LaCl_3对沸石物化性质和脱氮除磷抗菌性能的影响

为研究稀土盐LaCl3改性对沸石物化性质和脱氮除磷抗菌性能的影响,对天然沸石、改性沸石(NaCl-焙烧改性,载Ag)和镧负载改性沸石进行脱氮除磷抗菌的应用试验,结果表明,镧负载改性沸石具备了同步脱氮除磷抗菌性能,其脱氮和抗菌能力分别为90.98%和96.21%,除磷能力提高到92.45%。通过扫描电镜(SEM)和能谱图分析(EDS)、红外光谱(IR)、X射线衍射分析(XRD)、比表面积与孔径分析、离子交换容量(CEC)、Zeta电位等表征手段对镧负载前后各沸石分析发现,镧负载改性沸石的表面覆盖了一层均匀的氧化镧颗粒,沸石表面的La含量和Zeta电位明显增加。负载镧后的改性沸石的孔结构、孔容积、比表面积、平均孔径和阳离子交换容量等较改性沸石都有一定的减少,但是与天然沸石相比还是有很大的提高,从而在保证改性沸石脱氮抗菌能力的基础上,除磷能力大幅度提高。     

ICP-AES法连续测定土壤样品中的铜、铅、锌、铁、锰

采用混酸溶解土壤样品,用ICP - AES法连续测定铜、铅、锌、铁、锰五种元素,对比了三种消解体系,优化了盐酸复溶体系,优化了仪器的使用条件,方法检出限为Cu 3.31 μg·g-1、Pb 8.95μg·g-1、Zn 4.22 μg·g-1、Fe 3.85μg·g-1、Mn4.15 μg·g-1.在加标回收实验中,相对标准偏差为2.81％ ～3.92％ (n=10),方法回收率为96.2％ ～ 104.0％.用于分析矿石样品,分析结果与推荐值相符,可用于地质实验室对大量矿石样品的检测.     

LiNi0.8Co0.2O2的制备与修饰

由LiOH·H2O、NiO、Co2O3高温固相合成LiNi0.8Co0.2O2,并对制得的样品进行表面修饰.对所得产物进行了X光电子能谱、扫描电镜和X射线衍射测试,用合成的材料组装成电池进行充放电容量测试.实验结果表明:应用此工艺制备的LiNi0.8Co0.2O2具有高的充放电比容量,分别为184.8mA·h·g-1和160.7mA·h·g-1.包覆后初次充放电比容量分别为168.7mA·h·g-1和157.6mA·h·g-1.容量有所下降,但循环性能提高,说明表面修饰可以有效地抑制正极材料与电解液之间的恶性相互作用,能改善材料的循环性能.     

盐酸介质-火焰原子吸收光谱法测定矿石中铜、铅、锌和银

试样经盐酸-硝酸-氢氟酸-高氯酸四酸溶解,盐酸复溶作介质,用火焰原子吸收光谱法连续测定矿石中铜、铅、锌和银四种元素。实验结果表明,四酸溶样效果最佳,相对标准偏差(n=5)Cu:0.92%~2.63%,Pb:1.12%~3.04%,Zn:0.80%~2.47%,Ag:1.15%~2.98%;加标回收率Cu:96.8%~104.0%,Pb:96.8%~101.8%,Zn:98.1%~103.3%,Ag:97.2%~102.2%;测定范围Cu的为1~500μg·g-1,Pb的为5~2 000μg·g-1,Zn为5~1 000μg·g-1,Ag为0.5~200μg·g-1。方法前处理简单、实用,同时连续测得多种元素,满足地矿实验室的日常检测。     

聚酯基硫脲树脂改性活性炭纤维布吸附金的性能

采用一种新型的聚酯基硫脲树脂对活性炭纤维布进行改性制备出一种新型的复合吸附材料(ACFC/PDTU-I),并研究了ACFC/PDTU-I的结构。结果表明,ACFC上负载了PDTU-I树脂;ACFC/PDTU-I的比表面积高于PDTU-I,达到158.7 m2.g-1。30℃下静态吸附实验结果表明,ACFC/PDTU-I对Au3+的吸附容量达到4.85 mmol.g-1,吸附速率常数k=0.00855 min-1;吸附数据符合Boyd液膜扩散方程,液膜扩散为吸附主控步骤;等温吸附遵循Langmuir模型,为单分子吸附;吸附热力学证明反应过程为吸热过程,ΔH=8.877 kJ.mol-1;经过5次吸附-洗脱循环后,ACFC/PDTU-I的吸附容量变化很小;在二元金属离子溶液中ACFC/PDTU-I的对Au3+的分离因子均在400以上,说明其对Au3+具有良好的吸附选择性。     

D155树脂对铒(Ⅲ)的吸附行为研究

用树脂吸附的方法系统地研究了树脂D155对铒(Ⅲ)的吸附行为,测定了不同介质pH、温度、吸附时间等因素对吸附的影响.测得该阳离子交换树脂在HAc-NaAc体系pH=5.7时吸附Er3 的性能最佳,其静态最大吸附量为280mg·g-1;测得其表观吸附速率常数k298=2.58×10-5s-1;测得吸附热力学参数分别为:△H=13.05kJ·mol-1,△S=50.52J·mol-1·K-1,△G=-2.00kJ·mol-1,该树脂对Er3 的表观吸附活化能Ea=10.42kJ·mol-1;树脂吸附铒(Ⅲ)符合Freundlich经验式.并对负载树脂解吸进行探讨.     

聚乙烯醇辅助制备SBA-15微球北大核心

SBA-15型介孔二氧化硅(Si O2)是一种重要的具有较大介孔孔径的介孔材料,其中球形SBA-15在色谱分离、药物载体等领域具有重要的应用前景.本文报道了一种以聚乙烯醇(PVA)为添加剂、基于经典正硅酸四乙酯(TEOS)/P123/HCl (aq.)的路径,实现了SBA-15微球的简便制备.所得SBA-15微球具有长程有序的二维六方介孔结构,其介孔孔径为8. 8 nm,比表面积634 m2·g-1和孔体积0. 66 cm3·g-1.本工作还初步考察了包括PVA和不同的合成步骤等对SBA-15微球制备的影响.本法为SBA-15微球的制备提供了一种新的路径.     

聚乙烯醇辅助制备SBA-15微球

SBA-15型介孔二氧化硅(Si O2)是一种重要的具有较大介孔孔径的介孔材料,其中球形SBA-15在色谱分离、药物载体等领域具有重要的应用前景.本文报道了一种以聚乙烯醇(PVA)为添加剂、基于经典正硅酸四乙酯(TEOS)/P123/HCl (aq.)的路径,实现了SBA-15微球的简便制备.所得SBA-15微球具有长程有序的二维六方介孔结构,其介孔孔径为8. 8 nm,比表面积634 m2·g-1和孔体积0. 66 cm3·g-1.本工作还初步考察了包括PVA和不同的合成步骤等对SBA-15微球制备的影响.本法为SBA-15微球的制备提供了一种新的路径.     

制备体系酸度对AlMSU介孔材料结构性能的影响

利用β沸石纳米簇和曲拉通TX-100分别作为骨架构筑前驱物和孔道导向剂,在酸性介质中通过(N°H+)Cl-S+组装机制合成了蠕虫状孔道排列的AIMSU介孔材料,并借助测试手段对其进行了系统表征.结果表明:制备体系盐酸浓度对AlMSU的结构性能、骨架组成及收率有着显著影响.介质酸浓度较低(<0.5 mol/L)时所得Al-MSU的物化性质较差,而且产物收率低(基于样品粉末质量);而体系酸浓度大于2.5 mol/L时将造成部分铝原子从骨架中析出,导致最终产物中铝元素含量显著降低.基于结构性能、骨架组成和样品收率等综合因素,体系酸浓度介于1.5～2.0mol/L时是合成AlMSU介孔材料的合适区间.     

HY沸石的脱铝改性及其对CO2/H2O的吸附性能

采用不同浓度的盐酸溶液对HY沸石进行脱铝改性,利用XRD、TGA等分析手段对所制备样品的物相、结构等进行表征分析,研究了样品对CO2/H2O的吸附性能.结果表明：采用浓度为0.5 mol/L的盐酸溶液对沸石HY进行脱铝改性后,材料仍然具有较完好的晶体结构,在保持较高CO2吸附能力的同时疏水性能得到明显改善.     

Surface and Texture Properties of Tb-Doped Ceria-Zirconia Solid Solution Prepared by Sol-Gel Method

The three-way catalysts （TWCs） promoters Ce0.6Zr0.4- x TbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x = 0.05 to x = 0.15 favors an increase of surface area from 66.8 to 80.4 m^2· g^-1 compared with the undoped sample Ce0 .6oZr0.40O2 65.1 m^2·g^- 1 after calcination at 650℃. Transmission electron microscopy （TEM） observation indicated that the doped samples have a higher thermal stability. The XRD and Raman spectra confirmed that the Ce0.6Zr0.4-xTbxO2-y cubic solid solution is formed. XPS analysis revealed that Ce and Tb mainly existed in the form of Ce^4＋ and Tb^3 ＋ , and Zr existed in the form of Zr^4＋ on the surface of the samples. The doped samples were homogenous in composition ; the introduction of Tb into the CeO2-ZrO2 promoters resuited in the formation of a solid solution, and the concentration of surface lattice oxygen was increased.     

Influence of pH on Morphology and Formation Mechanism of CeO2 Nanocrystalline

Nanoparticles of cerium oxide were prepared by common precipitation method using cerium nitrate solution and ammonia reagent. Cerium oxide particles with different morphologies were synthesized through adjusting pH values of the solution. TEM and BET results showed that spherical crystal was gained in acid solution, with the specific surface of 148. 1944 m2·g^-1. The cerium oxide appeared in the form of spherical and rod-like grains under neutral condition, and the specific surface changed to 114.7975 m^2·g^-1. Moreover, in alkaline solution, cerium oxide powders were exhibited in rod-like form with the specific surface of 106.2465 m^2·g^-1. Precipitation formation mechanism of different morphologies was also discussed, which followed decomposition precipitation mechanism and topology reaction mechanism in acid and alkaline solution, respectively.     

Effect of Preparation Method on Surface Area and Crystalline Form of CeO2-ZrO2 Solid Solution

TheCeO2 ZrO2 solidsolutionisacrucialcompo nentinthethree waycatalysts(TWCs)usedtocatalyzethesimultaneouspurificationofCO ,HCandNOxfromanautomobileexhaust [1～ 3] .Besidesafeasiblecatalyticactivity ,itshouldhavehighthermalstabilityandoxygenstoragecapacity(OSC) .InordertogainhighperformanceCeO2 ZrO2 solidsolution ,varioustechniqueshavebeendeveloped .ItwasshownthataneffectofpreparationmethodonthesurfaceareaandcrystallineformofCeO2 ZrO2 isveryobvious .Intheearliestwork ,theCeO2 ZrO…     

Preparation of High-Surface Area Nano-CeO2 by Template-Assisted Precipitation Method

The high-surface area nano-CeO2 was prepared by Ce（NO3）3 by precipitation method, with surfactant cetyhrimethyl ammonium bromide （CTAB） as templating agent. The effects of the precipitating agents, reaction temperature, ageing time, and calcination temperature on the surface area, as well as the pore structure and the mean crystallite size of nano-CeO2 were studied. It was found that the reaction of Ce（NO3）3 with NaOH in the presence of CTAB at 90℃ for 12 h yieldsed a cerium oxide/surfaetant mixture, which after calcination at 400℃ resulted in high-surface area nano-CeO2. The mean crystallite size of CeO2 was approximately 6 nm, surface area was in excess of 200 m^2· g ^- 1, pore size was approximately 9 nm, and the pore distribution was concentrative. Moreover, the surface area can still reach 147 m^2·g^- 1 after calcination at 700 ℃, which showed the good thermal stability of the CeO2. The number of oxygen vacancies in the structure of CeO2 corresponded with the surface area of CeO2, and the high surface area was propitious to the formalion of oxygen vacancies.     

烧结温度对锂离子电池负极材料Li4Ti5O12性能的影响

采用钛酸四丁酯为钛源、一水合氢氧化锂为锂源，利用水热法制备锂离子电池负极材料Li₄Ti₅O₁₂（LTO），研究了水热后不同烧结温度对LTO相组成、微观形貌及电化学性能的影响。结果表明:当煅烧温度分别为500、550、600、650、700℃时，烧结LTO均为尖晶石型；500、550、600℃烧结LTO的微观形貌为纳米片状结构，当温度升高到650℃时，LTO出现纳米棒状结构，随着温度继续升高，LTO在700℃时生成较厚的纳米片状结构；当烧结温度为650℃时，LTO的比表面积为94.5907 m2·g-1，气孔体积为0.9663 mL·g-1，此时Li₄Ti₅O₁₂的放电比容量达到最大值240 mAh·g-1；电流密度100 mA·g-1、循环260次条件下，LTO容量保持率达96.45%，电流密度为1和2 A·g-1、循环1000次条件下，LTO容量保持率达92.97%和77.21%。     

Preparation and Characterization of CeO2-ZrO2 Solid Solution Ultrafine Particles Using Reversed Microemulsion

The development of the TWCs (three-way cata-lysts) was dictated bythe need to si multaneously con-vert the three main pollutants inthe exhaust gases ,i .e .,hydrocarbons (HCs) ,COand NOxpresent in theautomotive exhaust to H2O, CO2and N2[1]. Highestconvers…     

Novel Salt-Assisted Combustion Synthesis of High Surface Area Ceria Nanopowders by An Ethylene Glycol-Nitrate Combustion Process

Ceria and ceria-based powders are candidate ma-terials for a wide range of applications ,for example ,solid electrolytes for solid oxide fuel cells (SOFC)[1],three way catalysts for the treatment of automotive ex-haust gases[2],petroleum-cracking catalyst[3],oxygensensors[4], chemical-mechanical polishing for micro-electronics[5],and UVfilter[6].In recent years , since high surface area ceriananoparticles show superior physical and chemicalproperties to bulk particles , much effort has been …     

Phase Structure and Electrochemical Properties of RE-Mg Based Composite Hydrogen Storage Alloys

Rareearth basedAB5 typealloy ,akindofhy drogenstoragealloyusedasnegativeelectrodemateri alsofthenickel/metalhydride (Ni/MH )secondarybattery ,haseasyinitialactivation ,longcyclelifeandlowcost ,butstillasmalldischargecapacity ,poorhigh ratedischargeability(HRD)andpoorpropertiesatlowtemperature[1,2 ] .Therefore ,howtoincreaseitsdischargecapacityandtoimproveotherelectrochemi calpropertiesismeaningfulbothintheoryandinpracticalapplication .Mg basedhydrogenstorageal loysareremarkablebecauseofitsr…     

固相反应条件对磷酸铁锂电化学性能的影响

以碳酸锂(Li₂CO₃)为锂源, 磷酸二氢铵(NH₄H₂PO₄)为磷源, 草酸亚铁(FeC₂O₄·2H₂O)为铁源, 柠檬酸(C₆H₈O₇·H₂O)为碳源, 采用固相反应法制备橄榄石晶型磷酸铁锂。利用X射线衍射仪, 扫描电子显微镜, 能谱仪, 比表面积分析仪和电化学测试等设备和方法对磷酸铁锂材料的物相组成、结构、形貌和电化学性能进行表征, 研究煅烧温度和保温时间对磷酸铁锂电化学性能的影响, 并通过添加碳对试样进行包覆改性。结果表明, 在煅烧温度为700℃, 保温时间为12 h条件下制备的磷酸铁锂正极材料的电化学性能良好, 碳包覆能有效改善电极材料的性能。包覆碳后的磷酸铁锂电极材料在0.2C充电电流密度下首次放电比容量可达319.2 mAh·g-1; 在1C充电电流密度下循环100次后, 放电比容量保持在168.1 mAh·g-1。