Synthesis,Crystal and Band Structures,and Optical Properties of Mercury Pnictide Halide Hg_(19)As_(10)Br_(18)

A mercury pnictide halide semiconductor Hg19As10Br18（1） has been prepared by the solid-state reaction and structurally characterized by single-crystal X-ray diffraction analysis.Compound 1 crystallizes in triclinic,space group P with a = 11.262（4）,b = 11.352（4）,c = 12.309（5） ,α = 105.724（2）,β = 105.788（4）,γ = 109.0780（10）° and V = 1314.3（8） 3.The structure of 1 is composed of parallel perovskite-like layers bridged by the linearly coordinated Br atoms to form a three-dimensional framework.The optical properties were investigated in terms of the diffuse reflectance spectrum.The electronic band structure along with density of states（DOS） calculated by DFT method indicates that compound 1 is a semiconductor with an indirect band gap,and that the optical absorption is mainly originated from the charge transitions from Br-4p and As-4p to the Hg-6s states.

Nitrogen-doped graphene nanosheets as high efficient catalysts for oxygen reduction reaction

It is of great significance in exploring alternative catalysts to platinum (Pt)-based materials for oxygen reduction reaction (ORR),because this reaction is invariably involved in various fuel cells and metal-air batteries.We herein reported the nitrogen doped graphene nanosheets (NGNSs) with pore volume of as high as 3.42 m 3 /g and investigated their potential application as ORR catalysts,it was demonstrated the NGNSs featured high activity,improved kinetics and excellent long-term stability for ORR.The NGNSs were successfully used as cathode catalysts of microbial fuel cells (MFCs) and performed even better than the commercial Pt/C (Pt 10%) catalysts at the maximum power output.

Enhancement of Fenton oxidation for removing organic matter from hypersaline solution by accelerating ferric system with hydroxylamine hydrochloride and benzoquinone

Fenton oxidation is generally inhibited in the presence of a high concentration of chloride ions.This study investigated the feasibility of using benzoquinone（BQ） and hydroxylamine hydrochloride（HA） as Fenton enhancers for the removal of glycerin from saline water under ambient temperature by accelerating the ferric system.It was found that organics removal was not obviously affected by chloride ions of low concentration（less than 0.1 mol/L）,while the mineralization rate was strongly inhibited in the presence of a large amount of chloride ions.In addition,ferric hydrolysis-precipitation was significantly alleviated in the presence of HA and BQ,and HA was more effective in reducing ferric ions into ferrous ions than HA,while the H_2O_2 decomposition rate was higher in the BQ-Fenton system.Electron spin resonance analysis revealed that OH production was reduced in high salinity conditions,while it was enhanced after the addition of HA and BQ（especially HA）.This study provided a possible solution to control and alleviate the inhibitory effect of chloride ions on the Fenton process for organics removal.

Metal chelate affinity to immobilize horseradish peroxidase on functionalized agarose/CNTs composites for the detection of catechol

The paper reports a novel amperometric biosensor for catechol based on immobilization of a highly sensitive horseradish peroxidase by affinity interactions on metal chelate-functionalized agarose/carbon nanotubes composites. Metal chelate affinity takes advantage of the affinity of Ni2+ ions to bind strongly and reversibly to histidine or cysteine tails found on the surface of the horseradish peroxidase. Thus, enzymes with such residues in their molecules can be easily attached to functionalized agarose/carbon nanotubes composites support containing a nickel chelate. Linear sweep voltammograms and amperometry are used to study the proposed electrochemical biosensor. Catechol is determined by direct reduction of biocatalytically liberated quinone species at -0.05 V (vs. SCE). The effect of pH, applied electrode potential and the concentration of H2O2 on the sensitivity of the biosensor has been investigated. The performance of the proposed biosensor is tested using four different phenolic compounds, showing very high sensitivity, in particular, the linearity of catechol is observed from 2.0 × 10-8 to 1.05 × 10-5 M with a detection limit of 5.0 × 10-9 M.

Syntheses, Supramolecular Structures and Antibacterial Activities of Five Helical Transition Complexes with 5-Chloro-1-phenyl-1 H-pyrazole-3,4-dicarboxylic Acid

五新转变金属建筑群[ Cu ( HL ) 2 ( H2O ) 2 ]( 1 )，[ Cu ( HL ) 2 ( phen )]( 2 )，[ Cu ( HL ) 2 ( H2O )] 2 ( 4,4-bipy )( 3 )，[ Zn ( HL ) 2 ( H2O ) 2 ]楴汣獥?????????潆牵敩????????猠数瑣潲敭牴？？