Ultra-small platinum nanoparticles segregated by nickle sites for efficient ORR and HER processes

In the electrochemical process,Pt nanoparticles(NPs)in Pt-based catalysts usually agglomerate due to Oswald ripening or lack of restraint,ultimately resulting in reduction of the active sites and catalytic efficiency.How to uniformly disperse and firmly fix Pt NPs on carbon matrix with suitable particle size for catalysis is still a big challenge.Herein,to prevent the agglomeration and shedding of Pt NPs,Ni species is introduced and are evenly dispersed in the surface of carbon matrix in the form of Ni-N-C active sites(Ni ZIF-NC).The Ni sites can be used to anchor Pt NPs,and then effectively limit the further growth and agglomeration of Pt NPs during the reaction process.Compared with commercial Pt/C catalyst,Pt@Ni ZIF-NC,with ultralow Pt loading(7 wt%)and ideal particle size(2.3 nm),not only increases the active center,but also promotes the catalysis kinetics,greatly improving the ORR and HER catalytic activity.Under acidic conditions,its half-wave potential(0.902 V)is superior to commercial Pt/C(0.861 V),and the mass activity(0.38 A per mg Pt)at 0.9 V is 4.7 times that of Pt/C(0.08 A per mg Pt).Besides,it also shows outstanding HER performance.At 20 and 30 mV,its mass activity is even 2 and 6 times that of Pt/C,respectively.Whether it is under ORR or HER conditions,it still shows excellent durability.These undoubtedly indicate the realization of dual-functional catalysts with low-Pt and high-efficiency properties.

Catalytic Effect of SCN^- on Electrodeposition of Zinc-Nickle Alloy

The electrodeposition of zinc nickle alloy was obtained on a copper cathode of 1×1cm 2. The deposited alloys are quantitatively analyzed by atomic absorption spectrometry. The morphology of the deposits was observed by means of scanning electron microscopy(SEM).We observed that the electrodeposition of zinc nickle alloy is an anomalous codeposition. The catalytic effects of SCN - on the electrochemical behavior of Ni deposition and hydrogen discharge are obvious. SEM analysis shows that the surface morphology of the coating appears to be more compact and homogeneous with the increase of SCN - concentration.

Impact of modified electrodes on boosting power density of microbial fuel cell for effective domestic wastewater treatment:A case study of Tehran

Utilizing microbial fuel cells( MFCs) is a promising technology for energy-efficient domestic wastewater treatment,but it still faces practical barriers such as low power generation. In this study,the LaMnO_3 perovskite-type oxide nanoparticles and nickel oxide/carbon nanotube/polyaniline( NCP) nanocomposite( the cathode and anode catalysts,respectively) have been prepared and used to enhance power density of MFC. The prepared La-based perovskite oxide catalysts were characterized by X-ray diffraction( XRD) and scanning electron microscopies( SEM). The electrocatalytic properties of the prepared catalysts were investigated through cyclic voltammetry( CV) and electrochemical impedance spectroscopy( EIS) and Tafel plot at ambient temperature. Results show the exchange current densities of LaMnO_3/carbon cloth cathode and NCP nanocomposite/carbon cloth anode were 1.68 and 7 times more compared to carbon cloth cathode,respectively. In comparison to the bare carbon cloth anode,the MFC with the modified electrodes shows 11 times more enhancement in power density output which according to electrochemical results,it can be due to the enhancement of the electron transfer capability. These cathodic and anodic catalysts were examined in batch and semicontinuous modes to provide conditions close to industrial conditions. This study suggests that utilizing these low cost catalysts has promising potential for wastewater treatment in MFC with high power generation and good COD removal efficiency.

Identification of the structure of Ni active sites for ethylene oligomerization on an amorphous silica-alumina supported nickel catalyst

The structure of Ni active sites supported on amorphous silica-alumina supports with different contents of Al_(2)O_(3)loadings in relation to their activities in ethylene oligomerization were investigated.Two kinds of Ni sites were detected by in situ FTIR-CO and H_(2)-TPR experiments,that are Ni^(2+)cations as grafted on weak acidic silanols and Ni^(2+)cations at ion-exchange positions.The ethylene oligomerization activities of these Ni/ASA catalysts were found an ascending tendency as the Al_(2)O_(3)loading decreased,which could be attributed to the enriched concentration of Ni^(2+)species on acidic silanols with a weaker interaction with the amorphous silica-alumina support.These Ni^(2+)species were more easily to be evolved into Ni^(+)species,which has been identified to be the active sites of ethylene oligomerization.Thus,it seems reasonable to conclude that Ni^(2+)species grafted on acidic silanols were the precursors of active sites.

Syntheses and Structures of Two New Schiff Base Metal Complexes

The reaction of N,N?-bis(2-hydroxyacetophenone)-1,2-propanediamine (α,α?-Me- Salpd) with transition metal cations including CuII or NiII in methanol results in two complexes [Cu(α,α?-Me-Salpd)] 1 and [Ni(α,α?-Me-Salpd)] 2. Their crystal structures were determined by X-ray diffraction analysis. Crystal data for 1: monoclinic, space group P21/n, a = 12.3752(6), b = 10.5061(5), c = 26.5617(2) ?, β = 103.342(1)o, C38H40N4O4Cu2, Mr = 743.82, Z = 4, V = 3360.2(3) ?3, Dc = 1.470 g/cm3, μ = 1.313 mm-1, F(000) = 1544, R = 0.0681 and wR = 0.1555 for 4523 observed reflections (I > 2σ(I)); and those for 2: monoclinic, space group P21/n, a = 10.4207(2), b =12.4627(2), c = 25.7322(1) ?, β = 99.909(1)o, C38H40N4O4Ni2, Mr = 734.16, Z = 4, V = 3291.99(8) ?3, Dc = 1.481 g/cm3, μ = 1.192 mm-1, F(000) = 1536, R = 0.0766 and wR = 0.1873 for 3433 observed reflections (I > 2σ(I)).

Hydrothermal Synthesis, Structure and Magnetic Property of a Novel Hexa-NiⅡ Substituted Polyoxometalate

A novel hexa-NiⅡ substituted trilacunary Keggin polyoxometalate [{Ni6（μ3- OH）3（en）3（H2O）6}（B-α-PW9O34）]-6H2O 1 （en = ethylenediamine） has been hydrothermally synthesized and characterized by IR spectra, elemental analysis, thermogravimetric analysis （TGA）, single-crystal X-ray diffraction and magnetic property. Compound 1 crystallizes in the hexagonal space R3c with a = 20.4124（5）, c = 21.4427（4）A, γ = 120.000°, V = 7737.5（3）A3, Z = 6, GOF = 1.083, R （wR） = 0.0317 （0.0610）. Single-crystal X-ray diffraction indicates that 1 contains a hexa-Nin substituted trivacant Keggin [{Ni6（μ3-OH）3（en）3（H2O）6}（B-α-PW9O34）] unit. The magnetic study shows the presence of ferromagnetic coupling interactions within hexa-Nin clusters with J1 = 0.69 cm-1 and J2 = 0.92 cm^-1 for 1.

Syntheses and Crystal Structures of Two New Nickel(Ⅱ) Complexes with Salicylidene-2-ethanolamine

Two new Schiff base complexes of nickle（Ⅱ） [C18H20NiN2O4]·1.5H2O（1） and [C18H20N2NiO4]·H2O（2） were synthesized and characterized by elemental analysis,IR,UV-Vis and X-ray crystal structure analysis.Both 1 and 2 crystallize in the orthorhombic system.Crystal 1：space group Pbcn with a = 12.8591（19）,b = 14.779（2）,c = 19.749（3） ,V = 3753.3（10） 3,C18H23N2NiO5.5,Mr = 414.07,Z = 8,Dc = 1.445 g/cm3,μ = 1.067 mm-1,F（000） = 1712,S = 1.037,the final R = 0.0741 and wR = 0.2101 for 4353 observed reflections（I 〉 2σ（I）） and R = 0.1157 and wR = 0.2380 for all data.Crystal 2：space group P21 with a = 9.4673（17）,b = 11.559（2）,c = 16.347（3） ,V = 1788.9（6） 3,C18H22N2NiO5,Mr = 405.07,Z = 4,Dc = 1.497 g/cm3,μ = 1.116 mm-1,F（000） = 840,S = 1.085,the final R = 0.0330 and wR = 0.0869 for 3151 observed reflections（I 〉 2σ（I）） and R = 0.0362 and wR = 0.0887 for all data.Each Ni atom of 1 and 2 is six-coordinated with two nitrogen atoms and four oxygen atoms from two salicylidene-2-ethanolamine ligands yielding a distorted octahedral geometry.Dimer structure is observed in the packing diagram of 1.The thermal stability of complex 2 is also studied.

Preparation of Electrode of Copper-Nickel Composite Material and Its Capacitance Performance

Nickel oxide/copper oxide composites are prepared. Then the composites were transferred into autoclave and thermal sinter under different temperature and different time. As-prepared composites were analyzed by XRD, and it was concluded that with the increase of hydrothermal time, content of NiO and Ni0.75Cu0.25O increases, but particles become smaller;it would improve the electrochemical activity. By SEM images directed lower crystallinity of composites, deeper porosity and rougher surface would have better electrochemical activity. The electrochemical performance was investigated by cyclic voltametry, AC impedance and galvanostatic charge-discharge. All results show that under the condition of 150°C 30 h, the electrochemical performance is the best. The specific capacitance was 225.67 F·g-1 at the charge-discharge current of 1 A·g-1.

德国Nickl & Partner建筑设计股份有限公司 治愈式建筑

德国可持续建筑委员会成员(DGNB)掌握LEED和DGNB认证咨询中国北京分公司联络方式:北京市朝阳区三里屯SOHO A座709电话:010-85900338电子邮箱:mail@nickl-partner.cn网址:www.nickl-partner.com深圳第二儿童医院Shenzhen No.2 Children Hospital(国内合作方:筑博设计股份有限公司)

松材线虫的伴生微生物及其致病性研究概述

松材线虫(Bursaphelenchus xylophilus Nickle)是全球首要检疫性有害生物,在松材线虫的生长、繁殖、侵染和致病过程中,有多种生物因子参与其中,形成复杂的微生态系统,特别是松材线虫与其体表携带微生物形成了密切的伴生关系。本文综述了松材线虫伴生微生物种类的多样性,并探讨了松材线虫与其伴生微生物的相互关系及其致病性。伴生细菌以松材线虫为载体(附着于松材线虫体表)一同侵入松树寄主,松材线虫的存在有利于伴生细菌的繁殖和产毒,反过来,伴生细菌也可为松材线虫的生长发育、扩散、繁殖提供某些营养和有利的环境条件,促进其生长和繁殖,并有助于松材线虫降解松萜类物质,从而提高了松材线虫的适应性和致病性;伴生真菌能为松材线虫提供食物,维持松材线虫种群繁衍,促进扩散型松材线虫种群数量增加,提高松材线虫侵染、扩散机率。文中还结合伴生细菌在松材线虫病生物防治中的应用,提出了今后研究的方向。

Phosphorus-doped NiS_(2)electrocatalyst with a hybrid structure for hydrogen evolution

In this article,P-NiS_(2)/Ni_(x)P electrocatalysts were synthesized by dealloying the Ni-Al precursor followed by phosphosulfide treatment.We found that the hybrid structure of P-NiS_(2)/Ni_(x)P provides rich active sites for the surface hydrogen evolution reaction (HER),and the doping of P enhances the electronic conductivity of electrodes.In particular,the obtained electrode shows a low overpotential of 196 mV at 10 mA cm^(-2)and a small Tafel slope of only 110 mV dec^(-1)in the HER.Meanwhile,longterm constant current electrolysis test experiments indicate that P-NiS_(2)/Ni_(x)P has good service stability.This research will help to open a new window on the design and fabrication of HER electrocatalysts.

微创注射技术防治松材线虫病效果探析

松材线虫病[Bursaphelenchus xylophilus(Seiner&Buhere)Nickle]严重威胁着松林资源和生态安全。打孔注药是松材线虫病防控的重要方法之一。微创注射对树木损伤小,不受注射时间影响,相比传统打孔注药防治方法有着突出的优势。本试验通过对5个微创注射区域和对照区域的跟踪观察,2年内在注射区域观察到13株死树,死树率为0.21%,死树取样均未检出松材线虫;对照区域观察到121株死树,死树率为2.3%,死树取样松材线虫检出率59.5%,说明该措施对松材线虫病有良好的防治效果。

An Algorithm to Analyze Electron Backscatter Diffraction Data for Grain Reconstruction:from Methodology to Application

An algorithm for grain reconstruction based on electron backscatter diffraction data was proposed in this paper. This algorithm can well record the original data arrangement when an external file for the reconstructed grain（s） was exported for further post-processing. Assisted by an in-house MATLAB program, grain reconstruction, lattice rotations, orientation spreads, and slip system analysis can be performed. The validity of this algorithm has been successfully tested by polycrystalline Ni before and after channel die compression.