic Framework of Nickel and 1,2-Benzene Dicarboxylic Acid

Hydrogen ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 58-75
Author(s):  
Sheng-Mu You ◽  
Waleed M. A. El Rouby ◽  
Loïc Assaud ◽  
Ruey-An Doong ◽  
Pierre Millet
Keyword(s):  
Dicarboxylic Acid ◽  
Electrochemical Impedance ◽  
Metal Organic Framework ◽  
Linear Sweep Voltammetry ◽  
Tio2 Nanorods ◽  
Tem Analysis ◽  
Vis Spectroscopy ◽  
Metal Organic ◽  
Benzene Dicarboxylic Acid ◽  
Organic Framework

Photoanodes comprising a transparent glass substrate coated with a thin conductive film of fluorine-doped tin oxide (FTO) and a thin layer of a photoactive phase have been fabricated and tested with regard to the photo-electro-oxidation of water into molecular oxygen. The photoactive layer was made of a mat of TiO2 nanorods (TDNRs) of micrometric thickness. Individual nanorods were successfully photosensitized with nanoparticles of a metal–organic framework (MOF) of nickel and 1,2-benzene dicarboxylic acid (BDCA). Detailed microstructural information was obtained from SEM and TEM analysis. The chemical composition of the active layer was determined by XRD, XPS and FTIR analysis. Optical properties were determined by UV–Vis spectroscopy. The water photooxidation activity was evaluated by linear sweep voltammetry and the robustness was assessed by chrono-amperometry. The OER (oxygen evolution reaction) photo-activity of these photoelectrodes was found to be directly related to the amount of MOF deposited on the TiO2 nanorods, and was therefore maximized by adjusting the MOF content. The microscopic reaction mechanism which controls the photoactivity of these photoelectrodes was analyzed by photo-electrochemical impedance spectroscopy. Microscopic rate parameters are reported. These results contribute to the development and characterization of MOF-sensitized OER photoanodes.

scholarly journals Electro-Oxidation of Ammonia at Novel Ag2O−PrO2/γ-Al2O3 Catalysts

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 257
Author(s):  
Mariam Khan ◽  
Naveed Kausar Janjua ◽  
Safia Khan ◽  
Ibrahim Qazi ◽  
Shafaqat Ali ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Impedance ◽  
Precipitation Method ◽  
Impregnation Method ◽  
X Rays ◽  
Kinetic And Thermodynamic Parameters ◽  
Catalytic Support ◽  
Transmission Electron ◽  
Electro Oxidation ◽  
Oxidation Of Ammonia

An Ag2O(x)−PrO2(y)/γ-Al2O3 electrocatalyst series (X:Y is for Ag:Pr from 0 to 10) was synthesized, to use synthesized samples in electrochemical applications, a step in fuel cells advancements. Ag2O(x)−PrO2(y)/γ-Al2O3/Glassy-Carbon was investigated for electrochemical oxidation of ammonia in alkaline medium and proved to be highly effective, having high potential utility, as compared to commonly used Pt-based electrocatalysts. In this study, gamma alumina as catalytic support was synthesized via precipitation method, and stoichiometric wt/wt.% compositions of Ag2O−PrO2 were loaded on γ-Al2O3 by co-impregnation method. The desired phase of γ-Al2O3 and supported nanocatalysts was obtained after heat treatment at 800 and 600 °C, respectively. The successful loadings of Ag2O−PrO2 nanocatalysts on surface of γ-Al2O3 was determined by X-rays diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR), and energy dispersive analysis (EDX). The nano-sized domain of the sample powders sustained with particle sizes was calculated via XRD and scanning electron microscopy (SEM). The surface morphology and elemental compositions were examined by SEM, transmission electron microscopy (TEM) and EDX. The conductive and electron-transferring nature was investigated by cyclic voltammetry and electrochemical impedance (EIS). Cyclic voltammetric profiles were observed, and respective kinetic and thermodynamic parameters were calculated, which showed that these synthesized materials are potential catalysts for ammonia electro-oxidation. Ag2O(6)−PrO2(4)/γ-Al2O3 proved to be the most proficient catalyst among all the members of the series, having greater diffusion coefficient, heterogeneous rate constant and lesser Gibbs free energy for this system. The catalytic activity of these electrocatalysts is revealed from electrochemical studies which reflected their potentiality as electrode material in direct ammonia fuel cell technology for energy production.

scholarly journals Construction of Silver Quantum Dot Immobilized Zn-MOF-8 Composite for Electrochemical Sensing of 2,4-Dinitrotoluene

2019 ◽  
Vol 9 (22) ◽  
pp. 4952 ◽  
Author(s):  
Sushma Rani ◽  
Bharti Sharma ◽  
Shivani Kapoor ◽  
Rajesh Malhotra ◽  
Rajender S. Varma ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Limit Of Detection ◽  
Metal Organic Framework ◽  
Linear Sweep Voltammetry ◽  
Electrochemical Sensing ◽  
Amperometric Determination ◽  
Transmission Electron ◽  
Electro Catalysis ◽  
Metal Organic ◽  
Organic Framework

In the present study, we report a highly effective electrochemical sensor for detecting 2,4-dinitrotoluene (2,4-DNT). The amperometric determination of 2,4-DNT was carried out using a gold electrode modified with zinc–metal organic framework-8 and silver quantum dot (Zn-MOF-8@AgQDs) composite. The synthesized nanomaterials were characterized by using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). The synthesized nanocomposite proved to be efficient in electro-catalysis thereby reducing the 2,4-DNT. The unique combination present in Zn-MOF-8@AgQDs composite offered an excellent conductivity and large surface area enabling the fabrication of a highly sensitive (−0.238 µA µM−1 cm−2), selective, rapid and stable 2,4-DNT sensor. The dynamic linear range and limit of detection (LOD) was about 0.0002 µM to 0.9 µM and 0.041 µM, respectively. A 2,4-DNT reduction was also observed during the linear sweep voltammetry (LSV) experiments with reduction peaks at −0.49 V and −0.68 V. This is an unprecedented report with metal organic framework (MOF) composite for sensing 2,4-DNT. In addition, the presence of other species such as thiourea, urea, ammonia, glucose, and ascorbic acid displayed no interference in the modified electrode suggesting its practicability in various environmental applications.

Sign in / Sign up

Export Citation Format

Share Document