• Title, Summary, Keyword: carbon electrode

Search Result 1,211, Processing Time 0.043 seconds

The Treatment of Cyanide by Electro-Oxidation (전기산화를 이용한 Cyanide의 처리)

  • Kim, Hong-Tae;Lee, Young-Do;Kim, Kyu-Choul;Kim, Hak-Seok;Chun, Bong-Jun;Ku, Bong-Hun
    • Journal of Environmental Science International
    • /
    • v.17 no.3
    • /
    • pp.335-342
    • /
    • 2008
  • This study based on electro-coagulation & oxidation reaction is applied to wastewater treatment. Electro-oxidation reaction is used to remove cyanide(CN) which is contained in plating wastewater. Cyanide is transferred by gases such as $NH_3,\;NO_x,\;CO_2$. Analysis result and removal efficiency of Cyanide which is contained in heavy metal wastewater of plating plant, are shown as following paragraph. In electrode arrangement experiment, removal efficiency of carbon electrode(-)/STS316L electrode(+) arrangement method is superior to carbon electrode(-)/carbon electrode(+) arrangement method. Removal efficiencies of cyanide in different HRT such as 30 min, 45 min, 60 min, 75 min and 90 min are 85.5%, 93.1%, 98.0%, 98.7% and 99.4% respectively in carbon electrode(-)/STS316L electrode(+) arrangement method. Finally we can estimate the critical point at HRT of 60 min which the variation of removal efficiency is decreased and HRT to obtain removal efficiency of less than 1 mg/LCN is minimum 90 min.

Electrochemical Performance of Activated Carbon Electrode Materials with Various Post Treatments for EDLC (활성탄의 후 처리에 의한 EDLC 전극재의 전기화학 성능 개선)

  • Lee, Eunji;Kwon, Soon Hyung;Choi, Pooreum;Jung, Ji Chul;Kim, Myung-Soo
    • Korean Journal of Materials Research
    • /
    • v.24 no.6
    • /
    • pp.285-292
    • /
    • 2014
  • Commercial activated-carbon used as the electrode material of an electric double-layer capacitor (EDLC) was posttreated with various acids and alkalis to increase its capacitance. The carbon samples prepared were then heat-treated in order to control the amount of acidic functional groups formed by the acid treatments. Coin-type EDLC cells with two symmetric carbon electrodes were assembled using the prepared carbon materials and an organic electrolyte. The electrochemical performance of the EDLC was measured by galvanostatic charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy. Among the various activated carbons, the carbon electrodes (CSsb800) prepared by the treatments of coconutshell-based carbon activated with NaOH and $H_3BO_5$, and then heat treated at $800^{\circ}C$ under a flow of nitrogen gas, showed relatively good electrochemical performance. Although the specific-surface-area of the carbon-electrode material ($1,096m^2/g$) was less than that of pristine activated-carbon ($1,122m^2/g$), the meso-pore volume increased after the combined chemical and heat treatments. The specific capacitance of the EDLC increased from 59.6 to 74.8 F/g (26%) after those post treatments. The equivalent series resistance of EDLC using CSsb800 as electrode was much lower than that of EDLC using pristine activated carbon. Therefore, CSsb800 exhibited superior electrochemical performance at high scan rates due to its low internal resistance.

Desalination Effects of Capacitive Deionization Process Using Activated Carbon Composite Electrodes (활성 탄소 복합 전극을 이용한 Capacitive Deionization 공정의 제염 효과)

  • Lee, Jeong-Won;Kim, Hong-Il;Kim, Han-Joo;Shin, Hyun-Soo;Kim, Jeong-Sik;Jeong, Boong-Ik;Park, Soo-Gil
    • Journal of the Korean Electrochemical Society
    • /
    • v.12 no.3
    • /
    • pp.287-294
    • /
    • 2009
  • Desalination effects of Capacitive deionization(CDI) process using activated carbon $TiO_2$ composite electrode. In this study, we made the activated carbon electrod and activated carbon $TiO_2$ composite electrode, which analysed at cyclic voltammetry and charge-discharge. The results measured for discharge capacitance in cyclic voltammetry were 125 F/g in activated carbon electrode and capacitance of activatd carbon composite electrode was increased about two time, 243 F/g. The $TiO_2$ content of activated carbon composite electrode was 10 wt.%. When it was added wtih TiO2, electric double layer adsorption content was increased, so it was increased 25% in ion removal ratio of activated carbon electrode.

The Effect of Graphene on the Electrical Properties of a Stretchable Carbon Electrode (그래핀 첨가에 따른 신축성 카본전극의 전기적 특성 변화)

  • Lee, T.W.;Park, H.H.
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.21 no.4
    • /
    • pp.77-82
    • /
    • 2014
  • Stretchable electrodes are focused due to many demands for soft electronics. One of the candidates, carbon black composites have advantages of low cost, easy processing and decreasing resistivity in a certain range during stretching. However, the electrical conductivity of carbon black composites is not enough for electronic devices. Graphene is 2-dimensional nanostructured carbon based material which shows good electrical properties and flexibility. They may help to improve electrical conductivity of the carbon black composites. In this study, graphene was added to a carbon black electrode to enhance electrical properties and investigated. Electrical resistivity of graphene added carbon electrode decreased comparing with that of carbon black electrode because graphene bridged non-contacting carbon black aggregates to strengthen the conductive network. Also graphene reduced an increase in the resistance of the carbon black electrode applied to strain because they connected gap of separated carbon black aggregates and aligned along the stretching direction at the same time. In conclusion, an addition of graphene to carbon black gives two benefits on the electrical properties of carbon black composite as a stretchable electrode.

Preparation and Electrochemical Properties of Carbon Cryogel for Supercapacitor

  • Song, Min-Seob;Nahm, Sahn;Oh, Young-Jei
    • Journal of the Korean Ceramic Society
    • /
    • v.45 no.11
    • /
    • pp.662-666
    • /
    • 2008
  • Electrochemical properties of carbon cryogel electrode for the application of composite electrode materials mixed with metal oxide in supercapacitor have been studied. Carbon cryogels were synthesized by sol-gel polycondensation of resorcinol with form aldehyde, followed by a freeze drying, and then pyrolysis in an inert atmosphere. Physical properties of carbon cryogel were characterized by BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that carbon cryogel is amorphous material. The electrochemical properties of carbon cryogel were measured by cyclic voltammetry as a function of concentration of liquid electrolyte, galvanostatic charge-discharge with different scan rates and electrochemical impedance measurements. The result of cyclic voltammetry indicated that the specific capacitance value of a carbon cryogel electrode was approximately 150.2 F/g (at 5 mV/s in 6M KOH electrolyte).

Electrochemical Properties of EDLC Electrodes Prepared by Acid and Heat Treatment of Commercial Activated Carbons

  • Wu, Jin-Gyu;Hong, Ik-Pyo;Park, Sei-Min;Lee, Seong-Young;Kim, Myung-Soo
    • Carbon letters
    • /
    • v.9 no.2
    • /
    • pp.137-144
    • /
    • 2008
  • The commercial activated carbons are typically prepared by activation from coconut shell char or coal char containing lots of inorganic impurities. They also have pore structure and pore size distribution depending on nanostructure of precursor materials. In this study, two types of commercial activated carbons were applied for EDLC electrode by removing impurities with acid treatments, and controlling pore size distribution and contents of functional group with heat treatment. The effect of the surface functional groups on electrochemical performance of the activated carbon electrodes was investigated. The initial gravimetric and volumetric capacitance of coconut based activated carbon electrode which was acid treated by $HNO_3$ and then heat treated at $800^{\circ}C$ were 90 F/g and 42 F/cc respectively showing 94% of charge-discharge efficiency. Such a good electrochemical performance can be possibly applied to the medium capacitance of EDLC.

Carbon Corrosion at Pt/C Interface in Proton Exchange Membrane Fuel Cell Environment

  • Choi, Min-Ho;Beom, Won-Jin;Park, Chan-Jin
    • Corrosion Science and Technology
    • /
    • v.9 no.6
    • /
    • pp.281-288
    • /
    • 2010
  • This study examined the carbon corrosion at Pt/C interface in proton exchange membrane fuel cell environment. The Pt nano particles were electrodeposited on carbon substrate, and then the corrosion behavior of the carbon electrode was examined. The carbon electrodes with Pt nano electrodeposits exhibited the higher oxidation rate and lower oxidation overpotential compared with that of the electrode without Pt. This phenomenon was more active at $75^{\circ}C$ than $25^{\circ}C$. In addition, the current transients and the corresponding power spectral density (PSD) of the carbon electrodes with Pt nano electrodeposits were much higher than those of the electrode without Pt. The carbon corrosion at Pt/C interface was highly accelerated by Pt nano electrodeposits. Furthermore, the polarization and power density curves of PEMFC showed degradation in the performance due to a deterioration of cathode catalyst material and Pt dissolution.

Nonenzymatic Sensor Based on a Carbon Fiber Electrode Modified with Boron-Doped Diamond for Detection of Glucose (보론 도핑 다이아몬드로 표면처리된 탄소섬유 기반의 글루코스 검출용 비효소적 바이오센서)

  • Song, Min-Jung
    • Korean Chemical Engineering Research
    • /
    • v.57 no.5
    • /
    • pp.606-610
    • /
    • 2019
  • In this study, we demonstrated that the nonenzymatic glucose sensor based on the flexible carbon fiber bundle electrode with BDD nanocomposites (CF-BDD electrode). As a nano seeding method for the deposition of BDD on flexible carbon fiber, electrostatic self-assembly technique was employed. Surface morphology of BDD coated carbon fiber electrode was observed by scanning electron microscopy. And the electrochemical characteristics were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. This CF-BDD electrode exhibited a large surface area, a direct electron transfer between the redox species and the electrode surface and a high catalytic activity, resulting in a wider linear range (3.75~50 mM), a faster response time (within 3 s) and a higher sensitivity (388.8 nA/mM) in comparison to a bare CF electrode. As a durable and flexible electrochemical sensing electrode, this brand new CF-BDD scheme has promising advantages on various electrochemical and wearable sensor applications.

Charge-Discharge Properties of Polyaniline-Carbon Composite Electrodes for Supercapacitor (Supercapacitor용 Polyaniline-Carbon Composite전극의 충방전 특성)

  • Kang, Kwang-Woo;Kim, Jong-Uk;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.124-127
    • /
    • 2000
  • The purpose of this study is to research and develop PAn-Carbon composite electrode for Supercapacitor. Supercapacitor cell of PAn-Carbon composite electrode with 1M $LiClO_{4}/IPC$ brings out good capacitor performance below 4.0V. The radius of semicircle of PAn-Carbon composite electrode adding 30wt% Acetylene Black was absolutely small. The total resistance of Supercapacitor cell mainly depended on internal resistance of he electrode. The discharge capacitance of PAn-Carbon on composite with 30wt% Acetylene Black in 1st and 50th cycles was 29 and 31F/g at current density of $1mA/cm^2$. The capacitance of PAn-Carbon composite with 30wt% Acetylene Black capacitor was larger than that of PAn capacitor without Acetylene Black. The coulombic efficiency of supercapacitor at discharge process of 1 and 50 cycles were 94 and 100%. respectively. PAn-Carbon composite Supercapacitor with 30wt.% Acetylene Black content showed good capacitance and stability with cycling.

  • PDF

Electrochemical Oxidation of Carbon Felt for Redox Flow Battery (Redox flow battery용 carbon felt 전극의 전기화학적 산화)

  • Jung, Young-Guan;Hwang, Gab-Jin;Kim, Jae-Chul;Ryu, Cheol-Hwi
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.22 no.5
    • /
    • pp.721-727
    • /
    • 2011
  • All vanadium redox-flow battery (VRFB) has been studied actively as one of the most promising electrochemical energy storage systems for a wide rage of applications such as electric vehicles, photovoltaic arrays, and excess power generated by electric power plants at night time. In this study, carbon felt electrodes were treated by electrochemical oxidation with KOH, and the cyclic voltammetry were studied in order to investigate redox reactivity of vanadium ion species with carbon felt electrodes. Besides the effect of electrochemical oxidation on the surface chemistry of carbon felt electrodes were investigated using the X-ray photoelectron spectroscopy (XPS). After electrochemical oxidation, XPS analysis of PAN based GF20-3 carbon felt electrode revealed on increase in the overall surface oxygen content of the carbon felts after electrochemical oxidation. Redox reaction characteristics using cyclic voltammetry (CV) were ascertained that the electrochemical treated electrode were more reversible than the untreated electrode.