【作者】 王龙硕；

【导师】 邓建成；

【作者基本信息】 湘潭大学 ， 应用化学， 2008， 硕士

【摘要】 纳米材料由于其介观效应而表现出不同于常规材料的独特物理化学性质,因而对纳米材料的合成与表征研究己经成为材料科学、物理学以及化学学科的前沿.纳米氧化铜除具有一般纳米材料所特有的表面效应、量子尺寸效应和体积效应外,还因为它是一种禁带宽度很窄(1.2 eV)的P型半导体,在电、磁、催化等领域表现出不寻常的特性,故在超导、催化、气体传感、电池的阳极材料等方面得到广泛应用,因此,其研制具有重要的理论意义和实用价值。但由于现有绝大多数制备方法存在着一定的问题,如成本高、粒径不均匀、纯度差等,为此,有必要研究一种成本低、粒径小、纯度高的制备纳米材料新方法,使其制备得以工业化。本论文研究了一种制备高纯度纳米氧化铜及复合物纳米银/氧化铜的新方法─—配位氧化均匀沉淀法,并用该方法分别制备了纳米级的氧化铜和银/氧化铜复合粒子。采用扫描电镜、透射电镜、X射线衍射、热重-差热分析、红外光谱等手段对粒子的结构及形貌进行了表征分析,并初步探讨了氧化铜和银/氧化铜的催化性能。本论文以高纯度金属铜丝为铜源,以空气为氧化剂,廉价的氨水为配位剂,碳酸氢铵为沉淀剂,采用配位氧化均匀沉淀法这一新方法制备出了平均粒径为10-20nm的纳米氧化铜;同时以硫酸铜作为铜源经由配位均匀沉淀法制备出了纳米氧化铜粒子。研究了影响前驱物碱式碳酸铜生成的水释量、反应温度、反应时间及前驱物煅烧温度等因素,确定了最佳制备条件。本论文以金属铜和碳酸银为原料,采用配位均匀共沉淀法制备了纳米碱式碳酸铜和碳酸银前驱体,干燥后煅烧得到了分散性好的纳米银/氧化铜复合粒子,平均粒径在10nm纳米左右。对制备的纳米氧化铜和纳米银/氧化铜进行催化性能做了初步的研究,结果表明所得纳米产品对过氧化氢的分解都显示很强的催化活性,对苯酚羟基化反应也显示出一定的催化能力。更多还原

【Abstract】 Nanoparticles and nanocluster materials are a new class of advanced materials exhibiting unique chemical and physical properties compared to those of their bulk material. Nanosized copper oxide have attracted much attention because of their superior properties and applications in catalysis, metallurgy, electrode materials, solar energy transformation, semiconductors, gas sensors and high-Tc superconductors. Therefore, the relative research has very important theory significance and practicality value. Since there are many problems in existing methods, such as high cost, non-homogeneous of particle, and impurity, a new method with low cost, small particle and high purity is necessary to be studied and industrialized.A new method, namely, coordination oxidation homogenious precipitation method was described to synthesize high pure CuO and Ag/CuO nanoparticles. Field-emission scanning electron microscope (FESEM), transmission electron microscope (TEM), powder X–ray diffraction (XRD), thermal analysis (TG-DTA), infrared absorption spectroscopy (IR) were used to characterize the microstructure and morphologiy of the products. Furthermore, catalytic performances of the products were also investigated preliminarily.At first, very pure nanometer CuO with average particle diameters of 10-20nm was successfully prepared using metal copper, silver carbonate, ammonia, and ammonium bicarbonate as starting materials via coordination oxidation homogeneous precipitation method. Nanometer CuO was also obtained using cupric sulfate as copper source by coordination homogeneous precipitation method. The technological process conditions were explored and optimized in great depth, and the optimum conditions for preparing Cu2(OH)2CO3 precursors and CuO were obtained.Ag/CuO composite nanopowder was also successfully prepared using metal copper, silver carbonate, ammonia, and ammonium bicarbonate as starting materials via coordination oxidation homogeneous co-precipitation method. The method is new, facile, no need of washing process, and no need of expensive equipment. TEM images show as-prepared Ag/CuO nano-composites have uniform particle diameter (10nm) with minimal agglomeration.Finally, the catalysis of as-prepared products was also investigated in H2O2 decomposition and the phenol hydroxylation with H2O2. The results indicated that the products had a higher catalytic activity in the reactions.更多还原