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91.
Ultrasonically induced ZnO–biosilica nanocomposite for degradation of a textile dye in aqueous phase
In the present study, a porous clay-like support with unique characteristics was used for the synthesis and immobilization of ZnO nanostructures to be used as sonocatalyst for the sonocatalytic decolorization of methylene blue (MB) dye in the aqueous phase. As a result, the sonocatalytic activity of ZnO–biosilica nanocomposite (77.8%) was higher than that of pure ZnO nanostructures (53.6%). Increasing the initial pH from 3 to 10 led to increasing the color removal from 41.8% to 88.2%, respectively. Increasing the sonocatalyst dosage from 0.5 to 2.5 g/L resulted in increasing the color removal, while further increase up to 3 g/L caused an obvious drop in the color removal. The sonocatalysis of MB dye over ZnO–biosilica nanocomposite was temperature-dependent. The presence of methanol produced the most adverse effect on the sonocatalysis of MB dye. The addition of chloride and carbonate ions had a negligible effect on the sonocatalysis, while the addition of persulfate ion led to increasing the color removal from 77.8% to 99.4% during 90 min. The reusability test exhibited a 15% drop in the color removal (%) within three consecutive experimental runs. A mineralization efficiency of 63.2% was obtained within 4 h. 相似文献
92.
Guralchuk GY Sorokin AV Katrunov IK Yefimova SL Lebedenko AN Malyukin YV Yarmoluk SM 《Journal of fluorescence》2007,17(4):370-376
Optical spectroscopy experiments were used to study the features of cyanine dye 3,3′-dimethyl-9-(2-thienyl)-thiacarbocyanine
iodide (L-21) aggregation in binary solutions DMF:Tris–HCl buffer (pH = 8) containing nucleic acids (DNA or RNA). The appearance
of absorption and luminescence bands associated with J-aggregates and dimers that are formed within the minor groove of DNA
has been observed. The model of L-21 J-aggregate structure is proposed. It has been found that dimers are the building blocks
of L-21 J-aggregates. Disorientation in dimers caused by the minor groove curvature is reason of observation of Davydov splitting
in absorption spectrum of L-21 J-aggregates. In the solution containing DNA the absorption and luminescence bands of L-21
J-aggregates exhibit the specific properties that allows the dye L-21 to be used as a fluorescent probe for DNA detection. 相似文献
93.
总结了非平衡溶剂化新理论和在量子化学软件Q-Chem中基于含时密度泛函理论(TD-DFT)实现溶剂效应下计算电子吸收和发射光谱的数值解方法.采用该方法计算了染料敏化太阳能电池(DSSCs)中三苯胺型有机染料■在真空和乙腈溶剂中的电子结构与光谱性质,研究发现,π共轭桥上碳碳双键的个数和溶剂效应会促进光电转换. 相似文献
94.
The different oxidation states of sulphur atom play a significant role on functional materials. In this work, a aryl-thioether and its sulphone substituted benzo[c][1,2,5]oxadiazole dyes were synthesized and utilized to determine thiol-containing amino acids. The result of selectivity experiments showed they detected the cysteine and homocysteine under physiological condition with negligible interference from other amino acids. In comparison to the thioether dye, the sulphone-based dye exhibited much faster response time for Cys and Hcy. However, the sulphone restricted its thiol-reactivity and bioimaging performance in living cells. By reducing the oxidation state of sulphur atom, we amazedly found that the sulfoxide-based dye still maintained high selectivity ultrafast response time for Cys/Hcy under physiological condition. It was worth mentioning that it also had high reactivity and good bioimaging performance that sulfone compounds did not have. 相似文献
95.
Mapping of the Photoinduced Electron Traps in TiO2 by Picosecond X‐ray Absorption Spectroscopy
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Dr. M. Hannelore Rittmann‐Frank Dr. Chris J. Milne Dr. Jochen Rittmann Dr. Marco Reinhard Dr. Thomas J. Penfold Prof. Majed Chergui 《Angewandte Chemie (International ed. in English)》2014,53(23):5858-5862
Titanium dioxide (TiO2) is the most popular material for applications in solar‐energy conversion and photocatalysis, both of which rely on the creation, transport, and trapping of charges (holes and electrons). The nature and lifetime of electron traps at room temperature have so far not been elucidated. Herein, we use picosecond X‐ray absorption spectroscopy at the Ti K‐edge and the Ru L3‐edge to address this issue for photoexcited bare and N719‐dye‐sensitized anatase and amorphous TiO2 nanoparticles. Our results show that 100 ps after photoexcitation, the electrons are trapped deep in the defect‐rich surface shell in the case of anatase TiO2, whereas they are inside the bulk in the case of amorphous TiO2. In the case of dye‐sensitized anatase or amorphous TiO2, the electrons are trapped at the outer surface. Only two traps were identified in all cases, with lifetimes in the range of nanoseconds to tens of nanoseconds. 相似文献
96.
Peripherally and Axially Carboxylic Acid Substituted Subphthalocyanines for Dye‐Sensitized Solar Cells
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Dr. Mine Ince Dr. Anaïs Medina Dr. Jun‐Ho Yum Dr. Aswani Yella Dr. Christian G. Claessens Dr. M. Victoria Martínez‐Díaz Prof. Michael Grätzel Dr. Mohammad K. Nazeeruddin Prof. Tomás Torres 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(7):2016-2021
A series of subphthalocyanines (SubPcs) bearing a carboxylic acid group either at the peripheral or axial position have been designed and synthesized to investigate the influence of the COOH group positions on the dye‐sensitized solar cell (DSSC) performance. The DSSC devices based on SubPcs with axially substituted carboxylic acid groups showed low photovoltaic performance, whereas peripherally substituted one exhibited higher power conversion efficiency owing to improved injection from LUMO of SubPcs to the TiO2 conduction band. 相似文献
97.
高效液相色谱法同时测定化妆品中的11种紫外吸收剂 总被引:1,自引:0,他引:1
建立了高效液相色谱法准确、快速、灵敏测定化妆品中11种紫外吸收剂的方法。采用C18色谱柱,以乙腈和0.1%甲酸作为流动相,311 nm作为检测波长,在11.5 min内完成11种紫外吸收剂的基线分离。在优化的实验条件下,目标化合物的保留时间和峰面积的相对标准偏差分别小于0.05%和1.20%;另外,所有目标化合物的检出限均低于2.24 mg/L,并在5~500 mg/L内均具有良好的线性关系(R2>0.9990),样品加标回收率为77%~116%。上述结果表明,本方法具有简便、准确、灵敏的特点。对两种不同化妆品中2-羟基-4甲氧基二苯甲酮-5-磺酸、对-氨基苯甲酸等11种紫外吸收剂的测定结果表明,2-羟基-4-甲氧基二苯甲酮、丁基甲氧基二苯酰基甲烷、水杨酸-2-乙基己酯、3,3,5-三甲基环已烷水杨酸酯4种紫外吸收剂在具有防晒功能的化妆品中较为常见,其中3,3,5-三甲基环已烷水杨酸酯在所测化妆品中浓度最高。 相似文献
98.
99.
Spectrally dispersed femtosecond time-resolved coherent anti-Stokes Raman spectroscopy is utilized to study the ultrafast vibrational dynamics in rhodamine B dye in solution at room temperature. The anti-Stokes intensities are monitored as a function of time and wavenumber. By simply changing the timing of laser pulses, the vibrational dynamics of excited Raman transitions in rhodamine B molecules can be tracked and detected. 相似文献
100.
Hydrothermal carbonaceous materials and MnO2 have been proved to be promising adsorbents to remove organic dyes from wastewater. In this study, flexible MnO2 loaded hydrothermal carbon-coated electrospun poly-acrylonitrile(AC/MnO2/PAN) fiber membranes were fabricated by a facile one-step hydrothermal method and activated by NaOH solution. The composite fibers exhibited large adsorption capacity toward cationic dyes and excellent mechanical properties. The adsorption performance can be fitted well with pseudo-second-order model and Langmuir isotherm model. The maximum adsorption for methylene blue(MB), methyl violet(MV) and malachite green(MG) are 1173.27,1106.31 and 1129.89 mg/g, respectively, according to Langmuir fitting. The AC/MnO2/PAN fiber membrane also showed satisfactory performances for selective adsorption and recyclability. In addition, based on selective adsorption, the AC/MnO2/PAN fiber membranes that are repulsive to the anionic dye methyl orange(MO) can separate the MB/MO mixture solution by dynamic filtration. Thus, this work not only provides a facile strategy to fabricate large capacity adsorbents, but also demonstrates the potential applications in the dye wastewater treatment field. 相似文献