【作者】 赵丽燕；

【导师】 邹勃；

【作者基本信息】 吉林大学 ， 材料物理与化学， 2010， 硕士

【摘要】 本文以硫酸铜水溶液为原料,采用不同的实验方案,制备出多种形貌的CuO和Cu2O微粒。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见光谱分析(UV-Vis)等手段,对所得产物的晶体结构、尺寸及形貌特征进行表征,并研究了反应物浓度、反应时间的变化规律。首先,在合成CuO实验中,柠檬酸钠在反应中作为稳定剂,在氢氧化钾和CTAB的作用下还原得到二维的片状CuO。为了研究反应机理,我们做了许多平行实验,溶液中的柠檬酸钠与铜离子作用生成络合物,在OH-作用下形成Cu(OH)2,当溶液中Cu(OH)2浓度达到一定时便开始了结晶过程,进一步升温过程Cu(OH)2脱水形成CuO。实验中通过调节OH-与Cu2+的摩尔比率可控制形核数量的作用,而柠檬酸钠在反应过程中可减少溶液中的自由Cu2+从而控制Cu(OH)2的形核和结晶过程;而在Cu2O实验中,在氨水的作用下,柠檬酸钠既做还原剂又做表面活性剂构成了微米级的星状结构,这种结构是随着时间的延长由六面体逐渐结晶转变形成的。其次,在反应中,每一种反应物表现出不同的作用,在CuO的合成实验中,KOH的浓度对于得到CuO纳米晶的形貌有重要的影响,当KOH和CuSO4的比例小于1:1时,不会得到CuO的纳米片,只是得到无规则的纳米晶,随着KOH浓度不断增加产物的形貌变为片状结构,并且晶粒的结晶程度越来越好;当只调节CTAB的浓度时,可以得到不同尺寸的CuO纳米片,CTAB的量越多,得到的CuO纳米片的尺寸就越小,但是形貌没有发成变化,说明CTAB在实验中主要起到了控制尺寸的作用。最后,在合成Cu2O的实验中,不同粒子在溶液中表现出的选择吸附性影响了晶体结晶过程中的晶面的表面能,在不同的条件下,每一种影响因素的所表现出的强度不同,从而影响了不同晶向的生长速率随着时间的变化展现出不同的形貌结构来,基于这样的理论我们得到了诸如八面体,中空六面体,和内凹八面体等各种有趣的形貌。更多还原

【Abstract】 Cu-based oxide is an important metal oxide, which has wide potential in many fields. Firstly, cuprous oxide(Cu2O),a p-type semiconductor with unique optical and magnetic properties, has potential applications in solar energy conversion , electronics, magnetic storage, catalysis ,and gas sensors. Another Cu-based oxide, CuO is also a potential material with many applications in catalysis, gas sensing.In this paper, as the raw material, copper sulfate solution with different experiment programs were prepared by a variety of morphology of Cu2O particles. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy (UV-Vis) and other means, the product obtained the crystal structure, size and morphology, reactant concentration, reaction time variation of studied.Sodium citrate in the reaction was a surfactant. With CTAB and potassium hydroxide present, the final production was two-dimensional sheet CuO. To study the reaction mechanism, a lot of parallel experiments has been done. Cu2+ reacts with OH- and Cu(OH)2 was formed. When the solution of Cu(OH)2 concentration is high enough, crystallization process began. Cu(OH)2 will dehydration to be CuO in the condition of heating. Adjusting the OH-and Cu2+ molar ratio, the number of nucleation can be controlled, Free Cu2+ in solution was reduced thus control the rules of the final degree of crystalline CuO. The experiment of synthesis of Cu2O, as the influence of ammonia, sodium citrate works as both reductant and surface-active agent. The sample presents a star structure. This structure is extended over time by the six-sided crystals gradually changing shape.In the reaction, each reactant play different roles, ions in solution demonstrated different selective adsorption to the crystal during the crystallization process. In different conditions, each kinds of factors affecting the strength shown by the different, thus affecting the growth rate of different crystal to change over time show a different morphology structure.更多还原