Polyol-Intermediated Facile Synthesis of B-Site-Rich Ru-Based Nanocatalysts for CO-Free Hydrogen Production via Ammonia Decomposition.

Herein, a B-site-rich Ru/MgAlO nanocatalyst for the production of CO-free hydrogen from ammonia (NH) is synthesized using the polyol method. The polyol method enables size-sensitive Ru-nanoparticle growth and controlled B-site formation on the catalyst by tuning the carbon-chain length of the polyol solvent used, obviating the use of a separate stabilizer and enhancing electron donation from Ru (with a high surface electron density) and π-back bonding. The Ru/MgAlO (BG) catalyst synthesized using butylene glycol (a long-carbon-chain solvent) contains 2.

Photoplethysmogram Biometric Authentication Using a 1D Siamese Network.

In the head-mounted display environment for experiencing metaverse or virtual reality, conventional input devices cannot be used, so a new type of nonintrusive and continuous biometric authentication technology is required. Since the wrist wearable device is equipped with a photoplethysmogram sensor, it is very suitable for use for nonintrusive and continuous biometric authentication purposes. In this study, we propose a one-dimensional Siamese network biometric identification model using a photoplethysmogram.

Measurement of dielectric function and bandgap of germanium telluride using monochromated electron energy-loss spectroscopy.

Using a monochromator in transmission electron microscopy, a low-energy-loss spectrum can provide inter- and intra-band transition information for nanoscale devices with high energy and spatial resolutions. However, some losses, such as Cherenkov radiation, phonon scattering, and surface plasmon resonance superimposed at zero-loss peak, make it asymmetric. These pose limitations to the direct interpretation of optical properties, such as complex dielectric function and bandgap onset in the raw electron energy-loss spectra.

Colossal Dielectric Perovskites of Calcium Copper Titanate (CaCu Ti O ) with Low-Iridium Dopants Enables Ultrahigh Mass Activity for the Acidic Oxygen Evolution Reaction.

Oxygen evolution reaction (OER) under acidic conditions becomes of significant importance for the practical use of a proton exchange membrane (PEM) water electrolyzer. In particular, maximizing the mass activity of iridium (Ir) is one of the maiden issues. Herein, the authors discover that the Ir-doped calcium copper titanate (CaCu₃Ti₄O₁₂, CCTO) perovskite exhibits ultrahigh mass activity up to 1000 A g for the acidic OER, which is 66 times higher than that of the benchmark catalyst, IrO .

Observation of the Early Stages of Rapid Solid-Liquid Reaction in Closed Liquid Cell TEM Using Graphene Encapsulation.

In situ liquid cell transmission electron microscopy (TEM) is a very useful tool for investigating dynamic solid–liquid reactions. However, there are challenges to observe the early stages of spontaneous solid–liquid reactions using a closed-type liquid cell system, the most popular and simple liquid cell system. We propose a graphene encapsulation method to overcome this limitation of closed-type liquid cell TEM.

Green ammonia synthesis using CeO/RuO nanolayers on vertical graphene catalyst electrochemical route in alkaline electrolyte.

The electrochemical synthesis of ammonia at ambient temperature and pressure has the potential to replace the conventional process for the production of ammonia. However, the low ammonia yield and poor long-term stability of catalysts for the synthesis of ammonia hinders the application of this technology. Herein, we endeavored to tackle this challenge by synthesizing 3-D vertical graphene (VG) on Ni foam a one-step, low-temperature plasma process, which offered high conductivity and large surface area.

Comparison between FeO/C and FeC/FeO/Fe/C Electrocatalysts for N Reduction in an Alkaline Electrolyte.

Cost-effective and nonprecious iron-based catalysts were synthesized, evaluated, and compared for electrocatalytic N reduction reaction (NRR) under alkaline conditions in the potential range from -0.4 to 0.1 V [vs reversible hydrogen electrode (RHE)] at low temperature (≤60 °C) and atmospheric pressure.

Method of Ga removal from a specimen on a microelectromechanical system-based chip for in-situ transmission electron microscopy.

In-situ transmission electron microscopy (TEM) holders that employ a chip-type specimen stage have been widely utilized in recent years. The specimen on the microelectromechanical system (MEMS)-based chip is commonly prepared by focused ion beam (FIB) milling and ex-situ lift-out (EXLO). However, the FIB-milled thin-foil specimens are inevitably contaminated with Ga ions.

Realization of Wafer-Scale 1T-MoS Film for Efficient Hydrogen Evolution Reaction.

The octahedral structure of 2D molybdenum disulfide (1T-MoS ) has attracted attention as a high-efficiency and low-cost electrocatalyst for hydrogen production. However, the large-scale synthesis of 1T-MoS films has not been realized because of higher formation energy compared to that of the trigonal prismatic phase (2H)-MoS . In this study, a uniform wafer-scale synthesis of the metastable 1T-MoS film is performed by sulfidation of the Mo metal layer using a plasma-enhanced chemical vapor deposition (PE-CVD) system.

Electroplated Silver-Nickel Core-Shell Nanowire Network Electrodes for Highly Efficient Perovskite Nanoparticle Light-Emitting Diodes.

The low sheet resistance and high optical transparency of silver nanowires (AgNWs) make them a promising candidate for use as the flexible transparent electrode of light-emitting diodes (LEDs). In a perovskite LED (PeLED), however, the AgNW electrode can react with the overlying perovskite material by redox reactions, which limit the electroluminescence efficiency of the PeLED by causing the degradation of and generating defect states in the perovskite material. In this study, we prepared Ag-Ni core-shell NW electrodes using the solution-electroplating technique to realize highly efficient PeLEDs based on colloidal formamidinium lead bromide (FAPbBr) nanoparticles (NPs).

Rapid and mass-producible synthesis of high-crystallinity MoSe nanosheets by ampoule-loaded chemical vapor deposition.

MoSe is an attractive transition-metal dichalcogenide with a two-dimensional layered structure and various attractive properties. Although MoSe is a promising negative electrode material for electrochemical applications, further investigation of MoSe has been limited, mainly by the lack of MoSe mass-production methods. Here, we report a rapid and ultra-high-yield synthesis method of obtaining MoSe nanosheets with high crystallinity and large grains by ampoule-loaded chemical vapor deposition.

Wafer-Scale and Low-Temperature Growth of 1T-WS Film for Efficient and Stable Hydrogen Evolution Reaction.

The metallic 1T phase of WS (1T-WS ), which boosts the charge transfer between the electron source and active edge sites, can be used as an efficient electrocatalyst for the hydrogen evolution reaction (HER). As the semiconductor 2H phase of WS (2H-WS ) is inherently stable, methods for synthesizing 1T-WS are limited and complicated. Herein, a uniform wafer-scale 1T-WS film is prepared using a plasma-enhanced chemical vapor deposition (PE-CVD) system.

Amorphous TaMnO Layer as a Diffusion Barrier for Advanced Copper Interconnects.

An amorphous TaMnO layer with 1.0 nm thickness was studied as an alternative Cu diffusion barrier for advanced interconnect. The thermal and electrical stabilities of the 1.

Characteristics of an Amorphous Carbon Layer as a Diffusion Barrier for an Advanced Copper Interconnect.

The size of the advanced Cu interconnects has been significantly reduced, reaching the current 7.0 nm node technology and below. With the relentless scaling-down of microelectronic devices, the advanced Cu interconnects thus requires an ultrathin and reliable diffusion barrier layer to prevent Cu diffusion into the surrounding dielectric.

Electron beam irradiation induced crystallization behavior of amorphous GeSbTe chalcogenide material.

The crystallization of amorphous GeSbTe phase change material induced by electron beam irradiation was investigated by in-situ transmission electron microscopy (TEM). Amorphous matrix transformed into a partially crystalline state after being irradiated with a 200-keV electron beam for a long time. Real-time observation revealed that the crystallization of amorphous GeSbTe film occurs through a nucleation and growth mechanism under electron beam irradiation in TEM.

Evaluation of ion/electron beam induced deposition for electrical connection using a modern focused ion beam system.

Focused ion beam method, which has excellent capabilities such as local deposition and selective etching, is widely used for micro-electromechanical system (MEMS)-based in situ transmission electron microscopy (TEM) sample fabrication. Among the MEMS chips in which one can apply various external stimuli, the electrical MEMS chips require connection between the TEM sample and the electrodes in MEMS chip, and a connected deposition material with low electrical resistance is required to apply the electrical signal. Therefore, in this study, we introduce an optimized condition by comparing the electrical resistance for C-, Pt-, and W- ion beam induced deposition (IBID) at 30 kV and electron beam induced deposition (EBID) at 1 and 5 kV.

Millimeter-Scale Growth of Single-Oriented Graphene on a Palladium Silicide Amorphous Film.

It is widely accepted in condensed matter physics and material science communities that a single-oriented overlayer cannot be grown on an amorphous substrate because the disordered substrate randomizes the orientation of the seeds, leading to polycrystalline grains. In the case of two-dimensional materials such as graphene, the large-scale growth of single-oriented materials on an amorphous substrate has remained unsolved. Here, we demonstrate experimentally that the presence of uniformly oriented graphene seeds facilitates the growth of millimeter-scale single-oriented graphene with 3 × 4 mm on palladium silicide, which is an amorphous thin film, where the uniformly oriented graphene seeds were epitaxially grown.

Investigation of Zirconium Effect on the Corrosion Resistance of Aluminum Alloy Using Electrochemical Methods and Numerical Simulation in an Acidified Synthetic Sea Salt Solution.

Corrosion resistance of Zr that has been added to an Al alloy (U1070) is higher than that of a commercial Al alloy (A1070). A decreasing number and size of Al₃Fe intermetallic particles (IMPs) were observed by electron microprobe analysis and transmission electron microscopy. Based on the numerical corrosion simulation, it was confirmed that decreasing the number and size of IMPs was favorable for improving the corrosion resistance of the Al alloy due to the reduction of the galvanic effect.

Quantification of crystallinity using zero-loss filtered electron diffraction.

The quantity of the crystalline phases present in a nanomaterial is an important parameter that governs the correlation between its properties and microstructure. However, quantification of crystallinity in nanoscale-level applications by conventional methods (Raman spectroscopy and X-ray diffraction) is difficult because of the spatial limitations of sampling. Therefore, we propose a technique that involves using energy-filtered electron diffraction in transmission electron microscopy which offers improved spatial resolution.

Epitaxial-Growth-Induced Junction Welding of Silver Nanowire Network Electrodes.

In this study, we developed a roll-to-roll Ag electroplating process for metallic nanowire electrodes using a galvanostatic mode. Electroplating is a low-cost and facile method for deposition of metal onto a target surface with precise control of both the composition and the thickness. Metallic nanowire networks [silver nanowires (AgNWs) and copper nanowires (CuNWs)] coated onto a polyethylene terephthalate (PET) film were immersed directly in an electroplating bath containing AgNO.