Synergistic Effects of Fe2O3 Nanotube/Polyaniline Composites for an Electrochemical Supercapacitor with Enhanced Capacitance

α-Fe2O3, which is an attractive material for supercapacitor electrodes, has been studied to address the issue of low capacitance through structural development and complexation to maximize the use of surface pseudocapacitance. In this study, the limited performance of α-Fe2O3 was greatly improved by optimizing the nanotube structure of α-Fe2O3 and its combination with polyaniline (PANI). α-Fe2O3 nanotubes (α-NT) were fabricated in a form in which the thickness and inner diameter of the tube were controlled by Fe(CO)5 vapor deposition using anodized aluminum oxide as a template. PANI was combined with the prepared α-NT in two forms: PANI@α-NT-a enclosed inside and outside with PANI and PANI@α-NT-b containing PANI only on the inside. In contrast to α-NT, which showed a very low specific capacitance, these two composites showed significantly improved capacitances of 185 Fg−1 for PANI@α-NT-a and 62 Fg−1 for PANI@α-NT-b. In the electrochemical impedance spectroscopy analysis, it was observed that the resistance of charge transfer was minimized in PANI@α-NT-a, and the pseudocapacitance on the entire surface of the α-Fe2O3 nanotubes was utilized with high efficiency through binding and conductivity improvements by PANI. PANI@α-NT-a exhibited a capacitance retention of 36% even when the current density was increased 10-fold, and showed excellent stability of 90.1% over 3000 charge–discharge cycles. This approach of incorporating conducting polymers through well-controlled nanostructures suggests a solution to overcome the limitations of α-Fe2O3 electrode materials and improve performance.

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Enhancement of the cerium oxide primer layers deposited on AA2024-T3 aircraft alloy by preliminary Enhancement of the cerium oxide primer layers deposited on AA2024-T3 aircraft alloy by preliminary anodization

Journal of Electrochemical Science and Engineering ◽

10.5599/jese.478 ◽

2018 ◽

Cited By ~ 1

Author(s):

Stephan V. Kozhukharov ◽

Christian Girginov

Keyword(s):

Cerium Oxide ◽

Electrochemical Impedance ◽

Protective Coatings ◽

Salt Spray ◽

Neutral Salt ◽

Anodized Aluminum ◽

Cross Sectional ◽

Anodized Aluminum Oxide ◽

Linear Voltammetry ◽

And Performance

The possibility for combination between Anodized Aluminum Oxide (AAO) and Cerium Oxide Primer Layer (CeOPL) for elaboration of efficient protective coatings for AA2024-T3 aircraft alloy is proposed in the present research. The combined AAO/CeOPL coating characterizations include Electrochemical Impedance Spectroscopy (EIS) combined with Linear Voltammetry (LVA), for extended times (until 2520 hours) to a model corrosive medium (3.5% NaCl). Topographical and cross-sectional (SEM and EDX) observations were performed in order to determine the AAO/CeOPL film thickness and composition. The AAO/CeOPL layer durability tests were confirmed by standard Neutral Salt Spray (NSS). The data analysis from all the used measurement methods has undoubtedly shown that the presence of AAO film significantly improves the cerium oxide primer layer (CeOPL) protective properties and performance.

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A Novel Silicon-Based Packaging Platform for High-Efficiency LED Modules

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.314-316.359 ◽

2011 ◽

Vol 314-316 ◽

pp. 359-363

Author(s):

Cong Wang ◽

Won Sang Lee ◽

Nam Young Kim

Keyword(s):

Heat Dissipation ◽

High Efficiency ◽

Light Emitting Diode ◽

Chemical Vapor ◽

Anodized Aluminum ◽

Anodized Aluminum Oxide ◽

Insulating Layer ◽

Light Emitting ◽

New Type ◽

Silicon Based

A novel silicon-based packaging platform with the electroplated-based reflector and the electrode- guided interconnections is developed for the packaging component of a high-luminosity and high-efficiency multi-chip light-emitting diode (LED) module, which is patterned on a new type of insulating layer that consists of nanoporous anodized aluminum oxide (AAO) layer and plasma- enhanced chemical vapor deposition (PECVD) deposited silicon dioxide (SiO2) on a doped silicon substrate. The reflector and the electrical interconnections are successfully fabricated by using the electroplating method in the same body. In order to obtain the benefits of high efficiency LED modules, the requirements concerning thermal management and photomechanical layout have to be met. In this paper, we will discuss a novel fabrication method in LED module packaging platform, and then describe the thin layer of electroplated Cu/Ni/Au in order to reduce thermal resistance and to increase thermal diffusion efficiency. The heat generated by the LED chips is dissipated directly to the silicon body through the metal-plated platform, and truly excellent heat dissipation characteristics are observed. We demonstrate 987 lm 8 W-level cool-white light (5000 K, 16 V, 110 lm/W, CRI = 77) emission for 570 µm × 230 µm-chip LEDs at 600 mA operation.

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High-luminance and high-efficiency multi-chip light-emitting diode array packaging platform with nanoscale anodized aluminum oxide on silicon substrate

Thin Solid Films ◽

10.1016/j.tsf.2013.11.019 ◽

2014 ◽

Vol 557 ◽

pp. 346-350 ◽

Cited By ~ 5

Author(s):

Cong Wang ◽

Sung-Jin Cho ◽

Nam-Young Kim

Keyword(s):

Aluminum Oxide ◽

Silicon Substrate ◽

High Efficiency ◽

Light Emitting Diode ◽

Diode Array ◽

Anodized Aluminum ◽

High Luminance ◽

Anodized Aluminum Oxide ◽

Light Emitting

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Manufacturing of nanopillar (ultra-dispersed) catalytically active materials through chemical engineering

Тонкие химические технологии ◽

10.32362/2410-6593-2021-16-2-105-112 ◽

2021 ◽

Vol 16 (2) ◽

pp. 105-112

Author(s):

A. P. Antropov ◽

N. K. Zaytsev ◽

Ye. D. Ryabkov ◽

N. A. Yashtulov ◽

P. N. Mudrakova

Keyword(s):

Chemical Engineering ◽

Electrode Materials ◽

High Efficiency ◽

Active Material ◽

Metallic Nickel ◽

Anodized Aluminum ◽

Active Materials ◽

X Ray ◽

Significant Interest ◽

Catalytically Active

Objectives. Catalytically active materials are required in different chemical engineering processes. This makes the development of new materials with high efficiency and original ways in which to obtain them of significant interest. The present work investigates the synthesis of catalytically active material including electrode materials, as well as their improved efficiency due to the nanodecoration of their surface.Methods. An aluminum folio was nanoperforated (nanoscalloped) by high-voltage anodization in an acidic medium. The effective electrode material was obtained as a metallic nickel replica rather than an oxide layer of the product. To study the surface state of aluminum obtained in this manner, a scanning electron microscope (Hitachi-SU8200) was used. The elementary composition of the aluminum was determined by back-scattered X-ray irradiation.Results. The nickel replica obtained in the above-described process exceeded the catalytic activity estimated by methanol oxidation of the unprocessed nickel 70–150 times.Conclusions. The present paper demonstrates the potential of creating effective catalytically active nanopillar materials using the metallic rather than metal-oxide part of a layer of anodized aluminum as a matrix template.

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Evaluation of the electrochemical performance of Ag containing AAO layers after extended exposure to a model corrosive medium

Journal of Electrochemical Science and Engineering ◽

10.5599/jese.820 ◽

2020 ◽

Vol 10 (4) ◽

pp. 317-334

Author(s):

Stephan V. Kozhukharov ◽

Christian Girginov ◽

Denitsa Kiradzhiyska ◽

Aleksander Tsanev ◽

Georgy Avdeev

Keyword(s):

Corrosive Medium ◽

Photoelectron Spectroscopy ◽

Electrochemical Impedance ◽

Barrier Properties ◽

Anodized Aluminum ◽

Anodized Aluminum Oxide ◽

X Ray ◽

Protective Layers ◽

Research Activities

The coating procedure appears to be an indispensable finishing stage in the production of Al based industrial products, engineering facilities and equipment. For this reason, there is an ever-increasing interest towards the elaboration of reliable corrosion protective layers with apparent coverage, adhesion, and barrier properties. In this sense, both the formation of anodized aluminum oxide (AAO) layer and its further modification with silver enable the elaboration of advanced (Al-O-Ag) films with extended beneficial characteristics. The present research activities are aimed at the determination of the corrosion protective properties of electrochemically synthesized Al-O-Ag layers on the technically pure AA1050 alloy. The structures and compositions of the obtained Al-O-Ag layers were characterized by X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The research activities were accomplished by means of two independent electrochemical characterization methods: electrochemical impedance spectroscopy (EIS) and potentiodynamic scanning (PDS). The electrochemical measurements were performed after 24, 168 and 672 hours of exposure to 3.5 % NaCl solution used as a model corrosive medium (MCM), in order to determine the barrier properties and durability of the elaborated Al-O-Ag layers. The analysis of the obtained results has undoubtedly shown that the proposed electrochemical Al-O-Ag layer formation can successfully be used for the creation of self-standing layers with apparent corrosion protective properties. Besides, Al-O-Ag system can be used as a basis for development of efficient protective layers suitable for application in biologically contaminated media.

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Improvement of Ti/RuO2–IrO2 Anode Lifetime and Electrocatalytical Properties by Using an Eco-Friendly Thermal Decomposition Method Using Polyvinyl Alcohol as Solvent

10.26434/chemrxiv.7991129 ◽

2019 ◽

Author(s):

Charlys Bezerra ◽

Géssica Santos ◽

Marilia Pupo ◽

Maria Gomes ◽

Ronaldo Silva ◽

...

Keyword(s):

Thermal Decomposition ◽

Polyvinyl Alcohol ◽

High Efficiency ◽

Electrochemical Impedance ◽

Pechini Method ◽

Low Cost ◽

Charge Transfer Resistance ◽

Transfer Resistance ◽

Calcination Temperatures ◽

Service Lifetime

Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO2–IrO2 anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO2 and IrO2 have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO2–IrO2 anodes with improved properties that can be further extended to synthesise other MMO compositions.

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A fast-responding semi-transparent pressure-sensitive paint based on through-hole anodized aluminum oxide membrane

Sensors and Actuators A Physical ◽

10.1016/j.sna.2018.02.026 ◽

2018 ◽

Vol 274 ◽

pp. 10-18 ◽

Cited By ~ 4

Author(s):

Di Peng ◽

Jiawei Chen ◽

Lingrui Jiao ◽

Yingzheng Liu

Keyword(s):

Aluminum Oxide ◽

Pressure Sensitive Paint ◽

Anodized Aluminum ◽

Anodized Aluminum Oxide ◽

Pressure Sensitive ◽

Oxide Membrane ◽

Through Hole

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A Hierarchical Architecture of Functionalized Polyaniline/Manganese Dioxide Composite with Stable-Enhanced Electrochemical Performance

Journal of Composites Science ◽

10.3390/jcs5050129 ◽

2021 ◽

Vol 5 (5) ◽

pp. 129

Author(s):

Yapeng Wang ◽

Yanxiang Wang ◽

Chengjuan Wang ◽

Yongbo Wang

Keyword(s):

Electrochemical Performance ◽

Manganese Dioxide ◽

Specific Capacitance ◽

Current Density ◽

Electrode Materials ◽

High Efficiency ◽

Scanning Speed ◽

Hierarchical Architecture ◽

Electrochemical Window ◽

A Current

As one of the most outstanding high-efficiency and environmentally friendly energy storage devices, the supercapacitor has received extensive attention across the world. As a member of transition metal oxides widely used in electrode materials, manganese dioxide (MnO2) has a huge development potential due to its excellent theoretical capacitance value and large electrochemical window. In this paper, MnO2 was prepared at different temperatures by a liquid phase precipitation method, and polyaniline/manganese dioxide (PANI/MnO2) composite materials were further prepared in a MnO2 suspension. MnO2 and PANI/MnO2 synthesized at a temperature of 40 °C exhibit the best electrochemical performance. The specific capacitance of the sample MnO2-40 is 254.9 F/g at a scanning speed of 5 mV/s and the specific capacitance is 241.6 F/g at a current density of 1 A/g. The specific capacitance value of the sample PANI/MnO2-40 is 323.7 F/g at a scanning speed of 5 mV/s, and the specific capacitance is 291.7 F/g at a current density of 1 A/g, and both of them are higher than the specific capacitance value of MnO2. This is because the δ-MnO2 synthesized at 40 °C has a layered structure, which has a large specific surface area and can accommodate enough electrolyte ions to participate the electrochemical reaction, thus providing sufficient specific capacitance.

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Surface Enhanced Raman Spectroscopy With Electrodeposited Copper Ultramicro-Wires With/Without Silver Nanostars Decoration

Nanomaterials ◽

10.3390/nano11020518 ◽

2021 ◽

Vol 11 (2) ◽

pp. 518

Author(s):

Margherita Longoni ◽

Maria Sole Zalaffi ◽

Lavinia de Ferri ◽

Angela Maria Stortini ◽

Giulio Pojana ◽

...

Keyword(s):

Raman Spectroscopy ◽

Surface Enhanced Raman Spectroscopy ◽

Anodized Aluminum ◽

Anodized Aluminum Oxide ◽

Electrochemical Preparation ◽

Deposition Parameters ◽

Raman Enhancement ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Materials Used

The electrochemical preparation of arrays of copper ultramicrowires (CuUWs) by using porous membranes as templates is critically revisited, with the goal of obtaining cheap but efficient substrates for surface enhanced Raman spectroscopy (SERS). The role of the materials used for the electrodeposition is examined, comparing membranes of anodized aluminum oxide (AAO) vs. track-etched polycarbonate (PC) as well as copper vs. glassy carbon (GC) as electrode material. A voltammetric study performed on bare electrodes and potentiostatic tests on membrane coated electrodes allowed the optimization of the deposition parameters. The final arrays of CuUWs were obtained by chemical etching of the template, with NaOH for AAO and CH2Cl2 for PC. After total etching of the template, SERS spectra were recorded on CuUWs using benzenethiol as SERS probe with known spectral features. The CuUW substrates displayed good SERS properties, providing enhancement factor in the 103–104 range. Finally, it was demonstrated that higher Raman enhancement can be achieved when CuUWs are decorated with silver nanostars, supporting the formation of SERS active hot-spots at the bimetallic interface.

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