• Current Photovoltaic Research
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• 제2권1호
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• pp.18-27
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• 2014

Dye-sensitized solar cells (DSSCs), developed two decades ago, are considered to be an attractive technology among various photovoltaic devices because of their low cost, accessible dye chemistry, ease of fabrication, high power conversion efficiency, and environmentally friendly nature. A typical DSSCs consists of a dye-coated $TiO_2$ photoanode, a redox electrolyte, and a platinum (Pt)-coated fluorine-doped tin oxide (FTO) counter electrode. Among them, redox electrolytes have proven to be extremely important in improving the performance of DSSCs. Due to many drawbacks of iodide electrolytes, many research groups have paid more attention to seeking other alternative electrolyte systems. With regard to this, one-electron outer sphere redox shuttles based on cobalt complexes have shown promising results: In 2014, porphyrin dye (SM315) with the cobalt (II/III) redox couple exhibited a power conversion efficiency of 13% in DSSCs. In this review, we will provide an overview and perspectives of cobalt redox electrolytes in DSSCs.

• ETRI Journal
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• 제26권6호
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• pp.647-652
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• 2004

A new ionic liquid, 1-vinyl-3-heptylimidazolium iodide (VHpII), was synthesized and applied as a redox electrolyte for dye-sensitized solar cells. The chemical structure of the synthesized VHpII was confirmed using $^1H$ NMR. Thermogravimetric analysis showed that the VHpII was stable for thermal stress of up to $250^{\circ}C$. The energy conversion efficiencies of the VHpII-based dye-sensitized solar cells were investigated in terms of the effect of a lithium iodide addition. A solar cell containing the redox couple of VHpII and iodine showed a conversion efficiency of 2.63% under 1 sun light intensity at AM 1.5. Adding 0.4 M LiI results in a conversion efficiency of 3.63%, which was an improvement of about 40%. The increased conversion efficiency was ascribed to an increase in external quantum efficiency.

• 한국염색가공학회지
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• 제5권3호
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• pp.173-181
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• 1993

Dyeing cotton fabric with direct dye (C. I. Direct Blue 15) by redox sytem of ammonium persulfate as an oxidant and glucose as reductant was studied. It was found that covalent bond between dye and cellulose molecule can be formed by free radical produced by the redox system in the dye bath, which enhanced significantly the color strength. The retained color strength after DMF extraction was much better in the presence than in the absence of the redox sytem. The optimum dyeing condition was 0.028 mol/$\ell$(APS/Glucose each) of redox concentration, 65$^{\circle}C$ of dyeing temperature and 60min of dyeing time. The color variation on the dyed sample had not been observed as a result of fixed ${\lambda}_max$.

• 한국염색가공학회지
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• 제6권1호
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• pp.1-7
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• 1994

A low-temperature dyeing system for silk fabrics based on a redox system has been investigated. Some factors affecting dyeing of silk fabrics with levelling acid dyes in the absence and presence of certain redox system were investigated under different conditions. The variables studied were; type and concentration of redox system, dyeing conditions, i. e. temperature and time, dye concentration, material-to-liquor ration(LR) and colour fastness. The colour strength(K/S value) is outstandingly higher in the presence than in the absence of redox system. A comparison between the colour strength values of such dyeings abtained the three redox system would call for the following order ; Glyoxal/hydrogen peroxide>thiourea/hydrogen peroxide>glucose/hydrgen peroxide> nothing. In the presence of redox system, free radicals are supposed to be formed in both the fiber and the dye and the interaction between these free radicals bring about covalent fixation beside the usual electrostatic bonds, hydrogen bonds and Van der Waals forces.

• Mycobiology
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• 제47권2호
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• pp.217-229
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• 2019

Two manganese peroxidases (MnPs), MnP1 and MnP2, and a laccase, Lac1, were purified from Trametes polyzona KU-RNW027. Both MnPs showed high stability in organic solvents which triggered their activities. Metal ions activated both MnPs at certain concentrations. The two MnPs and Lac1, played important roles in dye degradation and pharmaceutical products deactivation in a redox mediator-free system. They completely degraded Remazol brilliant blue (25 mg/L) in 10-30 min and showed high degradation activities to Remazol navy blue and Remazol brilliant yellow, while Lac1 could remove 75% of Remazol red. These three purified enzymes effectively deactivated tetracycline, doxycycline, amoxicillin, and ciprofloxacin. Optimal reaction conditions were $50^{\circ}C$ and pH 4.5. The two MnPs were activated by organic solvents and metal ions, indicating the efficacy of using T. polyzona KU-RNW027 for bioremediation of aromatic compounds in environments polluted with organic solvents and metal ions with no need for redox mediator supplements.

• 한국염색가공학회지
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• 제8권1호
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• pp.15-25
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• 1996

Wool fabric and merino wool top were dyed with two dyes, C.I. Acid Red 13 and C.I. Direct Blue 1 in presence of hydrogen peroxide/glyoxal redox system at various conditions such as dyeing time, temperature and redox concentration. The pH of dye bath was 4.5 in buffer solution of $KH_{2}PO_{4}$ (0.1mol/1)/$Na_{2}HPO_{4}$ (0.1mol/1). Also dyeing of cotton fabric was carried out with C.I. Direct Blue 1 in absence or presence of redox system. The color depth(K/S) increased with redox concentration and dyeing temperature. The increases in dyeing rate and equilibrium dye exhaustion of Acid Acid 13 and Direct Blue 1 on wool fiber and fabric in the present of hydrogen peroxide/glyoxal have been caused by decreasing in pH value during dyeing process which due to the decomposition of hydrogen ion in glyoxal with the assistance of hydrogen peroxide. But the decreases in exhaustion of Direct Blue 1 on cotton may be attributed to repulsive interac ion between salt and salt.

• Journal of Microbiology and Biotechnology
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• 제29권7호
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• pp.1117-1123
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• 2019

Control of pine wilt disease, which is caused by pine wilt nematode Bursaphelenchus xylophilus, is heavily dependent on the use of chemicals such as abamectin. Although such chemicals are highly effective, demands for alternatives that are derived preferentially from natural sources, are increasing out of environmental concerns. One of the challenges to discovery of alternative control agents is lack of fast and efficient screening method that can be used in a high-throughput manner. Here we described the development of colorimetric assay for the rapid and accurate screening of candidate nematicidal compounds/biologics targeting B. xylophilus. Contrary to the conventional method, which relies on laborious visual inspection and counting of nematode population under microscope, our method utilizes a redox dye that changes its color in response to metabolic activity of nematode population in a given sample. In this work, we optimized parameters of our colorimetric assay including number of nematodes and amount of redox dye, and tested applicability of our assay for screening of chemicals and biologics. We demonstrated that our colorimetric assay can be applied to rapid and accurate quantification of nematode viability/mortality in a nematode population treated with candidate chemicals/biologics. Application of our method would facilitate high-throughput endeavors aiming at finding environment-friendly control agents for deadly disease of pine trees.

• Bulletin of the Korean Chemical Society
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• 제35권5호
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• pp.1433-1439
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• 2014

We report on the influence of water as an electrolyte on the photovoltaic performances. The photovoltaic performance was shown to be quite sensitive to the substituent on the donor group. An optimized efficiency of 4.41% in the presence of 100% water content using $I^-/I{_3}^-$ redox couple was obtained using the D21L6 organic dye.

• 전기화학회지
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• 제13권1호
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• pp.10-18
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• 2010

Nanostructured metal oxides have been widely used in the research fields of photoelectrochemistry, photochemistry and opto-electronics. Dye-sensitized solar cell is a typical example because it is based on nanostructured $TiO_2$. Since the discovery of dye-sensitized solar cell in 1991, it has been considered as a promising photovoltaic solar cell because of low-cost, colorful and semitransparent characteristics. Unlike p-n junction type solar cell, dye-sensitized solar cell is photoelectrochemical type and is usually composed of the dye-adsorbed nanocrystalline metal oxide, the iodide/tri-iodide redox electrolyte and the Pt and/or carbon counter electrode. Among the studied issues to improve efficiency of dye-sensitized solar cell, nanoengineering technologies of metal oxide particle and film have been reviewed in terms of improving optical property, electron transport and electron life time.

• 한국환경보건학회지
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• 제19권3호
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• pp.29-35
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• 1993

This study was performed to obtain optimal conditions for reduction of color in dye wastewaters using coagulation-sedimentation processes with redox reactions. The reduction of color as well as organic matters variation was observed after coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O and NaOCl. Coagulation-redox reaction was done with the dose of Coagulant and oxidant at various pH values. Redox reaction was done through jar-mixing and aeration. The results of study were as follows: 1. In the coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was heigher at pH 3. With variance of dosage of FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was higher at 250 mg/l. When coagulation-sedimentation using FeSO$_4$ $\cdot$ 7H$_2$O 250 mg/l was added at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 47.6%, 21.3% and 22.1%, respectively. 2. When NaOCI was added at level of 100 ppm in raw wastewater at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 30.2%, 5.5% and 6.2%, respectively. 3. After coagulation-sedimentation processes by addition of FeSO$_4$ $\cdot$ 7H$_2$O, when NaOCl was added at level of 250 mg/l in supernant, color reduction was 47.8% in aeration and 37.5% in jar-mixing. 4. Color reduction by aeration was higher than that by jar-mixing.