Search results for "Electron Transfer"

showing 10 items of 282 documents

Thiophene pyrenyl derivatives for the supramolecular processability of single-walled carbon nanotubes in thin film heterojunction

2017

Abstract A major problem for the use of single-wall carbon nanotubes (SWCNTs) in electronic devices relates to their poor processability. Chemical modification inevitably introduces defects in the nanotube lattice, resulting in a loss of electronic properties. In this contest, we report on a supramolecular approach with the aim of increasing the dispersion of SWCNTs in solution and in organic semiconductor matrices by ensuring the optoelectronic properties. In particular, new pyrenyl derivatives of thiophene have been synthesized and used to improve the solubility of SWCNTs for electron transfer in thin film heterojunction with poly(3-hexylthiophene) (P3HT) as donor system. Photoinduced ele…

Materials Chemistry2506 Metals and AlloysNanotubeMaterials scienceCarbon nanotubes02 engineering and technologyCarbon nanotube010402 general chemistryPhotochemistry01 natural sciencesCarbon nanotubePhotoinduced electron transferlaw.inventionchemistry.chemical_compoundElectron transferCarbon nanotubes; Fluorescence quenching; Heterojunctions; Organic photovoltaics; Pyrene; Electronic Optical and Magnetic Materials; Condensed Matter Physics; Mechanics of Materials; Mechanical Engineering; 2506; Materials Chemistry2506 Metals and AlloyslawElectronicMaterials ChemistryThiopheneMoietyOptical and Magnetic MaterialsAlkylSettore CHIM/02 - Chimica Fisicachemistry.chemical_classificationPyreneMechanical EngineeringMetals and AlloysSettore CHIM/05 - Scienza E Tecnologia Dei Materiali PolimericiSettore CHIM/06 - Chimica Organica021001 nanoscience & nanotechnologyCondensed Matter Physics0104 chemical sciencesElectronic Optical and Magnetic MaterialsFluorescence quenchingOrganic semiconductorchemistrySettore CHIM/03 - Chimica Generale E InorganicaMechanics of MaterialsOrganic photovoltaicsHeterojunctionsHeterojunctionOrganic photovoltaic25060210 nano-technologySynthetic Metals
researchProduct

Grand canonical rate theory for electrochemical and electrocatalytic systems I: General formulation and proton-coupled electron transfer reactions

2020

A generally valid rate theory at fixed potentials is developed to treat electrochemical and electrocatalytic potential-dependent electron, proton, and proton-coupled electron reactions. Both classical and quantum reactions in adiabatic and non-adiabatic limits are treated. The applicability and new information obtained from the theory is demonstrated for the gold catalyzed acidic Volmer reaction.

Materials science010304 chemical physicsProtonRenewable Energy Sustainability and the EnvironmentElectrochemical kineticsElectron010402 general chemistryCondensed Matter PhysicsElectrocatalystElectrochemistry01 natural sciences0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsCatalysisElectron transferChemical physics0103 physical sciencesMaterials ChemistryElectrochemistryProton-coupled electron transferAdiabatic processNuclear ExperimentQuantum
researchProduct

Enhanced electronic communication through a conjugated bridge in a porphyrin-fullerene donor-acceptor couple

2021

A ZnP-2EDOTV-C60 triad, with enhanced electronic communication between terminus donor and acceptor moieties, was synthesized and studied both experimentally and theoretically. Electrochemical measurements and density functional theory calculations support that the first oxidation takes place on the 3,4-ethylenedioxythiophenevinylene (2EDOTV) bridge followed by the oxidation of the ZnP moiety at slightly higher energies. The electronic communication between the terminal electron-donor ZnP and the electron-acceptor C60 units is enhanced by the conjugated EDOTV-based spacer leading to photoinduced electron transfer over the distance >2 nm in the picosecond time domain. The involvement of the s…

Materials science010405 organic chemistry116 Chemical sciencesGeneral ChemistryConjugated system010402 general chemistryPhotochemistry01 natural sciencesPorphyrinAcceptorPhotoinduced electron transfer0104 chemical scienceschemistry.chemical_compoundElectron transferchemistryPhotoinduced charge separationMaterials ChemistryMoietyDensity functional theory
researchProduct

Ultrafast Charge Separation at the CdSe/CdS Core/Shell Quantum Dot/Methylviologen Interface: Implications for Nanocrystal Solar Cells

2011

Exciton separation dynamics in the electron transfer system containing highly photostable CdSe/CdS core/shell nanocrystal quantum dots and adsorbed methylviologen was investigated by means of femtosecond absorption spectroscopy. The experiments revealed that electron extraction from the photoexcited core is possible, and the rate of the ET reaction strongly depends on the CdS shell thickness. A CdS associated exponential decay constant β of 0.33 A−1 was obtained reflecting the electronic barrier effect of the shell. These findings show that core/shell structures are well suited for the design of optimized QD-based solar cells.

Materials scienceAbsorption spectroscopyExcitonShell (structure)ElectronQuantum dot solar cellCondensed Matter::Mesoscopic Systems and Quantum Hall EffectSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsCondensed Matter::Materials ScienceElectron transferGeneral EnergyNanocrystalChemical physicsQuantum dotPhysics::Atomic and Molecular ClustersPhysical and Theoretical ChemistryAtomic physicsThe Journal of Physical Chemistry C
researchProduct

Photo-induced electron transfer at nanostructured semiconductor–zinc porphyrin interface

2014

Abstract Electron transfer at metal oxide–organic dye interface on ZnO nanorod (ZnOr) templates was studied by femtosecond absorption spectroscopy method. Further confirmation of the electron transfer was obtained from photoelectrical studies. The fastest electron transfer from zinc porphyrin (ZnP) to semiconductor was observed for ZnOr modified by a 5 nm layer of TiO2 (

Materials scienceAbsorption spectroscopybusiness.industryGeneral Physics and AstronomyPhotochemistryMetalZinc porphyrinElectron transferSemiconductorvisual_artFemtosecondvisual_art.visual_art_mediumNanorodPhysical and Theoretical Chemistrybusinessta116Layer (electronics)Chemical Physics Letters
researchProduct

Photoinduced charge transfer from Carbon Dots to Graphene in solid composite

2019

Abstract The emission in solid phase of Carbon Dots (CDs) deposited by drop-casting technique is investigated by means of micro-photoluminescence. Graphene and SiO2 are used as substrates, and the influence of their different nature – conductive or insulating – on the emission of CDs is highlighed. In particular, a systematic loss of efficiency in the emission of CDs on graphene is found, suggesting a CD-graphene interaction possibly due to a photoinduced electron transfer between the surface states of CDs and the conduction band of graphene. Finally, thanks to the negligible influence on CDs emission, SiO2 substrate is used as support to perform thermal processing of CDs in solid phase, sh…

Materials scienceComposite numberThermal processingchemistry.chemical_element02 engineering and technologySubstrate (electronics)01 natural sciencesPhotoinduced electron transferlaw.inventionCharge transfergraphene carbon dotslawPhase (matter)0103 physical sciencesThermalMaterials ChemistryCarbon dotsPhotoluminescenceSurface states010302 applied physicsbusiness.industryGrapheneMetals and AlloysSurfaces and Interfaces021001 nanoscience & nanotechnologySurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialschemistryOptoelectronicsGraphene0210 nano-technologybusinessCarbon
researchProduct

Electron transfer in ZnO–Fe2O3 aqueous slurry systems and its effects on visible light photocatalytic activity

2017

ZnFex (x = 0.025, 0.05, and 0.1) nanocomposites and pure ZnO and Fe2O3 photocatalysts were synthesized by a simple sol–gel route and characterized by means of specific surface area (SSA) analysis, X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), and transmission electron microscopy/energy dispersive X-ray spectroscopy (TEM/EDS). Their photocatalytic activity was investigated under visible light by using methylene blue (MB) and benzoic acid (BA) as model compounds. Coupling ZnO and Fe2O3 results in higher photocatalytic activity with respect to the pure materials. Photoelectrochemical characterization performed in slurry systems allowed the elucidation of the electronic struc…

Materials scienceDiffuse reflectance infrared fourier transformBand gap02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistry01 natural sciencesCatalysis0104 chemical sciencesElectron transferTransmission electron microscopyPhotocatalysisSettore CHIM/07 - Fondamenti Chimici Delle Tecnologie0210 nano-technologySpectroscopyAbsorption (electromagnetic radiation)Visible spectrumCatalysis Science & Technology
researchProduct

Electrochemical and Spectroelectrochemical Behavior of a Tetracyanotriphenodioxazine in Solution and Thin-Films

2018

International audience; We report the electrochemical behavior of a tetracyano triphenodioxazine bearing two triisopropylsilylethynyl moieties (TiPS‐TPDO‐tetraCN) during its reduction studied either in solution or after vacuum evaporation deposition on indium tin oxide (ITO) support. While in dichloromethane, it typically proceeds in two successive monoelectronic reactions, in acetonitrile, the mechanism appears more complex. Fine analysis of the spectroelectrochemical results combined with simulation of the voltammograms with various amount of water suggest the involvement of water and of a restructured dianion in the electrochemical process. In the solid‐state, the formation of the diprot…

Materials scienceDisproportionation02 engineering and technology010402 general chemistry021001 nanoscience & nanotechnologyElectrochemistryPhotochemistry01 natural sciencesCatalysis0104 chemical sciencesElectrochemistryProton-coupled electron transferThin film0210 nano-technology[CHIM.OTHE]Chemical Sciences/Other
researchProduct

Photoinduced Electron Transfer Reactions in a Porphyrin−Viologen Complex:  Observation of S2 to S1 Relaxation and Electron Transfer from the S2 State

1999

Photoinduced Energy Transfer Reactions in a Porphyrin-Viologen Complex: Observation of S2 to S1 Relaxation and Electron Transfer from the S2 state

Materials scienceEnergy transferViologenPhotochemistryPorphyrinPhotoinduced electron transferSurfaces Coatings and Filmschemistry.chemical_compoundElectron transferFörster resonance energy transferchemistryMaterials ChemistrymedicineRelaxation (physics)Physical and Theoretical ChemistryProton-coupled electron transfermedicine.drugThe Journal of Physical Chemistry B
researchProduct

Characterization and Electrochemical Properties of Oxygenated Amorphous Carbon (a-C) Films

2016

Amorphous carbon (a-C) films with varying oxygen content were deposited by closed-field unbalanced magnetron sputtering with the aim to understand the effect of oxygen on the structural and physical properties of the films and subsequently correlate these changes with electrochemical properties. The a-C films were characterized by transmission electron microscopy, helium-ion microscopy, atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and time-of-flight elastic recoil detection analysis. The electrochemical properties were studied by electrochemical impedance spectroscopy and cyclic voltammetry with several redox systems (Ru(NH3)62+/3+, Fe(CN)64−/3−, dopamine an…

Materials scienceGeneral Chemical EngineeringInorganic chemistryAnalytical chemistrychemistry.chemical_element02 engineering and technology010402 general chemistry01 natural sciencesOxygenRedoxunbalanced magnetron sputteringElectrochemistryoxygenated amorphous carbonta114ta213021001 nanoscience & nanotechnologyAscorbic acidelectron transfercyclic voltammetry0104 chemical sciencesAmorphous solidDielectric spectroscopyCarbon filmelectrochemical impedance spectroscopyAmorphous carbonchemistryCyclic voltammetry0210 nano-technologyElectrochimica Acta
researchProduct