One-Step Synthesis of Highly Active NiFe Electrocatalysts for the Oxygen Evolution Reaction.

Electrochemical water splitting is a key technology for the conversion of renewable energy into chemical resources such as hydrogen. However, the oxygen evolution reaction (OER), a half-reaction of water splitting, is so slow that various effective catalysts for the OER have been explored. In this study, we demonstrate a simple and direct process for the synthesis of OER-active NiFe catalysts over electrodes.

Precursor accumulation on nanocarbons for the synthesis of LaCoO nanoparticles as electrocatalysts for oxygen evolution reaction.

Oxygen evolution reaction (OER) is a key step in energy storage devices. Lanthanum cobaltite (LaCoO) perovskite is an active catalyst for OER in alkaline solutions, and it is expected to be a low-cost alternative to the state-of-the-art catalysts (IrO and RuO) because transition metals are abundant and inexpensive. For efficient catalysis with LaCoO, nanosized LaCoO with a high surface area is desirable for increasing the number of catalytically active sites.

Facile synthesis of nanostructured perovskites by precursor accumulation on nanocarbons.

Perovskite-type oxides have impacted various research fields, including materials and energy science. Despite their vast potential in various applications, general and simple synthesis methods for nano-perovskites remain limited. Herein, various nano-perovskites were synthesized by a facile approach involving the use of nanocarbons.

Upgrading of Ethanol to 1,1-Diethoxyethane by Proton-Exchange Membrane Electrolysis.

The direct acetalization of ethanol is a significant challenge for upgrading bioethanol to value-added chemicals. In this study, 1,1-diethoxyethane (DEE) is selectively synthesized by the electrolysis of ethanol using a proton-exchange membrane (PEM) reactor. In the PEM reactor, a Pt/C catalyst promoted the electro-oxidation of ethanol to acetaldehyde.

Catalytic Mechanism of Liquid-Metal Indium for Direct Dehydrogenative Conversion of Methane to Higher Hydrocarbons.

There is a great interest in direct conversion of methane to valuable chemicals. Recently, we reported that silica-supported liquid-metal indium catalysts (In/SiO) were effective for direct dehydrogenative conversion of methane to higher hydrocarbons. However, the catalytic mechanism of liquid-metal indium has not been clear.

The Active Center of Co-N-C Electrocatalysts for the Selective Reduction of CO to CO Using a Nafion-H Electrolyte in the Gas Phase.

To contribute a solution for the global warming problem, the selective electrochemical reduction of CO to CO was studied in the gas phase using a [CO(g), Co-N-C cathode | Nafion-H | Pt/C anode, H/water] system without using carbonate solutions. The Co-N-C electrocatalysts were synthesized by partial pyrolysis of precursors in inert gas, which were prepared from various N-bidentate ligands, Co(NO), and Ketjenblack (KB). The most active electrocatalyst was Co-(4,4'-dimethyl-2,2'-bipyridine)/KB pyrolyzed at 673 K, denoted Co-4,4'-dmbpy/KB(673K).

Coating of Silica Nanolayers on Carbon Nanofibers via the Precursor Accumulation Method.

Surface modification of nanocarbons, for example, by coating with oxide nanolayers, is a research topic of significant interest because of the drastic changes in the physicochemical properties of the modified nanocarbons. One simple method of creating these oxide nanolayer coatings on nanocarbons is the precursor accumulation (PA) technique, which entails the following: (1) a precursor solution is added dropwise onto nanocarbon powder; (2) the solvent is dried, leaving the accumulated precursor on the nanocarbon surface; and (3) hydrolysis or decomposition of the precursor in air leads to the formation of oxide nanolayers on the nanocarbons. In this study, tetraethoxysilane (TEOS) was used as a precursor for coating silica nanolayers onto carbon nanofibers (CNFs).

Theoretical Study on the C-H Activation of Methane by Liquid Metal Indium: Catalytic Activity of Small Indium Clusters.

The mechanism of C-H activation of methane by liquid indium, which is the first step of the dehydrogenative conversion of methane to higher hydrocarbons, was investigated using density functional theory calculations. In the first-principle molecular dynamics trajectory at the experimental temperature (1200 K), low-coordinated indium atoms continuously appear on the disordered liquid surface. The C-H cleavage is endothermic on clean surfaces, while the low-coordinated indium atoms reduce the endothermicity significantly.

Controlling surface energy of glass substrates to prepare superhydrophobic and transparent films from silica nanoparticle suspensions.

We fabricated superhydrophobic and transparent silica nanoparticle (SNP) films on glass plates via spray-coating technique. When suspensions containing 1-propanol and hydrophobic SNPs were sprayed over glass plates that were modified with dodecyl groups, superhydrophobic and transparent SNP films were formed on the substrates. Surface energy of the glass plates had a significant role to obtain superhydrophobic and transparent SNP films.

Microcontact printing for patterning carbon nanotube/polymer composite films with electrical conductivity.

Patterned carbon nanotube (CNT)/acrylic resin composite films were prepared using microcontact printing (μCP). To prepare ink for μCP, CNTs were dispersed into propylene glycol monomethyl ether acetate (PGMEA) solution in which acrylic resin and a commercially available dispersant (Disperbyk-2001) dissolved. The resulting ink were spin-coated onto poly(dimethylsiloxane) (PDMS) stamps.

Simple method for preparing superhydrophobic paper: spray-deposited hydrophobic silica nanoparticle coatings exhibit high water-repellency and transparency.

Superhydrophobic and transparent coatings are deposited onto paper by spraying alcohol suspensions of SiO(2) nanoparticles. Superhydrophobicity depends on the aggregation states of nanoparticles, which are determined by the type of alcohol used in the suspensions. The superhydrophobicity of the paper is maintained after touching the paper with a bare finger.

Hard and glossy-colored films composed of micropatterned organic dots and electrodeposited honeycomb-shaped nickel walls.

This paper proposes a novel approach for the preparation of colored films with a metallic luster and high hardness. The colored organic films were patterned as microdots by photolithography, and then honeycomb-shaped Ni walls were electrodeposited between the micropatterning. The organic/inorganic composite films showed the hardest grade in a pencil hardness test and high durability in wear resistance tests because the honeycomb-shaped Ni walls protected the colored organic dots.

One-step electrophoretic deposition for the preparation of superhydrophobic silica particle/trimethylsiloxysilicate composite coatings.

SiO(2) particle/silicone resin (trimethylsiloxysilicate (TMSS)) composite coatings were prepared by electrophoretic deposition (EPD), and their wettability was examined. SiO(2) coatings prepared by EPD baths without TMSS were hydrophilic, while superhydrophobicity was observed for SiO(2)/TMSS composite coatings. IR spectra and EDS analyses revealed that not only SiO(2) particles but also TMSS electrophoretically moved toward a cathode; as a result, hydrophilic SiO(2) particles turned into superhydrophobic composite coatings by one-step EPD.

Facile fabrication of colored superhydrophobic coatings by spraying a pigment nanoparticle suspension.

Superhydrophobic coatings were prepared by spraying a pigment nanoparticle suspension. By changing the type of pigment nanoparticles, the colors of the coating could be controlled. The particle size of the pigments, which determines the surface structure of the coatings, played an important role in exhibiting superhydrophobicity.

Method for patterning various nanomaterials: electrochemical deposition of patterned Ni thin films and their utilization as a strippable mask.

We report an interesting approach for preparing micropatternings of nanomaterials, such as carbon nanotubes and TiO(2) nanoparticles. In the method, exfoliation of electrodeposited Ni thin films was the key process. After patterning indium thin oxide (ITO) plates with an insulating photoresist by conventional photolithography, Ni was electrodeposited on only the exposed ITO areas.

Nano-scale hydroxyapatite formation on silica fiber by using carbon nanofibers as templates.

Nano-scale hydroxyapatite particle network with uniform morphology and good crystallinity was fabricated on silica fiber by using carbon nanofibers as templates and with a methanol solution of Ca(NO3)2 x 4H2O-H3PO4. Field emission scanning electron microscopy, coupled with X-ray diffraction analysis confirmed the template effect and the existence of hydroxyapatite on silica fiber. It was clearly verified that by tuning the formation of carbon nanofibers on silica fiber, it was possible to control the properties of the resulting hydroxyapatite on silica fiber.

Electrophoretic deposition of phthalocyanine in organic solutions containing trifluoroacetic acid.

The absorption spectra of copper phthalocyanine (CuPc) 1,2-dichloroethane (DCE) solutions containing trifluoroacetic acid (TFAA) shows that the number of protons coordinating to the CuPc molecule was 1 and 2 for the first and second proton adducts, respectively, which indicates the formations of CuPcH(+) and CuPcH(2)(2+). This CuPc molecule may act as a catalyst to dissociate TFAA into trifluoroacetate anion (A(-)) and H(+) and form the proton adducts. The electrical conductivity dependence of the solution on CuPc concentration also supports this mechanism.

Synthesis of super hard Ni-B/diamond composite coatings by wet processes.

Ni-B/diamond composite coatings were prepared using electrophoretic deposition and electroless deposition methods, leading to extremely high hardness which is comparable to hard coatings prepared by dry processes.

Immobilization of nanofibrous metal oxides on microfibers: a macrostructured catalyst system functionalized with nanoscale fibrous metal oxides.

Nanofibrous LaMnO(3) can be immobilized on macrostructured materials using carbon nanofibers as templates; their application as macro-nanostructured catalysts are also presented.