• 한국분말재료학회지
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• 제17권6호
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• pp.449-455
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• 2010

The hybrid structured photo-electrode for dye-sensitized solar cells was fabricated based on the composites of $TiO_2$ nanoparticles and nanowires. Three samples with different hybrid structures were prepared with 17 vol%, 43 vol%, and 100 vol% nanowires. The energy conversion efficiency was enhanced from 5.54% for pure nanoparticle cells to 6.01% for the hybrid structure with 17 vol% nanowires. For the hybrid structured layers with high nanowires concentration (43 vol% and 100 vol%), the efficiency decreased with the nanowire concentration, because of the decrease of specific surface area, and of thus decreased current density. The random orientations of $TiO_2$ nanowires can be preserved by the doctor blade process, resulted in the enhanced efficiency. The hybrid structured $TiO_2$ layer can possess the advantages of the high surface area of nanoparticles and the rapid electron transport rate and the light scattering effect of nanowires.

• Environmental Engineering Research
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• 제14권1호
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• pp.32-40
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• 2009

In this study, we have prepared three kinds of carbon nanometer tube $CNT/TiO_{2}$ electrodes through impregnation with different concentration titanium n-butoxide (TNB) solution. The prepared electrodes were characterized with surface properties, structural crystallinity, elemental identification and photoelectrocatalytic activity. The $N_2$ adsorption data showed that the composites had decreased surface area compared with the pristine CNT. This indicated the blocking of micropores on the surface of CNT, which was further supported by observation via SEM. XRD results showed patterns for the composites and a typical single and clear anatase crystal structure. The main elements such as C, O and Ti were existed for all samples from the EDX data. The catalytic efficiency of the developed electrode was evaluated by the photoelectrodegradation of methylene blue (MB). The positive potential applied in photoelectrocatalytic (PEC) oxidation was studied. It was found that photoelectrocatalytic (PEC) decomposition of MB solution could be attributed to combination effects between $TiO_2$ photocatalytic and CNT electro-assisted. Through the comparison between photocatalytic (PC) oxidation and photoelectrocatalytic (PEC) oxidation, it was found that the PEC oxidation efficiency for MB is higher than that of PC oxidation.

• 센서학회지
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• 제24권4호
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• pp.219-223
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• 2015

Indium free consisting of three alternating layers GTO/Ag/GTO has been fabricated by radio-frequency (RF) sputtering for the applications as transparent conducting electrodes and the structural, electrical and optical properties of the gallium tin oxide (GTO) films were carefully studied. The gallium tin oxide thin films deposited at room temperature are found to have an amorphous structure. Hall Effect measurements show a strong influence on the conductivity type where it changed from n-type to p-type at $700^{\circ}C$. GTO/Ag/GTO multilayer structured electrode with a few nm of Ag layer embedded is fabricated and show the optical transmittance of 86.48% in the visible range (${\lambda}$ = 380~770 nm) and quite low electrical resistivity of ${\sim}10^{-5}{\Omega}cm$. The resultant power conversion efficiency of 2.60% of the multilayer based OPV (GAG) is lower than that of the reference commercial ITO. GTO/Ag/GTO multilayer is a promising transparent conducting electrode material due to its low resistivity, high transmittance, low temperature deposition and low cost components.

• Journal of Electrochemical Science and Technology
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• 제8권1호
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• pp.25-34
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• 2017

Concurrent electrocatalysis and sensing of hydrazine, sulfite ions, and nitrite ions in a mixture were studied using electrodes modified by electrodeposited Au nanostructures (NSs). The ${\beta}$-cyclodextrin-mixed silicate sol-gel composite was drop-casted on the electrode surface and nucleation guided by ${\beta}$-cyclodextrin occurred, followed by the electrodeposition of Au NSs. The additive, ${\beta}$-cyclodextrin, played an evident role as a structure-directing agent; thus, small raspberry-like Au NSs were obtained. The modified electrodes were characterized by surface characterization techniques and electrochemical methods. The Au NSs-modified electrodes effciently electrocatalyzed the oxidation of toxic molecules such as hydrazine and sulfite and nitrite ions even in the absence of any other electron transfer mediator or enzyme immobilization. Well-resolved oxidation peaks along with decreased overpotentials were noticed during the electrooxidation process. The fabricated Au nanostructured electrode clearly distinguished the electrooxidation peaks of each of the three analytes from their mixture.

• 공업화학
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• 제26권5호
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• pp.521-525
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• 2015

2차원 구조와 우수한 물성을 지닌 그래핀 기반의 전극 재료들은 슈퍼커패시터에 많이 응용되어 왔다. 특히 3차원 구조의 그래핀 소재들은 전극 제조에 매우 중요한데 이는 3차원 구조가 넓은 표면적, 효과적이고 빠른 전기 및 이온 전달, 우수한 기계적 물성을 제공하기 때문이다. 최근에는 3차원 하이브리드 구조를 가지는 그래핀/금속 산화물 재료들이 슈퍼커패시터의 에너지와 파워 밀도를 동시에 증가시키고자 개발되어 왔다. 본 논문은 그래핀과 금속 산화물로 이루어진 3차원 나노복합체의 최근 연구 경향을 논하고자 한다. 3차원 나노복합체의 제조와 구조 및 이를 이용한 슈 퍼커패시터의 응용을 다룬다.

• 한국전기전자재료학회논문지
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• 제20권10호
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• pp.907-911
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• 2007

This paper dealt with the frequency spectrum analysis of acoustic signal produced by partial discharge (PD) in insulation oil and the positioning of PD occurrence to apply in diagnosis of oil insulated transformers. Three types of electrode system ; the needle-plane, the plane-plane, and the wire-wire structure were assembled to simulate partial discharges in oil insulated transformers. A low-noise amplifier and a decoupling circuit were designed to detect acoustic signal with high sensitivity The frequency spectrum of the acoustic signal were 50 kHz ${\sim}$ 260 kHz in the needle-plane, 50 kHz ${\sim}$ 250 kHz in the plane-plane, and 45 kHz${\sim}$195 kHz in the wire-wire electrode system. Their peak frequencies were 145 kHz, 130 kHz and 114 kHz, respectively The position of PD occurrence was calculated by the time difference of arrival (TOA) using three acoustic emission (AE) sensors, and we could find the position within the error of 1 % in the experimental apparatus.

• Nano
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• 제13권11호
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• pp.1850136.1-1850136.12
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• 2018

Three-dimensional (3D) mixed phases NiSe nanoparticles growing on the nickel foam were synthesized via a simple one-step hydrothermal method. A series of experiments were carried out to control the morphology by adjusting the amount of selenium in the synthetic reaction. Meanwhile, the as-prepared novel column-acicular structure NiSe exist three advantages including ideal electrical conductivity, high specific capacity and high cycling stability. It delivered a high capacitance of $10.8F\;cm^{-2}$ at a current density- of $5mA\;cm^{-2}$. An electrochemical capacitor device operating at 1.6 V was then constructed using NiSe/NF and activated carbon (AC) as positive and negative electrodes. Moreover, the device showed high energy density of $31W\;h\;kg^{-1}$ at a power density of $0.81kW\;kg^{-1}$, as well as good cycling stability (77% retention after 1500 cycles).

• 마이크로전자및패키징학회지
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• 제29권4호
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• pp.35-40
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• 2022

본 연구에서는 실버 파우더의 입자 크기, 즉 평균입자 크기가 2㎛, 7㎛, 이들의 혼합(50:50wt%), 이렇게 3가지 실버 페이스트를 제조하여 점도 및 점탄성, 경화후에 잔류용제 유무 확인을 위한 TGA측정, Strain에 따른 저항변화 및 전극 표면구조 변화에 대해서 검토한 결과 다음과 같은 결론을 얻을 수 있었다. 이러한 결과를 정리하면 Strain에 따른 저항변화를 최소화하기 위해서는 실버 파우더의 입자를 2㎛정도인 것이 가장 바람직함을 알 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.111.2-111.2
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• 2015

Typical electrodes (metal or indium tin oxide (ITO)), which were used in conventional organic light emitting devices (OLEDs) structure, have transparency and conductivity, but, it is not suitable as the electrode of the flexible OLEDs (f-OLEDs) due to its brittle property. Although Graphene is the most well-known alternative material for conventional electrode because of present electrode properties as well as flexibility, its carrier injection barrier is comparatively high to use as electrode. In this work, we performed plasma treatment on the graphene surface and alkali metal doping in the organic materials to study for its possibility as anode and cathode, respectively. By using Ultraviolet Photoemission Spectroscopy (UPS), we investigated the interfaces of modified graphene. The plasma treatment is generated by various gas types such as O2 and Ar, to increase the work function of the graphene film. Also, for co-deposition of organic film to do alkali metal doping, we used three different organic materials which are BMPYPB (1,3-Bis(3,5-di-pyrid-3-yl-phenyl)benzene), TMPYPB (1,3,5-Tri[(3-pyridyl)-phen-3-yl]benzene), and 3TPYMB (Tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane)). They are well known for ETL materials in OLEDs. From these results, we found that graphene work function can be tuned to overcome the weakness of graphene induced carrier injection barrier, when the interface was treated with plasma (alkali metal) through the value of hole (electron) injection barrier is reduced about 1 eV.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.305-307
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• 2016

We calculated Li ion migration energy barrier, applying three different models on Li ion insertion into $TiO_2$ nanolayers to elucidate the previously reported high rate of charge-discharge. With the existence of additional Li ion on the surface of $TiO_2$ structure, spontaneous insertion of Li ion into the second layer from the first layer was observed. Using this result, we showed the intrinsic property of $TiO_2$ structure and it has a contribution to the reported performance. In the end, we give a suggestion on the fabrication of $TiO_2-Graphene$ hybrid structure for Li ion battery electrode.