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991.
TiO2 photocatalysis has been studied widely in environment protection and energy generation applications. But, the intrinsic absence of visible light response and the high recombination rate of photo-generated charge carriers significantly limited the efficiency of photocatalysis with TiO2 materials. Herein, a facile approach was constructed to develop visible-light-induced TiO2 photocatalysis by co-modification with Eu and Au nanoparticles. The synthesized Au/Eu-TiO2 material was characterized by XRD, SEM, TEM, DRS, XPS, and N2 adsorption measurements. Visible light catalytic performance of the Au/Eu-TiO2 catalyst was evaluated by using the photodegradation of RhB as a model reaction. It was shown that this Au/Eu-TiO2 exhibited a better photocatalytic activity than the single Au modified TiO2 (Au/TiO2) or the single Eu modified TiO2 catalyst (Eu/TiO2), and also exhibited a good reusability for the targeted reaction. This remarkably improved performance of Au/Eu-TiO2 could be attributed to the synergetic effect of Eu and Au co-decoration, which not only enhanced visible light absorption but also promoted charge carriers transfers as evidenced by DRS, XPS and transient photocurrent spectra. Moreover, a possible reaction mechanism for the Au/Eu-TiO2 photocatalysis was proposed. 相似文献
992.
Near‐Infrared Light‐Driven Hydrogen Evolution from Water Using a Polypyridyl Triruthenium Photosensitizer 下载免费PDF全文
Yutaro Tsuji Keiya Yamamoto Dr. Kosei Yamauchi Prof. Ken Sakai 《Angewandte Chemie (International ed. in English)》2018,57(1):208-212
In order to realize artificial photosynthetic devices for splitting water to H2 and O2 (2 H2O+hν→2 H2+O2), it is desirable to use a wider wavelength range of light that extends to a lower energy region of the solar spectrum. Here we report a triruthenium photosensitizer [Ru3(dmbpy)6(μ‐HAT)]6+ (dmbpy=4,4′‐dimethyl‐2,2′‐bipyridine, HAT=1,4,5,8,9,12‐hexaazatriphenylene), which absorbs near‐infrared light up to 800 nm based on its metal‐to‐ligand charge transfer (1MLCT) transition. Importantly, [Ru3(dmbpy)6(μ‐HAT)]6+ is found to be the first example of a photosensitizer which can drive H2 evolution under the illumination of near‐infrared light above 700 nm. The electrochemical and photochemical studies reveal that the reductive quenching within the ion‐pair adducts of [Ru3(dmbpy)6(μ‐HAT)]6+ and ascorbate anions affords a singly reduced form of [Ru3(dmbpy)6(μ‐HAT)]6+, which is used as a reducing equivalent in the subsequent water reduction process. 相似文献
993.
Christoph Englert Dr. Ivo Nischang Cornelia Bader Philipp Borchers Julien Alex Michael Pröhl Martin Hentschel Dr. Matthias Hartlieb Dr. Anja Traeger Prof. Dr. Georg Pohnert Dr. Stephanie Schubert Dr. Michael Gottschaldt Prof. Dr. Ulrich S. Schubert 《Angewandte Chemie (International ed. in English)》2018,57(9):2479-2482
A benzoin‐derived diol linker was synthesized and used to generate biocompatible polyesters that can be fully decomposed on demand upon UV irradiation. Extensive structural optimization of the linker unit was performed to enable the defined encapsulation of diverse organic compounds in the polymeric structures and allow for a well‐controllable polymer cleavage process. Selective tracking of the release kinetics of encapsulated model compounds from the polymeric nano‐ and microparticle containers was performed by confocal laser scanning microscopy in a proof‐of‐principle study. The physicochemical properties of the incorporated and released model compounds ranged from fully hydrophilic to fully hydrophobic. The demonstrated biocompatibility of the utilized polyesters and degradation products enables their use in advanced applications, for example, for the smart packaging of UV‐sensitive pharmaceuticals, nutritional components, or even in the area of spatially selective self‐healing processes. 相似文献
994.
Yingliang Liu Jianghui Li Huayu Cao Shaokui Cao Zhijian Chen Lixin Xiao Qihuang Gong 《先进技术聚合物》2008,19(11):1584-1589
Two phenothiazine‐based polymers were synthesized by the Heck reaction of 3,7‐divinyl‐N‐octyl‐phenothiazine with 3,7‐diiodo‐N‐octyl‐phenothiazine and 5,8‐dibromo‐2,3‐diethylquinoxaline. The polymers were characterized by the measurements of 1H‐NMR, IR, TG, GPC, CV, UV–Vis, and FL. The results indicated that the introduction of quinoxaline group makes the absorption, PL, and EL emission maxima red‐shifted. The EL emission maximum and the CIE 1931 coordinate value are stabilized at a constant value with the increase in operating voltages. Therefore, the polymers have a stable electroluminescent emission property. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
995.
P. A. Troshin A. S. Peregudov S. I. Troyanov R. N. Lyubovskaya 《Russian Chemical Bulletin》2008,57(5):887-912
The results of the authors’ studies on the [2+3] cycloaddition of azomethine and nitrile ylides generated from picolylamine
and benzylamine derivatives to fullerenes are systematized and new experimental data are considered. Catalysts and microwave
radiation promoting the formation of ylides and their addition to fullerenes were successfully used for the first time. A
large series of new pyrrolidine and pyrroline derivatives of fullerenes C60 and C70 were synthesized and characterized. The proposed procedures afford the reaction products in yields twice as high (80–85%)
as those attained by the classical Prato reaction. The reactions proceed with virtually complete regio- (in the case of C70) and stereoselectivity to afford only cis-2′,5′-disubstituted and trans-1′,2′,5′-trisubstituted pyrrolidinofullerenes. Pyridyl-substituted pyrrolidinofullerenes react with metalloporphyrins and
phthalocyanines to form self-ordered coordination complexes. The latter are analogs of natural photosynthetic antenna systems
due to photoinduced charge separation that occurs in these complexes upon exposure to light.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 873–898, May, 2008. 相似文献
996.
当长链高分子高密度接枝到一个表面上时,由于分子链间的相互作用使得接枝的高分子链扩张而形成伸直链的构象,这种形态被称为高分子刷. 相似文献
997.
利用聚甲基氢硅氧烷(PHMS)与4-(β-羟基-γ-烯丙氧)丙氧基-2-羟基二苯甲酮(MUV-O)、α-烯基聚醚(F6)的硅氢化加成反应,合成了一种新型聚醚-二苯甲酮衍生物侧基聚硅氧烷PE-PUVSi,用红外光谱(IR)、紫外光谱(UV)、核磁共振氢谱(1H-NMR)以及原子力显微镜(AFM)等仪器对产物的结构和成膜形态进行了研究。结果表明,新合成的PE-PUVSi对波长为243.6、289.2、325.0nm的紫外光有强吸收作用。在纤维及单晶硅表面,PE-PUVSi均可成膜。但宏观上平滑的PE-PUVSi膜,微观上实则呈非均一、相分离结构,其中UV侧基以纤细尖峰分布在聚硅氧烷膜表面,而亲水性聚醚基团则卷曲堆积成峰包。 相似文献
998.
氢能作为未来理想的清洁能源之一,已经成为全球研究的重要领域,而在氢能的应用中最关键的问题是氢气的存储.近年来,人们的研究集中在固态储氢材料上,许多新型储氢材料不断出现,其中由轻元素组成的金属-氮-氢体系拥有储氢容量高、可逆性好等优点,被认为是最有前景的储氢材料之一.目前金属-氮-氢体系已经发展出许多体系,而研究最多的是Li-N-H和Li-Mg-N-H两种体系.本文重点综述了两者作为可逆储氢材料的研究现状,主要从制备方法、储氢性能、反应机理、理论计算和存在的问题等方面进行了讨论,同时指出了金属-氮-氢储氢体系的发展趋势. 相似文献
999.
WANG Zhi-long WANG Yu-hua ZHANG Jia-chi 《高等学校化学研究》2008,24(6):679-682
As an Hg-free lamp using phosphor, the Bi^3+ and EH^3+ co-doped Y2O2S phosphors were prepared and their luminescence properties under vacuum ultraviolet(VUV) excitation were investigated. The VUV photoluminescent intensity of Y2O2S:Eu^3+ was weak, however, considerably stronger red emission at 626 nm with good color purity was observed in Y2O2S:Eu^3+,Bi^3+ systems. Investigation on the photoluminescence reveals that the strong VUV luminescence of Y2O2S:Eu^3+,Bi^3+ at 147 nm is mainly because the Bi^3+ acts as a medium and effectively performs the energy transfer process: Y^3+-O^2-→Bi^3+→Eu^3+, while the intense emission band at 172 nm is attributed to the absorption of the characteristic ^1So-^1P1 transition of Bi^3+ and the direct energy transfer from Bi^3+ to Eu^3+. The Y2O2S:Eu^3+,Bi^3+ shows excellent VUV optical properties compared with the commercial (Y,Gd)BO3:Eu^3+. Thus, the Y2O2S:Eu^3+,Bi^3+ can be a potential red VUV-excited candidate applied in Hg-free lamps for backlight of liquid crystal display. 相似文献
1000.
As an Hg-free lamp using phosphor, the Bi3+ and Eu3+ co-doped Y2O2S phosphors were prepared and their luminescence properties under vacuum ultraviolet(VUV) excitation were investigated. The VUV photoluminescent intensity of Y2O2S:Eu3+ was weak, however, considerably stronger red emission at 626 nm with good color purity was observed in Y2O2S:Eu3+,Bi3+ systems. Investigation on the photoluminescence reveals that the strong VUV luminescence of Y2O2S:Eu3+,Bi3+ at 147 nm is mainly because the Bi3+ acts as a med... 相似文献