Functional Aerogels Composed of Regenerated Cellulose and Tungsten Oxide for UV Detection and Seawater Desalination.

Functional aerogels composed of regenerated cellulose and tungsten oxide were fabricated by implanting tungsten-oxide nanodots into regenerated cellulose fiber. This superfast photochromic property benefitted from the small size and even distribution of tungsten oxide, which was caused by the confinement effect of the regenerated cellulose fiber. The composite was characterized using XRD and TEM to illustrate the successful loading of tungsten oxide.

PVDF-Modified TiO Nanowires Membrane with Underliquid Dual Superlyophobic Property for Switchable Separation of Oil-Water Emulsions.

Separation membranes with underliquid dual superlyophobicity have recently caused widespread concern due to their switchable separation of oil-water mixtures and emulsions. However, the fabrication of the reported underliquid dual superlyophobic membranes is difficult, and the design of the underliquid dual superlyophobic surface of these membranes is challenging because of their complex surface composition. Theoretically, underliquid dual superlyophobicity is an underliquid Cassie state attainable by the synergy of the underliquid dual lyophobic surface and the construction of a high-roughness surface.

A Flexible, Self-Floating Composite for Efficient Water Evaporation.

A flexible, self-floating WO/carbon foam composite is fabricated by calcining melamine foam with WO as an adsorbate in N atmosphere. This self-floating property is simply realized by a carbonization process other than the complicated surface modification process. The simple synthesis procedure helps to increase not only the solar absorption but also the retention of WO in the porous net structure.

Hollow Metal-Organic-Framework Micro/Nanostructures and their Derivatives: Emerging Multifunctional Materials.

Hollow metal-organic framework (MOF) micro/nanostructures and their derivatives are attracting a great amount of research interest in recent years because their hierarchical porous structures not only provide abundant, easily accessed metal sites but also endow 3D channels for rapid mass transport. As a result, they demonstrate significant advantages in many applications including catalysis, gas sensors, batteries, supercapacitors, and so on. Nevertheless, studies on hollow MOFs and their derivatives are still at the beginning of this field, and the relationship between their structures and application performances is not yet reviewed comprehensively.

Synthesis and Characterization of N-Doped Porous TiO₂ Hollow Spheres and Their Photocatalytic and Optical Properties.

Three kinds of N-doped mesoporous TiO₂ hollow spheres with different N-doping contents, surface area, and pore size distributions were prepared based on a sol-gel synthesis and combined with a calcination process. Melamine formaldehyde (MF) microspheres have been used as sacrificial template and cetyltrimethyl ammonium bromide (CTAB) or polyvinylpyrrolidone (PVP) was selected as pore-directing agent. Core-shell intermediate spheres of titania-coated MF with diameters of 1.

Photothermal Conversion of WO with a Tunable Oxidation State.

WO with a tunable oxidation state was prepared by addition of NaNO or NaBH as a redox agent in the solvothermal system. The addition of redox agents has no influence on the crystallization of WO. The obtained WO structures keep their morphology as a bundle of nanowires with a regular hexagonal on the cross-section.

Tuning the Aggregation/Disaggregation Behavior of Graphene Quantum Dots by Structure-Switching Aptamer for High-Sensitivity Fluorescent Ochratoxin A Sensor.

The design of graphene quantum dots (GQDs)-aptamer bioconjugates as the new sensing platform is very important for developing high-sensitivity fluorescent biosensors; however, achieving new bioconjugates is still a great challenge. Herein, we report the development of a new high-sensitivity fluorescent aptasensor for the detection of ochratoxin A (OTA) based on tuning aggregation/disaggregation behavior of GQDs by structure-switching aptamers. The fluorescence sensing process for OTA detection involved two key steps: (1) cDNA-aptamer (cDNA, complementary to part of the OTA aptamer) hybridization induced the aggregation of GQD (fluorescence quenching) after cDNA was added into the GQDs-aptamer bioconjugate solution, and (2) the target of OTA triggered disaggregation of GQD aggregates (fluorescence recovery).

Porous TiO2 Assembled from Monodispersed Nanoparticles.

Porous TiO2 were assembled by evaporating or refluxing TiO2 colloid, which was obtained by dispersing the TiO2 nanoparticles with a crystallite size (d XRD) of 3.2 nm into water or ethanol without any additives. Porous transparent bulk TiO2 was obtained by evaporating the TiO2-C2H5OH colloid at room temperature for 2 weeks, while porous TiO2 nanospheres were assembled by refluxing the TiO2-H2O colloid at 80 °C for 36 h.

Synthesis of fluorinated carbazoles via C-H arylation catalyzed by Pd/Cu bimetal system and their antibacterial activities.

An effective intramolecular C-H arylation reaction catalyzed by a bimetallic catalytic system Pd(OAc)2/CuI for the synthesis of fluorine-substituted carbazoles from corresponding N-phenyl-2-haloaniline derivatives under ligand free conditions is demonstrated. The established method is effective for both N-phenyl-2-bromoaniline and N-phenyl-2-chloroaniline, and requires the low loading of Pd(OAc)2 (0.5 mol%).

Construction of Plasmonic Core-Satellite Nanostructures on Substrates Based on DNA-Directed Self-Assembly as a Sensitive and Reproducible Biosensor.

We report the successful construction of plasmonic core-satellite nanostructured assemblies on two-dimensional substrates, based on a strategy of combining DNA-functionalized plasmonic nanoparticles (NPs) with the specific recognition ability toward target to enable satellite NPs to self-assemble around the core immobilized on substrates. A strongly coupled plasmonic resonance band was observed because of the close proximity between core and satellite NPs, which presented significant red-shift and enhanced extinction with respect to the local surface plasmon resonance (LSPR) band of individual core NPs on the substrate. The functionality of this core-satellite nanostructured assembly as a biosensor was further explored, and the changes in extinction intensity and the peak shift of the plasmonic coupling resonance band arising from the probe-target DNA binding event all proved to be useful criteria for target DNA detection.

Assembly of Maghemite Nanoparticles Into Particulate Nanosheets and Their Application in Wastewater Treatment.

The maghemite particulate nanosheets (MPNs) are prepared in solvothermal system by connecting the nanoparticles in two-dimension. The interconnected MPNs sustain a mesopores structure with a high accessible surface area of 164 m2/g, and have a high performance for Cr6+ adsorption. The Cr6+ removal process fit with Langmuir adsorption model with an adsorption capacity of 20.

Observation of Body-Centered Cubic Gold Nanocluster.

The structure of nanoparticles plays a critical role in dictating their material properties. Gold is well known to adopt face-centered cubic (fcc) structure. Herein we report the first observation of a body-centered cubic (bcc) gold nanocluster composed of 38 gold atoms protected by 20 adamantanethiolate ligands and two sulfido atoms ([Au38S2(SR)20], where R=C10H15) as revealed by single-crystal X-ray crystallography.

A top-down route for preparation of ultrathin zinc oxide nanowires.

Zinc oxide nanowires have been successfully obtained through the splitting of layered basic zinc acetates. The layered basic zinc acetates nanobelts served as intermediates are prepared by adding water into zinc oxide ethanol colloids. Zinc oxide nanowires have uniform diameters of about 3-5 nm and lengths of several hundred nanometers.

Magnetic photocatalysts with a p-n junction: Fe3O4 nanoparticle and FeWO4 nanowire heterostructures.

Magnetic n-type semiconductor Fe3O4 nanoparticle and p-type semiconductor FeWO4 nanowire heterostructures were successfully synthesized without any surfactants or templates via a facile one-step hydrothermal process at 160 °C. The heterojunction structure and morphology were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Magnetic measurements indicated the coexistence of ferrimagnetic behavior of Fe3O4 and weak antiferromagnetic behavior of FeWO4.

Fast response and highly selective sensing of amine vapors using a luminescent coordination polymer.

Detecting volatile amines is a significant topic in the quality control of food and medical diagnosis. We report the first Eu-coordination polymer (CP) as a sensory material for the detection of a class of amine vapors with high selectivity and rapid response.

Synthesis of ultrasmall platinum nanoparticles and structural relaxation.

We report the synthesis of ligand-protected, ultrasmall Pt nanoparticles of ∼1 nm size via a one-phase wet chemical method. Using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), we determined the mass of the nanoparticles to be ∼8 kDa. Characterization of the Pt nanoparticles was further carried out by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), optical absorption spectroscopy, and X-ray photoelectron spectroscopy (XPS).

A facile synthetic approach for copper iron sulfide nanocrystals with enhanced thermoelectric performance.

Chalcopyrite CuFeS(2) nanocrystals with a diameter of 6.4 nm were synthesized using a facile solution-phase method. Due to quantum confinement, the CuFeS(2) nanocrystals exhibit a maximum ZT value of 0.

Synthesis and characterization of novel chiral NHC-palladium complexes and their application in copper-free Sonogashira reactions.

A new series of chiral N-heterocyclic carbene (NHC) palladium complexes were synthesized from a relatively inexpensive amino acid, l-phenylalanine. All these compounds were fully characterized by (1)H-NMR, (13)C-NMR and elemental analysis. The X-ray molecular structures of two of the complexes were reported.

Preparation of well-dispersed Mg-doped LaCoO3 nanocrystals with controllable particle size and high visible-light photocatalytic activity.

Mg-doped LaCoO3 nanocrystals are prepared by a modified sol-gel method. Excess MgO is used to inhibit the crystal growth and agglomeration during the calcination process. A series of Mg-doped LaCoO3 nanocrystals with average crystallite size varying from 13.

Influence of polyols on the formation of iron oxide nanoparticles in solvothermal system.

We reported a simple solvothermal route in phase-controllable synthesis of iron oxide nanoparticles by using polyols as solvent. Magnetite and hematite are selectively synthesized while Fe(NO3)3.9H2O is used as single iron source and without any additives.

Hexagonal mesocrystals formed by ultra-thin tungsten oxide nanowires and their electrochemical behaviour.

Hexagonal mesocrystals formed by tungsten oxide nanowires have been synthesized using a solvothermal method without any template. The selected area electron diffraction (SAED) analysis of the regular hexagonal mesocrystal demonstrates that the nanowires are highly ordered. Electrochemical behaviour of the mesocrystals has been evaluated by cyclic voltammograms.

Sonochemical synthesis of cerium oxide nanoparticles-effect of additives and quantum size effect.

Cerium oxide (CeO(2)) nanoparticles were prepared sonochemically, by using cerium nitrate and azodicarbonamide as starting materials, and ethylenediamine or tetraalkylammonium hydroxide as additives. The additives have a strong effect on the particle size and particle size distribution. CeO(2) nanoparticles with small particle size and narrow particle size distribution are obtained with the addition of additives; while highly agglomerated CeO(2) nanoparticles are obtained in the absence of additives.