均匀共沉淀-水热法制备纤维状羟基磷酸钙/壳聚糖复合粉体

以尿素沉淀剂，运用溶液均匀共沉淀法制得纤维状羟基磷灰石(HAP)和无定形颗粒状守壳聚糖(CS)的复合粉体，通过水势处理调整纤维状HAP晶粒尺寸的大小，对粉体进行了XRD、TEM、IR及化学组成(Ca／P)表征。均匀一水热共沉淀过程中，pH值对粉体Ca／P、XRD、TEM、IR有很大影响。     

共沉淀法制备掺钕钇铝石榴石透明激光陶瓷的研究

掺钕钇铝石榴石(Nd∶YAG)多晶透明陶瓷具有良好的化学稳定性、光学性能和耐高温性能,是一种很有前途的激光工作物质。以Al(NO3).9H2O,Y2O3,Nd2O3和NH4HCO3为原料,(NH4)2SO4为静电稳定剂,正硅酸乙酯为添加剂,采用共沉淀法和反滴定方式于1100℃合成出分散均匀、团聚程度轻、YAG立方晶相的Nd∶YAG纳米前驱体粉末,经1700℃真空烧结5 h制备出Nd∶YAG透明陶瓷材料。采用TG-DTA,XRD,TEM,FT-PL和FEG-ESEM等测试手段对Nd∶YAG陶瓷材料进行了表征。研究结果表明:前驱体粉末在800℃时为无定型态,当温度达到890℃时析出大量的YAlO3(YAP)和少量的Y3Al5O12(YAG)晶体,当温度达到1012℃时就全部转化为YAG立方晶相;前驱体纳米粉末中存在团聚。Nd∶YAG陶瓷材料的激光工作波长为1.065μm,和相同组分的单晶相比存在轻微的红移现象;随着透射光波长的增加,透光率逐渐增加,在可见光区透光率约为45%,在近红外光区透光率约为58%。     

Synthesis,textural and magnetic properties of doped and undoped CuO nanoparticles

We have fabricated undoped CuO, Co_0.1Ni_0.07Zn_0.04Cu_0.79O and Co_0.08Ni_0.07Zn_0.04Mg_0.03Cu_0.78O nanoparticles through thermal decomposition of their respective inorganic copper creatinate hydrazinate and mixed metal doped copper creatinate hydrazinate precursors which were prepared by the co-precipitation method and characterized through EDS, ICP-AES, IR, and TG-DTA analysis. Techniques such as EDS, ICP-AES, FT-IR, XRD, XPS, TEM, SEM, BET, and VSM analysis were employed to characterize the composition, structural phase, chemical state, morphological, textural, and magnetic properties of the nanoparticles.     

尺寸可控的固相萃取吸附剂Ni/Al LDH的制备

采用非稳态共沉淀方法制备了无定形的Ni/Al LDH纳米粒子,水热处理过程促进了无定形沉淀的结晶,从而得到稳定的六边片状Ni/Al LDH纳米粒子胶体分散体系。通过调整胶溶温度和胶溶时间控制Ni/Al LDH纳米粒子的形貌和尺寸,对比不同胶溶温度和胶溶时间下得到的样品,得出制备Ni/Al LDH纳米粒子的最佳条件为胶溶温度130℃,胶溶时间24 h。由于Ni/Al LDH纳米粒子独特的带电及结构性质,具有较好的吸附性能,可将其制作成固相萃取柱,实现纳米材料与样品前处理技术的有机结合,优化样品前处理技术。     

共沉淀法制备暖白光LED用Na2TiF6:Mn4+红色荧光粉及其发光性能研究

采用简便的共沉淀法制备了不同Mn⁴⁺ 掺杂摩尔分数的Na₂TiF₆:Mn⁴⁺ 红色荧光粉。通过X射线衍射仪、扫描电子显微镜、红外光谱仪、荧光光谱仪对荧光粉的结构、形貌、傅立叶红外光谱、激发和发射光谱及荧光寿命曲线进行了表征。结果表明,Mn⁴⁺的掺杂没有改变Na₂TiF₆的晶格结构,样品具有六方结构。Mn⁴⁺最佳掺杂摩尔分数为4.77%,量子效率为74%。在460 nm激发下,最强窄带发射峰位于628 nm处(²E_g-⁴A₂),色坐标为(0.681,0.317)。²E_g能级的荧光寿命曲线遵循双指数衰减,其荧光寿命值为3.148 ms。     

海刺猬状微纳结构钴镍化合物的合成与表征(英文)

采用均相沉淀法,以Co(NO_3)_2·6H_2O和Ni(NO_3)_2·6H_2O为原料,尿素作为沉淀剂,成功制备出了新型海刺猬状微/纳复合结构。通过调节反应温度,反应物浓度和物质的量的比,所获得的前驱体呈放射状纳米线构成的海刺猬结构。随后分别在氧气氛和氢气氛下对制备出的前驱体进行热处理,利用FE-SEM、TEM、XRD以及VSM等测试手段对制备出的微/纳复合结构前驱体及热处理产物进行了形貌表征、物相分析以及磁学性能表征。在氧气氛条件下处理得到的产物具有良好的亚铁磁性,并且很好地保持了前驱体的结构与形貌。结合热处理产物的分析,对该海刺猬微纳结构前驱体提出了一种可能的形成过程和机理。另外,在氢气还原条件下处理得到的产物为多孔微纳米球状结构,呈现出更为优异的亚铁磁性。     

不同反应物和工艺条件对CeO2/ZrO2复合纳米粉末性能的影响

分别采用ZrOCl2·8H2O、CeCl3·7H2O和ZrOCl2·8H2O、CeO2、HCl两类不同反应物,利用共沉淀法制备了氧化铈摩尔含量为12%的氧化铈/氧化锆复合纳米粉末.分析了实验过程中沉淀物未经醇洗和经过醇洗、常规干燥及微波干燥等不同工艺条件对所得复合粉料性能的影响.通过透射电镜(TEM)对粉末形貌及粒径观察和测定,以及X射线衍射法(XRD)对粉末的物相分析,表明以ZrOCl2·8H2O和CeCl3·7H2O为反应物所得凝胶,经过醇洗及微波干燥的方法可以得到21 nm左右且均匀性和分散性好的球形颗粒.     

高浓度吡虫啉农药废水催化湿式氧化催化剂

目的研究Cu／Ce复合金属氧化物对废水催化氧化程度的影响。方法采用湿式氧化法在2L反应釜中处理吡虫啉农药废水。结果Cu／Ce复合氧化物催化剂对吡虫啉农药废水具有较高的催化活性。结论优化催化剂的设计和制备方法，不但可以提高COD的去除率，而且可有效的降低Cu^2＋和Ce^4＋的溶出量，使该类催化剂具有广阔的使用前景。     

Synthesis and LPG sensing properties of nano-sized cadmium oxide

This paper reports the synthesis and liquid petroleum gas (LPG) sensing properties of nano-sized cadmium oxide (CdO). The nano-sized CdO powder was successfully synthesized by using a chemical co-precipitation method using cadmium acetate and the ammonium hydroxide, as starting materials and water as a carrier. The resulting nano-sized powder was characterized by X-ray diffraction (XRD) measurements and the transmission electron microscopy (TEM). The LPG sensing properties of the synthesized nano-sized CdO were investigated at different operating temperatures and LPG concentrations. It was found that the calcination temperature and the operating temperature significantly affect the sensitivity of the nano-sized CdO powder to the LPG. The sensitivity is found to be maximum when the calcination temperature was 400 °C. The sensitivity to 75 ppm of LPG is maximum at an operating temperature 450 °C and it was found to be ∼341%. The response and recovery times were found to be nearly 3-5 s and 8-10 s, respectively. The synthesized nano-sized CdO powder is able to detect up to 25 ppm for LPG with reasonable sensitivity at an operating temperature 450 °C and it can be reliably used to monitor the concentration of LPG over the range (25-75 ppm). The experimental results of the LPG sensing studies reveal that the nano-sized CdO powder synthesized by a simple co-precipitation method is a suitable material for the fabrication of the LPG sensor.     

Optimizing the Synthetic Conditions of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 from a Carbonate Co-precipitation Method

1 Introduction As a promising cathode material for lithium ion batteries,LiNi1/3Co1/3Mn1/3O2 attracted intensive attentions.Owing to high specific capacity,long circle life and excellent safety,it may be an alternative candidate for LiCoO2.As a complex composite,however,it is difficult to synthesize phase-pure LiNi1/3Co1/3Mn1/3O2 by a simple mixed calcination method[1].From this concern,carbonate co-precipitation method,which can prepare homogeneous LiNi1/3Co1/3Mn1/3O2 with typical layered structure,bec...