Revealing Site Occupancy in a Complex Oxide: Terbium Iron Garnet.

Complex oxide films stabilized by epitaxial growth can exhibit large populations of point defects which have important effects on their properties. The site occupancy of pulsed laser-deposited epitaxial terbium iron garnet (TbIG) films with excess terbium (Tb) is analyzed, in which the terbium:iron (Tb:Fe)ratio is 0.86 compared to the stoichiometric value of 0.

Direct and real-time observation of hole transport dynamics in anatase TiO using X-ray free-electron laser.

Carrier dynamics affects photocatalytic systems, but direct and real-time observations in an element-specific and energy-level-specific manner are challenging. In this study, we demonstrate that the dynamics of photo-generated holes in metal oxides can be directly probed by using femtosecond X-ray absorption spectroscopy at an X-ray free-electron laser. We identify the energy level and life time of holes with a long life time (230 pico-seconds) in nano-crystal materials.

Hole Dynamics in Photoexcited Hematite Studied with Femtosecond Oxygen K-edge X-ray Absorption Spectroscopy.

Hematite (α-FeO) is a photoelectrode for the water splitting process because of its relatively narrow bandgap and abundance in the earth's crust. In this study, the photoexcited state of a hematite thin film was investigated with femtosecond oxygen K-edge X-ray absorption spectroscopy (XAS) at the PAL-XFEL in order to follow the dynamics of its photoexcited states. The 200 fs decay time of the hole state in the valence band was observed via its corresponding XAS feature.

Femtosecond Charge Density Modulations in Photoexcited CuWO.

Copper tungstate (CuWO) is an important semiconductor with a sophisticated and debatable electronic structure that has a direct impact on its chemistry. Using the PAL-XFEL source, we study the electronic dynamics of photoexcited CuWO. The Cu L X-ray absorption spectrum shifts to lower energy upon photoexcitation, which implies that the photoexcitation process from the oxygen valence band to the tungsten conduction band effectively increases the charge density on the Cu atoms.

Direct observation of the electronic states of photoexcited hematite with ultrafast 2p3d X-ray absorption spectroscopy and resonant inelastic X-ray scattering.

Hematite, α-FeO, is an important semiconductor for photoelectrochemical water splitting. Its low charge carrier mobility and the presence of midgap states provide favourable conditions for electron-hole recombination, hence affecting the semiconductor's photoelectrochemical efficiency. The nature of the excited state and charge carrier transport in hematite is strongly debated.

Photoinduced anisotropic distortion as the electron trapping site of tungsten trioxide by ultrafast W L-edge X-ray absorption spectroscopy with full potential multiple scattering calculations.

Understanding the excited state of photocatalysts is significant to improve their activity for water splitting reaction. X-ray absorption fine structure (XAFS) spectroscopy in X-ray free electron lasers (XFEL) is a powerful method to address dynamic changes in electronic states and structures of photocatalysts in the excited state in ultrafast short time scales. The ultrafast atomic-scale local structural change in photoexcited WO was observed by W L edge XAFS spectroscopy using an XFEL.

Insights into the Synthesis Mechanism of Ag Nanoclusters.

The current understanding of the synthesis mechanisms of noble metal clusters is limited, in particular for Ag clusters. Here, we present a detailed investigation into the synthesis process of atomically monodisperse Ag clusters, prepared via reduction of AgNO in the presence of dithiolate ligands. Using optical spectroscopy, mass spectrometry, and X-ray spectroscopy, it was determined that the synthesis involves a rapid nucleation and growth to species with up to a few hundred Ag atoms.

Single Au Atom Doping of Silver Nanoclusters.

Ag nanoclusters capped with lipoic acid (LA) can be doped with Au. The doped clusters show enhanced stability and increased luminescence efficiency. We attribute the higher quantum yield to an increase in the rate of radiative decay.

Noninvasive Assessment of Elimination and Retention using CT-FMT and Kinetic Whole-body Modeling.

Fluorescence-mediated tomography (FMT) is a quantitative three-dimensional imaging technique for preclinical research applications. The combination with micro-computed tomography (µCT) enables improved reconstruction and analysis. The aim of this study is to assess the potential of µCT-FMT and kinetic modeling to determine elimination and retention of typical model drugs and drug delivery systems.

Combined Operando X-ray Diffraction/Raman Spectroscopy of Catalytic Solids in the Laboratory: The Co/TiO Fischer-Tropsch Synthesis Catalyst Showcase.

A novel laboratory setup for combined operando X-ray diffraction and Raman spectroscopy of catalytic solids with online product analysis by gas chromatography is presented. The setup can be used with a laboratory-based X-ray source, which results in important advantages in terms of time-on-stream that can be measured, compared to synchrotron-based experiments. The data quality was much improved by the use of a relatively high-energy MoK radiation instead of the more conventional CuK radiation.

Photo-spectroscopy of mixtures of catalyst particles reveals their age and type.

Within a fluid catalytic cracking (FCC) unit, a mixture of catalyst particles that consist of either zeolite Y (FCC-Y) or ZSM-5 (FCC-ZSM-5) is used in order to boost the propylene yield when processing crude oil fractions. Mixtures of differently aged FCC-Y and FCC-ZSM-5 particles circulating in the FCC unit, the so-called equilibrium catalyst (Ecat), are routinely studied to monitor the overall efficiency of the FCC process. In this study, the age of individual catalyst particles is evaluated based upon photographs after selective staining with substituted styrene molecules.

Penile anesthesia in Post SSRI Sexual Dysfunction (PSSD) responds to low-power laser irradiation: a case study and hypothesis about the role of transient receptor potential (TRP) ion channels.

Treatment of paroxetine-induced penile anesthesia in Post SSRI Sexual Dysfunction (PSSD) by Low-power Laser Irradiation (LPLI) is unknown in medical literature. The aim of the current article is to report partial efficacy of LPLI for paroxetine-induced persistent penile anesthesia. We report on a male patient who presented with a history of reversible loss of smell, taste and skin sensitivity occurring within a week after start of 20mg/day paroxetine-hemihydrate for a depressive period.

Correlating metal poisoning with zeolite deactivation in an individual catalyst particle by chemical and phase-sensitive X-ray microscopy.

Fluid catalytic cracking (FCC) is the main conversion process used in oil refineries. An X-ray microscopy method is used to show that metal poisoning and related structural changes in the zeolite active material lead to a non-uniform core–shell deactivation of FCC catalyst particles. The study links the detrimental effect of V and Ni poisoning with zeolite destruction and dealumination in a spatial manner within a single FCC catalyst particle.