Rapid Outgassing of Hydrophilic TiO Electrodes Achieves Long-Term Stability of Anion Exchange Membrane Water Electrolyzers.

The state-of-the-art anion-exchange membrane water electrolyzers (AEMWEs) require highly stable electrodes for prolonged operation. The stability of the electrode is closely linked to the effective evacuation of H or O gas generated from electrode surface during the electrolysis. In this study, we prepared a super-hydrophilic electrode by depositing porous nickel-iron nanoparticles on annealed TiO nanotubes (NiFe/ATNT) for rapid outgassing of such nonpolar gases.

Activity-Drop of Hydrogen Evolution Reaction in LiNO Based "Hydronium-in-Salt" Acidic Electrolytes on Platinum Enables Electrochemical Nitrate Reduction.

The electrochemical nitrate reduction reaction (NORR) involves multiple hydrogenation and deoxygenation steps, which compete with the hydrogen evolution reaction (HER). Therefore, NORR driven in acidic media is challenging in spite of advantageous fast hydrogen transfers in its elementary steps. The findings presented in this article first demonstrate that the NORR is significantly activated even in acidic lithium nitrate solutions at LiNO concentrations exceeding 6 m on a Pt electrode (the highly effective catalyst for HER) by the formation of a "hydronium-in-salt" electrolyte (HISE), a new type of aqueous high concentration salt electrolyte.

Thermomechanical and Structural Analysis of WO Array for Optimized Photoelectrochemical Chloride Oxidation Performance.

Understanding the crystal structure of WO is essential for optimizing its photoelectrochemical performance. This study comprehensively analyzes the structural characteristics of WO during synthesis and investigates their correlation with photoelectrochemical activity. Structural analysis, incorporating annealing procedure and WO thickness, identifies a blend of hexagonal, monoclinic, and orthorhombic phases within WO array.

Unlocking the Potential of BiS-Derived Bi Nanoplates: Enhanced Catalytic Activity and Selectivity in Electrochemical and Photoelectrochemical CO Reduction to Formate.

Various electrocatalysts are extensively examined for their ability to selectively produce desired products by electrochemical CO reduction reaction (CORR). However, an efficient CORR electrocatalyst doesn't ensure an effective co-catalyst on the semiconductor surface for photoelectrochemical CORR. Herein, BiS nanorods are synthesized and electrochemically reduced to Bi nanoplates that adhere to the substrates for application in the electrochemical and photoelectrochemical CORR.

Half-Bridge Silicon Strain Gauges with Arc-Shaped Piezoresistors.

Half-bridge silicon strain gauges are widely used in the fabrication of diaphragm-type high-pressure sensors, but in some applications, they suffer from low output sensitivity because of mounting position constraints. Through a special design and fabrication approach, a new half-bridge silicon strain gauge comprising one arc gauge responding to tangential strain and another linear gauge measuring radial strain was developed using Silicon-on-Glass (SiOG) substrate technology. The tangential gauge consists of grid patterns, such as the reciprocating arc of silicon piezoresistors on a thin glass substrate.

Reciprocating Arc Silicon Strain Gauges.

Currently, silicon-strain-gauge-based diaphragm pressure sensors use four single-gauge chips for high-output sensitivity. However, the four-single-gauge configuration increases the number of glass frit bonds and the number of aluminum wire bonds, reducing the long-term stability, reliability, and yield of the diaphragm pressure sensor. In this study, a new design of general-purpose silicon strain gauges was developed to improve the sensor output voltage while reducing the number of bonds.

Redox-Transition from Irreversible to Reversible Vitamin C by Pore Confinement in Microporous Carbon Network.

Enhancement of redox-reversibility in electroactive species has been studied because of fundamental interest and their importance for energy storage systems. Various electroactive molecules suffer from redox-irreversible behavior, and this is a critical reason for their exclusion as redox electrolytes in energy storage systems. In this article, we fully demonstrated that ascorbic acid (ASC), which is an abundant but redox-irreversible molecule, can become redox-reversible when it is confined in microporous carbon regimes.

Unraveling the Simultaneous Enhancement of Selectivity and Durability on Single-Crystalline Gold Particles for Electrochemical CO Reduction.

Electrochemical carbon dioxide reduction is a mild and eco-friendly approach for CO mitigation and producing value-added products. For selective electrochemical CO reduction, single-crystalline Au particles (octahedron, truncated-octahedron, and sphere) are synthesized by consecutive growth and chemical etching using a polydiallyldimethylammonium chloride (polyDDA) surfactant, and are surface-functionalized. Monodisperse, single-crystalline Au nanoparticles provide an ideal platform for evaluating the Au surface as a CO reduction catalyst.

Heterointerface Effect on Two-Step Nucleation Mechanism of Bi Particles.

The nucleation and crystallization of Bi particles on two matrices, crystalline bismuth sulfide (-BiS) and amorphized bismuth titanium oxide (-BiTiO), were studied by using in situ transmission electron microscopy (TEM) analysis. The atomic structures of the Bi particles were monitored by acquiring high-resolution TEM images in real time. The Bi particles were grown on -BiS and -BiTiO via a two-step nucleation mechanism; dense liquid clusters were clearly observed at the initial stage of nucleation, and the coalescence of clusters was frequently observed during the growth.

Electrochemical Generation of Mesopores and Residual Oxygen for the Enhanced Activity of Silver Electrocatalysts.

The development of stable and efficient electrocatalysts is of key importance for the establishment of a sustainable society. The activity of a metal electrocatalyst is determined by its electrochemically active surface area and intrinsic activity, which can be increased using highly porous structures and heteroatomic doping, respectively. Herein, we propose a general strategy of generating mesopores and residual oxygen in metal electrocatalysts by reduction of metastable metal oxides using AgO electrodeposited onto carbon paper as a model system and demonstrating that the obtained multipurpose porous Ag electrocatalyst has high activity for the electroreduction of O and CO.

Accelerated decomposition of BiS nanorods in water under an electron beam: a liquid phase transmission electron microscopy study.

Evaluating the stability of semiconductor photocatalysts is critical in the development of efficient catalysts. The morphological and microstructural behaviors of nanorod-shaped BiS semiconductors in aqueous solution were studied using a liquid cell transmission electron microscopy (TEM) technique. The rapid decomposition of BiS in water was observed under electron beam irradiation during TEM.

Understanding and Improving Photocatalytic Activity of Pd-Loaded BiVO Microspheres: Application to Visible Light-Induced Suzuki-Miyaura Coupling Reaction.

The effective utilization of visible light is required for exploiting photocatalytic reactions in indoor and outdoor environments. In this study, Pd-supported BiVO microspheres (Pd-BiVO) were prepared for visible light-induced photocatalytic reactions. Under irradiation with a white light-emitting diode, the obtained Pd-BiVO composite exhibited considerably improved catalytic activity for the decomposition of an organic dye compared with other BiVO catalysts.

Functionalization of Molybdenum Disulfide via Plasma Treatment and 3-Mercaptopropionic Acid for Gas Sensors.

Monolayer and multilayer molybdenum disulfide (MoS) materials are semiconductors with direct/indirect bandgaps of 1.2-1.8 eV and are attractive due to their changes in response to electrical, physicochemical, biological, and mechanical factors.

Comprehensive Study of the Growth Mechanism and Photoelectrochemical Activity of a BiVO/BiS Nanowire Composite.

A BiVO/BiS composite comprising BiS nanowires on top of a BiVO film was prepared via hydrothermal reaction. Because additional Bi ions were not delivered during the reaction, BiVO served as the Bi ion source for the development of BiS. A detailed growth mechanism of the nanowire was elucidated by an analysis of the concentration gradient of Bi and S ions during the reaction.

Enhanced Stability and Amplified Signal Output of Single-Wall Carbon Nanotube-Based NH-Sensitive Electrode after Dual Plasma Treatment.

Pristine nanomaterials are normally prepared using finely controlled fabrication processes. Because no imperfect nanostructure remains, they cannot be used directly as electrode substrates of functional devices. This is because perfectly organized nanostructures or nanomaterials commonly require posttreatment to generate intentionally, the kinds of desirable defects inside or on their surfaces that enable effective functionalization.

Enhancement of Withstand Voltage in Silicon Strain Gauges Using a Thin Alkali-Free Glass.

We present a cost-effective approach to produce silicon strain gauges that can withstand very high voltage without using any complex package design and without sacrificing any sensor performance. This is achieved by a special silicon strain gauge structure created on an alkali-free glass substrate that has a high breakdown voltage. A half-bridge silicon strain gauge is designed, fabricated, and then tested to measure its output characteristics.

Current research on single-entity electrochemistry for soft nanoparticle detection: Introduction to detection methods and applications.

In recent years, rapid progress in the field of single-entity electrochemistry (SEE) has opened a novel exploratory area in the field of analytical and electrochemistry. SEE is a method of studying the behavior of particles at the single particle level, which yields important information on the diffusion coefficient, individual particle size, size distribution, catalytic activity, collision frequency, and internal substances of the particles. Various types of particles have been studied through SEE.

A Micromachined Metal Oxide Composite Dual Gas Sensor System for Principal Component Analysis-Based Multi-Monitoring of Noxious Gas Mixtures.

Microelectronic gas-sensor devices were developed for the detection of carbon monoxide (CO), nitrogen dioxides (NO), ammonia (NH) and formaldehyde (HCHO), and their gas-sensing characteristics in six different binary gas systems were examined using pattern-recognition methods. Four nanosized gas-sensing materials for these target gases, i.e.

In Situ Growth of the BiS Nanowire Array on the BiMoO Film for an Improved Photoelectrochemical Performance.

A single-crystalline BiS nanowire array (BiSNWA) is synthesized by an in situ hydrothermal reaction on the surface of a BiMoO film. As no additional source of Bi is provided during the process, the BiMoO layer acts as the Bi source for the synthesis of BiS nanowires. The fabricated BiMoO/BiSNWA electrode exhibited an increased photoelectrochemical (PEC) sulfite oxidation activity, which is attributed mainly to the effective interface obtained by the in situ hydrothermal growth, compared to other BiS electrodes.

Understanding Reaction Kinetics by Tailoring Metal Co-catalysts of the BiVO Photocatalyst.

In this study, the reaction mechanisms of metal-semiconductor composites used as photocatalysts were demonstrated by first preparing bismuth vanadate (BiVO) and then performing photodeposition of metal nanoparticles. The photocatalytic activity of metal-BiVO (M-BiVO, where M = Pt, Au, Ag) composites were evaluated through dye decomposition under UV-vis irradiation. The photocatalytic efficiency was significantly enhanced after Pt deposition as compared to other M-BiVO composites.

Understanding metal-enhanced fluorescence and structural properties in Au@Ag core-shell nanocubes.

Au@Ag core-shell structures have received particular interest due to their localized surface plasmon resonance properties and great potential as oxygen reduction reaction catalysts and building blocks for self-assembly. In this study, Au@Ag core-shell nanocubes (Au@AgNCs) were fabricated in a facile manner stepwise Ag reduction on Au nanoparticles (AuNPs). The size of the Au@AgNCs and their optical properties can be simply modulated by changing the Ag shell thickness.

Facile Synthesis of BiVO for Visible-Light-Induced C-C Bond Cleavage of Alkenes to Generate Carbonyls.

BiVO crystals synthesized by an ultrasonic-assisted method (Sono-BiVO ) showed improved efficiency as a heterogeneous photocatalyst under visible-light irradiation. Sono-BiVO was successfully used for the C-C bond cleavage of alkenes to generate carbonyl compounds. Styrene derivatives were converted into carbonyl compounds in the presence of Sono-BiVO under highly sustainable conditions requiring only natural sources, that is, molecular oxygen, visible light, and water at room temperature.

Ultrasonic-assisted preparation of a pinhole-free BiVO photoanode for enhanced photoelectrochemical water oxidation.

A pinhole-free BiVO4 electrode was successfully synthesized using an ultrasonic-assisted synthetic method on a conductive substrate. The pinhole-free BiVO4 electrode showed highly improved photoelectrochemical activity for both sulfite oxidation and water oxidation. The blocking recombination processes were examined to clarify the enhanced photoelectrochemical performances.

Synthesis of Hollow Iron Oxide Nanospheres and Their Application to Gas Sensors.

Hollow nanomaterials have attracted great interest because of their many applications in catalysis, nanoreactors, drug delivery systems, for lubrication and in gas sensors. Here, carbon sphere templates were prepared from glucose under hydrothermal conditions to facilitate the synthesis of hollow Fe2O3 nanospheres. Thermal decomposition of an iron precursor in benzylalcohol with the carbon spheres resulted in the deposition of Fe3O4 nanoparticles on the carbon sphere templates.

A Fully Integrated Paper-Microfluidic Electrochemical Device for Simultaneous Analysis of Physiologic Blood Ions.

A fully integrated paper microfluidic electrochemical device equipped with three different cation permeable films is developed to determine blood ions (Cl, Na⁺, K⁺, and Ca) at a time. These blood ions that are normally dissolved in the real human blood stream are essential for cell metabolisms and homeostasis in the human body. Abnormal concentration of blood ions causes many serious disorders.