排序方式: 共有14条查询结果,搜索用时 265 毫秒
1.
2.
3.
Dr. Peiyu Ge Dr. Mohamad Hojeij Dr. Micheál D. Scanlon Prof. Hubert H. Girault 《Chemphyschem》2020,21(24):2630-2633
H2 may be evolved biphasically using a polarised liquid|liquid interface, acting as a “proton pump”, in combination with organic soluble metallocenes as electron donors. Sustainable H2 production requires methodologies to recycle the oxidised donor. Herein, the photo-recycling of decamethylferrocenium cations (DcMFc+) using aqueous core-shell semiconductor CdSe@CdS nanoparticles is presented. Negative polarisation of the liquid|liquid interface is required to extract DcMFc+ to the aqueous phase. This facilitates the efficient capture of electrons by DcMFc+ on the surface of the photo-excited CdSe@CdS nanoparticles, with hydrophobic DcMFc subsequently partitioning back to the organic phase and resetting the system. TiO2 (P25) and CdSe semiconductor nanoparticles failed to recycle DcMFc+ due to their lower conduction band energy levels. During photo-recycling, CdS (on CdSe) may be self-oxidised and photo-corrode, instead of water acting as the hole scavenger. 相似文献
4.
Andrés F. Molina-Osorio Alonso Gamero-Quijano Pekka Peljo Micheál D. Scanlon 《Current Opinion in Electrochemistry》2020
Breakthrough alternative technologies are urgently required to alleviate the critical need to decarbonise our energy supply. We showcase non-conventional approaches to battery and solar energy conversion and storage (ECS) system designs that harness key attributes of immiscible electrolyte solutions, especially the membraneless separation of redox active species and ability to electrify certain liquid–liquid interfaces. We critically evaluate the recent development of membraneless redox flow batteries based on biphasic systems, where one redox couple is confined to an immiscible ionic liquid or organic solvent phase, and the other couple to an aqueous phase. Common to all solar ECS devices are the abilities to harvest light, leading to photo-induced charge carrier separation, and separate the products of the photo-reaction, minimising recombination. We summarise recent progress towards achieving this accepted solar ECS design using immiscible electrolyte solutions in photo-ionic cells, to generate redox fuels, and biphasic “batch” water splitting, to generate solar fuels. 相似文献
5.
Scanlon MD Salaj-Kosla U Belochapkine S MacAodha D Leech D Ding Y Magner E 《Langmuir : the ACS journal of surfaces and colloids》2012,28(4):2251-2261
The high surface areas of nanostructured electrodes can provide for significantly enhanced surface loadings of electroactive materials. The fabrication and characterization of nanoporous gold (np-Au) substrates as electrodes for bioelectrochemical applications is described. Robust np-Au electrodes were prepared by sputtering a gold-silver alloy onto a glass support and subsequent dealloying of the silver component. Alloy layers were prepared with either a uniform or nonuniform distribution of silver and, post dealloying, showed clear differences in morphology on characterization with scanning electron microscopy. Redox reactions under kinetic control, in particular measurement of the charge required to strip a gold oxide layer, provided the most accurate measurements of the total electrochemically addressable electrode surface area, A(real). Values of A(real) up to 28 times that of the geometric electrode surface area, A(geo), were obtained. For diffusion-controlled reactions, overlapping diffusion zones between adjacent nanopores established limiting semi-infinite linear diffusion fields where the maximum current density was dependent on A(geo). The importance of measuring the surface area available for the immobilization was determined using the redox protein, cyt c. The area accessible to modification by a biological macromolecule, A(macro), such as cyt c was reduced by up to 40% compared to A(real), demonstrating that the confines of some nanopores were inaccessible to large macromolecules due to steric hindrances. Preliminary studies on the preparation of np-Au electrodes modified with osmium redox polymer hydrogels and Myrothecium verrucaria bilirubin oxidase (MvBOD) as a biocathode were performed; current densities of 500 μA cm(-2) were obtained in unstirred solutions. 相似文献
6.
Ge P Scanlon MD Peljo P Bian X Vubrel H O'Neill A Coleman JN Cantoni M Hu X Kontturi K Liu B Girault HH 《Chemical communications (Cambridge, England)》2012,48(52):6484-6486
The activities of a series of MoS(2)-based hydrogen evolution catalysts were studied by biphasic reactions monitored by UV/Vis spectroscopy. Carbon supported MoS(2) catalysts performed best due to an abundance of catalytic edge sites and strong electronic coupling of catalyst to support. 相似文献
7.
Geérard Aranda Jean-Yves Lallemand Robert Azerad Micheèle Maurs Manuel Cortes Hector Ramirez 《合成通讯》2013,43(18):2525-2535
Application of the Mitsunobu reaction to various 3β-(equatorial)-hydroxy-4,4-dimethyl terpenic compounds provides the 2-ene-derivatives in good yields. A discussion about the mechanisms involved, and full details on the modified experimental protocol are given. 相似文献
8.
Dr. Lucie Rivier Dr. Pekka Peljo Sunny Maye Dr. Manuel A. Méndez Dr. Heron Vrubel Dr. Laurent A. C. Vannay Prof. Clémence Corminboeuf Dr. Micheál D. Scanlon Prof. Hubert H. Girault 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(55):12769-12779
Detailed studies on hydrogen evolution by decamethylruthenocene ([Cp*2RuII]) highlighted that metallocenes are capable of photoreducing hydrogen without the need for an additional sensitizer. Electrochemical, gas chromatographic, and spectroscopic (UV/Vis, 1H and 13C NMR) measurements corroborated by DFT calculations indicated that the production of hydrogen occurs by a two-step process. First, decamethylruthenocene hydride [Cp*2RuIV(H)]+ is formed in the presence of an organic acid. Subsequently, [Cp*2RuIV(H)]+ is reversibly reduced in a heterolytic reaction with one-photon excitation leading to a first release of hydrogen. Thereafter, the resultant decamethylruthenocenium ion [Cp*2RuIII]+ is further reduced with a second release of hydrogen by deprotonation of a methyl group of [Cp*2RuIII]+. Experimental and computational data show spontaneous conversion of [Cp*2RuII] to [Cp*2RuIV(H)]+ in the presence of protons. Calculations highlight that the first reduction is endergonic (ΔG0=108 kJ mol−1) and needs an input of energy by light for the reaction to occur. The hydricity of the methyl protons of [Cp*2RuII] was also considered. 相似文献
9.
Urszula Salaj-Kosla Micheál D. Scanlon Tobias Baumeister Kawah Zahma Roland Ludwig Peter Ó Conghaile Domhnall MacAodha Dónal Leech Edmond Magner 《Analytical and bioanalytical chemistry》2013,405(11):3823-3830
Nanoporous and planar gold electrodes were utilised as supports for the redox enzymes Aspergillus niger glucose oxidase (GOx) and Corynascus thermophilus cellobiose dehydrogenase (CtCDH). Electrodes modified with hydrogels containing enzyme, Os-redox polymers and the cross-linking agent poly(ethylene glycol)diglycidyl ether were used as biosensors for the determination of glucose and lactose. Limits of detection of 6.0 (±0.4), 16.0 (±0.1) and 2.0 (±0.1) μM were obtained for CtCDH-modified lactose and glucose biosensors and GOx-modified glucose biosensors, respectively, at nanoporous gold electrodes. Biofuel cells composed of GOx- and CtCDH-modified gold electrodes were utilised as anodes, together with Myrothecium verrucaria bilirubin oxidase (MvBOD) or Melanocarpus albomyces laccase as cathodes, in biofuel cells. A maximum power density of 41 μW/cm2 was obtained for a CtCDH/MvBOD biofuel cell in 5 mM lactose and O2-saturated buffer (pH 7.4, 0.1 M phosphate, 150 mM NaCl). 相似文献
10.
Berduque A Scanlon MD Collins CJ Arrigan DW 《Langmuir : the ACS journal of surfaces and colloids》2007,23(13):7356-7364
The electrochemistry of a series of dendrimers was examined at the interface between two immiscible electrolyte solutions (ITIES), enabling study of non-redox-active dendrimers. Different generations of poly(propylenimine) (DAB-AM-n) and poly(amidoamine) (PAMAM) dendrimers were studied. In their protonated states, the dendrimers were transferred across the ITIES, with the electrochemical behavior observed depending on the dendrimer family, the generation number, and the experimental pH. The electrochemistry of the lower generations studied was characterized by well-defined peaks for both dendrimer families and with small peak-peak separations in the case of the PAMAM family. The voltammetry of the higher generations was more complex, showing distorted voltammograms and instability of the interface. The charges of the transferring dendrimers were calculated by convolution of the voltammetric data and were similar to the theoretical charges for DAB-AM-n. For PAMAM, only the lowest generation exhibited reversible behavior, with higher generations having irreversible behavior. Using cyclic voltammetry, low micromolar concentrations of the dendrimers were detected. The results show that electrochemistry at the ITIES can be a useful method for characterization of ionizable dendrimers and that voltammetry can be a simple method for detection of low concentrations of these multicharged species. 相似文献