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1.
The liquid structures of deep eutectic solvents (DESs) based on hydrated metal halides and their application as electrolytes have been widely studied. However, little attention has been paid to the direct use of this type of DES in the preparation of micro‐/nanomaterials. Herein, an FeCl3 ? 6 H2O/urea DES was used in the one‐step synthesis of NiFe‐LDH_D with a nanoflower morphology. In alkaline media, this catalyst promoted excellent electrocatalytic activity for the oxidation of urea at potential of 1.32 V (vs. RHE) and for the oxygen‐evolution reaction at a potential of 1.39 V to achieve a current density of 10 mA cm?2. These results were superior to the results with NiFe‐LDH/NF that was obtained from an aqueous solution of FeCl3, as well as most of the previously reported transition‐metal catalysts. Furthermore, NiFe‐LDH_D/NF could be readily implemented as both a cathode and an anode for the electrolysis of urea and water splitting. The use of hydrated‐metal‐halide‐based DESs for the preparation of LDH catalysts through a dipping‐redox strategy should both enrich the research of DESs and offer guidance for the rational surface engineering of catalysts for the electrolysis of urea and overall water splitting with high performance. 相似文献
2.
Electrocatalytic water splitting to produce hydrogen and oxygen is regarded as one of the most promising methods to generate clean and sustainable energy for replacing fossil fuels. However, the design and development of an efficient bifunctional catalyst for simultaneous generation of hydrogen and oxygen remains extremely challenging yet is critical for the practical implementation of water electrolysis. Here, we report a facile method to fabricate novel N‐doped carbon nanotube frameworks (NCNTFs) by the pyrolysis of a bimetallic metal organic framework (MIL‐88‐Fe/Co). The resultant electrocatalyst, Co3Fe7@NCNTFs, exhibits excellent oxygen evolution reaction (OER) activity, achieving 10 mA/cm2 at a low overpotential of just 264 mV in 1 M KOH solution, and 197 mV for the hydrogen evolution reaction. The high electrocatalytic activity arises from the synergistic effect between the chemistry of the Co3Fe7 and the NCNTs coupled to the novel framework structure. The remarkable electrocatalytic performance of our bifunctional electrocatalyst provides a promising pathway to high‐performance overall water splitting and electrochemical energy devices. 相似文献
3.
A Photoelectrochemical Solar Cell Consisting of a Cadmium Sulfide Photoanode and a Ruthenium–2,2′‐Bipyridine Redox Shuttle in a Non‐aqueous Electrolyte
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Yosuke Kageshima Hiromu Kumagai Tsutomu Minegishi Prof. Jun Kubota Prof. Kazunari Domen 《Angewandte Chemie (International ed. in English)》2015,54(27):7877-7881
A photoelectrochemical (PEC) cell consisting of an n‐type CdS single‐crystal electrode and a Pt counter electrode with the ruthenium–2,2′‐bipyridine complex [Ru(bpy)3]2+/3+ as the redox shuttle in a non‐aqueous electrolyte was studied to obtain a higher open‐circuit voltage (VOC) than the onset voltage for water splitting. A VOC of 1.48 V and a short‐circuit current (ISC) of 3.88 mA cm?2 were obtained under irradiation by a 300 W Xe lamp with 420–800 nm visible light. This relatively high voltage was presumably due to the difference between the Fermi level of photo‐irradiated n‐type CdS and the redox potential of the Ru complex at the Pt electrode. The smooth redox reaction of the Ru complex with one‐electron transfer was thought to have contributed to the high VOC and ISC. The obtained VOC was more than the onset voltage of water electrolysis for hydrogen and oxygen generation, suggesting prospects for application in water electrolysis. 相似文献
4.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(32):9440-9445
An active and stable photocatalyst to directly split water is desirable for solar‐energy conversion. However, it is difficult to accomplish overall water splitting without sacrificial electron donors. Herein, we demonstrate a strategy via constructing a single site to simultaneously promote charge separation and catalytic activity for robust overall water splitting. A single Co1‐P4 site confined on g‐C3N4 nanosheets was prepared by a facile phosphidation method, and identified by electron microscopy and X‐ray absorption spectroscopy. This coordinatively unsaturated Co site can effectively suppress charge recombination and prolong carrier lifetime by about 20 times relative to pristine g‐C3N4, and boost water molecular adsorption and activation for oxygen evolution. This single‐site photocatalyst exhibits steady and high water splitting activity with H2 evolution rate up to 410.3 μmol h−1 g−1, and quantum efficiency as high as 2.2 % at 500 nm. 相似文献
5.
Jie Yin Jing Jin Hong Zhang Min Lu Yong Peng Bolong Huang Pinxian Xi Chun‐Hua Yan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(51):18849-18855
We report a novel modulation strategy by introducing transition metals into NiS2 nanosheets (NSs) to flexibly optimize the electronic configurations and atomic arrangement. The Co‐NiS2 NSs exhibit excellent hydrogen evolution reaction (HER) performance with an overpotential of 80 mV at j=10 mA cm?2 and long‐term stability of 90 h in alkaline media. The turnover frequencies (TOFs) of 0.55 and 4.1 s?1 at an overpotential of 100 and 200 mV also confirm their remarkable performance. DFT calculations reveal that the surface dopants abnormally sensitize surface Ni‐3d bands in the long‐range order towards higher electron‐transfer activity, acting as the electron‐depletion center. Meanwhile, the high lying surface S‐sites possess substantially high selectivity for splitting the adsorbing H2O that guarantee the high HER performance within alkaline conditions. This work opens opportunities for enhancing water splitting by atomic‐arrangement‐assisted electronic modulation via a facile doping strategy. 相似文献
6.
A Polyimide Nanolayer as a Metal‐Free and Durable Organic Electrode Toward Highly Efficient Oxygen Evolution
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Yun‐Xiao Lin Wei‐Jie Feng Jun‐Jun Zhang Zhong‐Hua Xue Tian‐Jian Zhao Hui Su Prof. Shin‐Ichi Hirano Prof. Xin‐Hao Li Prof. Jie‐Sheng Chen 《Angewandte Chemie (International ed. in English)》2018,57(38):12563-12566
The exploitation of metal‐free organic polymers as electrodes for water splitting reactions is limited by their presumably low activity and poor stability, especially for the oxygen evolution reaction (OER) under more critical conditions. Now, the thickness of a cheap and robust polymer, poly(p‐phenylene pyromellitimide) (PPPI) was rationally engineered by an in situ polymerization method to make the metal‐free polymer available for the first time as flexible, tailorable, efficient, and ultra‐stable electrodes for water oxidation over a wide pH range. The PPPI electrode with an optimized thickness of about 200 nm provided a current density of 32.8 mA cm?2 at an overpotential of 510 mV in 0.1 mol L?1 KOH, which is even higher than that (31.5 mA cm?2) of commercial IrO2 OER catalyst. The PPPI electrodes are scalable and stable, maintaining 92 % of its activity after a 48‐h chronoamperometric stability test. 相似文献
7.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(15):4270-4274
Z‐scheme water splitting is a promising approach based on high‐performance photocatalysis by harvesting broadband solar energy. Its efficiency depends on the well‐defined interfaces between two semiconductors for the charge kinetics and their exposed surfaces for chemical reactions. Herein, we report a facile cation‐exchange approach to obtain compounds with both properties without the need for noble metals by forming Janus‐like structures consisting of γ‐MnS and Cu7S4 with high‐quality interfaces. The Janus‐like γ‐MnS/Cu7S4 structures displayed dramatically enhanced photocatalytic hydrogen production rates of up to 718 μmol g−1 h−1 under full‐spectrum irradiation. Upon further integration with an MnOx oxygen‐evolution cocatalyst, overall water splitting was accomplished with the Janus structures. This work provides insight into the surface and interface design of hybrid photocatalysts, and offers a noble‐metal‐free approach to broadband photocatalytic hydrogen production. 相似文献
8.
Electrocatalysis of Water Oxidation by H2O‐Capped Iridium‐Oxide Nanoparticles Electrodeposited on Spectroscopic Graphite
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Naghmehalsadat Mirbagheri Dr. Jacques Chevallier Dr. Jakob Kibsgaard Prof. Flemming Besenbacher Prof. Elena E. Ferapontova 《Chemphyschem》2014,15(13):2844-2850
Electrocatalysis of water oxidation by 1.54 nm IrOx nanoparticles (NPs) immobilized on spectroscopic graphite electrodes was demonstrated to proceed with a higher efficiency than on all other, hitherto reported, electrode supports. IrOx NPs were electrodeposited on the graphite surface, and their electrocatalytic activity for water oxidation was correlated with the surface concentrations of different redox states of IrOx as a function of the deposition time and potential. Under optimal conditions, the overpotential of the reaction was reduced to 0.21 V and the electrocatalytic current density was 43 mA cm?2 at 1 V versus Ag/AgCl (3 M KCl) and pH 7. These results beneficially compete with previously reported electrocatalytic oxidations of water by IrOx NPs electrodeposited onto glassy carbon and indium tin oxide electrodes and provide the basis for the further development of efficient IrOx NP‐based electrocatalysts immobilized on high‐surface‐area carbon electrode materials. 相似文献
9.
《化学:亚洲杂志》2017,12(20):2727-2733
Hydrogen production by catalytic water splitting using sunlight holds great promise for clean and sustainable energy source. Despite the efforts made in the past decades, challenges still exist in pursuing solid catalysts with light‐harvesting capacity, large surface areas and efficient utilities of the photogenerated carrier, at the same time. Here, a multiple structure design strategy leading to highly enhanced photocatalytic performance on hydrogen production from water splitting in Dion–Jacobson perovskites KCa2Nan ‐3Nbn O3n +1 is described. Specifically, chemical doping (N/Nb4+) of the parent oxides via ammoniation improved the ability of sunlight harvesting efficiently; subsequent liquid exfoliation of the doped perovskites yielded ultrathin [Ca2Nan ‐3Nbn O3n +1]− nanosheets with greatly increased surface areas. Significantly, the maximum hydrogen evolution appears in the n =4 nanosheets, which suggests the most favorable thickness for charge separation in such perovskite‐type catalysts. The optimized black N/Nb4+‐[Ca2NaNb4O13]− nanosheets show greatly enhanced photocatalytic performance, as high as 973 μmol h−1 with Pt loading, on hydrogen evolution from water splitting. As a proof‐of‐concept, this work highlights the feasibility of combining various chemical strategies towards better catalysts and precise thickness control of two‐dimensional materials. 相似文献
10.
Hierarchical NiCo2O4 Hollow Microcuboids as Bifunctional Electrocatalysts for Overall Water‐Splitting
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Xuehui Gao Hongxiu Zhang Quanguo Li Prof. Xuegong Yu Prof. Zhanglian Hong Prof. Xingwang Zhang Dr. Chengdu Liang Prof. Zhan Lin 《Angewandte Chemie (International ed. in English)》2016,55(21):6290-6294
Bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline electrolyte may improve the efficiency of overall water splitting. Nickel cobaltite (NiCo2O4) has been considered a promising electrode material for the OER. However, NiCo2O4 that can be used as an electrocatalyst in HER has not been studied yet. Herein, we report self‐assembled hierarchical NiCo2O4 hollow microcuboids for overall water splitting including both the HER and OER reactions. The NiCo2O4 electrode shows excellent activity toward overall water splitting, with 10 mA cm?2 water‐splitting current reached by applying just 1.65 V and 20 mA cm?2 by applying just 1.74 V across the two electrodes. The synthesis of NiCo2O4 microflowers confirms the importance of structural features for high‐performance overall water splitting. 相似文献
11.
Wataru Kurashige Yutaro Mori Shuhei Ozaki Masanobu Kawachi Sakiat Hossain Tokuhisa Kawawaki Cameron J. Shearer Akihide Iwase Gregory F. Metha Seiji Yamazoe Akihiko Kudo Yuichi Negishi 《Angewandte Chemie (International ed. in English)》2020,59(18):7076-7082
The activity of many water‐splitting photocatalysts could be improved by the use of RhIII–CrIII mixed oxide (Rh2?xCrxO3) particles as cocatalysts. Although further improvement of water‐splitting activity could be achieved if the size of the Rh2?xCrxO3 particles was decreased further, it is difficult to load ultrafine (<2 nm) Rh2?xCrxO3 particles onto a photocatalyst by using conventional loading methods. In this study, a new loading method was successfully established and was used to load Rh2?xCrxO3 particles with a size of approximately 1.3 nm and a narrow size distribution onto a BaLa4Ti4O15 photocatalyst. The obtained photocatalyst exhibited an apparent quantum yield of 16 %, which is the highest achieved for BaLa4Ti4O15 to date. Thus, the developed loading technique of Rh2?xCrxO3 particles is extremely effective at improving the activity of the water‐splitting photocatalyst BaLa4Ti4O15. This method is expected to be extended to other advanced water‐splitting photocatalysts to achieve higher quantum yields. 相似文献
12.
Electrocatalytic and Solar‐Driven CO2 Reduction to CO with a Molecular Manganese Catalyst Immobilized on Mesoporous TiO2
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Timothy E. Rosser Dr. Christopher D. Windle Dr. Erwin Reisner 《Angewandte Chemie (International ed. in English)》2016,55(26):7388-7392
Electrocatalytic CO2 reduction to CO was achieved with a novel Mn complex, fac‐[MnBr(4,4′‐bis(phosphonic acid)‐2,2′‐bipyridine)(CO)3] ( MnP ), immobilized on a mesoporous TiO2 electrode. A benchmark turnover number of 112±17 was attained with these TiO2| MnP electrodes after 2 h electrolysis. Post‐catalysis IR spectroscopy demonstrated that the molecular structure of the MnP catalyst was retained. UV/vis spectroscopy confirmed that an active Mn–Mn dimer was formed during catalysis on the TiO2 electrode, showing the dynamic formation of a catalytically active dimer on an electrode surface. Finally, we combined the light‐protected TiO2| MnP cathode with a CdS‐sensitized photoanode to enable solar‐light‐driven CO2 reduction with the light‐sensitive MnP catalyst. 相似文献
13.
Larissa N. Ikryannikova Leila Yu. Ustynyuk Alexander N. Tikhonov 《Magnetic resonance in chemistry : MRC》2010,48(5):337-349
An explicit DFT modeling of water surroundings on the electron paramagnetic resonance properties of 4‐amino‐2,2,6,6‐tetramethyl‐piperidine‐N‐oxyl (TA) has been performed. A stepwise hydration of TA is accompanied with certain changes in geometrical parameters (bond lengths and angles) and redistribution of partial electric charges in TA. An aqueous cluster of 45 water molecules can be considered as an appropriate model for a complete aqueous shell around TA, although most of the structural and electronic characteristics of TA already converge at about 10 water molecules. Water surroundings induce an increase in electron spin density on the nitrogen atom of the nitroxide fragment due to stabilization of the polar resonance structure > N+?? O? at the expense of less polar structure > N? O?. The water‐induced rise of the isotropic splitting constant aiso, calculated from the contact term of the hyperfine interaction, comprises Δaiso(ρN2) = 2.2–2.5 G, which is typical of experimental value for TA. There are two contributions to the solvent effect on the aiso(ρN2) value: the redistribution of spin density in the nitroxide fragment (polarity effect) and water‐induced distortions of TA geometry. Microscopic variations in a hydrogen‐bonded water network cause noticeable fluctuations of the splitting constant aiso(ρN2). Calculations of the atomic spin density (σN2) allowed us to compute the splitting constant from the relationship aiso(σN2) = QσN2, where Q = 36.2 G. A practical advantage of using this relationship is that it gives ‘smoothed’ values of the splitting constant, which are sensitive to the environment polarity but remain tolerant to microscopic fluctuations of the hydrogen‐bonded water network around a spin‐label molecule. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
14.
Efficient Visible‐Light‐Driven Z‐Scheme Overall Water Splitting Using a MgTa2O6−xNy /TaON Heterostructure Photocatalyst for H2 Evolution
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Shanshan Chen Yu Qi Dr. Takashi Hisatomi Qian Ding Tomohiro Asai Zheng Li Dr. Su Su Khine Ma Prof. Fuxiang Zhang Prof. Kazunari Domen Prof. Can Li 《Angewandte Chemie (International ed. in English)》2015,54(29):8498-8501
An (oxy)nitride‐based heterostructure for powdered Z‐scheme overall water splitting is presented. Compared with the single MgTa2O6?xNy or TaON photocatalyst, a MgTa2O6?xNy /TaON heterostructure fabricated by a simple one‐pot nitridation route was demonstrated to effectively suppress the recombination of carriers by efficient spatial charge separation and decreased defect density. By employing Pt‐loaded MgTa2O6?xNy /TaON as a H2‐evolving photocatalyst, a Z‐scheme overall water splitting system with an apparent quantum efficiency (AQE) of 6.8 % at 420 nm was constructed (PtOx‐WO3 and IO3?/I? pairs were used as an O2‐evolving photocatalyst and a redox mediator, respectively), the activity of which is circa 7 or 360 times of that using Pt‐TaON or Pt‐MgTa2O6?xNy as a H2‐evolving photocatalyst, respectively. To the best of our knowledge, this is the highest AQE among the powdered Z‐scheme overall water splitting systems ever reported. 相似文献
15.
Dandan Guo Zhiwen Wang Zhijin Fan Hui Zhao Wei Zhang Jiagao Cheng Jiaqiang Yang Qingjun Wu Youjun Zhang Qian Fan 《中国化学》2012,30(10):2522-2532
Twenty nine novel N‐4‐methyl‐1,2,3‐thiadiazole‐5‐carbonyl‐N′‐phenyl ureas were designed and synthesized, and their structures were confirmed by proton nuclear magnetic resonance (1H NMR), infra red spectroscopy (IR) and high‐resolution mass spectroscopy (HRMS). Compounds V‐9 , V‐11 , V‐12 , V‐15 , V‐19 , V‐21 , V‐22 and V‐24 exhibit excellent activity against Culex pipiens pallens. Compounds V‐12 and V‐22 present good insecticidal activity against Plutella xylostella L. Their median lethal concentrations (LC50) are 164.15 and 89.69 mg·L?1, respectively. Compound V‐11 also has potential wide spectrum of fungicide activity. Its median effective concentrations (EC50) detected from 3.82 µg·mL?1 against Physalospora piricola to 31.60 µg·mL?1 against Cercospora arachidicola. Compounds V‐15 and V‐24 show outstanding induction activities as same as positive controls TDL and ningnanmycin, furthermore V‐24 has the highest induction activity of 41.85%±4.43%. To elucidate the structure activity relationship in these compounds, a 3D‐QSAR model has been built. The established model showed a reliable predicting ability with q2 values of 0.643 and r2 values of 0.982. 相似文献
16.
Kerli Martin Sandip A. Kadam Ulriika Mattinen Johan Bobacka Ivo Leito 《Electroanalysis》2019,31(6):1061-1066
The construction and study of solid‐contact acetate‐selective electrodes is described using a 1,3‐bis(carbazolyl)urea derivative as a neutral hydrogen‐bonding ionophore and poly(3,4‐ethylenedioxythiophene) as the solid contact. It was shown recently that this ionophore binds acetate (logKass=4.98) that is used as primary ion in this study. The electrodes show linearity over the activity range of 10?4.50–10?1.10 with a sub‐Nernstian slope of ?51.3 mV per decade and a detection limit of 10?5.00. The anion‐selectivity pattern of these electrodes deviates markedly from the Hofmeister pattern. When adding ionophore to the membrane the logarithm of the selectivity coefficient (logK) for SCN? decreased from 6.5 to 1.2, logK for I? decreased from 5.7 to 0.9, logK for NO3? decreased from 4.3 to 0.6 and logK for Br? decreased from 3.3 to 0.1. The selectivity coefficients of hydrophilic anions such as Cl?, F?, HPO42?, and SO42? are significantly lower than in case of the ionophore‐free membrane. It was discovered that the constructed electrodes are also relatively selective to bicarbonate. This work is an important step towards the further development of solid‐contact anion‐selective electrodes. 相似文献
17.
J. Sharath Kumar Saikat Bolar Naresh Chandra Murmu R. Sankar Ganesh Hiroshi Inokawa Amit Banerjee Tapas Kuila 《Electroanalysis》2019,31(11):2120-2129
A core‐shell structure with CuO core and carbon quantum dots (CQDs) and carbon hollow nanospheres (CHNS) shell was prepared through facile in‐situ hydrothermal process. The composite was used for non‐enzymatic hydrogen peroxide sensing and electrochemical overall water splitting. The core‐shell structure was established from the transmission electron microscopy image analysis. Raman and UV‐Vis spectroscopy analysis confirmed the interaction between CuO and CQDs. The electrochemical studies showed the limit of detection and sensitivity of the prepared composite as 2.4 nM and 56.72 μA μM?1 cm?2, respectively. The core‐shell structure facilitated better charge transportation which in turn exhibited elevated electro‐catalysis towards hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and overall water splitting. The overpotential of 159 mV was required to achieve 10 mA cm?2 current density for HER and an overpotential of 322 mV was required to achieve 10 mA cm?2 current density for OER in 1.0 M KOH. A two‐electrode system was constructed for overall water splitting reaction, which showed 10 and 50 mA cm?2 current density at 1.83 and 1.96 V, respectively. The prepared CuO@CQDs@CHNS catalyst demonstrated excellent robustness in HER and OER catalyzing condition along with overall water splitting reaction. Therefore, the CuO@CQDs@CHNS could be considered as promising electro‐catalyst for H2O2 sensing, HER, OER and overall water splitting. 相似文献
18.
Yao Yuan Samira Adimi Xuyun Guo Tiju Thomas Ye Zhu Haichuan Guo G. Sudha Priyanga Pilsun Yoo Jiacheng Wang Jian Chen Peilin Liao J. Paul Attfield Minghui Yang 《Angewandte Chemie (International ed. in English)》2020,59(41):18036-18041
The oxygen evolution reaction (OER) is key to renewable energy technologies such as water electrolysis and metal–air batteries. However, the multiple steps associated with proton‐coupled electron transfer result in sluggish OER kinetics and catalysts are required. Here we demonstrate that a novel nitride, Ni2Mo3N, is a highly active OER catalyst that outperforms the benchmark material RuO2. Ni2Mo3N exhibits a current density of 10 mA cm?2 at a nominal overpotential of 270 mV in 0.1 m KOH with outstanding catalytic cyclability and durability. Structural characterization and computational studies reveal that the excellent activity stems from the formation of a surface‐oxide‐rich activation layer (SOAL). Secondary Mo atoms on the surface act as electron pumps that stabilize oxygen‐containing species and facilitate the continuity of the reactions. This discovery will stimulate the further development of ternary nitrides with oxide surface layers as efficient OER catalysts for electrochemical energy devices. 相似文献
19.
Roshan Khadka Nihan Aydemir Colm Carraher Cyril Hamiaux Paul Baek Jamal Cheema Andrew Kralicek Jadranka Travas‐Sejdic 《Electroanalysis》2019,31(4):726-738
This article aims to demonstrate an electrochemically stable and reliable gold electrode‐electrolyte system to develop an insect odorant receptor (Drosophila melanogaster Or35a) based bioelectronic nose. Cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS) of bare gold electrodes, after modification with the self‐assembled monolayer (SAM) of 6‐mercaptohexanoic acid (MHA) and after immobilization with Or35a integrated into the lipid bilayers of liposomes were conducted in the presence of four different redox probes. Potassium ferri/ferrocyanide [Fe(CN)6]3?/[Fe (CN)6]4? and hydroquinone (H2Q) redox probes revealed variable and irreversible signals at the time scale of our measurements, with atomic force microscopy (AFM) images and x‐ray photoelectron spectroscopy (XPS) results suggesting gold surface etching due to the presence of CN? ions in case of [Fe(CN)6]3?/[Fe (CN)6]4?. Although the hexaammineruthenium complex showed stable electrochemical behaviour at all stages of biosensor development, changes in CV and EIS readings after each surface modifications were insignificant. PBS buffer as a non‐Faradaic medium, was found to provide reliable systems for electrochemical probing of modified gold electrodes with Or35a/liposomes in aqueous media. Using this system, we have shown that this novel biosensor can detect its known odorant E2‐hexenal selectively compared to methyl salicylate down to femtomolar concentration. 相似文献
20.
The Interaction of Water with Free Mn4O4+ Clusters: Deprotonation and Adsorption‐Induced Structural Transformations
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Dr. Sandra M. Lang Prof. Dr. Thorsten M. Bernhardt Denis M. Kiawi Dr. Joost M. Bakker Dr. Robert N. Barnett Prof. Dr. Uzi Landman 《Angewandte Chemie (International ed. in English)》2015,54(50):15113-15117
As the biological activation and oxidation of water takes place at an inorganic cluster of the stoichiometry CaMn4O5, manganese oxide is one of the materials of choice in the quest for versatile, earth‐abundant water splitting catalysts. To probe basic concepts and aid the design of artificial water‐splitting molecular catalysts, a hierarchical modeling strategy was employed that explores clusters of increasing complexity, starting from the tetramanganese oxide cluster Mn4O4+ as a molecular model system for catalyzed water activation. First‐principles calculations in conjunction with IR spectroscopy provide fundamental insight into the interaction of water with Mn4O4+, one water molecule at a time. All of the investigated complexes Mn4O4(H2O)n+ (n=1–7) contain deprotonated water with a maximum of four dissociatively bound water molecules, and they exhibit structural fluxionality upon water adsorption, inducing dimensional and structural transformations of the cluster core. 相似文献