A Membrane-Free Rechargeable Seawater Battery Unlocked by Lattice Engineering.

Seawater batteries that directly utilize natural seawater as electrolytes are ideal sustainable aqueous devices with high safety, exceedingly low cost, and environmental friendliness. However, the present seawater batteries are either primary batteries or rechargeable half-seawater/half-nonaqueous batteries because of the lack of suitable anode working in seawater. Here, a unique lattice engineering to unlock the electrochemically inert anatase TiO anode to be highly active for the reversible uptake of multiple cations (Na, Mg, and Ca) in aqueous electrolytes is demonstrated.

Rhodium-Catalyzed -Bis-Silylation Reactions of 2-Ethynyl-3-pentamethyldisilanylpyridines.

Rhodium-catalyzed reactions of 2-ethynyl-3-pentamethyldisilanylpyridine derivatives ( and ) are reported. The reactions of compounds and in the presence of catalytic amounts of rhodium complexes at 110 °C gave the corresponding pyridine-fused siloles () and () through intramolecular -bis-silylation cyclization. The reaction of 2-bromo-3-(1,1,2,2,2-pentamethyldisilanyl)pyridine with 3-phenyl-1-propyne in the presence of PdCl(PPh)-CuI catalysts afforded 1:2 bis-silylation adduct .

Lewis acid-triggered photocatalytic hydrogen peroxide production in an aluminum-based metal-organic framework.

Al-MIL-101-NH, which was previously regarded as being inactive as a photocatalyst, produces hydrogen peroxide (HO) O reduction under visible-light irradiation, accompanied by efficient suppression of undesired HO decomposition. The low-coordination Lewis acid sites in trimetric Al-oxo clusters are crucial for the electron transfer to O.

Synthesis of Pyridine-Fused Siloles by Palladium-Catalyzed Intramolecular Bis-Silylation.

Silole derivatives are attracting significant attention as new functional materials with excellent electronic and photophysical properties. Thus, the development of synthesis methods to afford such derivatives is highly desirable. Herein, the synthesis of pyridine-fused siloles under the conditions of the Sonogashira coupling reaction is described.

Revealing hydrogen spillover pathways in reducible metal oxides.

Hydrogen spillover, the migration of dissociated hydrogen atoms from noble metals to their support materials, is a ubiquitous phenomenon and is widely utilized in heterogeneous catalysis and hydrogen storage materials. However, in-depth understanding of the migration of spilled hydrogen over different types of supports is still lacking. Herein, hydrogen spillover in typical reducible metal oxides, such as TiO, CeO, and WO, was elucidated by combining systematic characterization methods involving various techniques, kinetic analysis, and density functional theory calculations.

Highly Active and Renewable Catalytic Electrodes for Two-Electron Oxygen Reduction Reaction.

This study has shown that antimony-doped tin oxide (ATO) works as a robust "renewable catalyst" for the electrochemical synthesis of hydrogen peroxide (HO) from water and oxygen. Antimony doping into SnO gives rise to remarkable electrocatalytic activity for two-electron oxygen reduction reaction (2e-ORR) by water with a volcano-type relation between the activity and doping levels (). Density functional theory simulations highlight the importance of an isolated Sb atom of ATO inducing the high activity and selectivity for 2e-ORR due to the effects of O adsorption enhancement, decrease in the activation energy, and lowering the adsorptivity of HO.

Elucidating the Strain-Vacancy-Activity Relationship on Structurally Deformed Co@CoO Nanosheets for Aqueous Phase Reforming of Formaldehyde.

Lattice strain modulation and vacancy engineering are both effective approaches to control the catalytic properties of heterogeneous catalysts. Here, Co@CoO heterointerface catalysts are prepared via the controlled reduction of CoO nanosheets. The experimental quantifications of lattice strain and oxygen vacancy concentration on CoO, as well as the charge transfer across the Co-CoO interface are all linearly correlated to the catalytic activity toward the aqueous phase reforming of formaldehyde to produce hydrogen.

Defect Engineering of Pt/TiO Photocatalysts via Reduction Treatment Assisted by Hydrogen Spillover.

Defect engineering of metal oxides is a facile and promising strategy to improve their photocatalytic activity. In the present study, Pt/TiO was prepared by a reduction treatment assisted by hydrogen spillover to pure rutile, anatase, and brookite and was subsequently used for hydrogen production from an aqueous methanol solution. With increasing reduction temperature, the photocatalytic activity of the rutile Pt/TiO increased substantially, whereas the activity of anatase Pt/TiO decreased and that of brookite Pt/TiO was independent of the treatment temperature.

Surface-Induced Desolvation of Hydronium Ion Enables Anatase TiO as an Efficient Anode for Proton Batteries.

Hydrogen ion is an attractive charge carrier for energy storage due to its smallest radius. However, hydrogen ions usually exist in the form of hydronium ion (HO) because of its high dehydration energy; the choice of electrode materials is thus greatly limited to open frameworks and layered structures with large ionic channels. Here, the desolvation of HO is achieved by using anatase TiO as anodes, enabling the H intercalation with a strain-free characteristic.

A quasi-stable molybdenum sub-oxide with abundant oxygen vacancies that promotes CO hydrogenation to methanol.

Production of methanol from anthropogenic carbon dioxide (CO) is a promising chemical process that can alleviate both the environmental burden and the dependence on fossil fuels. In catalytic CO hydrogenation to methanol, reduction of CO to intermediate species is generally considered to be a crucial step. It is of great significance to design and develop advanced heterogeneous catalysts and to engineer the surface structures to promote CO-to-methanol conversion.

Hydrogen spillover-driven synthesis of high-entropy alloy nanoparticles as a robust catalyst for CO hydrogenation.

High-entropy alloys (HEAs) have been intensively pursued as potentially advanced materials because of their exceptional properties. However, the facile fabrication of nanometer-sized HEAs over conventional catalyst supports remains challenging, and the design of rational synthetic protocols would permit the development of innovative catalysts with a wide range of potential compositions. Herein, we demonstrate that titanium dioxide (TiO) is a promising platform for the low-temperature synthesis of supported CoNiCuRuPd HEA nanoparticles (NPs) at 400 °C.

The Effects of Oxygen Functional Groups on Graphene Oxide on the Efficient Adsorption of Radioactive Iodine.

Oxygen-containing functional groups tend to induce a strong interaction between solid adsorbents and iodine molecules, yet have not been systematically investigated. Herein, on the basis of a series of nitric acid-treated graphene oxide (GO) with different contents of oxygen functional groups for iodine adsorption, it was found that the iodine uptake capacity is proportionate to the oxygen content and the diversities of oxygen-containing groups. The density functional theory (DFT) calculation results also suggest that oxygen-containing groups result in strong interactions between iodine molecules and the adsorbents through a covalent bond-forming process, among which -OH groups possess a higher adsorption energy averagely.

Controlled release of hydrogen isotope compounds and tunneling effect in the heterogeneously-catalyzed formic acid dehydrogenation.

The hydrogen isotope deuterium is widely used in the synthesis of isotopically-labeled compounds and in the fabrication of semiconductors and optical fibers. However, the facile production of deuterium gas (D) and hydrogen deuteride (HD) in a controlled manner is a challenging task, and rational heterogeneously-catalyzed protocols are still lacking. Herein, we demonstrate the selective production of hydrogen isotope compounds from a combination of formic acid and DO, through cooperative action by a PdAg nanocatalyst on a silica substrate whose surface is modified with amine groups.

Ultrasmall Silver Clusters Stabilized on MgO for Robust Oxygen-Promoted Hydrogen Production from Formaldehyde Reforming.

Efficient molecular hydrogen generation from renewable biomass-derived resources and water is of great importance to the sustainable development of the future society. Herein, ultrasmall Ag nanoclusters supported on a defect-rich MgO matrix (AgUCs/MgO) are synthesized by a facile impregnation/calcination method and are applied to robust oxygen-promoted formaldehyde reforming into H at room temperature. Density functional theory calculations and experimental observations show that the catalyst spatially builds up a channel for directional electron transfer from electron-rich Ag sites to the anti-bonding π orbital of chemisorbed bridged O molecules, leading to the implementation of low-temperature O adsorption and activation.

Highly Efficient and Selective Oxidation of Ethanol to Acetaldehyde by a Hybrid Photocatalyst Consisting of SnO Nanorod and Rutile TiO with Heteroepitaxial Junction.

Single-crystal SnO nanorods were grown on rutile TiO with a heteroepitaxial relation of SnO {001}/TiO {001} (SnO -NR#TiO ) by a hydrothermal reaction. Resulting compressive lattice strain in the SnO -NR near the interface induces a continuous increase in the a-axis length extending over 60 nm to relax towards the [001] direction from the root to the tip. UV-light irradiation of the robust SnO -NR#TiO stably progresses the selective oxidation of ethanol to acetaldehyde with an external quantum yield of 25.

Ultrathin Silicon Oxide Film-Induced Enhancement of Charge Separation and Transport of Nanostructured Titanium(IV) Oxide Photoelectrode.

The development of nanostructured semiconductor electrodes represented by a mesoporous TiO nanocrystalline (mp-TiO ) film is currently bringing great progresses in photoelectrochemical (PEC) devices for solar-to-electricity and solar-to-chemical conversion. Two serious losses can occur in PEC devices: 1) recombination between the conduction band (CB) electrons and valence band (VB) holes in the bulk and at the surface and 2) back reaction or electron trapping by oxidant in the electrolyte solution during transport to the electron-collecting electrode. Thus, the major challenge in common with the nanostructured semiconductor photoanodes is to achieve efficient charge separation and electron transport.

Cu MS (M=V, Nb, Ta) and its Solid Solutions with Sulvanite Structure for Photocatalytic and Photoelectrochemical H Evolution under Visible-Light Irradiation.

Solid solutions with of Cu VS with either Cu NbS or Cu TaS (Cu Nb V S or Cu Ta V S ) were prepared by a solid-state reaction and adopted a sulvanite structure. Their band gaps were 1.6-1.

Room-Temperature Activation of the C-H Bond in Methane over Terminal Zn-Oxyl Species in an MFI Zeolite: A Combined Spectroscopic and Computational Study of the Reactive Frontier Molecular Orbitals and Their Origins.

Oxygenase reactivity toward selective partial oxidation of CH to CHOH requires an atomic oxygen-radical bound to metal (M-O: oxyl intermediate) that is capable of abstracting an H atom from the significantly strong C-H bond in CH. Because such a reaction is frequently observed in metal-doped zeolites, it has been recognized that the zeolite provides an environment that stabilizes the M-O intermediate. However, no experimental data of M-O have so far been discovered in the zeolite; thus, little is known about the correlation among the state of M-O, its reactivity for CH, and the nature of the zeolite environment.

Expansion of the photoresponse window of a BiVO photocatalyst by doping with chromium(vi).

Doping of Cr into BiVO was examined in this study. A new absorption band with a 1.84 eV energy threshold appeared with Cr-doping.

Photoluminescence Properties of Layered Perovskite-Type Strontium Scandium Oxyfluoride Activated With Mn.

In this research, we have found that layered perovskite titanate SrTiO doped with Mn exhibits photoluminescence even at room temperature despite no luminescence from Mn-doped SrTiO with a three-dimensional bulky perovskite structure. The relative position of t orbital of Mn to the valence band is a key factor for appearance of Mn-emission in SrTiO:Mn. This result suggested usefulness of layered perovskite-type materials as hosts for Mn-activated phosphors than the bulky perovskite-type materials.

A nanocrystalline oxygen-deficient bismuth oxide as an efficient adsorbent for effective visible-light-driven photocatalytic performance toward organic pollutant degradation.

In this work, a simple binary oxygen-deficient BiO oxide was prepared, and its crystal structure, optical property, band structure and electronic structure were systematically investigated. Plane-wave-based density functional theory (DFT) calculations were also carried out to determine that BiO is a typical indirect-gap semiconductor with the bandgap of 1.1 eV.

Surface Engineering of a Supported PdAg Catalyst for Hydrogenation of CO to Formic Acid: Elucidating the Active Pd Atoms in Alloy Nanoparticles.

The hydrogenation of carbon dioxide (CO) to formic acid (FA; HCOOH), a renewable hydrogen storage material, is a promising means of realizing an economical CO-mediated hydrogen energy cycle. The development of reliable heterogeneous catalysts is an urgent yet challenging task associated with such systems, although precise catalytic site design protocols are still lacking. In the present study, we demonstrate that PdAg alloy nanoparticles (NPs) supported on TiO promote the efficient selective hydrogenation of CO to give FA even under mild reaction conditions (2.

Platinum-Catalyzed Reactions of 2,3-Bis(diisopropylsilyl)thiophene with Alkynes.

The reactions of 2,3-bis(diisopropylsilyl)thiophene () with diphenylacetylene, phenylacetylene, trimethylsilylacetylene, and mesitylacetylene have been reported. The reactions of with diphenylacetylene and phenylacetylene in the presence of a catalytic amount of tetrakis(triphenylphosphine)platinum(0) at 80 °C gave [1,4]disilino[2,3-]thiophene derivatives. With trimethylsilylacetylene, afforded two types of products arising from sp-hybridized C-H bond activation of the acetylene, together with [1,3]disilolo[4,5-]thiophene derivatives.

Why do zeolites induce an unprecedented electronic state on exchanged metal ions?

Understanding the exact position and the detailed role of the Al array in zeolites is essential for elucidating the origin of unique properties that can be derived from the metal-ion exchanged in zeolite samples and for designing zeolite materials with high efficiency in catalytic and adsorption processes. In this work, we investigate, for the first time, the important role of the Al array in the reactivity observed on the metal-ion exchanged in zeolites on the basis of the calculation method by utilizing the spontaneous heterolytic cleavage of H observed experimentally on the Zn-ion exchanged in MFI-type zeolites (Zn-MFI) as the model reaction. In the case of calculation, two main types of models for considering the Al positions in MFI-type zeolites were adopted: in the first type, the Al atoms with appropriate distances are aligned in the circumferential direction of the straight channel (abbreviated as a circumferentially arrayed Al-Al site); in the second type, the nearest neighbouring Al atoms with appropriate distances are directed toward the straight channel axis (abbreviated as a channel directionally arrayed Al-Al site).

A Rational Solid-State Synthesis of Supported Au-Ni Bimetallic Nanoparticles with Enhanced Activity for Gas-Phase Selective Oxidation of Alcohols.

A facile confined solid-state seed-mediated alloying strategy is applied for the rational synthesis of supported Au-Ni bimetallic nanoparticles (BMNPs). The method sequentially deposits nickel salts and AuNP seeds into the ordered array of extra-large mesopores (EP-FDU-12 support) followed by a high-temperature annealing process. The size, structure, and composition of the AuNi BMNPs can be well tuned by varying the AuNP seeds, annealing temperature, and feeding ratio of metal precursors.