【作者】 潘路；

【导师】 张祖德；

【作者基本信息】 中国科学技术大学 ， 无机化学， 2010， 博士

【摘要】 铁、钴和镍的氧化物及复合氧化物在磁性材料、催化剂、传感材料及电池等方面有着及其广泛的应用。探索铁、钻及镍的复合氧化物合成方法及扩展其应用范围具有重要的意义。本论文的主要内容归纳如下：1.主要采用水热法合成了具有不同形貌的铁、钴及镍的单一氧化物产物。控制条件下成功地制备了Fe₃O₄纳米片、Fe₂O₃纳米粒子、Co₃O₄纳米片、纳米管及纳米粒子以及NiO纳米片和空心球。将氧化物产物修饰到玻碳电极上通过循环伏安法考察了其在碱性介质中对对硝基苯酚还原的催化性能。结果表明,Fe₃O₄纳米片、Co₃O₄纳米管及纳米粒子和NiO纳米空心球显示了较高的电催化活性。可见光照射下,考察了铁、钴及镍的氧化物催化双氧水氧化降解甲基橙的催化活性,各种形貌的氧化物对甲基橙的降解都有一定的催化性能。2.采用水热法制备了Ag/Fe₃O₄纳米球和纳米粒子,球状Cu/Fe₃O₄复合氧化物,以及不同Cu/Fe摩尔比的CuO/Fe₂O₃纳米结构的复合氧化物产物。采用循环伏安法研究了在碱性介质中修饰到玻碳电极上的各产物对对硝基苯酚还原的电催化的性能。相对于裸玻碳电极,这些复合产物对对硝基苯酚还原的催化主要表现为峰电流明显增大。不同Cu/Fe摩尔比的CuO/Fe₂O₃纳米复合氧化物用于可见光照射下双氧水氧化降解甲基橙及对硝基苯酚的催化剂,它们对甲基橙及对硝基苯酚的降解均显示出较强催化性能。3.采用简单易控的方法合成了片状和管状的Ag/Co₃O₄、低维的MO/Co₃O₄ （M=Cu, Ni, Zn和Cd）复合氧化物材料。XRD物相分析表明,以草酸铵沉淀剂制备的M/Co摩尔比为1：2的M-Co （M=Cu, Ni和Zn）复合氧化物具有Co₃O₄型尖晶石结构,而Cd-Co复合氧化物则为混杂氧化物组成。研究了合成的复合氧化物在碱性条件下对对硝基苯酚还原的电催化性能。结果表明,Ag-Co复合氧化物能使对硝基苯酚在较低的电位下有效进行反应,Cu-Co复合氧化物催化对硝基苯酚以较大的峰电流进行还原,而M-Co （M=Ni, Zn和Cd）复合氧化物对对硝基苯酚的还原表现出一般或较弱的催化性能。沉淀法制备的CuO/Co₃O₄复合氧化物对甲基橙降解的光催化性能表明,Cu/Co摩尔比高的复合物显示了较高的催化活性。4.使用水热／溶剂热合成方法制备了Ag/NiO纳米粒子、纳米片、空心球,Au/NiO空心球以及CuO/NiO纳米片复合氧化物。采用循环伏安法研究了M/NiO （M=Ag, Au）产物在碱性条件下对对硝基苯酚还原的电催化性能。结果显示这些复合氧化物能使对硝基苯酚在较低的电位下有效进行还原。研究了CuO/NiO纳米片在可见光照射下双氧水氧化降解对硝基苯酚的催化性能。结果表明,高Cu/Ni摩尔比的复合氧化物对对硝基苯酚的降解显示出较高的催化活性。更多还原

【Abstract】 Iron, cobalt and nickel oxides and composite oxides are widely applied in magnetic materials, catalyst, sensor materials, cell, and so on. It is significant to explore novel synthesis methods and expond the application extents of iron and cobalt and nickel composite oxides. The main contents can be summarized as follows:1.Individual iron, cobalt and nickel oxide with different morphologies were synthesized mainly using hydrothermal method. Under controlled conditions, Fe3O4 nanosheet, Fe2O3 nanoparticle, Co3O4 nano-sheet,-tube and -particle, as well as NiO nanosheet and empty sphere, were prepared successfully respectively. Using a cyclic voltammetry method, the electocatalytic property of the as-synthesized oxide modified on a glassy carbon electrode (GCE) for the reduction of p-nitrophenol existing in a basic medium were investigated. The results indicate that Fe3O4 nanosheet, Co3O4 nano-tube and -particle, and NiO empty sphere all exhibit higher electrocatalytic activity. Under irradiation of visible light, the photocatalytic property of methyl orange degradation by oxidation of oxydol using the as-prepred oxides as photocatalysts with different morphologies were investigated, which are indicative of a certain potocatalytic activity for methyl orange degradation.2.Ag/Fe3O4 nano-sphere and-particle, sphere-like Cu/Fe3O4, and CuO/Fe2O3 composite nanostructres with different Cu/Co molar ratios, were fabricated. Via a cyclic voltammetry method, the electrocatalytic property of the as-synthesized samples decorated on a GCE for p-nitrophenol reduction in a basic solution were investigated. By comparison with a bare GCE,p-nitrophenol reduction is carried out with a magnified peak current using these as-prepared composite samples as catalysts. Under irradiation of visible light, CuO/Fe2O3 composites with different Cu/Fe molar ratios were used as the photocatalysts for degradation of methyl orange and p-nitrophenol by oxidation of oxydol, and exhibited higher photocatalytic activity for metyl orange and p-nitrophenol degradation. 3.Sheet- and tube-like Ag/Co3O4 as well as low dimensional MO/Co3O4 (M=Cu, Ni, Zn and Cd) composite oxides were synthesized via an facile and easy-controlled method. Through the analysis with XRD diffraction, the M-Co (M=Cu, Ni and Zn) composte oxides with M/Co molar ratio of 1:2 demonstrate a spinel structure of Co3O4 but Cd-Co one with the same molar ratio is verified as hybrid oxides using (NH4)2C2O4 as precipitation reagent. The electrocatalytic property of the as-prepared products for p-nitrophenol reduction in a basic solution was investigated. The results indicate that p-nitrophenol reduction could be carried out at lower potential under the catalysis of Ag-Co composites, and could be done with a large peak current with the Cu-Co ones, but M-Co (M=Ni, Zn and Cd) composite oxides show common or weak electrocatalytic activity for p-nitrophenol reduction. The photocatalytic property for methyl orange degradation with CuO/Co3O4 composites prepared via a precipitation method demonstrates that the samples with higher Cu/Co molar ratio exhibit higher photocatalytic activity.4. Ag/NiO nano-particle,-sheet and empty sphere, Au/NiO empty sphere, and CuO/NiO nanosheet, were synthesized using a hydrothermal/solvothermal metod. Using a cyclic voltammetry method, the electrocatalytic property of the M/NiO (M= Ag, Au) samples for p-nitrophenol reduction in a basic solution was investigated. The results show that p-nitrophenol can be reduced effectively at lower potential under the catalysis of the as-synthesized products. The photocatalytic property of CuO/NiO nanosheets for p-nitrophenol degradation by oxidation of oxydol under irradiation of visible light was examined. The results indicate that CuO/NiO composites oxide with higher Cu/Ni molar ratio exhibit higher photocatalytic activity.更多还原