CO-Driven Oxygen Vacancy Diffusion and Healing on TiO(110) at Ambient Pressure.

Understanding how TiO interacts with CO at the molecular level is crucial in the CO reduction toward value-added energy sources. Here, we report in situ observations of the CO activation process on the reduced TiO(110) surface at room temperature using ambient pressure scanning tunneling microscopy. We find that oxygen vacancies (V) diffuse dynamically along the bridging oxygen (O) rows of the TiO(110) surface under ambient CO(g) environments.

Solvent Free Ambient Pressure CO Cycloaddition Catalyzed by Cobalt-Impregnated 2D-Nanofibrous COFs.

Covalent organic frameworks (COFs) constitute an evolving class of permanently porous and ordered materials, and they have recently attracted increased interest due to their intriguing morphological features and numerous applications in gas storage, adsorption, and catalysis. However, their low aqueous stabilities and tedious syntheses generally hamper their use in heterogeneous catalysis. Nonetheless, a capable and water-stable heterogeneous catalytic system for coupling CO/epoxides to generate industrially important cyclic carbonates is still of great interest.

Abnormal Silicon Etching Behaviors in Nanometer-Sized Channels.

Modern semiconductor fabrication is challenged by difficulties in overcoming physical and chemical constraints. A major challenge is the wet etching of dummy gate silicon, which involves the removal of materials inside confined spaces of a few nanometers. These chemical processes are significantly different in the nanoscale and bulk.

Density Functional Theory-Based Approach For Dielectric Constant Estimation of Soluble Polyimide Insulators.

Evaluation of the insulating properties of polymers, such as the dielectric constant and dissipation factor, is crucial in electronic devices, including field-effect transistors and wireless communication applications. This study applies density functional theory (DFT) to predict the dielectric constant of soluble polyimides (SPIs). Various SPIs containing trifluoromethyl groups in the backbone with different pendant types, numbers, and symmetries are successfully synthesized, and their dielectric constants are evaluated and compared with the DFT-estimated values.

Synergistic Surface Modification for High-Efficiency Perovskite Nanocrystal Light-Emitting Diodes: Divalent Metal Ion Doping and Halide-Based Ligand Passivation.

Surface defects of metal halide perovskite nanocrystals (PNCs) substantially compromise the optoelectronic performances of the materials and devices via undesired charge recombination. However, those defects, mainly the vacancies, are structurally entangled with each other in the PNC lattice, necessitating a delicately designed strategy for effective passivation. Here, a synergistic metal ion doping and surface ligand exchange strategy is proposed to passivate the surface defects of CsPbBr PNCs with various divalent metal (e.

Selectively Nitrogen Doped ALD-IGZO TFTs with Extremely High Mobility and Reliability.

Achieving high mobility and reliability in atomic layer deposition (ALD)-based IGZO thin-film transistors (TFTs) with an amorphous phase is vital for practical applications in relevant fields. Here, we suggest a method to effectively increase stability while maintaining high mobility by employing the selective application of nitrous oxide plasma reactant during plasma-enhanced ALD (PEALD) at 200 °C process temperature. The nitrogen-doping mechanism is highly dependent on the intrinsic carbon impurities or nature of each cation, as demonstrated by a combination of theoretical and experimental research.

VO Cluster-Stabilized HO Adsorption on a TiO (110) Surface at Room Temperature.

We probe the adsorption of molecular HO on a TiO (110)-(1 × 1) surface decorated with isolated VO clusters using ultrahigh-vacuum scanning tunneling microscopy (UHV-STM) and temperature-programmed desorption (TPD). Our STM images show that preadsorbed VO clusters on the TiO (110)-(1 × 1) surface induce the adsorption of HO molecules at room temperature (RT). The adsorbed HO molecules form strings of beads of HO dimers bound to the 5-fold coordinated Ti atom (5c-Ti) rows and are anchored by VO.

Gold single-atoms confined at the CeO-TiOinterfaces with enhanced low-temperature activity toward CO oxidation.

We use CeO-TiOhetero-interfaces generated on the surface of CeO-TiOhybrid oxide supporting powders to stabilize Au single-atoms (SAs) with excellent low-temperature activity toward CO oxidation. Based on intriguing density functional theory calculation results on the preferential formation of Au-SAs at the CeO-TiOinterfaces and the high activity of Au-SAs toward the Mars-van Krevelen type CO oxidation, we synthesized a Au/CeO-TiO(ACT) catalyst with 0.05 wt.

In-Bi Electrocatalyst for the Reduction of CO to Formate in a Wide Potential Window.

The CO atmospheric concentration level hit the record at more than 400 ppm and is predicted to keep increasing as the dependence on fossil fuels is inevitable. The CO electrocatalytic conversion becomes an alternative due to its environmental and energy-friendly properties and benign operation condition. Lately, bimetallic materials have drawn significant interest as electrocatalysts due to their distinct properties, which the parents' metal cannot mimic.

Interspersing CeO Clusters to the Pt-TiO Interfaces for Catalytic Promotion of TiO-Supported Pt Nanoparticles.

We propose an interface-engineered oxide-supported Pt nanoparticle-based catalyst with improved low-temperature activity toward CO oxidation. By wet-impregnating 1 wt % Ce on TiO, we synthesized hybrid oxide support of CeO-TiO, in which dense CeO clusters formed on the surface of TiO. Then, the Pt/CeO-TiO catalyst was synthesized by impregnating 2 wt % Pt on the CeO-TiO supporting oxide.

Effects and Mechanism of Surface Water Wettability and Operating Frequency on Response Linearity of Flexible IDE Capacitive Humidity Sensor.

Flexible capacitive humidity sensors are promising for low-cost, wearable, and radio frequency identification sensors, but their nonlinear response is an important issue for practical applications. Herein, the linearity of humidity response was controlled by surface water wettability and operating frequency of sensor, and the mechanism was explained in detail by surface water condensation. For a sensor with a Ag interdigitated electrode (IDE) on a poly(ethylene terephthalate) substrate, the capacitance showed a small linear increase with humidity up to 70% RH but a large nonlinear increase in the higher range.

Sub-micro droplet reactors for green synthesis of LiVO anode materials in lithium ion batteries.

The conventional solid-state reaction suffers from low diffusivity, high energy consumption, and uncontrolled morphology. These limitations are competed by the presence of water in solution route reaction. Herein, based on concept of combining above methods, we report a facile solid-state reaction conducted in water vapor at low temperature along with calcium doping for modifying lithium vanadate as anode material for lithium-ion batteries.

Direct Growth of Highly Conductive Large-Area Stretchable Graphene.

The direct synthesis of inherently defect-free, large-area graphene on flexible substrates is a key technology for soft electronic devices. In the present work, in situ plasma-assisted thermal chemical vapor deposition is implemented in order to synthesize 4 in. diameter high-quality graphene directly on 10 nm thick Ti-buffered substrates at 100 °C.

How Rh surface breaks CO molecules under ambient pressure.

Utilization of carbon dioxide (CO) molecules leads to increased interest in the sustainable synthesis of methane (CH) or methanol (CHOH). The representative reaction intermediate consisting of a carbonyl or formate group determines yields of the fuel source during catalytic reactions. However, their selective initial surface reaction processes have been assumed without a fundamental understanding at the molecular level.

Recyclable aqueous metal adsorbent: Synthesis and Cu(II) sorption characteristics of ternary nanocomposites of FeO nanoparticles@graphene-poly-N-phenylglycine nanofibers.

Metal pollutant adsorbents are an essential material platform for sustainable environmental remediation, but the adsorbents are typically disposable after sorption, which secondarily contaminates the environment. We report on recyclable Cu(II) adsorbent of deprotonated poly-N-phenylglycine nanofibers (d-PPG NFs)-grafted reduced graphene oxide (rGO) sheets intercalated with FeO nanoparticles (NPs), which are synthesized via wet chemical process. The adsorption performances of ternary FeO NPs@rGO-d-PPG NFs and binary FeO NPs@rGO composites are compared, and the ternary ones exhibit much higher Cu-adsorption capacity than binary ones under diverse pH conditions due to both high specific surface area and high cationic affinity of d-PPG NFs that follow the Freundlich adsorption model.

Precious metal recovery from electronic waste by a porous porphyrin polymer.

Urban mining of precious metals from electronic waste, such as printed circuit boards (PCB), is not yet feasible because of the lengthy isolation process, health risks, and environmental impact. Although porous polymers are particularly effective toward the capture of metal contaminants, those with porphyrin linkers have not yet been considered for precious metal recovery, despite their potential. Here, we report a porous porphyrin polymer that captures precious metals quantitatively from PCB leachate even in the presence of 63 elements from the Periodic Table.

Engineering of Pd Nanosponge Armored with Graphene Dots Using Br toward High-Performance and Stable Electrocatalyst for the Hydrogen Evolution Reaction.

In this study, we report a facile synthetic pathway to three-dimensional (3D) Pd nanosponge-shaped networks wrapped by graphene dots (Pd@G-NSs), which show superior electrocatalytic activity toward the hydrogen evolution reaction (HER) and exhibited excellent long-term stability in acidic media. Pd@G-NSs were synthesized by simply mixing Pd precursors, reducing agent, carbon dots (Cdots), and Br ion at 30 °C. Experimental results and density functional theory (DFT) calculations suggested that the Br ions played an essential role in accelerating the exfoliation of Cdot, supplying graphene layers, which could wrap the nanosponge-shaped Pd and finally form Pd@G-NS.

Oxygen activation on the interface between Pt nanoparticles and mesoporous defective TiO during CO oxidation.

Platinum-based heterogeneous catalysts are mostly used in various commercial chemical processes because of their high catalytic activity, influenced by the metal/oxide interaction. To design rational catalysts with high performance, it is crucial to understand the relationship between the metal-oxide interface and the reaction pathway. Here, we investigate the role of oxygen defect sites in the reaction mechanism for CO oxidation using Pt nanoparticles supported on mesoporous TiO catalysts with oxygen defects.

Solar-to-Steam Generation via Porous Black Membranes with Tailored Pore Structures.

Solar-to-steam generation is a powerful, intense, and efficient method to harvest solar energy. Many efforts have been devoted to the development of a durable, affordable, and easy-to-manufacture solar steam device. In this study, we use a versatile polydimethylsiloxane material to fabricate an open porous black membrane with different pore structures using a simple salt water etching process and vapor deposition polymerization of pyrrole into a matrix.

Efficient Sn Recovery from SnO by Alkane (CH, 0 ≤ x ≤ 4) Reduction.

We study the mechanism of alkane reduction of SnO for efficient low-temperature recovery of Sn from SnO. Based on thermodynamic simulation results, we comparatively analyze the reduction behavior and the efficiency of SnO reduction by H and alkanes (CH, 0 ≤ x ≤ 4). We found that alkanes (n·CH) with the higher nx generally complete the reduction of SnO (T) at the lower temperature.

Unravelling inherent electrocatalysis of mixed-conducting oxide activated by metal nanoparticle for fuel cell electrodes.

Highly active metal nanoparticles are desired to serve in high-temperature electrocatalysis, for example, in solid oxide electrochemical cells. Unfortunately, the low thermal stability of nanosized particles and the sophisticated interface requirement for electrode structures to support concurrent ionic and electronic transport make it hard to identify the exact catalytic role of nanoparticles embedded within complex electrode architectures. Here we present an accurate analysis of the reactivity of oxide electrodes boosted by metal nanoparticles, where all particles participate in the reaction.

Minimising oxygen contamination through a liquid copper-aided group IV metal production process.

This paper demonstrates for the first time the fabrication of Zr-Cu alloy ingots from a Hf- free ZrO precursor in a molten CaCl medium to recover nuclear-grade Zr. The reduction of ZrO in the presence of CaO was accelerated by the formation of Ca metal in the intermediate stage of the process. Tests conducted with various amounts of ZrO indicate that the ZrO was reduced to the metallic form at low potentials applied at the cathode, and the main part of the zirconium was converted to a CuZr alloy with a different composition.