Highly selective oxidation of benzene to phenol with air at room temperature promoted by water.

Phenol is one of the most important fine chemical intermediates in the synthesis of plastics and drugs with a market size of ca. $30b and the commercial production is via a two-step selective oxidation of benzene, requiring high energy input (high temperature and high pressure) in the presence of a corrosive acidic medium, and causing serious environmental issues. Here we present a four-phase interface strategy with well-designed Pd@Cu nanoarchitecture decorated TiO as a catalyst in a suspension system.

A Z-Scheme Heterojunctional Photocatalyst Engineered with Spatially Separated Dual Redox Sites for Selective CO Reduction with Water: Insight by In Situ µs-Transient Absorption Spectra.

Solar-driven CO reduction by water with a Z-scheme heterojunction affords an avenue to access energy storage and to alleviate greenhouse gas (GHG) emissions, yet the separation of charge carriers and the integrative regulation of water oxidation and CO activation sites remain challenging. Here, a BiVO /g-C N (BVO/CN) Z-scheme heterojunction as such a prototype is constructed by spatially separated dual sites with CoO clusters and imidazolium ionic liquids (IL) toward CO photoreduction. The optimized CoO -BVO/CN-IL delivers an ≈80-fold CO production rate without H evolution compared with urea-C N counterpart, together with nearly stoichiometric O gas produced.

Investigation on the Fatigue Crack Propagation of Medium-Entropy Alloys with Heterogeneous Microstructures.

The behavior and the mechanism of fatigue crack propagation in CrCoNi medium-entropy alloys (MEAs) with heterogeneous microstructures were investigated in this paper. After cold-rolling and recrystallization annealing at different temperatures and times, five sets of heterostructured specimens were acquired with different recrystallization levels. Then, the structure characterizations of these five sets of specimens were carried out by nanoindentation testing and electron back-scatter diffraction (EBSD) mapping.

Modification of Covalent Triazine-Based Frameworks for Photocatalytic Hydrogen Generation.

The conversion of solar energy and water to hydrogen via semiconductor photocatalysts is one of the efficient strategies to mitigate the energy and environmental crisis. Conjugated polymeric photocatalysts have advantages over their inorganic counterparts. Their molecular structures, band structures, and electronic properties are easily tunable through molecular engineering to extend their spectral response ranges, improve their quantum efficiencies, and enhance their hydrogen evolution rates.

Investigation of Charge Performance in Anatase TiO Powder for Methane Conversion by Vis-NIR Spectroscopy.

The intrinsic behavior of photogenerated charges and reactions with chemicals are key for a photocatalytic process. To observe these basic steps is of great importance. Here we present a reliable and robust system to monitor these basic steps in powder photocatalysts, and more importantly to elucidate the key issue in photocatalytic methane conversion over the benchmark catalyst TiO.

Rational Design of High-Concentration Ti in Porous Carbon-Doped TiO Nanosheets for Efficient Photocatalytic Ammonia Synthesis.

Photocatalytic ammonia synthesis is exciting but quite challenging with a very moderate yield at present. One of the greatest challenges is to develop highly active centers in a photocatalyst for N reduction under ambient conditions. Herein, porous carbon-doped anatase TiO (C-TiO ) nanosheets with high-concentration active sites of Ti are presented, which are produced by layered Ti SiC through a reproducible bottom-up approach.

From UV to NIR: A Full-Spectrum Metal-Free Photocatalyst for Efficient Polymer Synthesis in Aqueous Conditions.

Photo-mediation offers unparalleled spatiotemporal control over controlled radical polymerizations (CRP). Photo-induced electron/energy transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization is particularly versatile owing to its oxygen tolerance and wide range of compatible photocatalysts. In recent years, broadband- and near-infrared (NIR)-mediated polymerizations have been of particular interest owing to their potential for solar-driven chemistry and biomedical applications.

Platinum- and CuO -Decorated TiO Photocatalyst for Oxidative Coupling of Methane to C Hydrocarbons in a Flow Reactor.

Oxidative coupling of methane (OCM) is considered one of the most promising catalytic technologies to upgrade methane. However, C products (C H /C H ) from conventional methane conversion have not been produced commercially owing to competition from overoxidation and carbon accumulation at high temperatures. Herein, we report the codeposition of Pt nanoparticles and CuO clusters on TiO (PC-50) and use of the resulting photocatalyst for OCM in a flow reactor operated at room temperature under atmospheric pressure for the first time.

Synergistic oxygen substitution and heterostructure construction in polymeric semiconductors for efficient water splitting.

Herein, we present a synergistic oxygen-substitution and heterostructure construction strategy to produce a two-dimensional oxygenated-triazine-heptazine-conjugated carbon nitride nanoribbon (TOH-CN). The TOH-CN was proved to have an internal donor-acceptor heterostructure that could promote interfacial charge separation and transport, while the oxygen substitution effect modulated the nanoribbon morphology with increased surface/edge active sites and tuned the electronic structure to extend visible-light absorption as well as to improve band structure alignment. Benefiting from these advantages, the TOH-CN served as an efficient bifunctional photocatalyst for both H2 and O2 evolution under visible-light irradiation, exhibiting a 16 times higher photocatalytic H2 evolution rate than that of its melon-based carbon nitride (g-C3N4) counterpart, and a remarkable apparent quantum yield of 7.

Tunable Covalent Triazine-Based Frameworks (CTF-0) for Visible-Light-Driven Hydrogen and Oxygen Generation from Water Splitting.

Covalent triazine-based frameworks (CTFs), a group of semiconductive polymers, have been identified for photocatalytic water splitting recently. Their adjustable band gap and facile processing offer great potential for discovery and development. Here, we present a series of CTF-0 materials fabricated by two different approaches, a microwave-assisted synthesis and an ionothermal method, for water splitting driven by visible-light irradiation.

Dimension-Matched Zinc Phthalocyanine/BiVO Ultrathin Nanocomposites for CO Reduction as Efficient Wide-Visible-Light-Driven Photocatalysts via a Cascade Charge Transfer.

Cascade charge transfer was realized by a H-bond linked zinc phthalocyanine/BiVO nanosheet (ZnPc/BVNS) composite, which subsequently works as an efficient wide-visible-light-driven photocatalyst for converting CO into CO and CH , as shown by product analysis and C isotopic measurement. The optimized ZnPc/BVNS nanocomposite exhibits a ca. 16-fold enhancement in the quantum efficiency compared with the reported BiVO nanoparticles at the excitation of 520 nm with an assistance of 660 nm photons.

Key factors affecting photoelectrochemical performance of g-CN polymer films.

We investigated the relationship between crystallinity, deep trap states and PEC performance of g-CN photoelectrodes. Long-lived charge carriers were present in the more poorly crystalline samples, due to deeper trap states, which inversely correlated with photoelectrochemical performance. The charge diffusion length in a compact g-CN film was determined to be ca.

Ultrasensitive On-Site Detection of Biological Active Ricin in Complex Food Matrices Based on Immunomagnetic Enrichment and Fluorescence Switch-On Nanoprobe.

Ricin is a highly toxic protein largely existing in castor beans, which could be used as a warfare agent due to its unique properties. As a deadenylase, inactivation of ricin means a loss of its toxic threat. Therefore, developing simple, accurate, and sensitive on-site detection of biologically active ricin in wide types of complex matrices is most valuable.

Nanoporous Carbon: Liquid-Free Synthesis and Geometry-Dependent Catalytic Performance.

Nanostructured carbons with different pore geometries are prepared with a liquid-free nanocasting method. The method uses gases instead of liquid to disperse carbon precursors, leach templates, and remove impurities, minimizing synthetic procedures and the use of chemicals. The method is universal and demonstrated by the synthesis of 12 different porous carbons with various template sources.

Effects of Loading Frequency and Loading Type on High-Cycle and Very-High-Cycle Fatigue of a High-Strength Steel.

High-cycle and very-high-cycle fatigue tests via rotary bending (52.5 Hz), electromagnetic resonance (120 Hz) axial cycling, and ultrasonic (20 kHz) axial cycling were performed for a high-strength steel with three heat treatment conditions, and the effects of loading frequency and loading type on fatigue strength and fatigue life were investigated. The results revealed that the loading frequency effect is caused by the combined response of strain rate increase and induced temperature rise.

Mimicking Natural Photosynthesis: Solar to Renewable H Fuel Synthesis by Z-Scheme Water Splitting Systems.

Visible light-driven water splitting using cheap and robust photocatalysts is one of the most exciting ways to produce clean and renewable energy for future generations. Cutting edge research within the field focuses on so-called "Z-scheme" systems, which are inspired by the photosystem II-photosystem I (PSII/PSI) coupling from natural photosynthesis. A Z-scheme system comprises two photocatalysts and generates two sets of charge carriers, splitting water into its constituent parts, hydrogen and oxygen, at separate locations.

A Nanojunction Polymer Photoelectrode for Efficient Charge Transport and Separation.

A metal-free photoanode nanojunction architecture, composed of B-doped carbon nitride nanolayer and bulk carbon nitride, was fabricated by a one-step approach. This type of nanojunction (s-BCN) overcomes a few intrinsic drawbacks of carbon nitride film (severe bulk charge recombination and slow charge transfer). The top layer of the nanojunction has a depth of ca.