共查询到19条相似文献,搜索用时 187 毫秒
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随着四氧化三锰应用范围的不断拓展,特别是电子信息工业的飞速发展,Mn3O4市场越来越被人们看好。本文从工艺特点及反应性质归纳出Mn3O4的制备方法,并对其应用与发展前景进行了简要论述。 相似文献
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以硫酸锰、氢氧化钠为原料,采用络合沉淀法制备高密度四氧化三锰,通过单因素实验对反应条件进行了优化。结果表明,以EDTA为络合剂,在硫酸锰的锰含量为80 g·L-1、氢氧化钠浓度为125 g·L-1、反应温度为70℃、搅拌速率为250 r·min-1、反应pH值为8~10、反应时间为30 h的最优条件下,可得到锰含量为71.03%、振实密度为2.58 g·cm-3、中位粒径为15.240μm的电池级四氧化三锰。 相似文献
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在90℃下,采用空气氧化法于弱碱性介质中氧化Mn2+制备Mn3O4。X-射线衍射和扫描电镜表明,产物为四方结构的Mn3O4,纯度高、结晶良好,具有近似球形形貌。电化学测试结果表明,在50 mA/g的电流密度下,Mn3O4作为阳极材料的初始放电容量为198 mA.h/g。在不同电流密度下循环50次后,放电容量基本可以回到初始值。 相似文献
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为了降低四氧化三锰的生产成本,介绍了以价格低廉的软锰矿为原料,使用相转变法制备四氧化三锰的基本原理和工艺过程。在实验条件下,以投料比m(软锰矿):m(硫铁矿):V(硫酸)=10g:9g:3.5mL,液固质量比10:1,反应时间5h,反应温度90℃进行反应,经净化处理后可制备出纯净的硫酸锰溶液。进一步向溶液中滴加一定浓度的氨水溶液,控制溶液pH在10左右,过滤洗涤后,溶液在50℃下,通入空气反应3.5h,再经过滤洗涤、干燥和粉碎,可制备出高纯度的四氧化三锰,反应总收率达90%以上。 相似文献
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催化氧化法制备高比表面四氧化三锰 总被引:5,自引:0,他引:5
研究了以铵盐作催化剂,利用高纯度锰粉悬浮液通空气催化氧化来制备高比表面四氧化三锰,并讨论了各因素对实验结果的影响,确定了反应的最佳条件,并对产品进行了检测和表征,经XRD检测确定产物为四氧化三锰,粒度分析仪测定了产品的粒径小于4μm,比表面分析仪测定SBET比表面积可达15.06m^2/g,锰的含量可达71.92%。 相似文献
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A López-Ortega M Estrader G Salazar-Alvarez S Estradé IV Golosovsky RK Dumas DJ Keavney M Vasilakaki KN Trohidou J Sort F Peiró S Suriñach MD Baró J Nogués 《Nanoscale》2012,4(16):5138-5147
Inverted soft/hard, in contrast to conventional hard/soft, bi-magnetic core/shell nanoparticles of Mn(x)Fe(3-x)O(4)/Fe(x)Mn(3-x)O(4) with two different core sizes (7.5 and 11.5 nm) and fixed shell thickness (~0.6 nm) have been synthesized. The structural characterization suggests that the particles have an interface with a graded composition. The magnetic characterization confirms the inverted soft/hard structure and evidences a strong exchange coupling between the core and the shell. Moreover, larger soft core sizes exhibit smaller coercivities and loop shifts, but larger blocking temperatures, as expected from spring-magnet or graded anisotropy structures. The results indicate that, similar to thin film systems, the magnetic properties of soft/hard core/shell nanoparticles can be fine tuned to match specific applications. 相似文献
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钙钛矿结构CaCu3Mn4O12的传统制备方法是热压法(几万个大气压,1000℃)。人们发现它的居里点Tc=355K,磁电阻MR值比相同条件下的La0.6Y0.07Ca0.33MnO3大得多,并且从低温到高于居里点的温度范围内都存在较大的磁电阻值。另外,Ca(Mn3-xCux)Mn4O12(x=3)的饱和磁化场,在室温300K时,饱和磁化场仅为0.03T本实验中,在常压和1070K的条件下合成了Ca(Mn3-xCux)Mn4O12,从而大大简化了Ca(Mn3-xCux)Mn4O12的制备条件。关于该材料的导电机制,铁磁磁畴再取向饱和场与磁电阻饱和场相同,表明Ca(Mn3-xCux)Mn4O12的MR来源于磁畴间或颗粒间的隧道机制。 相似文献
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以高锰酸钾和葡萄糖为原料,通过水热反应制备了四氧化三锰纳米晶颗粒,探讨了过渡金属离子掺杂的影响,并考察制备的产物作为催化剂在催化一氧化碳氧化反应中的性能。采用X射线衍射(XRD)、扫描电镜
(SEM)、透射电镜(TEM)、X射线光电子能谱(XPS)、氢气程序升温还原(H2-TPR)等手段对产物进行结构表征。结果表明,过渡金属离子掺杂可消除产物中的MnOOH杂相。制备的产物具有八面体形貌,尺寸随掺杂离子的变化而变化。掺杂还可以提高四氧化三锰纳米晶催化一氧化碳氧化反应的活性,呈现掺杂效应。 相似文献
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《Journal of the European Ceramic Society》2007,27(13-15):3927-3930
The erbium-based manganite ErMnO3 has been partially substituted at the manganese site by Co in the general formula ErCoxMn1−xO3. The perovskite orthorhombic structure is found from x(Co) = 0.3 up to x(Co) = 0.7, provided that the synthesis is performed under oxygenation conditions to favour the presence of Co3+. Magnetic properties show unusual phenomena, correlated with the presence of different magnetic entities (i.e., Er3+, Co2+, Co3+, Mn3+, Mn4+): the overall magnetic moment reverses its sign when the sample is cooled under an external magnetic field, while the magnetization loops performed at T < 4 K show intersecting branches at low fields and a sudden jump at high fields. A phenomenological model of two interacting sublattices, coupled by an antiferromagnetic exchange interaction, explains the inversion of the overall spin, while the high-field discontinuity is explained in terms of dynamical models. 相似文献
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采用氧化法和正硅酸乙酯水解法制备了Mn3O4@SiO2核壳结构磁性纳米材料,研究了其对水溶液中Mo(VI)离子的吸附效果。运用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、红外光谱仪(IR)及磁强计(VSM) 等多种手段对Mn3O4@SiO2核壳磁性复合材料进行了表征,并研究了溶液的初始pH、Mo(VI)离子初始浓度和温度对Mo(VI)吸附量的影响。结果表明:在298 K条件下Mn3O4@SiO2核壳结构磁性复合材料对Mo (VI)的饱和吸附量为145.35 mg/g; Mn3O4@SiO2对Mo (VI)的吸附过程符合Langmuir等温吸附模型,吸附动力学符合准二级动力学模型;吸附热力学分析表明Mn3O4@SiO2复合材料对Mo (VI) 的吸附行为是自发的、放热过程。 相似文献
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《Journal of the European Ceramic Society》1999,19(13-14):2421-2426
Some properties of oxide composites based on Al2O3 and LaPO4 (La-monazite) are examined. A composite consisting of woven Al2O3 fibers with a porous matrix of Al2O3 and LaPO4 is shown to be damage tolerant and notch insensitive. The feasibility of achieving fiber sliding and pullout in a composite with a fully dense matrix is investigated using a small hot-pressed composite of sapphire fibers and LaPO4 matrix. 相似文献
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Mn(3)O(4) morphologies with tetragonal single-crystal nanostructures including nanoparticles, nanorods and nanofractals were successfully prepared by a widely applicable chemical reaction route. The morphologies were synthesized using the reactants MnCl(2)·4H(2)O, H(2)O(2), and NaOH in a suitable surfactant and alkaline solution. The dripping speed of the NaOH solution plays an important role in the microstructure evolution of Mn(3)O(4) morphologies. The difference in the dripping speed of NaOH solutions leads to different Mn(3)O(4) nanomorphologies, which are called nanoparticles, nanorods and nanofractals. The average grain size of the Mn(3)O(4) nanoparticles ranged from a few to several tens of nanometers. The Mn(3)O(4) nanorods were smooth, straight, and the geometrical shape was structurally perfect. Their lengths ranged from several hundred nanometers to a few micrometers, and their diameters ranged from 10 nm to 30 nm. The fractal branches of the Mn(3)O(4) nanofractals were a few micrometers in length and several hundred nanometers in width. The catalytic properties of these Mn(3)O(4) nanomorphologies for the degradation of phenol were evaluated in detail. The results indicated that the Mn(3)O(4) nanofractals possess remarkable catalytic activity for the degradation of phenol in water treatment. 相似文献