Harnessing Ultrasound-Derived Hydroxyl Radicals for the Selective Oxidation of Aldehyde Functions.

Ultrasonic irradiation holds potential for the selective oxidation of non-volatile organic substrates in the aqueous phase by harnessing hydroxyl radicals as chemical initiators. Here, a mechanistic description of hydroxyl radical-initiated glyoxal oxidation is constructed by gleaning insights from photolysis and radiation chemistry to explain the yields and kinetic trends for oxidation products. The mechanistic description and kinetic measurements reported herein reveal that increasing the formation rate of hydroxyl radicals by changing the ultrasound frequency increases both the rates of glyoxal consumption and the selectivity towards C acid products over those from C-C cleavage.

Tough and Strain-Sensitive Organohydrogels Based on MXene and PEDOT/PSS and Their Effects on Mechanical Properties and Strain-Sensing Performance.

Conductive hydrogels have shown promising application prospects in the field of flexible sensors, but they often suffer from poor mechanical properties, low sensitivity, and lack of frost resistance. Herein, we report a tough, highly sensitive, and antifreeze strain sensor assembled from a conductive organohydrogel composed of a dual-cross-linked polyacrylamide and poly(vinyl alcohol) (PVA) network, as well as MXene nanosheets as nanofillers and poly(3,4-ethylenedioxythiophene)-doped poly(styrenesulfonate) (PEDOT/PSS) as the main conducting component (PPMP-OH organohydrogel). The tensile strength and toughness of PPMP-OH had been greatly enhanced by MXene nanosheets due to the mechanical reinforcement of MXene nanosheets, as well as various strong noncovalent interactions formed in the organohydrogels.

Copper-Loaded Nanoheterojunction Enables Superb Orthotopic Osteosarcoma Therapy via Oxidative Stress and Cell Cuproptosis.

Catalytic tumor therapy based on two-dimensional (2D) nanomaterials is a burgeoning and promising tumor therapeutic modality. However, the inefficient utilization and conversion of exogenous stimulation, single catalytic modality, and unsatisfactory therapeutic efficiency in the tumor microenvironment (TME) have seriously restricted their further application in tumor therapy. Herein, the heterogeneous carbon nitride-based nanoagent named T-HCN@CuMS was successfully developed, which dramatically improved the efficiency of the tumor therapeutic modality.

Nanofibrous Dressing with Nanocomposite Monoporous Microspheres for Chemodynamic Antibacterial Therapy and Wound Healing.

The excessive use of antibiotics and consequent bacterial resistance have emerged as crucial public safety challenges for humanity. As a promising antibacterial treatment, using reactive oxygen species (ROS) can effectively address this problem and has the advantages of being highly efficient and having low toxicity. Herein, electrospinning and electrospraying were employed to fabricate magnesium oxide (MgO)-based nanoparticle composited polycaprolactone (PCL) nanofibrous dressings for the chemodynamic treatment of bacteria-infected wounds.

High Efficiency of Formaldehyde Removal and Anti-bacterial Capability Realized by a Multi-Scale Micro-Nano Channel Structure in Hybrid Hydrogel Coating Cross-Linked on Microfiber-Based Polyurethane.

Inspired by the transpiration in the tree stem having a vertical and porous channel structure, high efficiency of formaldehyde removal is realized by the multi-scale micro-nano channel structure in a hybrid P(AAm/DA)-Ag/MgO hydrogel coating cross-linked on microfiber-based polyurethane. The present multi-scale channel structure is formed by a joint effect of directional freezing and redox polymerization as well as nanoparticles-induced porosity. Due to the large number of vertically aligned channels of micrometer size and an embedded porous structure of nanometer size, the specific surface area is significantly increased.

Highly conductive and tough polyacrylamide/sodium alginate hydrogel with uniformly distributed polypyrrole nanospheres for wearable strain sensors.

Conductive hydrogels have attracted widespread attention because of their integrated characteristics of being stretchable, deformable, adhesive, self-healable, and conductive. Herein, we report a highly conductive and tough double-network hydrogel based on a double cross-linked polyacrylamide (PAAM) and sodium alginate (SA) network with conducting polypyrrole nanospheres (PPy NSs) uniformly distributed in the network (PAAM-SA-PPy NSs). SA was employed as a soft template for synthesis of PPy NSs and distribution of PPy NSs uniformly in the hydrogel matrix to construct SA-PPy conductive network.

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.

Strong Metal-Support Interaction for 2D Materials: Application in Noble Metal/TiB Heterointerfaces and their Enhanced Catalytic Performance for Formic Acid Dehydrogenation.

Strong metal-support interaction (SMSI) is a phenomenon commonly observed on heterogeneous catalysts. Here, direct evidence of SMSI between noble metal and 2D TiB supports is reported. The temperature-induced TiB overlayers encapsulate the metal nanoparticles, resulting in core-shell nanostructures that are sintering-resistant with metal loadings as high as 12.

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.

The coupling of hemin with persistent free radicals induces a nonradical mechanism for oxidation of pollutants.

Herein, we report that persistent free radicals (PFRs) based on MWCNTs significantly accelerate the pollutant removal rate. EPR measurement combined with the electrochemical test indicated that a nonradical mechanism was responsible for the enhancement, which is different from the previously reported radical pathway on PFRs.

High Density Gold Nanoparticles Within Three-Dimensionally Mesoporous SBA-15: Adsorption Behavior and Optical Properties.

Unprecedentedly high-density (up to 79 wt%) immobilization of monodispersed gold nanoparticles (AuNPs) within mesoporous silica SBA-15 is achieved by variation of their pore size and pore-pore connectivity to enable a full access of AuNPs to the large and high-affinity internal surface of mesoporous silica (MPS) SBA-15. In addition, according to the adsorption kinetics, dipole-induced dipole interaction is suggested to be the primary driving force for adsorption of AuNPs on silica. Interestingly, the high internal surface of MPS shows much higher affinity to AuNPs than the external surface.

Au/BiOCl heterojunction within mesoporous silica shell as stable plasmonic photocatalyst for efficient organic pollutants decomposition under visible light.

A new mesoporous silica protected plasmonic photocatalyst, Au/BiOCl@mSiO2, was prepared by a modified AcHE method and a subsequent UV light induced photodeposition process. The surfactant-free heterojunction allows the electrons spontaneously flow from Au to nearby BiOCl surface, leading to the accumulation of positive charges on Au surface, and negative charges on Bi species under visible light. Au/BiOCl@mSiO2 exhibits high visible light photocatalytic efficiency in complete oxidation of aqueous formaldehyde and Rhodamin B.

Sub-10 nm Au-Pt-Pd alloy trimetallic nanoparticles with a high oxidation-resistant property as efficient and durable VOC oxidation catalysts.

Sub-10 nm AuPtPd alloy trimetallic nanoparticles (TMNPs) with a high oxidation-resistant property were prepared by photo-deposition followed by a high temperature (700-900 °C) air annealing process.

Platinum nanoparticles supported on Ca(Mg)-zeolites for efficient room-temperature alcohol oxidation under aqueous conditions.

Platinum nanoparticles supported on Ca(Mg)-ZSM-5 is an efficient, highly selective and stable catalyst for room-temperature oxidation of alcohols in water. Based on in situ EPR measurement and the radical trapping technique, we propose that the generation of ˙OH radicals by cleavage of the O-O bond in the H2O2 intermediate is the rate determining step, which participated in the abstraction of H from the α-C-H bond of alcohol molecules to produce aldehydes/ketones.

Solid phase metallurgy strategy to sub-5 nm Au-Pd and Ni-Pd bimetallic nanoparticles with controlled redox properties.

A solid phase metallurgy strategy is applied to synthesize Au-Pd and Ni-Pd bimetallic nanoparticles (BMNPs) with a tight sub-5 nm particle size distribution. The near-surface elemental composition and redox properties of Au-Pd BMNPs can be well tailored, which leads to an optimized catalytic performance in n-hexane combustion.

Ordered, extra-large mesopores with highly loaded gold nanoparticles: a new sintering- and coking-resistant catalyst system.

Ordered, extra-large mesopores with highly loaded gold nanoparticles (AuNPs) exhibits unique sintering- and coking-resistant properties in gas-phase, cyclohexanol selective aerobic oxidation.

Photo-assisted cyanation of transition metal nitrates coupled with room temperature C-C bond cleavage of acetonitrile.

It is a challenge to use acetonitrile as a cyanating agent because of the difficulty in cleaving its C-CN bond. Herein, we report a mild photo-assisted route to conduct the cyanation of transition metal nitrates using acetonitrile as the cyanating agent coupled with room-temperature C-C bond cleavage. DFT calculations and experimental observations suggest a radical-involved reaction mechanism, which excludes toxicity from free cyanide ions.

[Effects of simulated nitrogen deposition on soil enzyme activities in a Betula luminifera plantation in Rainy Area of West China].

From January 2008 to January 2009, a field experiment was conducted to investigate the effects of simulated nitrogen (N) deposition (0, 5, 15, and 30 g N x m(-2) x a(-1)) on the soil enzyme activities in a Betula luminifera plantation in Rainy Area of West China. As compared with the control (0 g N x m(-2) x a(-1)), simulated N deposition stimulated the activities of soil hydrolases (beta-fructofuranosidase, cellulase, acid phosphatase, and urease) significantly, but depressed the activities of soil oxidases (polyphenol oxidase and peroxidase). These results suggested that the increased exogenous inorganic N could stimulate soil microbial activity and increase the demands of both B.

Radical-involved photosynthesis of AuCN oligomers from Au nanoparticles and acetonitrile.

We show here the first radical route for the direct photosynthesis of AuCN oligomers with different sizes and shapes, as evidenced by TEM observations, from an Au nanoparticle/benzaldehyde/CH(3)CN ternary system in air under UV-light irradiation. This photochemical route is green, mild, and universal, which makes itself distinguishable from the common cyanidation process. Several elementary reaction steps, including the strong C-C bond dissociation of CH(3)CN and subsequent •CN radical addition to Au, have been suggested to be critical in the formation of AuCN oligomers based on the identification of •CN radical by in situ EPR and the radical trapping technique, and other reaction products by GC-MS and (1)H NMR, and DFT calculations.

Visible-light-driven surface reconstruction of mesoporous TiO2: toward visible-light absorption and enhanced photocatalytic activities.

The surface structure of mesoporous TiO(2) is reconstructed via a visible-light-driven reaction with benzyl alcohol molecules at mild, anaerobic conditions, which substantially extends its visible-light absorption and photocatalytic activities.

[Effects of simulated nitrogen deposition on soil respiration in a Neosinocalamus affinis plantation in rainy area of west China].

From December 2007 to November 2008, an in situ experiment was conducted to study the effects of simulated nitrogen deposition on the soil respiration in a Neosinocalamus affinis plantation in Rainy Area of West China. Four treatments were installed, i.e.

[Soil enzyme activities in a Pleioblastus amurus plantation in Rainy Area of West China under simulated nitrogen deposition].

From November 2007 to May 2009, a simulation test was conducted in a Pleioblastus amarus plantation in Rainy Area of West China to study the effects of nitrogen deposition on the activities of soil enzymes. Four treatments were installed, i.e.

[Effects of simulated nitrogen deposition on litter decomposition in Neosinocalamus affinis stands in rainy area of West China].

An in situ experiment was conducted to study the effects of simulated nitrogen deposition on the litter decomposition in Neosinocalamus affinis stands in rainy area of West China. Four treatments were installed, i.e.