Double-Layered Polymer Microcapsule Containing Non-Flammable Agent for Initial Fire Suppression.

Fire in energy storage systems, such as lithium-ion batteries, has been raised as a serious concern due to the difficulty of suppressing it. Fluorine-based non-flammable agents used as internal substances leaked through the fine pores of the polymer outer shell, leading to a degradation of fire extinguishing performance. To improve the durability of the fire suppression microcapsules and the stability of the ouster shell, a complex coacervation was used, which could be microencapsulated at a lower temperature, and the polymer shell was coated with urea-formaldehyde (UF) resin.

Water Orientation at the Anatase TiO Nanoparticle Interface: A Probe of Surface p Values.

The acid-base properties of surfaces significantly influence catalytic and (photo)electrochemical processes. Estimation of acid dissociation constants (p values) for colloids is commonly performed through electroanalytical techniques or spectroscopic methods employing label molecules. Here, we show that polarimetric angle-resolved second harmonic scattering (AR-SHS) can be used as an all-optical, label-free probe of colloid surface p values.

Effects of the Crystalline Properties of Hollow Ceria Nanostructures on a CuO-CeO Catalyst in CO Oxidation.

The development of an efficient and economic catalyst with high catalytic performance is always challenging. In this study, we report the synthesis of hollow CeO nanostructures and the crystallinity control of a CeO layer used as a support material for a CuO-CeO catalyst in CO oxidation. The hollow CeO nanostructures were synthesized using a simple hydrothermal method.

Bead-Shaped Mesoporous Alumina Adsorbents for Adsorption of Ammonia.

It is of great importance to remove toxic gases by efficient methods for recovering the atmosphere to safe levels. The adsorption of the toxic gas molecules on solid adsorbents is one of the most useful techniques because of its simple operation and economic feasibility. Here, we report the uniform Bead-Shaped Mesoporous Alumina (BSMA) with tunable particle size for use as an adsorbent for removal of toxic ammonia.

Biotransformation of methane into methanol by methanotrophs immobilized on coconut coir.

This study aimed to establish a unique approach for the production of methanol from methane (CH) in the presence of paraffin oil mediated by methanotrophs immobilized on coconut coir (CC). Immobilization of different methanotrophs through covalent method increased the immobilization yield and relative efficiency for methanol production to 48.6% and 96.

Controlled drug release with surface-capped mesoporous silica nanoparticles and its label-free in situ Raman monitoring.

Mesoporous silica nanoparticles (MSNs) have drawn attention as efficient nanocarriers for drug delivery systems owing to their unique physiochemical properties. However, systemically controlling the kinetics of drug release from the nanocarriers and in situ monitoring of the drug release are still challenging. Here, we report surface-capped MSNs used for controlled drug release and demonstrate label-free in situ Raman monitoring of released drugs based on the molecule-specific spectral fingerprints.

Controllable one-pot synthesis of uniform colloidal TiO particles in a mixed solvent solution for photocatalysis.

This study reports on the controllable synthesis of uniform colloidal titanium dioxide (TiO) particles and their photocatalytic applications toward rhodamine B (RhB) degradation. The monodispersed TiO particles were synthesized under mixed solvent conditions by sol-gel chemistry in a one-pot process. Varying the ratio of solvent composition, the concentration of surfactant and TiO precursor was used to control the particle diameter, degree of monodispersity and morphology.

Facile Amplification of Solution-State Surface-Enhanced Raman Scattering of Small Molecules Using Spontaneously Formed 3D Nanoplasmonic Wells.

Surface-enhanced Raman scattering (SERS) has recently been considered as one of the most promising tools to directly analyze small molecules without labels, owing to advantages in sensitivity, specificity, and speed. However, collecting reproducible SERS signals from small molecules on substrates or in solutions is challenging because of random molecular adsorption on surfaces and laser-induced molecular convection in solutions. Herein, we report a novel and efficient way to collect SERS signals from solution samples using three-dimensional nanoplasmonic wells spontaneously formed by interfacial reactions between liquid polydimethylsiloxane (PDMS) and small droplets of metal ion solutions (e.

Dual-Pore Carbon Shells for Efficient Removal of Humic Acid from Water.

A template-mediated process for the preparation of mesoporous carbon shells with high surface area, dual-pore structure, and excellent performance in the adsorption of humic acid is reported. Their synthesis involves templating phenolic resin against wrinkled silica nanospheres, subsequent carbonization under Ar atmosphere, and final release of dual-pore mesoporous carbon shells by etching the silica templates. An additional silica layer was used to protect the phenolic resin from aggregation during carbonization, and its subsequent removal gives the carbon shells a hydrophilic surface, which significantly improves their dispersity in aqueous media.

Reductive dechlorination of carbon tetrachloride by bioreduction of nontronite.

Reductive dechlorination of carbon tetrachloride (CT) was investigated during bioreduction of iron-containing clay mineral (i.e., nontronite) by iron-reducing bacteria (Shewanella putrefaciens CN32 (CN32)).

Water-assisted crystallization of mesoporous anatase TiO2 nanospheres.

We report a facile water-assisted crystallization process for the conversion of amorphous sol-gel derived TiO2 into mesoporous anatase nanostructures with a high surface area and well-controlled porosity and crystallinity. As an alternative to conventional calcination methods, this approach works under very mild conditions and is therefore much desired for broad biological, environmental and catalytic applications.

Ethylene glycol-assisted coating of titania on nanoparticles.

Coating titania shells onto sub-micron sized particles has been widely studied recently, with success mainly limited to objects with sizes above 50 nm. Direct coating on particles below this size has been difficult to attain especially with good control over properties such as thickness and crystallinity. Here we demonstrate that titanium-glycolate formed by reacting titanium alkoxide and ethylene glycol is an excellent precursor for coating titania on aqueous nanoparticles.

Thermal synthesis of silver nanoplates revisited: a modified photochemical process.

The well-known photochemical and thermal methods for silver nanoplate synthesis have been generally regarded as two parallel processes without strong connections. Here we report a surprising finding that both visible light and ambient O2, which are critically important in the photochemical process, also play determining roles in the thermal synthesis. By designing a series of control experiments, we reveal that the typical thermal synthesis is essentially a modified photochemical synthesis coupled with the unique redox properties of H2O2.

Decoration of size-tunable CuO nanodots on TiO2 nanocrystals for noble metal-free photocatalytic H2 production.

We report a simple yet effective approach for the decoration of the TiO2 nanocrystal surface with size-tunable CuO nanodots for high-performance noble metal-free photocatalytic H2 production. Modification with polyacrylic acid enables the surface of TiO2 nanocrystals to be selectively deposited with Cu(OH)2 nanodots, which can be subsequently converted to CuO through dehydration without changing their morphologies. UV irradiation of the nanocomposite solution in the presence of a hole scavenger produces photogenerated electrons which reduce CuO to metallic Cu nanodots, making them effective co-catalysts in a role similar to Pt for promoting photocatalytic H2 production.

Promotion of atomic hydrogen recombination as an alternative to electron trapping for the role of metals in the photocatalytic production of H2.

The production of hydrogen from water with semiconductor photocatalysts can be promoted by adding small amounts of metals to their surfaces. The resulting enhancement in photocatalytic activity is commonly attributed to a fast transfer of the excited electrons generated by photon absorption from the semiconductor to the metal, a step that prevents deexcitation back to the ground electronic state. Here we provide experimental evidence that suggests an alternative pathway that does not involve electron transfer to the metal but requires it to act as a catalyst for the recombination of the hydrogen atoms made via the reduction of protons on the surface of the semiconductor instead.

Stacked multilayers of alternating reduced graphene oxide and carbon nanotubes for planar supercapacitors.

A simple layer-by-layer approach has been developed for constructing 2D planar supercapacitors of multi-stacked reduced graphene oxide and carbon nanotubes. This sandwiched 2D architecture enables the full utilization of the maximum active surface area of rGO nanosheets by using a CNT layer as a porous physical spacer to enhance the permeation of a gel electrolyte inside the structure and reduce the agglomeration of rGO nanosheets along the vertical direction. As a result, the stacked multilayers of rGO and CNTs are capable of offering higher output voltage and current production.

A sulfated ZrO2 hollow nanostructure as an acid catalyst in the dehydration of fructose to 5-hydroxymethylfurfural.

Mesoporous hollow colloidal particles with well-defined characteristics have potential use in many applications. In liquid-phase catalysis, in particular, they can provide a large active surface area, reduced diffusion resistance, improved accessibility to reactants, and excellent dispersity in reaction media. Herein, we report the tailored synthesis of sulfated ZrO2 hollow nanostructures and their catalytic applications in the dehydration of fructose.

Core-shell nanostructured catalysts.

Novel nanotechnologies have allowed great improvements in the syn-thesis of catalysts with well-controlled size, shape, and surface properties. Transition metal nanostructures with specific sizes and shapes, for instance, have shown great promise as catalysts with high selectivities and relative ease of recycling. Researchers have already demonstrated new selective catalysis with solution-dispersed or supported-metal nanocatalysts, in some cases applied to new types of reactions.

Correlating the excited state relaxation dynamics as measured by photoluminescence and transient absorption with the photocatalytic activity of Au@TiO2 core-shell nanostructures.

The spectroscopic and photocatalytic properties of a series of Au@TiO(2) core-shell nanostructures are characterized. The crystallinity of the TiO(2) shells was varied by changing the etching and calcination conditions. Measurements of the photoluminescence, transient absorption, and H(2) production rate permit us to look for correlations between the spectroscopic and catalytic behaviors.

Preparation of nanoporous carbons via a grafting method for the application to electrochemical double layer capacitors.

Nanoporous carbon materials with a controlled pore size and surface area were prepared using grafting method. The use of 3-mercaptopropyltrimethoxysilane (MPTMS) as a grafting material played an important role in producing a porous structure by linking the silica to the polymer, with the subsequent formation of a silica-polymer composite. Importantly, the use of an organic solvent, compared to an aqueous solvent, has a positive effect in forming uniform and well-developed carbon structures, due to the high degree of dispersion with well-mixing of the carbon and silica precursors.