• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2002년도 춘계총회 및 학술발표회
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• pp.41-41
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• 2002

• 한국환경보건학회지
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• 제35권4호
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• pp.295-303
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• 2009

A simulated wastewater containing the dye Rhodamine B (RhB) was electrolytically treated using a three-dimensional electrode reactor equipped with granular activated carbon (GAC) as particle electrode. The effect of type of packing material (GAC, ACF, Nonwoven fabric fiber coated with activated carbon), amounts of GAC packing (25-100 g), current (0.5-3 A) and electrolyte concentration (0.5-3 g/l) was evaluated. Experimental results showed that performance for RhB decolorization of the 3 three-dimensional electrodes lie in: GAC > Nonwoven fabric fiber > ACF. When considered RhB decolorization, oxidants concentration and electric power, optimum GAC dosage was 50 g. Generated concentration of 3 oxidants ($ClO_2$, free Cl, $H_2O_2$) was increased with increase of applied current, however optimum current for RhB degradation was 2.5 A. The oxidants concentration was increased with increase of NaCl concentration and optimum NaCl dosage for RhB degradation was 1.5 g/l.

• Carbon letters
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• 제20권
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• pp.76-80
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• 2016

• 대한안전경영과학회지
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• 제2권2호
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• pp.95-108
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• 2000

Electrochemical charateristics of activated carbon fiber cloth(ACFC) electrode were studied with propylene carbonate(PC), ${\gamma}$-butyrolactone(GBL) and N,N-dimethyl-formamide(DMF) as a solvent and tetraethylammoniumtetrafluoroborate(TEABF$_4$), tetraethylammoniumhexafluorophosphate(TEABF$_{6}$), tetrabutylammoniumtetrafluoroborate(TBABF$_4$) and tetrabutylammonium hexafluorophosphate(TBAPF$_6$) as an electrolytes(active material). The concentrations of electrolytes were in the range of 0.2~1.2 N, the volume ratios of PC and DMF as a mixed solvent system, were 90：10, 80：20, 70：30, 60：40, 50：50, and 40：60 vol%. Electrochemical characteristics such as electric conductivity, internal resistance, and electric capacitance of fabricated unit cells were measured after the moisture of activated material was removed with molecular sieve. Electrochemical characteristics were better in mixed solvents system than in mono solvent system. The mono solvent system of 1.0 N electrolyte of GBL/TEABF$_4$ with activated carbon cloth electrodes showed better result but the mixed solvent system with PC and DMF/TEABF$_4$(50：50 vol%) and the concentration of 1.0 N electrolyte showed the best characteristics. Internal resistance was 3.47 $\Omega$ and specific capacitance was 19.1 F/g respectively.y.

• 자원리싸이클링
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• 제8권3호
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• pp.18-25
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• 1999

화학제염이나 전지화학제염을 통해 발생된 방사성 폐액을 정화처리할 수 있는 새로운 방법으로, 다공성 활성탄소섬유(ACF)상에서 폐액중 코발트이온의 전기적 흡·탈착에 대한 연구를 수행하였다. 회전원판 전극을 사용하여 순환전압전류법으로 전기이중층 충전만이 발생하는 전위 영역을 조사하였다. ACF 전극을 사용한 회분식 전기흡착 실험결과, 음의 전위 가용은 저위 미가용 시의 흡착에 비해 코발트이온의 흡착을 증가시켰다. 또한 흡착된 코발트 이온은 역전된 가용전위에 의해 용액으로 용출되었으며 이와 동시에 탄소체 전극이 재생되어, 전기흡착 공정의 가역성을 확인 할 수 있었다.

• Carbon letters
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• 제15권1호
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• pp.71-76
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• 2014

Activated carbon nanofibers (ACNF) were prepared from polyacrylonitrile (PAN)-based nanofibers using $CO_2$ activation methods with varying activation process times. The surface and structural characteristics of the ACNF were observed by scanning electron microscopy and X-ray diffraction, respectively. $N_2$ adsorption isotherm characteristics at 77 K were confirmed by Brunauer-Emmett-Teller and Dubinin-Radushkevich equations. As experimental results, many holes or cavernous structures were found on the fiber surfaces after the $CO_2$ activation as confirmed by scanning electron microscopy analysis. Specific surface areas and pore volumes of the prepared ACNFs were enhanced within a range of 10 to 30 min of activation times. Performance of the porous PAN-based nanofibers as an electrode for electrical double layer capacitors was evaluated in terms of the activation conditions.

• Carbon letters
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• 제27권
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• pp.64-71
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• 2018

$TiO_2$-doped activated carbon fibers (ACFs) were successfully prepared as capacitive deionization (CDI) electrode materials by facile ultrasonication-assisted process. ACFs were treated with titanium isopropoxide (TTIP) and isopropyl alcohol solutions of different concentrations and then calcinated by ultrasonication without heat-treatment. The results show that a certain amount of anatase $TiO_2$ was present on the ACF surface. The specific capacitance of the $TiO_2$-doped ACF electrode was remarkably improved (by 93.8% at scan rate of $50mV\;s^{-1}$) over that of the untreated ACF electrode, despite decreases in the specific surface area and total pore volume upon $TiO_2$ doping. From the CDI experiments, the salt adsorption capacity and charge efficiency of the sample with TTIP percent concentration of 15% were found to considerably increase by 71.9 and 57.1%, respectively. These increases are attributed to the improved wettability of the electrode, which increases the number of surface active sites and facilitates salt ion diffusion in the ACF pores. Additionally, the Ti-OH groups of $TiO_2$ act as electrosorption sites, which increases the electrosorption capacity.

• 공업화학
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• 제10권6호
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• pp.814-821
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• 1999

고비표면적의 활성탄소섬유(ACF: activated carbon fiber)를 분극성 전극으로 이용한 전기이중층 캐패시터(electric double layer capacitor)의 단위 cell test를 통하여, ACF의 비표면적, 세공의 크기 및 전기전도도가 캐패시터의 비축전용량에 커다란 영향을 미치고 있음을 확인할 수 있었고, 전해질은 $H^+$ 이온을 함유한 $H_2SO_4$이 가장 좋은 축전용량을 나타내었으나, 집전체 부식 등의 문제로 인하여, 실용화에 있어서는 우수한 충방전 거동을 나타낸 KOH계 전해질이 적당한 것으로 확인되었다. 분극성 전극으로 사용되는 ACF를 탄화 또는 후활성화 등이 후처리를 통하여 비축전용량을 급격히 증가시킬수 있었고, 3만회까지의 연속 충방전 실험에서 전기이중층 캐패시터는 2차전지에서는 찾아 볼 수 없는 매우 높은 충방전 효율과 긴 사용수명을 가지는 것을 확인할 수 있었다.

• Korean Chemical Engineering Research
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• 제43권1호
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• pp.60-65
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• 2005

연속적 전기흡착 셀에서 활성탄소섬유 부직포 전극을 사용하여 U(VI) 함유 폐액을 처리하였다. 더 낮은 전위에서 U(VI)의 전기흡착 효율을 높이기 위하여 ACFs를 화학약품으로 표면처리하고 그의 세공구조 및 관능기의 변화를 조사하였으며 처리조건이 U(VI)의 흡착에 미치는 영향을 고찰하였다. 표면처리한 모든 ACFs의 비표면적은 감소하였다. 중성염 및 염기성 용액으로 처리한 ACFs의 산성관능기는 감소했지만 산성 용액으로 처리한 ACFs의 산성관능기는 증가하였다. 산성관능기는 U(VI)의 흡착을 차단하여 산성용액 처리 ACFs 전극은 처리하지 않은 ACFs 전극에 비하여 U(VI)의 흡착용량이 감소했다. 중성염과 염기성 용액으로 처리한 ACFs 전극은 흡착용량이 크게 증가하여 -0.3 V의 낮은 전위에서도 처리하지 않은 ACFs 전극의 -0.9 V에 상응하는 결과를 얻었다. 이러한 결과는 ACFs 표면의 산성관능기 감소에 의한 이온의 차단효과(Shielding effect)가 줄어들 뿐만 아니라 음전위 가용에 의한 전기이중층 내에서의 $OH^-$의 증가로 U(VI) 흡착이 효율적으로 진행되었기 때문이다.

• 한국재료학회지
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• 제32권2호
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• pp.107-113
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• 2022

Fibrous supercapacitors (FSs), owing to their high power density, good safety characteristic, and high flexibility, have recently been in the spotlight as energy storage devices for wearable electronics. However, despite these advantages, FCs face many challenges related to their active material of carbon fiber (CF). CF has low surface area and poor wettability between electrode and electrolyte, which result in low capacitance and poor long-term stability at high current densities. To overcome these limits, fibrous supercapacitors made using surface-activated CF (FS-SACF) are here suggested; these materials have improved specific surface area and better wettability, obtained by introducing porous structure and oxygen-containing functional groups on the CF surface, respectively, through surface engineering. The FS-SACF shows an improved ion diffusion coefficient and better electrochemical performance, including high specific capacity of 223.6 mF cm^-2 at current density of 10 ㎂ cm^-2, high-rate performance of 171.2 mF cm^-2 at current density of 50.0 ㎂ cm^-2, and remarkable, ultrafast cycling stability (96.2 % after 1,000 cycles at current density of 250.0 ㎂ cm^-2). The excellent electrochemical performance is definitely due to the effects of surface functionalization on CF, leading to improved specific surface area and superior ion diffusion capability.