Intermetallic Pt2Si：magnetron-sputtering preparation and electrocatalysis toward ethanol oxidation

Although most transition metals have been tested as the promoter to Pt for electrocatalysis toward fuel cell reactions,semi-conductor elements,such as Si,have hitherto not been examined.Here we report a simple synthesis of intermetallic Pt2Si electrode using magnetron sputtering and the electrocatalysis toward ethanol oxidation reaction（EOR）.In comparison to Pt,the intermetallic Pt2Si surface turns out to be much more active in catalyzing the EOR：the onset potential shifts negatively by 150 mV,and the current density at 0.6 V increases by a magnitude of one order.Such an enormous enhancement in EOR catalysis is ascribed to the promotion effects of Si,which can not only provide active surface oxygenated species to accelerate the removal of COads,but also strongly alter the electronic property of Pt,as clearly indicated by the core-level shift in XPS spectrum.     

Manipulation of Organic Afterglow by Thermodynamic and Kinetic Control

The fabrication of room-temperature organic phosphorescence and afterglow materials, as well as the transformation of their photophysical properties, has emerged as an important topic in the research field of luminescent materials. Here, we report the establishment of energy landscapes in dopant-matrix organic afterglow systems where the aggregation states of luminescent dopants can be controlled by doping concentrations in the matrices and the methods of preparing the materials. Through manipulation by thermodynamic and kinetic control, dopant-matrix afterglow materials with different aggregation states and diverse afterglow properties can be obtained. The conversion from metastable aggregation state to thermodynamic stable aggregation state of the dopant-matrix afterglow materials to leads to the emergence of intriguing afterglow transformation behavior triggered by thermal and solvent annealing. The thermodynamically unfavorable reversible afterglow transformation process can also be achieved by coupling the dopant-matrix afterglow system to mechanical forces.     

New achievements from CE-3 mission

正The Chang'E-3(CE-3)mission began with a smooth countdown and flawless launch on the Long March 3B rocket from the Xichang satellite launch center at 01:30 CST on December 2,2013.It landed on the northeastern Imbrium basin(340.49°E,44.12°N)at 21:11 CST on December 14,2013,and the Yutu rover was deployed from the lander the next morning at 04:35.The lander was equipped with a number of remote-sensing     

Synthesis and Characterization of Side Group-Modified Tetradentate Cyclotriphosphazene Derivatives

Abstract

A series of novel side group-modified cyclotriphosphazene derivatives were synthesized by the reaction of hexachlorocyclotriphosphazene [N₃P₃Cl₆] with 2,2′-diphenol and the potassium salt of 4-hydroxybenzaldehyde, and subsequent reduction of aldehyde groups to alcohol groups by the use of sodium borohydride. The bromination reaction was carried out with PBr₃ to give N₃P₃(O₂C₁₂H₈) (p-BrCH₂-C₆H₄-O-)₄. This compound was employed in reactions with macrocyclic polyamides, imidazole, or morpholine to produce title compounds. The target compounds were characterized by ¹H NMR, ³¹P NMR, ¹³C NMR, and electrospray ionization mass spectrometry.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Preparation of polyaniline grafted multiwalled carbon nanotubes and conductive application in polyetherimide

A methodology for improving antistatic property of polyetherimide (PEI) composite using polyaniline (PANI) grafted multi‐walled carbon nanotubes (MWNTs) as conductive medium was proposed. First, the MWNTs grafted with PANI (PANI‐g‐MWNTs) were prepared by in‐situ polymerization in an emulsion system. Subsequently, PANI‐g‐MWNTs were blended with PEI using N‐methyl‐2‐pyrrolidone as solvent. After removing the solvent, the PEI/PANI‐g‐MWNT composite was prepared. As assisted conductive medium, the grafted PANI molecular chains on MWNT surface were dispersed in the PEI matrix to decrease the percolation value of the antistatic composites. The structure and morphology of PANI‐g‐MWNTs were characterized by Fourier transform infrared spectroscopy, transmission electron microscope, thermogravimetric analysis, and X‐ray powder diffraction, respectively. The dispersion of PANI‐g‐MWNTs in PEI matrix was studied by scanning electron microscope. The electrical performance was characterized by highly resistant meter. The volume resistivity of the conductivity percolation threshold was 1.781 × 10^?8 S/cm when the loading of PANI‐g‐MWNTs was 1.0 wt%. The conductivity of PANI‐g‐MWNTs/PEI composites was found to be higher than that of pristine MWNTs/PEI composite. Copyright © 2012 John Wiley & Sons, Ltd.     

CuI‐Catalyzed Multicomponent Synthesis of Aminoindolizines from Aldehydes,Amines, and Alkynes under Solvent‐Free Conditions

A direct and efficient approach to 1‐aminoindolizines through three‐component one‐pot reaction of heteroaryl aldehydes, secondary amines and terminal alkynes catalyzed by CuI under solvent‐free conditions has been developed. This methodology provides a rapid access to substituted aminoindolizines with good yields (up to 97%).     

Copper(II)‐Catalyzed Tandem Synthesis of Substituted 3‐Methyleneisoindolin‐1‐ones

An efficient strategy for the synthesis of a variety of 3‐methyleneisoindolin‐1‐ones has been developed. The reaction proceeded from coupling of 2‐iodobenzamides (or 2‐bromobenzamides) and terminal alkynes via Cu(OAc)₂·H₂O/2,2′‐biimidazole catalyzed in DMF at 60°C and subsequent additive cyclization produced substituted 3‐methyleneisoindolin‐1‐ones in good to excellent yields.