A Review on Engineering Transition Metal Compound Catalysts to Accelerate the Redox Kinetics of Sulfur Cathodes for Lithium–Sulfur Batteries

Engineering transition metal compounds(TMCs)catalysts with excellent adsorption-catalytic ability has been one of the most effec-tive strategies to accelerate the redox kinetics of sulfur cathodes.Herein,this review focuses on engineering TMCs catalysts by cation doping/anion doping/dual doping,bimetallic/bi-anionic TMCs,and TMCs-based heterostructure composites.It is obvious that introducing cations/anions to TMCs or constructing heterostructure can boost adsorption-catalytic capacity by regulating the electronic structure including energy band,d/p-band center,electron filling,and valence state.Moreover,the elec-tronic structure of doped/dual-ionic TMCs are adjusted by inducing ions with different electronegativity,electron filling,and ion radius,resulting in electron redistribution,bonds reconstruction,induced vacancies due to the electronic interaction and changed crystal structure such as lat-tice spacing and lattice distortion.Different from the aforementioned two strategies,heterostructures are constructed by two types of TMCs with different Fermi energy levels,which causes built-in electric field and electrons transfer through the interface,and induces electron redistribution and arranged local atoms to regulate the electronic structure.Additionally,the lacking studies of the three strategies to comprehensively regulate electronic structure for improving catalytic performance are pointed out.It is believed that this review can guide the design of advanced TMCs catalysts for boosting redox of lithium sulfur batteries.

THE RELATIONSHIP BETWEEN THE STRUCTURAL TYPE OF ANIONIC GROUP AND SHG EFFECT IN BORON-OXYGEN COMPOUNDS

The relationship between the Structural type of anionic group and SHG effect in oxide compounds has been reviewed.

Separation of Phenolic Compounds and Organic Anions Using ODS Column Coated with Meso-octamethylcalix[4]pyrrole and Water as Eluent

Octadecylsilanized silica (ODS) was coated with meso-octamethylcalix[4]pyrrole to obtain a novel calix[4]pyrrole containing stationary phase for HPLC. Compared to ODS, the new stationary phase showed a relatively large retention and an improved separation for phenolic compounds and organic anions, using pure water as mobile phase. The results can be ascribed to the interaction between analytes and calix[4]pyrrole.

Synthesis of crystal-phase and color tunable mixed anion co-doped titanium oxides and their controllable photocatalytic activity

B and N mixed anions co-doped titania with various crystal phases such as anatase,brookite,and rutile were successfully synthesized by a hydrothermal synthesis followed by heat treatment in an ammonia gas atmosphere at 550-650℃(denoted as BN-Ana_x,BN-Bro_x,and BN-Rut_x,x is the treatment temperature).The colors of as-prepared BN-Ana,BN-Bro,and BN-Rut are red,yellow-green,and cyangreen,respectively.The color changing mechanism of titania was related to their various band gap structure and the existence of B-N bonding.The nitridation temperature exhibits effective color changing compared to that of nitridation time.The different phases of the mixed anion codoped titania possess different photocatalytic deNO_(x) activity.The BN-Ana and BN-Rut show poor photocatalytic deNO_(x) activity,while the BN-Bro shows excellent photocatalytic deNO_(x) activity,better than that of standard titania photocatalyst Degussa P25.The colorful titania with low-photocatalytic activity is heavy metal elements free,indicating their possible applications as nontoxic color pigments or novel cosmetic raw materials.

Ni-Co基纳米针簇无酶葡萄糖电化学传感器性能研究

对Ni-Co基前驱体材料分别进行氧化和硫化处理,制备了尖晶石结构的NiCo_(2)O_(4)和NiCo_(2)S_(4)纳米针簇,并将合成材料作为电催化剂修饰于氧化铟锡(ITO)导电玻璃表面以构建无酶葡萄糖电化学传感电极。通过电化学表征技术,研究Ni-Co基双金属化合物的阴离子种类对其电催化氧化葡萄糖的性能影响。结果表明,基于NiCo_(2)S_(4)的传感电极具有更高的电催化活性,更快的电子转移速率。NiCo_(2)O_(4)/ITO电极在0.1~0.7 mmol/L的线性范围内灵敏度为81.8μA/(mmol/L)·cm^(2),而NiCo2S4/ITO电极的线性范围为0.1~2.0 mmol/L,且灵敏度提升至166.8μA/(mmol/L)·cm^(2)。NiCo_(2)S_(4)/ITO电极选择性、稳定性和重现性良好,在血糖检测中具有较好的应用前景。

液相色谱-离子色谱联用体系同时测定环境基质中的6种硝基芳烃类化合物和3种阴离子

同时测定环境土壤和水基质中的硝基芳烃类化合物和阴离子对于选择合适的硝基芳烃类化合物降解方法和实现地表水水质监测具有重要意义。本文通过两个六通阀和一根富集柱将高效液相色谱和离子色谱连接,搭建了色谱联用体系。系统操作可分为4个阶段:(A)样品加载到定量环;(B)分离硝基芳烃类化合物和阴离子;(C)阴离子在AG20柱中富集;(D)高效液相色谱和离子色谱分别测定硝基芳烃类化合物和阴离子。通过将液相色谱柱直接连接电导率检测器,确定阴离子流出液相色谱柱的时间,优化六通阀的切换时间,保证方法的准确性。在最优条件下,阴离子的检出限为0.005~0.020 mg/L,硝基芳烃类化合物的检出限为0.043~0.150 mg/L。3组不同加标浓度样品的平均回收率为88.20%~105.38%,相对标准偏差为2.0%~11.5%。该方法被用于检测5份地表水样品和5份土壤样品,硝基芳烃类化合物均未检出,3种阴离子在地表水样品中的检出量为0.41~55.3 mg/L,在土壤样品中的检出量为0.56~30.2 mg/kg。经过方法学验证和实际样品检测,证明该色谱联用体系检测方法自动化程度高,操作简单,重复性好,准确度高,具有广泛的适用性和较高的灵敏度,适用于环境基质中硝基芳烃类有机物和亚硝酸根离子等阴离子含量的快速测定。

Preparation,Characterization and Application of ZnAlLa-Hydrotalcite-Like Compounds

The preparation of ZnAlLa-hydrotalcite-like compounds [ZnAlLa-HTLcs] wasstudied. ZnAlLa-HTLcs were synthesized by a method of variable pH with the raw materials ofZn(NO_3)_2, Al(NO_3)_3, La(NO_3)_3, and NaOH. The eS'ccts of some factors (i.e. pH values, the moleratio of Al^(3+) to La^(3+), temperature and the period of hydrothermal treatment) on thepreparation of HTLcs were discussed systematically. XRD, TG-DTA, FT-IR spectroscopy, and ICP wereperformed to characterize ZnAlLa-HTLcs samples, and the thermal stability of HTLcs was alsodiscussed. It was shown that unique ZnAlLa-HTLcs with high crystallinity can be prepared, under theconditions of pH = 5.5-6.5, n(Zn^(2+))/n(Al^(3+) + La^(3+))=2 and the atomic ratio of La^(3+) toAl^(3+) ranging from 0.07 to 2, hydrothermal treatment at 120 ℃ for 5 h. When the calcination ofthe HTLcs is performed at temperatures above 200 ℃, ZnO phase is detected with Al_2O_3 and La_2O_3spreading on its top. The complex metal oxides derived from ZnAlLa-HTLcs at 500 ℃ have highercatalytic activity and selectivity than those from ZnAl-HTLcs for the esterification of acetic acidwith n-butanol under the same reaction conditions.

Intercalation of multiply solvated hexafluorophospate anion into graphite electrode from mixtures of methyl acetate,ethyl methyl and ethylene carbonates

Graphite is a universal host material for ion intercalation. Li+-graphite intercalation compounds (GICs) have been successfully utilized as the anode material in commercial lithium-ion batteries.Similarly, anion-graphite intercalation compounds (AGICs) have been coming into their own in dual-ion batteries [1]. It is imperative to deepen an understanding of anion storage mechanisms in graphite electrode.

Effect of anions on preparation of ultrafine α-Al_2O_3 powder

Ultrafine alumina power was obtained by calcining the precursor at 1 200 ℃ for 2 h, which was prepared by homogeneous precipitation method using aluminium salts and urea as raw materials. The effects of anions on the morphology, particle size, surface area and configuration of the precursors were studied. The results show that the reactions of urea with aluminium nitrate and aluminium chloride result in agglomerates gels with bad filtering performance, the morphology is fibrillar. Aluminium sulphate-urea reactions result in the direct formation of amorphous powders with good filtering performance, of which morphology are regular spherical particles with larger granularity and smaller surface area. The reaction of mutual compound of aluminium sulphate and aluminium nitrate with molar ratio of 40:60 with urea can produce precursor with good filtering performance, spherical morphology, and uniform granularity distribution in the particle size range of 2-3 μm.

STUDIES ON THE PERMEABILITY OF P VC/EBBA OVERLAPPED ULTRATHIN COMPOSITE MEMBRANES MODIFIED BY PLASMA-POLYMERIZATION WITH FLUOROCARBON MONOMERS

The PVC/EBBA ultrathin composite membranes with thickness of about 100 nm were prepared by spreading the solution on water surface. The overlapped composite membrane showed a characteristic aggregation structure in which the polymer matrix exists as a three-dimensional spongy network and the liquid crystal domains werc observed. Tne surface modification for the overlapped membranes was carried out by means of plasma-polymerization with the monomers of fluorocarbon compounds. Both Arrhenius plots of permeability coefficients for oxygen ((?)_O_2) in the membrane samples before and after modification showed significant increase in the vicinity of the T_(KN) of EBBA.

Synthesis and Crystal Structure of an Ionic Compound [Fe(CN)_6(phCH_2NC_5H_5)3]·(H_2O)_4

A novel ionic compound [Fe（CN）6（phCH2NC5H5）3]·（H2O）4（Mr = 794.71） has been synthesized and its structure was characterized by IR, elemental analysis and X-my diffraction. The compound crystallizes in monoclinic, space group P21/c with a = 10.837（2）, b = 16.551（3）, c = 23.402（5） A, p = 97.531（4）°, V = 4161.0（15） A3, Z = 4, Dc = 1.269 g/cm^3, F（000） = 1668, p = 0.414 mm^-1, R = 0.0479 and wR = 0.1232. The building unit of the title compound consists of three （phCH2N＋C5H5） ions, one [Fe（CN）6]^3- anion and four water molecules. According to the structural analysis, UFe（CN）6]^3- are linked together by O-H…N and O-H…O hydrogen bonds, but UFe（CN）6]^3- and [ （phCH2N＋ C5H5）3] ions are bound by electrostatic force to form an ionic compound.

Synthesis and Crystal Structure of an Ionic Compound [Fe(CN)_6·(PhCH_2NC_9H_7)_4]·12H_2O

A novel ionic compound [Fe（CN）6·（PhCHeNC9H7）4]·12H2O（C70H80FeN10O12, Mr = 1309.29） has been synthesized and its structure was characterized by I-R, elemental analysis and X-ray diffraction. The compound crystaUizes in triclinic, space group P1, with a = 10.968（7）, b = 11.466（7）, c = 14.077（8）A, α= 87.014（7）, β= 78.124（7）, γ = 72.708（7）°, V = 1654.1（17）A3, Z = 1, Dc = 1.314 g·cm^-3, F（000） = 692, p = 0.298 mm^-1, the final R = 0.0519 and wR = 0.1355. The building unit of the title compound consists of four （PhCH2N＋C9H7） ions, one [Fe（CN）6]4- anion, and a dozen water molecules. According to the structural analysis, [Fe（CN）6]4- ions are linked together by O-H…O and O-H…N hydrogen bonds, while （PhCH2N＋C9HT） and [Fe（CN）6]4- ions interact with each other by electrostatic force to form an ionic compound.

SORPTION OF PHENOL AND P-NITROPHENOL ONTO A WEAKLY ANION EXCHANGER: XPS ANALYSIS AND MECHANISM

X-ray photoelectron spectroscopy(XPS)was adopted to elucidate sorption mechanism of phenol and p-nitrophenol onto a weakly anion exchanger D301.The distribution of specific forms of tertiary amino group on D301 was obtained and effect of free tertiary amino group on phenol sorption onto D301 was discussed. The result indicated that the percent of the protonated tertiary amine group on polymeric matrix was much lower than the reference compound N,N-dimethylbenzylamine at an identical pH value in solution due to the much lower activity degree of hydrogen ion in inner resin phase than in the external solution. Less free amino group on D301 results in less sorption capacity of phenol and p-nitrophenol in an acidic solution. Under the experimental conditions both phenol sorption onto D301 can be explained as solid extraction and the distribution coefficient varies linearly with the content of free amino group on D301.

阴-非离子型Gemini表面活性剂的合成研究进展

介绍了磺酸盐型、羧酸盐型和其他类型阴-非离子型Gemini表面活性剂的合成研究进展,简述了阴-非离子型Gemini表面活性剂与其他表面活性剂复配体系的性能特点及相关应用,并对阴-非离子型Gemini表面活性剂的发展趋势进行了展望。

混合阴离子型化合物Ba_(2)Gd(BO_(3))_(2)Cl:Ln的力致发光性能

力致发光材料具有将机械刺激转变为光子发射的独特性能,因而被广泛应用于结构健康诊断、信息防伪、生物工程和电子皮肤等力学传感领域。然而,已报道的力致发光材料种类有限,且对于力致发光相关的载流子跃迁过程理解不够深入,极大地限制了其开发和应用。针对上述问题,本工作开发了新型混合阴离子型力致发光材料Ba_(2)Gd(BO_(3))_(2)Cl:Ln(Ln=Eu,Tb,Dy,Sm,Nd),并探究了其光致发光性能与相关载流子跃迁过程。该研究通过X射线粉末衍射、扫描电子显微镜、多模式激发下的稳态和瞬态光谱技术研究了样品的结构形貌、光致发光与力致发光性能,提出了该材料可能的发光机制。研究结果表明,在280 nm光激发下,Ba_(2)Gd-(BO_(3))_(2)Cl:Eu的发射峰位于536,594,613,625,654,695,710 nm,第一个宽峰和其余窄峰分别对应于Eu^(2+)和Eu^(3+)的发射,即掺杂的Eu呈现混合价态。而在机械作用下,Ba_(2)Gd(BO_(3))_(2)Cl:Eu几乎只表现出Eu^(3+)的橙红光发射,这可能是由于机械作用优先激发基质中的价带电子所致。此外,Eu的光致发光和力致发光最佳掺杂浓度均为2%。在0.23~1.55 mJ的冲击能下,力致发光强度与冲击能量呈线性关系。通过改变掺杂镧系元素的种类,实现了力致发光从可见光区域到近红外区域的拓展。这项工作为解释混合价态材料的力致发光机制提供了思路,并在应力传感领域呈现出潜在的应用价值。

碳氟-碳氢表面活性剂混合水溶液在油面上铺展

本文研究RfCONH(CH2 ) 3N(C2 H5) 2 CH3I CnH2n + 1 COONa及RfCOONa CmH2m + 1 N(CH3) 3Br(Rf=F[CF(CF3)CF2 O]2 CF(CF3) ;n =7,9,11,13;m =8,10 ,12 )两类正、负离子碳氟 碳氢表面活性剂混合水溶液在油面上的铺展及对油面的密封性能。研究表明在碳氟表面活性剂中加入异电性碳氢表面活性剂可大大降低碳氟表面活性剂水溶液的铺展浓度 ,也可使一些因表面张力较高而不能铺展的碳氟表面活性剂水溶液在油面上铺展。在碳氟表面活性剂中加入异电性碳氢表面活性剂可提高水膜对油面的密封性。若在混合表面活性剂中加入黄原胶 。

NiMgAl三元类水滑石的制备研究

在Ni(NO3)2 Mg(NO3)2 Al(NO3)3 NaOH体系中,研究了共沉淀法制备NiMgAl三元类水滑石的合成规律。考察了pH值、Ni Mg Al比、沉淀生成温度及水热处理条件对合成NiMgAl HTLcs的影响,借助XRD、ICP、FT IR对合成样品进行表征。实验结果表明,合成NiMgAl HTLcs的适宜pH范围为5 5～7 0,Ni Mg=2 0～4 0,水热处理条件为100℃,7h。通过对合成物热行为研究表明,NiMgAl HTLcs结构开始破坏温度为300℃,经焙烧后可得Ni元素高度分散的复合氧化物。

环氧改性氟碳纳米复合船舶涂料的研制

通过环氧树脂对氟聚合物进行改性,分析了氟聚合物、环氧树脂、固化剂、助剂2,4,6-三(二甲基氨甲基)苯酚(DMP-30)、二月桂酸二丁基锡(DBTSL)等对改性氟碳涂料性能的影响,利用IR光谱研究了环氧改性氟树脂-聚氨酯体系中-NCO的反应.通过原位聚合方法引入纳米TiO2,提高了舰船涂料的力学性能和耐盐雾性能.由环氧改性氟树脂、N-3390固化剂、纳米二氧化钛组成的氟碳涂料具有良好的物理机械性能和耐盐雾性能,表面能较低,可用于舰船的防污防腐.

CuMgAl类水滑石的制备和表征

用盐-碱制备法合成了CuMgAl三元类水滑石化合物.探讨了原料配比、合成方式、水热处理温度和时间对合成过程的影响,筛选出合成HTLs的适宜条件,并对HTLcs结构的热稳定性进行初步研究.结果表明,制备HTLcs主要取决于pH值,同时由于Cu2+的姜-太勒效应,合成结构单一的CuMgAl类水滑石要求原料配比中n(Cu):n(Mg)不得超过1.0,CuMgAl-HTLcs热稳定性较差,300℃焙烧2h结构破坏,600℃开始烧结,在300～500℃之间,随焙烧温度提高所得复合氧化物比表面积增大,最高可达200m2/g.

含铜三元类水滑石化合物的合成及其性质

以Cu(NO3 ) 2 ,Zn(NO3 ) 2 和Al(NO3 ) 3 为原料 ,以NaOH为沉淀剂 ,利用共沉淀法合成了含铜三元类水滑石化合物CuZnAl HTLcs .从不同Cu/Zn/Al比的混合原料溶液的滴定曲线入手 ,详细探讨了溶液 pH值、原料加入方式、组分配比及水热处理条件对类水滑石合成的影响 ,利用XRD ,ICP及比表面积测定对合成物进行了表征 ,并以苯酚羟基化为探针反应评价了催化剂的催化性能 .结果表明 ,在体系pH =5 .0～ 6 .2 ,(Cu +Zn) /Al摩尔比 =2 .0 ,Cu/Zn摩尔比≤ 1.0及室温条件下共沉淀后 ,于 10 0℃水热处理 3h ,即可得到晶相单一和结晶度高的CuZnAl HTLcs.变化 pH法合成的样品的相对结晶度为10 0 %,低过饱和法为 76 .5 %,高过饱和法为 75 .9%.合成的CuZnAl HTLcs中Cu2 + 的含量均比原料液中Cu2 + 的含量有所增加 ,这可能是由于在 pH =5 8时Cu2 + 对Al(OH) 3 的同晶取代能力比Zn2 + 强 .随着CuZnAl HTLcs中Cu含量的增加 ,催化剂对苯酚羟化反应的催化活性逐渐增大 .