Single-Atom Catalysts on CN: Minimizing Single Atom Pt Loading for Maximized Photocatalytic Hydrogen Production Efficiency.

The use of metal single atoms (SAs) as co-catalysts on semiconductors has emerged as a promising technology to enhance their photocatalytic hydrogen production performance. In this study, we describe the deposition of very low amounts of Pt SAs (<0.1 at %) on exfoliated graphitic carbon nitride (CN) by a direct Pt-deposition approach from highly dilute chloroplatinic acid precursors.

Pt Single Atoms Loaded on Thin-Layer TiO Electrodes: Electrochemical and Photocatalytic Features.

Recently, the use of Pt in the form of single atoms (SA) has attracted considerable attention to promote the cathodic hydrogen production reaction from water in electrochemical or photocatalytic settings. First, produce suitable electrodes by Pt SA deposition on Direct current (DC)-sputter deposited titania (TiO) layers on graphene-these electrodes allow to characterization of the electrochemical properties of Pt single atoms and their investigation in high-resolution HAADF-STEM. For Pt SAs loaded on TiO, electrochemical H evolution shows only a very small overpotential.

Lifshitz Transition in a Single-Atom-Thick GdYbPb Kagome Compound on Si(111).

Lanthanide (Ln) elements Gd and Yb alloyed with a Pb monolayer on the Si(111) substrate form LnPb compounds having the same crystal structure. They comprise a single-atom-thick Pb layer arranged in a slightly distorted kagome lattice with Ln atoms filling the hexagonal voids. They have similar electronic band structures except for the Fermi level position, which varies between the divalent Yb- and trivalent Gd-containing compounds by ∼0.

Pt Single Atoms on TiO Can Catalyze Water Oxidation in Photoelectrochemical Experiments.

Photoelectrochemical water splitting on n-type semiconductors is highly dependent on catalysis of the rate-determining reaction of O evolution. Conventionally, in electrochemistry and photoelectrochemistry O evolution is catalyzed by metal oxide catalysts like IrO and RuO, whereas noble metals such as Pt are considered unsuitable for this purpose. However, our study finds that Pt, in its single-atom form, exhibits exceptional cocatalytic properties for photoelectrochemical water oxidation on a TiO photoanode, in contrast to Pt in a nanoparticle form.

Stable and Highly Active Single Atom Configurations for Photocatalytic H Generation.

The employment of single atoms (SAs), especially Pt SAs, as co-catalysts in photocatalytic H generation has gained significant attention due to their exceptional efficiency. However, a major challenge in their application is the light-induced agglomeration of these SAs into less active nanosized particles under photocatalytic conditions. This study addresses the stability and reactivity of Pt SAs on TiO surfaces by investigating various post-deposition annealing treatments in air, Ar, and Ar-H environments at different temperatures.

Slow magnetic relaxation in a complex of photochromic spiropyran in a merocyanine form and cobalt(II) hexafluoroacetylacetonate.

The interaction between photochromic 8-methoxy-1',3',3'-trimethyl-6-nitro-spiro[chromene-2,2'-indole] (MNSP) and cobalt(II) hexafluoroacetylacetonate yields a deep red-violet solution due to the coordination-induced transition of MNSP from a colorless closed state to a colored open merocyanine (MC) form. The resulting complex {Co(hfac)·MNSP} (1) is obtained as crystals, and its structure at 250 K shows the coordination of two oxygen atoms from MNSP with Co, forming a distorted octahedral surrounding around Co. The unit cell of 1 contracts below 170 K by 5.

Photocatalytic H Generation: Controlled and Optimized Dispersion of Single Atom Co-Catalysts Based on Pt-TCPP Planar Adsorption on TiO.

When using single atoms (SAs) as a co-catalyst in photocatalytic H generation, achieving a well-dispersed, evenly distributed and adjustable SA surface density on a semiconductor surface is a challenging task. In the present work we use the planar adsorption of tetrakis-(4-carboxyphenyl)-porphyrin (TCPP) and its platinum coordinated analogue, Pt-TCPP, onto anatase TiO surfaces to establish a spatially controlled decoration of SAs. We show that the surface Pt SA density can be very well controlled by co-adsorption of Pt-TCPP and TCPP in the planar monolayer regime, and by adjusting the Pt-TCPP to TCPP ratio a desired well dispersed surface density of SAs up to 2.

2D Metal-Organic Framework Nanosheets based on Pd-TCPP as Photocatalysts for Highly Improved Hydrogen Evolution.

In this report, a 2D MOF nanosheet derived Pd single-atom catalyst, denoted as Pd-MOF, was fabricated and examined for visible light photocatalytic hydrogen evolution reaction (HER). This Pd-MOF can provide a remarkable photocatalytic activity (a H production rate of 21.3 mmol/gh in the visible range), which outperforms recently reported Pt-MOFs (with a H production rate of 6.

Characterization of a Timepix detector for use in SEM acceleration voltage range.

Hybrid pixel direct electron detectors are gaining popularity in electron microscopy due to their excellent properties. Some commercial cameras based on this technology are relatively affordable which makes them attractive tools for experimentation especially in combination with an SEM setup. To support this, a detector characterization (Modulation Transfer Function, Detective Quantum Efficiency) of an Advacam Minipix and Advacam Advapix detector in the 15-30 keV range was made.

Reactive Deposition Versus Strong Electrostatic Adsorption (SEA): A Key to Highly Active Single Atom Co-Catalysts in Photocatalytic H Generation.

In recent years, the use of single atoms (SAs) has become of a rapidly increasing significance in photocatalytic H generation; here SA noble metals (mainly Pt SAs) can act as highly effective co-catalysts. The classic strategy to decorate oxide semiconductor surfaces with maximally dispersed SAs relies on "strong electrostatic adsorption" (SEA) of suitable noble metal complexes. In the case of TiO - the classic benchmark photocatalyst - SEA calls for adsorption of cationic Pt complexes such as [(NH ) Pt] which then are thermally reacted to surface-bound SAs.

Low-cost electron detector for scanning electron microscope.

Electron microscopy is an indispensable tool for the characterization of (nano) materials. Electron microscopes are typically very expensive and their internal operation is often shielded from the user. This situation can provide fast and high quality results for researchers focusing on e.

Light-Induced Agglomeration of Single-Atom Platinum in Photocatalysis.

With recent advances in the field of single-atoms (SAs) used in photocatalysis, an unprecedented performance of atomically dispersed co-catalysts has been achieved. However, the stability and agglomeration of SA co-catalysts on the semiconductor surface may represent a critical issue in potential applications. Here, the photoinduced destabilization of Pt SAs on the benchmark photocatalyst, TiO , is described.

Gold Interlayer Promotes Superconductivity in Single and Double Atomic Pb Layers on Si(100).

Introducing an atomic Au monolayer between a Pb film and a Si(100) substrate allows us to fabricate Pb films with single- and double-atom thicknesses. The Pb films have a 2D square-lattice structure with the 1D atomic chains of Pb adatoms on their top, forming Si(100)1 × 7-(Pb, Au) and Si(100)5 × 1-(Pb, Au) superstructures for single and double atomic Pb layers, respectively. Their common characteristic feature is the occurrence of bundles of quasi-1D metallic bands.

Facet-Control versus Co-Catalyst-Control in Photocatalytic H Evolution from Anatase TiO Nanocrystals.

Titanium dioxide (TiO ) and, in particular, its anatase polymorph, is widely studied for photocatalytic H production. In the present work, we examine the importance of reactive facets of anatase crystallites on the photocatalytic H evolution from aqueous methanol solutions. For this, we synthesized anatase TiO nanocrystals with a large amount of either {001} facets, that is, nanosheets, or {101} facets, that is, octahedral nanocubes, and examined their photocatalytic H evolution and then repeated this procedure with samples where Pt co-catalyst is present on all facets.

Trends in Population-Based Studies: Molecular and Digital Epidemiology (Review).

The development of high-throughput technologies has sharply increased the opportunities to research the human body at the molecular, cellular, and organismal levels in the last decade. Rapid progress in biotechnology has caused a paradigm shift in population-based studies. Advances in modern biomedical sciences, including genomic, genome-wide, post-genomic research and bioinformatics, have contributed to the emergence of molecular epidemiology focused on the study of the personalized molecular mechanism of disease development and its extrapolation to the population level.

[Production and internalization of extracellular vesicules in normal and under conditions of hyperglycemia and insulin resistance].

Extracellular vesicles (EVs) are spherical structures of cell membrane origin, ranging in the size from 40 nm to 5000 nm. They are involved in the horizontal transfer of many proteins and microRNAs. The mechanisms EV internalization include clathrin-dependent endocytosis, caveolin-dependent endocytosis, raft-mediated endocytosis, and macropinocytosis.

Helicobacter pylori infection: place of serological and cultural diagnostics in clinical guidelines.

The purpose of this work was to familiarize doctors with the methods and significance of serological and cultural diagnostics of H. pylori infection on the example of the test for diagnosing the state of the gastric mucosa «Gastropanel». Blood serum tests were performed for 1057 patients and 122 healthy people aged 18-64 years: pepsinogen I (PG I), pepsinogen II (PG II), gastrin-17 (G-17), basal/stimulated), antibodies (IgGHp) to H.

Photoelectrochemical performance of facet-controlled TiO nanosheets grown hydrothermally on FTO.

Single crystal anatase TiO nanosheets (TiO-NSs) are grown hydrothermally on fluorine-doped tin oxide (FTO). By systematically changing the hydrothermal conditions such as reaction time, initial concentration of Ti precursor, F precursor, and HCl as an additive, a wide variety of TiO-NSs, with different morphologies and faceting have been synthesized. For the different morphologies and different facet ratios (anatase / ), the photoelectrochemical response is characterized and compared.

[The role of adipose tissue and laboratory predictors of primary osteoporosis.].

The purpose of this work was to determine the information content of alkaline phosphatase (ALP), total calcium (Ca) as predictors for the diagnosis of osteoporosis. By laboratory methods, 2451 people were divided into two groups according to the presence/absence of metabolic syndrome (MetS+ / MetS-): 1946 women (MetS- 1119, MetS+ 827) and 505 men (MetS- 264, MetS+ 241). Patients with laboratory signs of liver pathology are excluded.

Atomic, electronic and transport properties of In-Au 2D compound on Si(1 0 0).

Two-dimensional (In, Au)/Si(1 0 0)c(2 [Formula: see text] 2) compound was synthesized and its atomic arrangement, electron band structure and low-temperature transport properties were characterized using scanning tunneling microscopy, angle-resolved photoelectron spectroscopy and four-point-probe resistivity measurements assisted with first-principles density-functional-theory calculations. The present results are compared to those obtained earlier for the parent (Tl, Au)/Si(1 0 0)c(2 [Formula: see text] 2) system.

A Dewetted-Dealloyed Nanoporous Pt Co-Catalyst Formed on TiO Nanotube Arrays Leads to Strongly Enhanced Photocatalytic H Production.

Pt nanoparticles are typically decorated as co-catalyst on semiconductors to enhance the photocatalytic performance. Due to the low abundance and high cost of Pt, reaching a high activity with minimized co-catalyst loadings is a key challenge in the field. We explore a dewetting-dealloying strategy to fabricate on TiO nanotubes nanoporous Pt nanoparticles, aiming at improving the co-catalyst mass activity for H generation.

Self-Enhancing H Evolution from TiO Nanostructures under Illumination.

Illumination of anatase in an aqueous methanolic solution leads to the formation of Ti sites that are catalytically active for the generation of dihydrogen (H ). With increasing illumination time, a light-induced self-amplification of the photocatalytic H production rate can be observed. The effect is characterized by electron paramagnetic resonance (EPR) spectroscopy, reflectivity, and photoelectrochemical techniques.

Observation of the nesting and defect-driven 1D incommensurate charge density waves phase in the 2D system.

We report on the low-temperature scanning tunneling microscopy/spectroscopy (STM/STS) study of the (Bi, Na)/Si(1 1 1)[Formula: see text] reconstruction that is known to possess Fermi surface with apparently good nesting. We found that defects on this surface produce a one-dimensional-like pattern with the periodicity of 8.2 [Formula: see text] 0.

Weak Antilocalization at the Atomic-Scale Limit of Metal Film Thickness.

Creation of the 2D metallic layers with the thickness as small as a few atomic layers and investigation of their properties are interesting and challenging tasks of the modern condensed-matter physics. One of the possible ways to grow such layers resides in the synthesis of the so-called metal-induced reconstructions on silicon (i.e.