【作者】 郑东华；

【导师】 郭广生；

【作者基本信息】 北京化工大学 ， 应用化学， 2004， 硕士

【摘要】 本论文采用均匀沉淀法、液-固相法制备了纳米金属镍及纳米氧化镍粒子。详细研究了制备过程中反应条件对粒子形貌、粒径和分散度的影响,并采用透射电镜、X射线衍射仪、热重-差热分析仪、振动磁强计等仪器对粒子的化学组成及各种性能进行了表征。均匀沉淀法制备纳米氧化镍粒子的实验研究中,首先比较了不同沉淀剂(碳酸铵、碳酸氢铵、氨水、尿素)制备的纳米氧化镍粒子;接着采用以尿素为沉淀剂的均匀沉淀法制备纳米氧化镍粒子,通过改变反应条件:反应温度、反应时间、反应浓度比、煅烧温度,确定最佳的反应条件;最后初步探讨了均匀沉淀法制备纳米粒子的反应机理。此方法制备出的纳米氧化镍粒子粒径小(15nm),分散性好,晶型完整,产率较高,具有良好的工业应用前景。液-固相法制备纳米金属镍及纳米氧化镍粒子的实验研究中,主要研究了液相反应体系中,反应物溶剂的醇、水比例(体积比)对前驱物产率的影响,以及固相反应体系中,热分解反应时间、反应温度以及反应气氛对最终产物的物质组成、平均粒径、分散性的重要影响。在最佳反应条件下获得的纳米氧化镍粒子和纳米镍粒子的平均粒径均为10～20nm,粒子呈球状,分散性良好。详细研究了固相反应中,不同气氛下各个反应的反应机理并详细解释了前驱物热分解过程以及乙醇在液相反应和固相反应中所起的重要作用。更多还原

【Abstract】 In this thesis, nickel oxide (NiO) and nickel metal (Ni) nanoparticles were prepared by methods of homogeneous precipitation and thermal decomposition of nickel oxalate. The effects of the various reaction conditions on the yield, mean size and dispersivity of the nanoparticles were discussed. The samples of precursors, Ni and NiO particles were characterized by transmission electron microscopy, thermal analysis balance, X-ray diffraction and vibrating sample magnetometer.In the study of homogeneous precipitation method, the different precipitators such as ammonium carbonate, ammonium hydrogen carbonate, ammonia and urea were used to synthesize NiO nanoaprticles, and then the urea being the relatively well precipitator was considered to prepare NiO nanoaprticles. Though changing Ni(NO3)2·6H2O/CO(NH2)2 concentration ratios, reaction temperatures and heat-treating temperatures, optimum conditions for preparing NiO nanoaprticles were be obtained. The prepared NiO particles were pure and well dispersed with spherical sharp, and the mean size was about 15nm.In the other synthesis study, Nickel and nickel oxide nanoparticles were prepared from Ni(NO3)2·6H2O and (COOH)2·2H2O through a <WP=5>two-step chemical process, the deposition reaction and the self-reduction reaction. The result showed that the solvent of Ni(NO3)2·6H2O in the deposition reaction had an important effect on the reaction time and nickel oxalate yields. In the self-reduction reaction, the reaction time, the reaction temperature and the different atmospheres affected the particles’ composition, mean size, and dispersivity. Moreover, the self-reduction reaction mechanism was also discussed in this paper. The as-prepared Ni and NiO particles were also pure and well dispersed with spherical volume and the average diameter was in the range from 10 to 20nm.更多还原