• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.87-87
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• 2010

Photoelectrochemical (PEC) systems are promising methods of producing H2 gas using solar energy in an aqueous solution. The photoelectrochemical properties of numerous metal oxides have been studied. Among them, the PEC systems based on TiO2 have been extensively studied. However, the drawback of a PEC system with TiO2 is that only ultraviolet (UV) light can be absorbed because of its large band gap (3.2 - 3.4 eV). Two approaches have been introduced in order to use PEC cells in the visible light region. The first method includes doping impurities, such as nitrogen, into TiO2, and this technique has been extensively studied in an attempt to narrow the band gap. In comparison, research on the second method, which includes visible light water splitting in molecular photosystems, has been slow. Mallouk et al. recently developed electrochemical water-splitting cells using the Ru(II) complex as the visible light photosensitizer. the dye-sensitized PEC cell consisted of a dye-sensitized TiO2 layer, a Pt counter electrode, and an aqueous solution between them. Under a visible light (< 3 eV) illumination, only the dye molecule absorbed the light and became excited because TiO2 had the wide band gap. The light absorption of the dye was followed by the transfer of an electron from the excited state (S*) of the dye to the conduction band (CB) of TiO2 and its subsequent transfer to the transparent conducting oxide (TCO). The electrons moved through the wire to the Pt, where the water reduction (or H2 evolution) occurred. The oxidized dye molecules caused the water oxidation because their HOMO level was below the H2O/O2 level. Organic dyes have been developed as metal-free alternatives to the Ru(II) complexes because of their tunable optical and electronic properties and low-cost manufacturing. Recently, organic dye molecules containing multi-branched, multi-anchoring groups have received a great deal of interest. In this work, tri-branched tri-anchoring organic dyes (Dye 2) were designed and applied to visible light water-splitting cells based on dye-sensitized TiO2 electrodes. Dye 2 had a molecular structure containing one donor (D) and three acceptor (A) groups, and each ended with an anchoring functionality. In comparison, mono-anchoring dyes (Dye 1) were also synthesized. The PEC response of the Dye 2-sensitized TiO2 film was much better than the Dye 1-sensitized or unsensitized TiO2 films.

• 대한화학회지
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• 제55권3호
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• pp.418-429
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• 2011

[ $N^1,N^2$ ]bis(3-((3-hydroxynaphthalen-2-yl)methylene-amino)propyl)phthalamide ($H_4L$, 1) 의 새로운 크롬(III), 망간(II), 철(III), 코발트(II), 니켈(II), 구리(II), 루테늄(III) 및 산화 지르코늄(II) 착물을 합성하여 원소분석, 물리적 성질 및 분광학적으로 특성을 규명하였다. 분광학적 결과를 통해 이 리간드는 $[H_4LMX_2(H_2O)]{\cdot}nH_2O$ (M = Cu(II), Ni(II), Co(II), X = Cl 또는 $NO_3$)의 일반식을 갖는 착물2-5에서는 중성의 삼배위 리간드로 행동한다. 또는 $[H_4L(ZrO)_2Cl_2]{\cdot}8H_2O$ 의 일반식을 갖는 착물 6-9 에서는 이염기성 육배위 리간드로 행동한다. DMF 용액에서의 몰전기전도도 실험결과 이들 착물은 비이온성을 나타낸다. 고체 구리착물 2, 5 및 6 의 ESR 스펙트럼에서 $g_{\parallel}$ >g> $g_e$을 보이는데, 이는 일그러진 팔면체구조와 큰 공유결합성을 갖는 $d{_x}^2{_{-y}}^2$ 오비탈에 비공유 전자쌍이 존재함을 의미한다. 이합체 구리(II) 착물 $[H_2LCu_2Cl_2(H_2O)_4]{\cdot}3H_2O$ (6)에 대해 두 구리원자 사이의 거리를 ESR 스펙트럼으로부터 추정한 parallel component 의 field zero splitting 파라메타를 이용하여 계산하였다. 이들 화합물의 항박테리아 및 항균 활성도를 측정한 결과, 몇가지 금속 착물의 경우 표준시약인 tetracycline (박테리아) 및 Amphotricene B (균류)보다 더 큰 저해효과를 보였다.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1605-1610
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• 2017

The electrochemical luminescence (ECL) device was investigated, which has similar structure to the dye-sensitized solar cell. The structure of the ECL cell in this experiment reliably induces a large amount of the oxidation around electrodes. The band gap of the ECL electrode is of 3.0 - 3.2 eV. Titanium dioxide ($TiO_2$) nanoparticle has following properties: a band gap of 3.4 eV, a low-priced material, and 002 preferred orientation (Z-axis). Zinc Oxide (ZnO) nanorod is easy to grow in a vertical direction. In this paper, in order to determine material suitable for the ECL device, the properties of various materials for electrodes of ECL devices such as ZnO nanorod (ZnO-NR) and $TiO_2$ nanoparticle ($TiO_2-NP$) were compared. The threshold voltage of the light emission of the ZnO-NR was 2.0 V which is lower than 2.5 V of $TiO_2-NP$. In the other hand, the luminance of $TiO_2-NP$ was $44.66cd/m^2$ and was higher than that of $34cd/m^2$ of ZnO-NR at the same applied voltage of 4 V. Based on the experimental results, we could conclude that $TiO_2-NP$ is a more suitable electrode material in ECL device than the ZnO-NR.