LaFeO3 Modified RuO2 for Enhancing Electrochemical Performances

LaFeO3 nanoparticles-modified RuO2 and RuO2 samples were fabricated by a thermal decomposition and was characterized by powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and cyclic voltammetry tests. XRD results reveal that the RuO2 and RuO2-LaFeO3 samples are mainly a rutile structure. Compared with the RuO2 sample, the RuO2-LaFeO3 sample has smaller crystalline grain size. Cyclic voltammetry analysis shows the voltammetric behaviour and the characteristic potentials of the RuO2 and the RuO2-LaFeO3 samples are similar in 1.0 M KOH solution. Voltammetric charge analysis reveals that the RuO2-LaFeO3 sample has higher concentrated of surface active species and larger exposed surface area than the RuO2 sample. Capacitive measurement results show the Double-layer capacitance (Cdl) and the electrochemical surface area (ECSA) values of the RuO2-LaFeO3 sample are approximately 2 times larger than those of the RuO2 sample, indicating that the electrochemical active surface area increase when integrating of RuO2 with LaFeO3 nanoparticles.

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Flowerlike submicrometer gold particles: Size- and surface roughness-controlled synthesis and electrochemical characterization

Journal of Materials Research ◽

10.1557/jmr.2010.0242 ◽

2010 ◽

Vol 25 (9) ◽

pp. 1755-1760 ◽

Cited By ~ 7

Author(s):

Changsheng Shan ◽

Dongxue Han ◽

Jiangfeng Song ◽

Ari Ivaska ◽

Li Niu

Keyword(s):

Surface Area ◽

Photoelectron Spectroscopy ◽

Electrocatalytic Activity ◽

Active Surface ◽

Molar Ratio ◽

Active Surface Area ◽

Step Method ◽

Gold Particles ◽

X Ray ◽

One Step

Flowerlike submicrometer gold particles were synthesized through a simple one-step method using p-diaminobenzene as a reductant in the presence of poly(sodium 4-styrenesulfonate) in aqueous solution. The particle size with diameters ranging from 267 to 725 nm could be tuned by varying the molar ratio of poly(sodium 4-styrenesulfonate) to HAuCl4, which also resulted in tunable roughness. The gold particles were confirmed by scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. Cyclic voltammetry showed that the specific surface area of the flowerlike particles was larger than that of sphere particles. The obtained flowerlike particles with higher surface area also exhibited higher electrocatalytic activity toward H2O2 and O2. The increase of electrocatalytic activity could be attributed to the increase of the active surface area.

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Facile Fabrication of Double-Layered Electrodes for a Self-Powered Energy Conversion and Storage System

Nanomaterials ◽

10.3390/nano10122380 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2380

Author(s):

Seungju Jo ◽

Nagabandi Jayababu ◽

Daewon Kim

Keyword(s):

Energy Conversion ◽

Surface Area ◽

Active Surface ◽

Triboelectric Nanogenerator ◽

Active Surface Area ◽

Electrochemical Performances ◽

Energy Conversion And Storage ◽

Facile Fabrication ◽

Self Powered ◽

And Storage

An aluminum double-layered electrode (DE-Al) was successfully employed as two electrodes in a symmetrical supercapacitor (double-layered electrode symmetric SC (DE-SC)) and as a positive layer of a triboelectric nanogenerator (DE-TENG) with the aim of energy conversion and storage using a selfsame structured, self-powered flexible device. A facile water-assisted oxidation (WAO) process and metal sputtering after the WAO process can allow the electrodes to greatly improve the active surface area and the conductivity, leading to the enhancement of the electrochemical performances of a supercapacitor (SC). Particularly, this double-layered structure fabrication process is extremely less time-consuming and cost-effective. The electrochemical test of the proposed DE-Al was systematically conducted by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS), along with the in-depth characterizations of the surface. From these studies, the DE-Al offers exceptional electrochemical properties compared with other structures, which were utilized as the electrodes in the polyvinyl alcohol/phosphoric acid (PVA/H3PO4) gel electrolyte. The improved performance apparently evidenced from the electrochemical tests of fabricated SC resulted from the enhanced electrical conductivity and large active surface area. The specific capacitance and cycle-life stability of the DE-SC were investigated by using a GCD analysis. Additionally, the EIS curves before and after stability test (for 3500 cycles) were obtained to prove the long-term endurance of DE-SC. A vertical contact and the separation mode of the TENG were also fabricated by using the same DE-Al as a positive layer and polydimethylsiloxane (PDMS) as a negative layer. Finally, the fabricated SC and TENG were successfully combined using a bridge rectifier to convert and store the mechanical energy as electrical energy. This simple design and facile fabrication of a double-layered-electrode-based structure is promising for the development of an energy conversion and storage device.

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Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

10.26434/chemrxiv.7770338.v1 ◽

2019 ◽

Cited By ~ 1

Author(s):

Kailun Yang ◽

Recep Kas ◽

Wilson A. Smith

Keyword(s):

Surface Area ◽

High Surface ◽

High Surface Area ◽

Catalyst Layer ◽

Active Surface ◽

Active Surface Area ◽

High Concentration ◽

Copper Electrodes ◽

Surface Enhanced ◽

Local Current

This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO2 electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO2 electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO2 electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer.

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Reduction of cogging torque of PMBLDC motor by changes in active surface area

IET-UK International Conference on Information and Communication Technology in Electrical Sciences (ICTES 2007) ◽

10.1049/ic:20070648 ◽

2007 ◽

Author(s):

R. Somanatham ◽

P.V.N. Prasad

Keyword(s):

Surface Area ◽

Active Surface ◽

Active Surface Area ◽

Cogging Torque

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Reduced Graphene Oxide-Supported Pt-Based Catalysts for PEM Fuel Cells with Enhanced Activity and Stability

Catalysts ◽

10.3390/catal11020256 ◽

2021 ◽

Vol 11 (2) ◽

pp. 256

Author(s):

Irina V. Pushkareva ◽

Artem S. Pushkarev ◽

Valery N. Kalinichenko ◽

Ratibor G. Chumakov ◽

Maksim A. Soloviev ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Surface Area ◽

Pem Fuel Cells ◽

Polyol Process ◽

Proton Exchange ◽

Active Surface Area ◽

Electrochemical Performances ◽

Simultaneous Reduction ◽

Reduced Graphene

Platinum (Pt)-based electrocatalysts supported by reduced graphene oxide (RGO) were synthesized using two different methods, namely: (i) a conventional two-step polyol process using RGO as the substrate, and (ii) a modified polyol process implicating the simultaneous reduction of a Pt nanoparticle precursor and graphene oxide (GO). The structure, morphology, and electrochemical performances of the obtained Pt/RGO catalysts were studied and compared with a reference Pt/carbon black Vulcan XC-72 (C) sample. It was shown that the Pt/RGO obtained by the optimized simultaneous reduction process had higher Pt utilization and electrochemically active surface area (EASA) values, and a better performance stability. The use of this catalyst at the cathode of a proton exchange membrane fuel cell (PEMFC) led to an increase in its maximum power density of up to 17%, and significantly enhanced its performance especially at high current densities. It is possible to conclude that the optimized synthesis procedure allows for a more uniform distribution of the Pt nanoparticles and ensures better binding of the particles to the surface of the support. The advantages of Pt/RGO synthesized in this way over conventional Pt/C are the high electrical conductivity and specific surface area provided by RGO, as well as a reduction in the percolation limit of the components of the electrocatalytic layer due to the high aspect ratio of RGO.

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Increasing Active Surface Area to Fabricate Ultra-Hydrophobic Surface by Using “Black Silicon” with Bosch Etching Process

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2012.4906 ◽

2012 ◽

Vol 12 (6) ◽

pp. 4919-4927 ◽

Cited By ~ 3

Author(s):

Nithi Atthi ◽

Jakrapong Supadech ◽

Gaetan Dupuy ◽

On-uma Nimittrakoolchai ◽

Apirak Pankiew ◽

...

Keyword(s):

Surface Area ◽

Hydrophobic Surface ◽

Active Surface ◽

Etching Process ◽

Black Silicon ◽

Active Surface Area

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Preparation and Electrochemical Performances of Calcium Zincate Synthesized by Microwave Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.868 ◽

2011 ◽

Vol 236-238 ◽

pp. 868-871 ◽

Cited By ~ 1

Author(s):

Meng Liang Tong ◽

Xuan Yan Liu

Keyword(s):

Cyclic Voltammetry ◽

Active Material ◽

Electrochemical Performances ◽

Microwave Method ◽

X Ray ◽

Battery Charge ◽

Secondary Battery ◽

Initial Capacity ◽

Charge Discharge ◽

Discharge Test

Calcium zincate as an active material in Zn/Ni secondary battery has been successfully synthesized by microwave method. The chemical composition of Ca(OH)2·2Zn(OH)2·2H2O was confirmed by X-ray powder diffraction pattern and weight loss in thermogravimetric analysis.The results of cyclic voltammetry and experimental Zn/Ni battery charge–discharge test showed that the material of calcium zincate had excellent electrochemical performances: a high discharging platform of 1.685 V and a good cycleability, discharge capacity would be 70.0% of initial capacity after circulated 120 times.

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