Influence of the Structure of Hydrothermal-Synthesized TiO Nanowires Formed by Annealing on the Photocatalytic Reduction of CO in HO Vapor.

The present study investigates the photocatalytic properties of hydrothermally synthesized TiO nanowires (NWs) for CO reduction in HO vapor. It has been demonstrated that TiO NWs, thermally treated at 500-700 °C, demonstrate an almost tenfold higher yield of products compared to the known commercial powder TiO P25. It has been found that the best material is a combination of anatase, TiO-B and rutile.

Estimation of phase distortions of the photoplethysmographic signal in digital IIR filtering.

Pre-processing of the photoplethysmography (PPG) signal plays an important role in the analysis of the pulse wave signal. The task of pre-processing is to remove noise from the PPG signal, as well as to transmit the signal without any distortions for further analysis. The integrity of the pulse waveform is essential since many cardiovascular parameters are calculated from it using morphological analysis.

The Composite TiO-CuO Layers Formed by Electrophoretic Method for CO Gas Photoreduction.

This study demonstrates the ability to control the properties of TiO-CuO composite layers for photocatalytic applications by using a simple electrophoretic deposition method from isopropanol-based suspension. To obtain uniform layers with a controlled composition, the surfactant sodium lauryl sulfate was used, which influenced the electrophoretic mobility of the particles and the morphology of the deposited layers. The TiO-CuO composite layers with different CuO contents (1.

Data-Centric Heterogeneous Catalysis: Identifying Rules and Materials Genes of Alkane Selective Oxidation.

Artificial intelligence (AI) can accelerate catalyst design by identifying key physicochemical descriptive parameters correlated with the underlying processes triggering, favoring, or hindering the performance. In analogy to genes in biology, these parameters might be called "materials genes" of heterogeneous catalysis. However, widely used AI methods require big data, and only the smallest part of the available data meets the quality requirement for data-efficient AI.

Excitonic Mechanisms of Stimulated Emission in Low-Threshold ZnO Microrod Lasers with Whispering Gallery Modes.

Whispering gallery mode (WGM) ZnO microlasers gain attention due to their high -factors and ability to provide low-threshold near-UV lasing. However, a detailed understanding of the optical gain mechanisms in such structures has not yet been achieved. In this work, we study the mechanisms of stimulated emission (SE) in hexagonal ZnO microrods, demonstrating high-performance WGM lasing with thresholds down to 10-20 kW/cm and -factors up to ~3500.

Morphology and Luminescence of Flexible Free-Standing ZnO/Zn Composite Films Grown by Vapor Transport Synthesis.

A method for fabricating flexible free-standing ZnO/Zn composite films from the vapor phase using a regular array of silicon microwhiskers as a substrate is presented. The structural and morphological peculiarities, as well as luminescent properties of the films, were studied. The films have a hybrid structure consisting of two main microlayers.

Interference Phenomena and Stimulated Emission in ZnO Films on Sapphire.

We studied the texturing, roughness, and morphology features of ZnO films grown on the R (11¯02)-, M (101¯0)-, A (112¯0)-, and C (0001)-planes of sapphire, as well as their optical and luminescent properties. We showed that the growth conditions, substrate orientation, and the presence of a buffer layer significantly affected the structure and morphology of the growing films, which was reflected in their optical and radiative properties. In particular, films grown on the A- and M- planes of sapphire showed the highest UV radiation brightness values and exhibited stimulated emissions upon pulsed photoexcitation.

The Influence of the Chemical Potential on Defects and Function of Perovskites in Catalysis.

A Sm-deficient SmMnO perovskite was prepared on a gram scale to investigate the influence of the chemical potential of the gas phase on the defect concentration, the oxidation states of the metals and the nature of the oxygen species at the surface. The oxide was treated at 450°C in nitrogen, synthetic air, oxygen, water vapor or CO and investigated for its properties as a catalyst in the oxidative dehydrogenation of propane both before and after treatment. After treatment in water vapor, but especially after treatment with CO, increased selectivity to propene was observed, but only when water vapor was added to the reaction gas.

Ultraviolet Luminescence of ZnO Whiskers, Nanowalls, Multipods, and Ceramics as Potential Materials for Fast Scintillators.

The presented work is dedicated to the study and comparison of scintillating properties of zinc oxide samples prepared in different morphologies: whiskers, nanowalls, multipods, and ceramics. It was shown that total transmittance, photo- and radioluminescence spectra, and radioluminescence kinetics can vary significantly depending on sample structure and preparation conditions. The highest total transmittance was registered for ZnO ceramics (>50% at 0.

Ethanol to Acetaldehyde Conversion under Thermal and Microwave Heating of ZnO-CuO-SiO Modified with WC Nanoparticles.

The nonoxidative conversion of ethanol to acetaldehyde under thermal and microwave heating was studied on mixed oxide ZnO-CuO-SiO catalysts modified with additives of tungsten carbide nanoparticles. The results revealed that the WC-modified catalyst exhibited superior activity and selectivity under microwave heating conditions. It is assumed that when microwave heating is used, hot zones can appear at the contact points of WC nanoparticles and active centers of the mixed oxide ZnO-CuO-SiO catalyst, which intensively absorb microwave energy, allowing the more efficient formation of acetaldehyde at moderate temperatures.

Materials genes of heterogeneous catalysis from clean experiments and artificial intelligence.

Abstract: The performance in heterogeneous catalysis is an example of a complex materials function, governed by an intricate interplay of several processes (e.g., the different surface chemical reactions, and the dynamic restructuring of the catalyst material at reaction conditions).

Al Pt for Oxygen Evolution in Water Splitting: A Strategy for Creating Multifunctionality in Electrocatalysis.

The production of hydrogen via water electrolysis is feasible only if effective and stable catalysts for the oxygen evolution reaction (OER) are available. Intermetallic compounds with well-defined crystal and electronic structures as well as particular chemical bonding features are suggested here to act as precursors for new composite materials with attractive catalytic properties. Al Pt combines a characteristic inorganic crystal structure (anti-fluorite type) and a strongly polar chemical bonding with the advantage of elemental platinum in terms of stability against dissolution under OER conditions.

Ni Single Atom Catalysts for CO Activation.

We report on the activation of CO on Ni single-atom catalysts. These catalysts were synthesized using a solid solution approach by controlled substitution of 1-10 atom % of Mg by Ni inside the MgO structure. The Ni atoms are preferentially located on the surface of the MgO and, as predicted by hybrid-functional calculations, favor low-coordinated sites.

High-Performance Supported Iridium Oxohydroxide Water Oxidation Electrocatalysts.

The synthesis of a highly active and yet stable electrocatalyst for the anodic oxygen evolution reaction (OER) remains a major challenge for acidic water splitting on an industrial scale. To address this challenge, we obtained an outstanding high-performance OER catalyst by loading Ir on conductive antimony-doped tin oxide (ATO)-nanoparticles by a microwave (MW)-assisted hydrothermal route. The obtained Ir phase was identified by using XRD as amorphous (XRD-amorphous), highly hydrated Ir oxohydroxide.

Microwave-Assisted Synthesis of Stable and Highly Active Ir Oxohydroxides for Electrochemical Oxidation of Water.

Water splitting for hydrogen production in acidic media has been limited by the poor stability of the anodic electrocatalyst devoted to the oxygen evolution reaction (OER). To help circumvent this problem we have synthesized a class of novel Ir oxohydroxides by rapid microwave-asisted hydrothermal synthesis, which bridges the gap between electrodeposited amorphous IrO films and crystalline IrO electrocatalysts prepared by calcination routes. For electrode loadings two orders of magnitude below current standards, the synthesized compounds present an unrivalled combination of high activity and stability under commercially relevant OER conditions in comparison to reported benchmarks, without need for pretreatment.

Cu-based catalyst resulting from a Cu,Zn,Al hydrotalcite-like compound: a microstructural, thermoanalytical, and in situ XAS study.

A Cu-based methanol synthesis catalyst was obtained from a phase pure Cu,Zn,Al hydrotalcite-like precursor, which was prepared by co-precipitation. This sample was intrinsically more active than a conventionally prepared Cu/ZnO/Al2O3 catalyst. Upon thermal decomposition in air, the [(Cu0.