• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.164-174
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• 2018

The purpose of this work designed hybrid-structured and plasma effect photocatalyst of $Ag/In_2O_3/TiO_2/HNTs$ via sol-gel and photo-reduction methods. The structures, morphologies, optical and photoelectric performances of as-prepared photocatalysts were characterized via XRD, TEM, XPS, BET, UV-vis DRS, PL and photocurrents. The photocatalytic activity was evaluated by degradation of TC. The results showed that the hybrid-structure and plasma effect can effectively cause the multi-transfer of electrons and increase the separation rate of electron and hole pairs which obtained high photocatalytic activity. The photocatalytic degradation processes reveal that $^{\bullet}O_2{^-}$ and $h^+$ are major active species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1544-1551
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• 2004

Effects of pH, sugar, ascorbic acid, organic acids and light sources on the stability of anthocyanin pigment extracted from Korean purple-fleshed potatoes (PL-6, PL-28, PL-31 and Jasim) were studied. The pH had remarkable influence on the color stability of anthocyanin pigment. With increasing pH, the color gradually fades as colorless pseudobases are formed. In acidic pH, anthocyanin was stable, but with increasing pH the color gradually changed to colorless. The addition of sugar decrease in color stability of the pigment during storage period. The most of organic acids, such as a tartaric, citric and succinic acids, were found to improve the stability of the pigment, while malic and malonic acid reduced the stability of the pigment. The addition of ascorbic acid considerable decreased in anthocyanin pigment stability, but the effect was not decreased by adding thiourea. The effect of light sources such as a darkroom, a fluorescent light, and sunlight, reduced gradually the stability of anthocyanin pigment. Therefore the pigment degradation could be minimized by shielding the light from the pigment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.473-474
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• 2005

Blue-emitting polymers containing carbazole units In main chains were synthesized by palladium catalyzed polycondensation of aniline with dibromo-substituted monomers such as 3,6-dibromocarbazole, N-(2-ethylhexyl)-3,6-dibromocarbazole, and bis[6-bromo-N-(2-ethylhexyl)-carbazole-3-yl], respectively. All synthesized polymers exhibited relatively good solubility in common organic solvents, considerable molecular weights and high resistance to thermal degradation. From UV-Vis absorption and photoluminescence (PL) spectra of these solution-processable polymers, $\lambda_{max,UV}$ were in the range of 290 ~ 340 nm and $\lambda_{max,PL}$ were in the blue emission range of 440 ~ 478 nm, The polymers had HOMO energy (-5.19 ~ -5.64 eV) and wide band gap energy (2,91 - 3.42 eV).

• Korean Journal of Metals and Materials
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• v.49 no.5
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• pp.406-410
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• 2011

ZnO nanorods were prepared by the electrodeposition route on conductive Au/Si substrates. The effects of deposition time on the microstructural evolution and optical properties of ZnO nanorods were investigated. With increasing deposition time from 1 h to 20 h, the diameter and length of the ZnO nanorods increased gradually to about 328 nm and 6.55${\mu}m$, respectively. The ZnO nanorods were dense and vertically well-aligned. The photoluminescence (PL) peaks corresponding to the near band edge of ZnO were observed. With increasing deposition time, the intensity of PL peaks increased with nanorod growth up to 4 h and then decreased. This might be due to the degradation of crystal quality caused by merging of nanorods.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.459-464
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• 1991

The mackerel meat was packed in square No 3B can, and thermally processed at $121.1^{\circ}C$ to reach Fo values of 5, 10 and 15. On heating at $121.1^{\circ}C$, pH and volatile basic nitrogen content increased markedly, and histamine was detected at concentrations of 3.98 mg/100g in raw meat, 10.45 mg/100g in Fo 5 sample, 7.54 mg/100g in Fo 15 sample, respectively. Total free amino acid content of mackerel meat decreased with increasing Fo values. Little changes were observed in free amino acid composition, but histidine decreased significantly during heat treatment. Degradation of inosine monophosphate was proceeded during preparation and thermal processing of samples, and trimethylamine oxide changed to trimethylamine almost equivalently. In changes of lipid components, peroxide and carbonyl values were increased markedly during heat treatment. When the sample was heated at the Fo values of 5 or higher, content of non-polar lipid(NL) was increased while that of polar lipid(PL) was decreased, and percentages of polyenes such as 22 : 6 decreased with increasing Fo values. The decomposition of polyunsaturated fatty acids in PL were much greater than those in total lipid and NL.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.356-361
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• 2015

$Cd_{0.5}Zn_{0.5}S/ZnO$ composite photocatalysts were synthesized using the precipitation method and characterized by XRD, UV-vis DRS, PL and FE-SEM. Photocatalytic activities of the materials were evaluated by measuring the degradation of rhodamine B under visible light irradiation. Contrary to ZnO, $Cd_{0.5}Zn_{0.5}S/ZnO$ materials absorb visible light as well as UV and their absorption intensities in visible region increased with increasing the $Cd_{0.5}Zn_{0.5}S$ amount. The increment in the $Cd_{0.5}Zn_{0.5}S$ content in $Cd_{0.5}Zn_{0.5}S/ZnO$ also leads to reducing the particle size and consequently increasing the specific surface area. $Cd_{0.5}Zn_{0.5}S/ZnO$ materials with the larger $Cd_{0.5}Zn_{0.5}S$ content showed the higher activity in the photocatalytic degradation of rhodamine B under visible light irradiation. Therefore, the heterojunction effect between $Cd_{0.5}Zn_{0.5}S$ and ZnO as well as the adsorption capacity seems to give important contributions to the photocatalytic activity of the $Cd_{0.5}Zn_{0.5}S/ZnO$.

• Nano
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• v.13 no.10
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• pp.1850121.1-1850121.11
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• 2018

In this study, a series of $LaMnO_3$-diamond composites with varied $LaMnO_3$ mass contents supported on micro-diamond have been synthesized using a sol-gel method. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and the Fourier transform infrared spectra (FTIR). Meanwhile, the photocatalytic performances were also tested by photoluminescence (PL) spectroscopy, ultraviolet-visible diffuse reflection spectra (UV-Vis DRS) and the degradation of weak acid red C-3GN (RC-3GN). Results show that the peak position of $LaMnO_3$ is shifted to low angle after the introduction of diamond, and perovskite particles uniformly distributed on the surface of diamond, forming a network structure, which can increase the active sites and the absorption of dye molecules. When the mass ratio of $LaMnO_3$ and diamond is 1:2 (LMO-Dia-2), the composite shows the most excellent photocatalytic activity. This result offers a sample route to enlarge the range of the application of micro-diamond and provide a new carrier for perovskite photocatalysts.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.4
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• pp.132-138
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• 2023

Doped and undoped-BiVO₄ samples with different elements (Li, Mg) and amounts were synthesized with a hydrothermal method. The synthesized samples were characterized using various techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffusion reflectance spectroscopy (UV-Vis DRS), and photoluminescence (PL) spectroscopy. Photocatalytic activity of the samples was evaluated by measuring the degradation of methyl blue (MB) under visible light irradiation. The results indicated that the incorporation of Mg and Li into BiVO₄ caused lattice distortion, the presence of surface hydroxyl groups, a narrower band gap, and a reduced recombination ratio of photo-induced electron-hole pairs. Notably, the photocatalytic activity of Mg5%-Li5% co-doped BiVO₄ sample exhibited a significant improvement compared to that of undoped BiVO₄ sample.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3576-3580
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• 2012

Larva-like GaS nanostructures synthesized by the thermal evaporation of Ga metals and S powders were coated with $SiO_2$ by the sputtering technique. Transmission electron microscopy and X-ray diffraction analyses revealed that the cores and shells of the GaS-core/$SiO_2$-shell larva-like nanostructures were single crystal wurtzite-type hexagonal structured-GaS and amorphous $SiO_2$, respectively. Photoluminescence (PL) measurements at room temperature showed that the passivation of the larva-like GaS nanostructures was successfully achieved with $SiO_2$ without nearly harming the major emission from the wires. However, subsequent thermal annealing treatment was found to be undesirable owing to the degradation of their emission in intensity.

• Bulletin of the Korean Chemical Society
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• v.21 no.1
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• pp.61-64
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• 2000

FT-IR/ATR analysis shows that the oriental lacquer coating network degrades mostly in the unsaturated side chain. The rate of increase in carbonyl intensity (a measure of photodegradation) during the accelerated weathering test was substantially different for the unstabilized and stabilized samples; adding 2 wt% HALS into the oriental lacquer formulation enhanced photostabilization up to three times. Weight loss measurements, another indication of photodegradation, and SEM analysis support this conclusion. Despite the presence of the photo-stabilizer, the other properties of the lacquer were not significantly affected. In particular, the curing behavior of purified lacquer (PL) and HALS-stabilized samples is similar, although the in-situ DETA analysis showed that addition of HALS can slightly retard the cure reaction rate in oriental lacquer coating. It is hypothesized that this cure retardation may be related to the salt formation between HALS and acid of oriental lacquer.