Showing papers on "Absorption spectroscopy published in 2004"
TL;DR: X-ray absorption spectroscopy and x-ray Raman scattering were used to probe the molecular arrangement in the first coordination shell of liquid water and set a strong limit for possible local structure distributions in liquid water.
Abstract: X-ray absorption spectroscopy and x-ray Raman scattering were used to probe the molecular arrangement in the first coordination shell of liquid water. The local structure is characterized by comparison with bulk and surface of ordinary hexagonal ice Ih and with calculated spectra. Most molecules in liquid water are in two hydrogen– bonded configurations with one strong donor and one strong acceptor hydrogen bond in contrast to the four hydrogen– bonded tetrahedral structure in ice. Upon heating from 25°C to 90°C, 5 to 10% of the molecules change from tetrahedral environments to two hydrogen– bonded configurations. Our findings are consistent with neutron and x-ray diffraction data, and combining the results sets a strong limit for possible local structure distributions in liquid water. Serious discrepancies with structures based on current molecular dynamics simulations are observed.
1,278 citations
TL;DR: In this article, an efficient bulk-heterojunction solar cells can be made using ZnO nanoparticles and a conjugated polymer, and the incident photon to current conversion efficiency (IPCE) closely resembles the absorption spectrum of the MDMO-PPV layer on glass, and reaches a value of 40 % at the absorption max.
Abstract: The authors show that efficient bulk-heterojunction solar cells can be made using ZnO nanoparticles and a conjugated polymer. These cells can be processed from soln. and exhibit an incident photon to current conversion efficiency up to 40 %. Nanocryst. ZnO (nc-ZnO) of approx. 5 nm diam. was synthesized and used. As the n-type semiconductor. Complexes with MDMO-PPV were used, with Aluminum and a PEDOT-PSS/ITO-coated glass hole-conducting electrode. The incident photon to current conversion efficiency (IPCE)closely resembles the absorption spectrum of the MDMO-PPV:nc-ZnO layer on glass, and reaches a value of 40 % at the absorption max. MDMO-PPV. Integration of this spectral response with the solar spectrum (AM1.5G, normalized 100 mW cm-2) affords an est. of the short-circuit c.d. of Jsc = 3.3 mA/cm2 under AM1.5 (1 sun) conditions. C.d.-voltage (J-V) measurements, carried out in the dark reveal excellent diode behavior, with electron current dominating the c.d. in forward bias. TEM micrographs showed intimate mixing of the ZnO and the MDMO-PPV, with the majority of the polymer domains smaller than a few tens of nanometers, which has been shown to be the exciton diffusion length in a similar PPV polymer.
920 citations
TL;DR: In this article, the performance of photovoltaic devices with different weight ratios of conjugated poly(3-hexylthiophene) (P3HT) and the fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) was studied.
Abstract: Composites of conjugated poly(3-hexylthiophene) (P3HT) and the fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) demonstrate an efficient photogeneration of mobile charge carriers. Thermal annealing of P3HT:PCBM based devices gives rise to a significant increase of the photovoltaic efficiency, as follows from measurements of the external quantum efficiency and the current-voltage characteristics. Upon annealing, the absorption spectrum of the P3HT:PCBM composite undergoes a strong modification, whereas in the pure components it remains unchanged. The absorption of the annealed blends becomes stronger and red shifted in the wavelength region ascribed to P3HT, while the absorption due to the PCBM contribution does not change. Atomic force microscope measurements on P3HT:PCBM disclose some variation in morphology due to the crystallization of PCBM. The concentration of the PCBM clusters and their size (up to 500 nm) were found to be correlated with the amount of PCBM in the blend. We have studied the performance of photovoltaic devices with different weight ratios of P3HT:PCBM, namely, 1:3, 1:2, 1:1.5, 1:1, 1:0.9, 1:0.8, and 1:0.7. The photocurrent and the power conversion efficiency showed a maximum between 1:1 and 1:0.9. We conclude the variation in the absorption spectrum and the red shift to result from molecular diffusion of PCBM out of the polymer matrix upon annealing. The growth of the PCBM clusters leads to formation of percolation paths and, therefore, improves the photocurrent. Above a certain concentration, the PCBM crystals provide mechanical stress on the metal electrode, therefore possibly damaging the interface. Optimization of the composite weight ratio reveals the important role played by morphology for the transport properties of bulk heterojunction P3HT:PCBM based solar cells.
722 citations
TL;DR: The results of synchronous fluorescence spectra and UV-vis absorption spectra show that the conformation of bovine serum albumin has been changed, and the quenching mechanism of fluorescence of BSA by monoammonium glycyrrhizinate was discussed.
586 citations
TL;DR: In this article, a series of novel oligoene dyes which have different lengths of methine units, cyano groups and/or carboxylic groups as the electron acceptor units, and amino groups as electron donor units was designed and synthesized.
Abstract: As highly efficient organic sensitizers for dye-sensitized solar cells, a series of novel oligoene dyes which have different lengths of methine units, cyano groups and/or carboxylic groups as the electron acceptor units, and amino groups as the electron donor units was designed and synthesized. The bathochromic shift of the absorption spectrum was achieved by expansion of the π-conjugated system by increasing the number of methine units and by introduction of both electron-withdrawing and -accepting groups, which induced charge-transfer-type absorption character. Redox potential of the dyes was also controlled by the substitution of the functional groups. Dye-sensitized solar cells (DSCs) based on the oligoene dyes showed excellent response of incident photon to current conversion efficiency (>80%), leading to good photovoltaic performances up to 6.6% under 1 sun irradiation conditions. Femtosecond transient absorption spectroscopy in the mid-IR region revealed the very fast electron injection from the ex...
553 citations
TL;DR: X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopic experiments are used to investigate the oxidation state of cerium ions in ceria nanoparticles.
511 citations
TL;DR: It is proposed that the long wavelength absorption tail of HS appears to arise from a continuum of coupled states, and that this behavior results from intramolecular charge-transfer interactions between hydroxy-aromatic donors and quinoid acceptors formed by the partial oxidation of lignin precursors.
Abstract: Absorption and fluorescence spectroscopy and laser photobleaching experiments were employed to probe the origins of the optical properties of humic substances (HS). Luminescence quantum yields and the wavelengths of maximum emission were acquired for Suwannee River humic acid (SRHA) and fulvic acid (SRFA) at an extensive series of excitation wavelengths across the ultraviolet and visible. Laser irradiation at a series wavelength across the ultraviolet and visible was further employed to destroy selectively chromophores absorbing at specific wavelengths, using absorption spectroscopy to follow the absorption losses with irradiation time. The results provide unequivocal evidence that the absorption and emission spectra of these materials cannot result solely from a simple linear superposition of the spectra of numerous independent chromophores. Instead, the long wavelength absorption tail of HS (>350 nm) appears to arise from a continuum of coupled states. We propose that this behavior results from intramolecular charge-transfer interactions between hydroxy-aromatic donors and quinoid acceptors formed by the partial oxidation of lignin precursors. We further propose that these donor-acceptor interactions may be a common phenomenon, occurring within all natural hydroxy- or polyhydroxy-aromatic polymers that form appropriate acceptors upon partial oxidation. Examples of such species include lignin, polyphenols, tannins, and melanins.
474 citations
TL;DR: In this paper, a wide variety of surfactants for their efficiency in dissolving isolated single-walled carbon nanotubes (SWNTs) in water was investigated.
Abstract: We have investigated a wide variety of surfactants for their efficiency in dissolving isolated single-walled carbon nanotubes (SWNTs) in water. In doing so, we have completely avoided the harsh chemical or mechanical conditions, such as acid or ultrasonic treatments, that are known to damage SWNTs. Bile salts in particular are found to be exceptionally effective in dissolving individual tubes, as evidenced by highly resolved optical absorption spectra, bright bandgap fluorescence, and the unprecedented resolution (∼ 2.5 cm - 1 ) of the radial breathing modes in Raman spectra. This is attributed to the formation of very regular and stable micelles around the nanotubes providing an unusually homogeneous environment. Quantitative information concerning the degree of solubilization is obtained from absorption spectroscopy.
469 citations
TL;DR: In this paper, a superposition of the free and trapped electron spectra was obtained by subtracting the electron spectrum from the transient absorption spectrum, and the spectrum of trapped holes was obtained.
Abstract: Reactive species, holes, and electrons in photoexcited nanocrystalline TiO2 films were studied by transient absorption spectroscopy in the wavelength range from 400 to 2500 nm. The electron spectrum was obtained through a hole-scavenging reaction under steady-state light irradiation. The spectrum can be analyzed by a superposition of the free-electron and trapped-electron spectra. By subtracting the electron spectrum from the transient absorption spectrum, the spectrum of trapped holes was obtained. As a result, three reactive speciestrapped holes and free and trapped electronswere identified in the transient absorption spectrum. The reactivity of these species was evaluated through transient absorption spectroscopy in the presence of hole- and electron-scavenger molecules. The spectra indicate that trapped holes and electrons are localized at the surface of the particles and free electrons are distributed in the bulk.
437 citations
TL;DR: In this article, a series of vanadium-doped TiO 2 catalysts were synthesized by two modified sol-gel methods, and the TEM micrographs showed the sizes of primary particles were in the range of 6-20nm.
Abstract: A series of vanadium-doped TiO 2 catalysts were synthesized by two modified sol–gel methods. V-doped TiO 2 was found to be mainly preserved its anatase phase after calcination at 400 °C. The TEM micrographs showed the sizes of primary particles were in the range of 6–20 nm. The increase of vanadium doping promoted the particle growth, and enhanced “red-shift” in the UV-Vis absorption spectra. The XPS (X-ray photoelectron spectroscopy) could not detect vanadium indicating negligible vanadium on the surface of catalysts, furthermore, there were also no peak of vanadium oxide in the XRD patterns. XAS (X-ray absorption spectroscopy) analysis indicating V 4+ instead of V 5+ implied that vanadium either substituted Ti 4+ site or embedded in the vacancy of TiO 2 structure. Therefore, vanadium was concluded to be highly dispersed inside the TiO 2 structure. The photocatalytic activity was evaluated by the degradation of crystal violet (CV) and methylene blue (MB) under visible light irradiation. The degradation rate of CV and MB on V-doped TiO 2 were higher than those of pure TiO 2 . As the results, V-doped TiO 2 possessed better absorption ability of visible light.
427 citations
TL;DR: Ultrafast x-ray techniques using diffraction and absorption are discussed with an emphasis on the absorption techniques, and sources and detectors for use in x-rays absorption spectroscopy are reviewed.
Abstract: A review. Ultrafast x-ray techniques using diffraction and absorption are discussed with an emphasis on the absorption techniques. Ultrafast x-ray sources and detectors for use in x-ray absorption spectroscopy are also reviewed. [on SciFinder (R)]
TL;DR: The far-infrared absorption and index of refraction of high resistivity, float-zone, crystalline silicon has been measured by terahertz time-domain spectroscopy.
Abstract: The far-infrared absorption and index of refraction of high-resistivity, float-zone, crystalline silicon has been measured by terahertz time-domain spectroscopy. The measured new upper limit for the absorption of this most transparent dielectric material in the far infrared shows unprecedented transparency over the range from 0.5 to 2.5 THz and a well-resolved absorption feature at 3.6 THz. The index of refraction shows remarkably little dispersion, changing by only 0.0001 over the range from 0.5 to 4.5 THz.
TL;DR: It is demonstrated for the first time that the Au:PVP NPs act as catalyst toward homocoupling of phenylboronic acid in water under aerobic conditions and suppression of biphenyl formation under anaerobic conditions indicates that molecular oxygen dissolved in water is intimately involved in the coupling reactions.
Abstract: Gold nanoparticles (<2 nm) stabilized by poly(N-vinyl-2-pyrrolidone) (Au:PVP NPs) were prepared by reduction of AuCl4- with NaBH4 in the presence of PVP and characterized via an array of methods including optical absorption spectroscopy, transmission electron microscopy, X-ray diffraction, X-ray absorption near-edge structure, extended X-ray absorption fine structure, and X-ray photoelectron spectroscopy. We demonstrate for the first time that the Au:PVP NPs act as catalyst toward homocoupling of phenylboronic acid in water under aerobic conditions. Suppression of biphenyl formation under anaerobic conditions indicates that molecular oxygen dissolved in water is intimately involved in the coupling reactions. A mechanism of the aerobic homocoupling catalyzed by the Au:PVP NPs is proposed on the basis of a crucial role of dissolved oxygen, steric effects on the product yields, and the well-established mechanism for the Pd(II)-based catalysts.
TL;DR: Swelling (and shrinking) of poly(2-vinylpyridine), P2VP, polymer brushes, caused by pH changes, could be readily monitored by transmission surface plasmon resonance, T-SPR, spectroscopy.
Abstract: Swelling (and shrinking) of poly(2-vinylpyridine), P2VP, polymer brushes, caused by pH changes, could be readily monitored by transmission surface plasmon resonance, T-SPR, spectroscopy. Gold nanoparticles attached to the P2VP polymer brushes dramatically enhanced the pH-induced shift in the T-SPR absorption spectra. (A 50 nm shift of the absorption maximum of the T-SPR spectrum of the supporting gold nanoislands was observed upon changing the pH from 5.0 to 2.0, corresponding to a swelling of the polymer brushes from 8.1 ± 0.7 to 24.0 ± 2.0 nm. Same shift in the opposite direction was observed upon changing the pH from 2.0 to 5.0.)
TL;DR: In this paper, microstructured silicon surfaces with femtosecond laser irradiation in the presence of SF6 were shown to display strong absorption of infrared radiation at energies below the band gap of crystalline silicon.
Abstract: We microstructured silicon surfaces with femtosecond laser irradiation in the presence of SF6. These surfaces display strong absorption of infrared radiation at energies below the band gap of crystalline silicon. We report the dependence of this below-band gap absorption on microstructuring conditions (laser fluence, number of laser pulses, and background pressure of SF6) along with structural and chemical characterization of the material. Significant amounts of sulfur are incorporated into the silicon over a wide range of microstructuring conditions; the sulfur is embedded in a disordered nanocrystalline layer less than 1 μm thick that covers the microstructures. The most likely mechanism for the below-band gap absorption is the formation of a band of sulfur impurity states overlapping the silicon band edge, reducing the band gap from 1.1 eV to approximately 0.4 eV.
TL;DR: The absorption of a single isolated metal cluster is directly measured using a novel far-field optical technique based on modulation of its position using optically detected single gold nanoparticles dispersed on a transparent substrate.
Abstract: The absorption of a single isolated metal cluster is directly measured using a novel far-field optical technique based on modulation of its position. Single gold nanoparticles with average diameters down to 5 nm, dispersed on a transparent substrate, are optically detected and their absolute absorption cross section determined.
TL;DR: It is shown how current directly injected into a freely suspended individual single-wall carbon nanotube can be used to excite, detect and control a specific vibrational mode of the molecule.
Abstract: The interplay between discrete vibrational and electronic degrees of freedom directly influences the chemical and physical properties of molecular systems. This coupling is typically studied through optical methods such as fluorescence, absorption and Raman spectroscopy. Molecular electronic devices provide new opportunities for exploring vibration-electronic interactions at the single molecule level. For example, electrons injected from a scanning tunnelling microscope tip into a metal can excite vibrational excitations of a molecule situated in the gap between tip and metal. Here we show how current directly injected into a freely suspended individual single-wall carbon nanotube can be used to excite, detect and control a specific vibrational mode of the molecule. Electrons tunnelling inelastically into the nanotube cause a non-equilibrium occupation of the radial breathing mode, leading to both stimulated emission and absorption of phonons by successive electron tunnelling events. We exploit this effect to measure a phonon lifetime of the order of 10 ns, corresponding to a quality factor of well over 10,000 for this nanomechanical oscillator.
TL;DR: The semiempirical quantum-chemical (ZINDO) method can assign the characteristic bands of the "camel-back" absorption spectrum to one charge transfer state at lower energy localized on the TBT unit, and one delocalized excitonic state at higher energy corresponding to the pi-conjugated electron system.
Abstract: We calculate the electronic states of the low bandgap polyfluorene-based copolymer DiO-PFDTBT, which consists of alternating 9,9-dioctyl-9H-fluorene and 4,7-di-thiophen-2-ylbenzo[1,2,5]thiadiazole (TBT) units, and compare with the steady-state absorption, emission, and excitation spectrum. Using the semiempirical quantum-chemical (ZINDO) method we can assign the characteristic bands of the “camel-back” absorption spectrum to one charge transfer state at lower energy localized on the TBT unit, and one delocalized excitonic state at higher energy corresponding to the π-conjugated electron system. Additional “dark” charge transfer states in the gap between these bands have been revealed. Calculations are also made on the red light emitting polyfluorene-based copolymer poly(fluorene-co-benzothiadiazole) (F8BT), which contains benzo[1,2,5]thiadiazole instead of TBT. The nature of the electronic states in F8BT and DiO-PFDTBT are found to be qualitatively the same.
TL;DR: Fluorescence emission, electron paramagnetic resonance, and X-ray absorption spectroscopy provide evidence for the presence of Mn in the interior as well as on the surface of the nanocrystals of Mn-doped ZnO.
Abstract: We report the synthesis and characterization of several sizes of Mn-doped ZnO nanocrystals, both in the free-standing and the capped particle forms. The sizes of these nanocrystals could be controlled by capping them with polyvinylpyrollidone under different synthesis conditions and were estimated by X-ray diffraction and transmission electron microscopy. The absorption properties of PVP-capped Mn-doped ZnO exhibit an interesting variation of the band gap with the concentration of Mn. Fluorescence emission, electron paramagnetic resonance, and X-ray absorption spectroscopy provide evidence for the presence of Mn in the interior as well as on the surface of the nanocrystals.
TL;DR: In this article, the compositional properties of the layers were analyzed by FTIR and ATR infrared spectroscopy techniques, and a correlation between the N-H concentration and absorption loss was verified for silicon oxynitride slab waveguides.
TL;DR: XAS as a Characterization Method: Pt/C 4.1.
Abstract: 1.Introduction
2.X-ray Absorption Spectroscopy
2.1. XANES
2.2. EXAFS
3.Data Collection and In Situ Cells
4.XAS as a Characterization Method: Pt/C
4.1. Particle Size
4.2. Potential Dependence
4.3. Adsorbates
5.Pt Containing Alloy Catalysts
5.1. PtRu Alloys
5.1.1. Compositional Analysis
5.1.2. Potential Dependence
5.1.3. Adsorbates
5.2. Other Pt Containing Alloy Anode Catalysts
5.3. Pt Containing Alloy Cathode Catalysts
6.Non-Pt Catalysts
7.Conclusion
8.References
TL;DR: In this paper, one-dimensional arrays of Co3O4 nanoparticles were obtained via the thermal treatment of cobalt oxalate nanorods, which were synthesized through a convenient solvothermal route.
Abstract: One-dimensional arrays of Co3O4 nanoparticles were obtained via the thermal treatment of cobalt oxalate nanorods, which were synthesized through a convenient solvothermal route. The optical properties of Co3O4 nanoparticles were investigated. The optical absorption spectrum indicates that the direct band gaps of Co3O4 nanoparticles are 1.52 and 2.01 eV. The galvanostatic experiment shows the excellent electrochemical performance between 3.0 and 0.2 V.
TL;DR: Infrared reflection absorption spectroscopy (IRAS) has been used to study CO adsorption on Au clusters ranging in size from 1.8 to 3.1 nm, supported on TiO(2), and the adsorbed CO vibrational frequency blue-shifts slightly and the heats of adsOrption increase sharply with decreasing cluster size.
Abstract: Infrared reflection absorption spectroscopy (IRAS) has been used to study CO adsorption on Au clusters ranging in size from 1.8 to 3.1 nm, supported on TiO2. The adsorbed CO vibrational frequency blue-shifts slightly (approximately 4 cm-1) compared to that adsorbed on bulk Au, whereas the heats of adsorption (−ΔHads) increase sharply with decreasing cluster size, from 12.5 to 18.3 kcal/mol.
TL;DR: In this paper, a suite of 27 common, Fe-bearing reference compounds, including sulfides, carbonates, phosphates, oxides, oxyhydroxides, and phyllosilicates, was analyzed to empirically assess the utility of X-ray absorption near-edge structure (XANES) and extended Xray absorption fine structure (EXAFS) for identifying a particular Fe mineral (or class of minerals) in a soil or sediment mixture.
Abstract: Synchrotron X-ray absorption spectroscopy (XAS) is becoming an increasingly popular tool for the analysis of element speciation in complex natural mixtures such as soils and sediments. Identification of a particular mineral or amorphous solid in a heterogeneous mixture by XAS depends on the spectral uniqueness of the element in the bonding environment associated with a component, and on absorption effects from the components and the matrix. A suite of 27 common, Fe-bearing reference compounds, including sulfides, carbonates, phosphates, oxides, oxyhydroxides, and phyllosilicates, was analyzed to empirically assess the utility of X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) for identifying a particular Fe mineral (or class of minerals) in a soil or sediment mixture. We show that XANES spectral features are useful for distinguishing qualitatively among major mineral classes, but not necessarily for identifying minerals within classes. A practical detection limit (based on empirical mixtures) for most mineral classes is on the order of 5% of the total atomic Fe absorption, but detection limits vary depending on the spectral uniqueness of the components, the number of components, and the matrix. Calibration curves for Fe sulfide and non-sulfide (phyllosilicate ± oxide) component mixtures were made independently from the analyses of XANES and EXAFS fluorescence spectra of binary and ternary mineral mixtures (at 5% total Fe) in a quartz matrix to mimic natural sediments. Because of differences in sample and matrix absorption and fluorescence among sulfide and phyllosilicate minerals, apparent component fractions of pyrite derived from fits deviated significantly from linear binary mixtures. We show that corrections for non-linear fluorescence (as much as 20%) are particularly important for binary mineral mixtures with different densities and absorption characteristics (such as sulfides and phyllosilicates), and for mixtures with similar component abundances (i.e., far from one end-member). An application of the fluorescence calibration for XANES and EXAFS is shown for natural samples. This study points out the importance of a high-quality, experimentally consistent reference compound library, and the need for calibration of fluorescence spectra, in order to quantify accurately the component fractions of complex mixtures using XAS.
TL;DR: Broadband infrared luminescence from bismuth-doped germanium oxide glasses prepared by a conventional melting-quenching technique was discovered and Codoping of aluminum and bismUTH was indispensable for the broadband infrared Luminescence in GeO2:Bi, Al glass.
Abstract: Broadband infrared luminescence from bismuth-doped germanium oxide glasses prepared by a conventional melting-quenching technique was discovered. The absorption spectrum of the glasses covered a wide range from the visible to the near-infrared wavelength regions and consisted of five broad peaks below 370, 500, 700, 800, and 1000 nm. The fluorescence spectrum exhibited broadband characteristics (FWHM) greater than 300 nm with a maximum at 1300 nm pumped by an 808-nm laser. The fluorescence lifetime at room temperature decreased with increasing Bi2O3 concentration in the glass. Codoping of aluminum and bismuth was indispensable for the broadband infrared luminescence in GeO2:Bi, Al glass.
TL;DR: In this paper, the influence of different salt ions or polymer molecules on the size and distribution of the final titania particles was investigated, and electron microscopy, thermogravimetry, 1H-MAS NMR, X-ray absorption spectroscopy, and electrophoresis.
Abstract: Monodisperse spherical titania particles of variable sizes are produced in a sol−gel synthesis from Ti(EtO)4 in ethanol with addition of a salt or a polymer solution. The influence of different salt ions or polymer molecules on the size and the size distribution of the final particles was investigated. The amorphous hydrous titania particles were characterized by electron microscopy, thermogravimetry, 1H-MAS NMR, X-ray absorption spectroscopy, and electrophoresis. Nitrogen absorption measurements revealed that the addition of polymers yields hollow and porous titania colloids.
TL;DR: In this article, the extent of solarization is strongly influenced by many factors such as glass matrix, dopants, or irradiation source, which can be detected with optical and EPR spectroscopy.
TL;DR: Waveguide terahertz time-domain spectroscopy is demonstrated to have the sensitivity to characterize nanometer-thick water layers on the surfaces of a parallel-plate metal waveguide.
Abstract: Waveguide terahertz time-domain spectroscopy is demonstrated to have the sensitivity to characterize nanometer-thick water layers on the surfaces of a parallel-plate metal waveguide. The measured far-infrared absorption and index of refraction of the 20-nm water layers are in reasonable self-consistent agreement with those of bulk water.
TL;DR: Results show that a direct charge injection process from an occupied dye molecular state to a nanoparticle excited state localized on a few Ti atoms, rather than to a delocalized conduction state, effectively takes place in this system, in agreement with recent experimental evidence.
Abstract: Time-dependent DFT calculations have been performed on the absorption spectrum of [Fe(CN)6]4- adsorbed on a TiO2 anatase nanoparticle model to provide a detailed description of the electronic structure for this prototype system and to understand the character of the states involved in the molecule → semiconductor charge transfer process. Our results show that a direct charge injection process from an occupied dye molecular state to a nanoparticle excited state localized on a few Ti atoms, rather than to a delocalized conduction state, effectively takes place in this system, in agreement with recent experimental evidence.
TL;DR: Li et al. as discussed by the authors studied the first cycle characteristics of Li[Ni1/3Co 1/3Mn 1 /3]O2 charged up to 4.7 ǫ.