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211.
Application of the Tris(acetylacetonato)iron(III)/(II) Redox Couple in p‐Type Dye‐Sensitized Solar Cells
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Ishanie Rangeeka Perera Dr. Torben Daeneke Satoshi Makuta Dr. Ze Yu Prof. Dr. Yasuhiro Tachibana Dr. Amaresh Mishra Prof. Dr. Peter Bäuerle Dr. C. André Ohlin Prof. Dr. Udo Bach Prof. Dr. Leone Spiccia 《Angewandte Chemie (International ed. in English)》2015,54(12):3758-3762
An electrolyte based on the tris(acetylacetonato)iron(III)/(II) redox couple ([Fe(acac)3]0/1?) was developed for p‐type dye‐sensitized solar cells (DSSCs). Introduction of a NiO blocking layer on the working electrode and the use of chenodeoxycholic acid in the electrolyte enhanced device performance by improving the photocurrent. Devices containing [Fe(acac)3]0/1? and a perylene–thiophene–triphenylamine sensitizer (PMI–6T–TPA) have the highest reported short‐circuit current (JSC=7.65 mA cm?2), and energy conversion efficiency (2.51 %) for p‐type DSSCs coupled with a fill factor of 0.51 and an open‐circuit voltage VOC=645 mV. Measurement of the kinetics of dye regeneration by the redox mediator revealed that the process is diffusion limited as the dye‐regeneration rate constant (1.7×108 M ?1 s?1) is very close to the maximum theoretical rate constant of 3.3×108 M ?1 s?1. Consequently, a very high dye‐regeneration yield (>99 %) could be calculated for these devices. 相似文献
212.
Sunlight‐Driven Formation and Dissociation of a Dynamic Mixed‐Valence Thallium(III)/Thallium(I) Porphyrin Complex
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Victoria Ndoyom Luca Fusaro Vincent Dorcet Bernard Boitrel Stéphane Le Gac 《Angewandte Chemie (International ed. in English)》2015,54(12):3806-3811
Inspired by a Newton’s cradle device and interested in the development of redox‐controllable bimetallic molecular switches, a mixed‐valence thallium(III)/thallium(I) bis‐strap porphyrin complex, with TlIII bound out of the plane of the N core and TlI hung to a strap on the opposite side, was formed by the addition of TlOAc to the free base and exposure to indirect sunlight. In this process, oxygen photosensitization by the porphyrin allows the oxidation of TlI to TlIII. The bimetallic complex is dynamic as the metals exchange their positions symmetrically to the porphyrin plane with TlIII funneling through the macrocycle. Further exposure of the complex to direct sunlight leads to thallium dissociation and to total recovery of the free base. Hence, the porphyrin plays a key role at all stages of the cycle of the complex: It hosts two metal ions, and by absorbing light, it allows the formation and dissociation of TlIII. These results constitute the basis for the further design of innovative light‐driven bimetallic molecular devices. 相似文献
213.
Ferrocenylethynyl‐Terminated Azobenzenes: Synthesis,Electrochemical, and Photoisomerization Studies
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Jian‐Feng Yan Da‐Qiang Lin Xin‐Gang Wang Kai‐Qiang Wu Dr. Li‐Li Xie Prof. Dr. Yao‐Feng Yuan 《化学:亚洲杂志》2015,10(3):614-621
Ferrocenylethynyl‐terminated derivatives 8 – 12 have been synthesized and characterized by electrochemistry and UV/Vis spectroscopy. The electrochemical and photophysical studies indicate that the electronic communication in ferrocenylethynyl‐substituted derivatives is strongly influenced by the substituted position of the ferrocenylethynyl moiety. In situ electrochemical oxidation or chemical oxidation caused a characteristically weak ligand‐to‐metal charge‐transfer (LMCT) band to appear at 700–1000 nm. Subsequent electrochemical reduction or chemical reduction recovered the most of the original curve and the color of the solution as well. Among the derivatives, compound 8 exhibits the highest cis/trans molar ratio (64:36) in the photostationary state (PSS) upon light irradiation at 365 nm. Compound 8 exhibits excellent fatigue resistance and reversibility under several repeated reversible isomerization cycles. 相似文献
214.
Electro‐oxidation and reduction of H2 on platinum studied by scanning electrochemical microscopy for the purpose of local detection of H2 evolution
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Sina S. Jamali Simon E. Moulton Dennis E. Tallman Jan Weber Gordon G. Wallace 《Surface and interface analysis : SIA》2015,47(13):1187-1191
Electrochemical detection of H2 using scanning electrochemical microscopy (SECM) has shown to hold great promise as a sensitive characterization method with high spatial resolution for active surfaces generating H2. Herein, the factors contributing to the current that is measured by SECM in generation/collection mode for H2 detection are studied. In particular, the concentration gradient of H2 at the substrate, the H2/H+ recycling between the SECM tip and substrate and hemispherical profile of H2 diffusion has been discussed. It was postulated that H2/H+ recycling plays a dominant role in the oxidative current measured in generation/collection mode of SECM when the microelectrode is positioned in close vicinity of substrate. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
215.
不同WO含量对CeO-ZrO-WO催化剂在NH选择性催化还原NO中的影响 《燃料化学学报》2015,43(6):701-707
采用水热法制备了CeO2-ZrO2-WO3(CZW)催化剂,考察了WO3含量对CZW催化剂上NH3选择性催化还原NOx性能的影响,并利用X射线衍射、N2吸附-脱附、H2程序升温还原、NH3和NO程序升温脱附等方法对其进行了表征。结果表明,WO3以无定形的形式存在于催化剂中,添加WO3后显著提高了催化剂的表面酸性,并且在CZW催化剂上出现了强吸附的NO物种,从而有利于提高催化剂的活性。另外,适量的WO3引入将增大催化剂的比表面积,促进催化剂的氧化还原性能,这将有利于提高SCR的催化活性。和CeO2-ZrO2催化剂相比,当WO3的含量为20%时,CZW催化剂表现出良好的抗硫性能。此外,当空速为60 000 h-1时,在200~463 ℃,该催化剂显示出了大于90% NOx转化率。 相似文献
216.
High capacity and cycling stability of poly(diaminoanthraquinone) as an organic cathode for rechargeable lithium batteries
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Yi Fei Shen Ding Ding Yuan Xin Ping Ai Han Xi Yang Min Zhou 《Journal of Polymer Science.Polymer Physics》2015,53(4):235-238
Poly(1,5‐diaminoanthraquinone) is synthesized by oxidative polymerization of diaminoanthraquinone monomers and investigated as an organic host for Li‐storage reaction. Benefiting from its high density of redox‐active, Li+‐associable benzoquinone groups attached to conducting polyaniline backbones, this polymer undergoes its cathodic reaction predominately through Li+‐insertion/extraction processes, delivering a very high reversible capacity of 285 mAh g?1. In addition, the PDAQ polymer cathode exhibits an excellent rate capability (125 mAh g?1 at 800 mA g?1) and a considerable cyclability with a capacity retention of ~160 mAh g?1 over 200 cycles, possibly serving as a sustainable, high capacity Li+ host cathode for Li‐ion batteries. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 235–238 相似文献
217.
Steffen Styra Dr. Mohand Melaimi Dr. Curtis E. Moore Prof. Arnold. L. Rheingold Timo Augenstein Prof. Dr. Frank Breher Prof. Guy Bertrand 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(23):8441-8446
A stable cyclic (alkyl)(amino)carbene (CAAC) 1 inserts into the para‐CF bond of pentafluoropyridine, and after fluoride abstraction, the iminium‐pyridyl adduct [ 3 ]+ was isolated. A cyclic voltammetry study shows a reversible three‐state redox system involving [ 3 ]+, [ 3 ] ? , and [ 3 ] ? . The CAAC‐pyridyl radical [ 3 ] ? , obtained by reduction of [ 3 ]+ with magnesium, has been spectroscopically and crystallographically characterized. In contrast to the lack of π communication between the CAAC and the pyridine units in cation [ 3 ]+, the unpaired electron of [ 3 ] ? is delocalized over an extended π system involving both heterocycles. 相似文献
218.
Tuning the Redox Properties of a Nonheme Iron(III)–Peroxo Complex Binding Redox‐Inactive Zinc Ions by Water Molecules
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Dr. Yong‐Min Lee Suhee Bang Heejung Yoon Seong Hee Bae Dr. Seungwoo Hong Dr. Kyung‐Bin Cho Dr. Ritimukta Sarangi Prof. Dr. Shunichi Fukuzumi Prof. Dr. Wonwoo Nam 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(30):10676-10680
Redox‐inactive metal ions play important roles in tuning chemical properties of metal–oxygen intermediates. Herein we report the effect of water molecules on the redox properties of a nonheme iron(III)–peroxo complex binding redox‐inactive metal ions. The coordination of two water molecules to a Zn2+ ion in (TMC)FeIII‐(O2)‐Zn(CF3SO3)2 ( 1 ‐Zn2+) decreases the Lewis acidity of the Zn2+ ion, resulting in the decrease of the one‐electron oxidation and reduction potentials of 1 ‐Zn2+. This further changes the reactivities of 1 ‐Zn2+ in oxidation and reduction reactions; no reaction occurred upon addition of an oxidant (e.g., cerium(IV) ammonium nitrate (CAN)) to 1 ‐Zn2+, whereas 1 ‐Zn2+ coordinating two water molecules, (TMC)FeIII‐(O2)‐Zn(CF3SO3)2‐(OH2)2 [ 1 ‐Zn2+‐(OH2)2], releases the O2 unit in the oxidation reaction. In the reduction reactions, 1 ‐Zn2+ was converted to its corresponding iron(IV)–oxo species upon addition of a reductant (e.g., a ferrocene derivative), whereas such a reaction occurred at a much slower rate in the case of 1 ‐Zn2+‐(OH2)2. The present results provide the first biomimetic example showing that water molecules at the active sites of metalloenzymes may participate in tuning the redox properties of metal–oxygen intermediates. 相似文献
219.
Biofunctionalization of Polyoxometalates with DNA Primers,Their Use in the Polymerase Chain Reaction (PCR) and Electrochemical Detection of PCR Products
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Dr. Ahmed M. Debela Dr. Mayreli Ortiz Dr. Valerio Beni Prof. Serge Thorimbert Dr. Denis Lesage Prof. Richard B. Cole Prof. Ciara K. O'Sullivan Prof. Bernold Hasenknopf 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17721-17727
The bioconjugation of polyoxometalates (POMs), which are inorganic metal oxido clusters, to DNA strands to obtain functional labeled DNA primers and their potential use in electrochemical detection have been investigated. Activated monooxoacylated polyoxotungstates [SiW11O39{Sn(CH2)2CO}]8? and [P2W17O61{Sn(CH2)2CO}]6? have been used to link to a 5′‐NH2 terminated 21‐mer DNA forward primer through amide coupling. The functionalized primer was characterized by using a battery of techniques, including electrophoresis, mass spectrometry, as well as IR and Raman spectroscopy. The functionality of the POM‐labeled primers was demonstrated through hybridization with a surface‐immobilized probe. Finally, the labeled primers were successfully used in the polymerase chain reaction (PCR) and the PCR products were characterized by using electrophoresis. 相似文献
220.
《Electroanalysis》2017,29(6):1651-1657
Gluconobacter oxydans (G. oxydans ) cells together with an osmium redox polymer (ORP) [Osmium (2,2’‐bipyridine)2(poly‐vinylimidazole)10Cl]Cl were combined with a glassy carbon paste electrode (GCPE) to form a bioanode for a microbial fuel cell (MFC) based on G. oxydans . Although there are G.oxydans / ORP combined bioanode in the literature, as far as it is known, this system is the first one where G.oxydans /ORP bioanode is combined with a cathode and a MFC is formed. After the optimization of experimental parameters, analytical characteristics of ORP/G. oxydans /GCPE bioanode were investigated. ORP/G. oxydans /GCPE showed two linear ranges for ethanol substrate as 1.0–30 mM (R2=0.902) and 30–500 mM (R2=0.997) and analytical range as 1.0–1000 mM. Limit of detection (3.0 s/m) and limit of quantification (10 s/m) values were calculated as 1.29 mM and 4.30 mM respectively where the RSD value was 1.16 % for n=5. Combining the developed bioanode in the presence of 5.0 mM K3Fe(CN)6 mediator with a Pt wire cathode a double compartment MFC was obtained via a salt bridge. G. oxydans /GCPE bioanode based MFC had maximum power density of 0.133 μW cm−2 (at 33.5 mV), maximum current density as 8.73 μA cm−2 and OCP value of 156 mV. On the other hand, ORP/G. oxydans /GCPE based MFC showed maximum power density as 0.26 μW cm−2 (at 46.8 mV), maximum current density as 15.079 μA cm‐2 and OCP value of 176 mV. 相似文献