纳米材料选修课作业.doc

氧化镍纳米结构的制备及其催化性能姓名： 学号： 班级：电气信息II类摘要：纳米科学技术的基础是纳米结构材料的合成它是纳米科技在分散与包覆、高比表面材料、功能纳米器件、强化材料等方面实现突破的起点。纳米颗粒（f1100 nm)本身具有宏观量子隧道效应、量子尺寸效应、表面效应许多独特的性能，其制备研究日益得到广泛关注和重视。氧化镍是一类广泛应用于催化、电子、电池等领域的无机材料,纳米氧化镍由于晶粒尺寸小、比表面积大、量子效应明显和表面微观结构在纳米尺度上的可调性,使其具有区别于传统材料的优异的物理化学性能。因此在诸如催化材料、电极材料等方面有广阔的应用前景。本文对多种氧化镍纳米结构的制备方法及其催化性能进行探讨。关键词：氧化镍；NiO纳米结构；固相法；催化性能；湿化学法光催化性能1.引言: 引言纳米材料 (Nanomaterials)是指在三维空间中至少有一维处于纳米尺度范围或由它们作为基本单元构成的材料。由于表面和界面效应、量子尺寸效应、宏观量子隧道效应等，纳米材料具有不同于一般材料的物理和化学性能，这些物理化学性能不仅取决于纳米材料的尺寸而且还与它的形貌有关，同时不同形貌的纳米结构也是构建纳米器件的基本基元。因此，有关不同形貌纳米结构的可控合成及其物理化学性能的研究都具有非常重要的科学意义，氧化镍(NiO)是一种重要的无机功能材料，它在铿离子电池、光伏器件、气敏元件、磁性、催化剂、玻璃及陶瓷着色剂等原料和冶金材料等方面有着广泛的应用。这些纳米材料的物理化学性能在很大程度上是取决于氧化镍的形貌和尺寸的。所以氧化镍纳米结构的可控合成及其物理化学性能的研究异常活跃，人们已经用各种方法制备了不同形貌的纳米结构，并研究了不同的性能。 本论文主要是讨论不同形貌氧化镍的制备和电化学性能研究。而对氧化镍形貌的研究主要是基于水热法对氧化镍前驱体形貌的研究，这里所研究的前驱体包括碱式碳酸镍，碳酸氢镍和氢氧化镍。本章的主要内容是摸索水热法制备三种不同形貌氧化镍前驱体的条件，包括超薄自组装层级结构氧化镍前驱体，花球状层级结构前驱体和片状结构氧化镍前驱体。1.1 NiO纳米结构的制备制备氧化镍纳米结构的方法主要有:湿化学法和固相法。其中湿化学法主要包括溶液化学法、溶剂热法和水热法等。1.1.1固相法固相法是一般是用低热固相配位化学反应先合成出前驱配合物，前驱配合物再经热分解就得到了纳米氧化镍，这种方法是制备纳米氧化镍纳米颗粒的常用方法，方法简单但产物的形貌不容易控制。其纳米颗粒的尺寸大约在30一40nm之间，但颗粒间的分散性较差。通过将NiCl26H2O和碳酸钠的粉末混合研磨后先得到了碳酸镍的前驱物，然后再将制备出的前躯体与氯化钠和烷基酚聚氧乙烯(9)醚(NP一9)混合研磨后，经热分解就得到了NIO纳米棒，其棒的长度大约为十几个微米，直径大约30一80nln，(见图1一1)，固相法实验操作虽然简单方便，但是产物的形貌却不容易控制(由于在低热固相反应的研磨过程中，反应速度非常的快，但是扩散和生长的速度却非常的慢，这样就使反应成核后的晶核不能迅速的生长，导致成核的速度快而晶体生长的速度慢，生成晶体粒度较小而均匀的粉体。1.1.2湿化学法目前人们采用湿化学法己经制备出了NiO纳米结构的不同形貌，其中主要有纳米线、纳米棒、纳米带、纳米颗粒、纳米空心球、纳米六边形、纳米八面体、纳米多面体、纳米薄膜、纳米花、纳米片、纳米环、海胆状结构及纳米颗粒组装的三维超晶格结构等。近年来，氧化镍纳米结构的制备一般都是通过不同的制备方法先制备出不同形貌的前驱体结构，然后再将制备出的前驱体结构在空气中通过不同的温度热处理一定的时间，就得到了氧化镍的纳米结构。所以，我们依据制备前驱物方法的不同将制备方法主要分为溶液化学法、微乳液法、水热法和模板法等。湿化学法与固相法相比，合成温度较低，设备操作简单，得到的产物结构多，而且产率高，易于大规模的生产，是实验室目前制备不筒形貌的纳米结构的主要方法。1.1.3溶液化学法该方法主要是通过化学沉淀反应，制备出不同的前躯体，其中主要的前躯体有氢氧化镍、丁二酮镍、苹果酸镍和碱式碳酸镍等，前躯体经热分解后就得到了不同形貌的NiO纳米结构。纳米带见图。2. NiO纳米结构的性质研究2.1磁学性能关于磁学性能的研究主要是对纳米颗粒的研究，关于其它纳米结构形貌的磁学性质研究的较少。Parada等人对尺寸约为nnm的NiO纳米颗粒进行了磁性分析，分析结果显示的是弱铁磁特性，其矫顽力约为 700Oe。Ichiyanagia等人138对尺寸分别约为3.0、3.1和5.4nm的NIO纳米颗粒进行了磁性分析，结果显示它们都具有弱的铁磁性，其矫顽力约为 750Oe，与此同时，他们还发现随着纳米颗粒尺寸的增加，饱和磁化强度就会减小。Park等人1391对尺寸约为7nm的NiO纳米颗粒进行了磁性分析，结果表明在不同温度下均显示的是超顺磁行为。2.2气敏性能近几年，气敏传感性能的研究主要集中在NIO纳米薄膜方面，同样关于其它纳米结构形貌的敏传感性能的研究较少。目前，用NIO纳米薄膜制成的传感器主要有NO2传感器40，甲醛传感器41，42和H2传感器43及Li等人44用空心球做生物传感器等。Hotovy等人140研究了NiO纳米薄膜制成的传感器对NO2气体的灵敏度影响，在测试温度为160”c时，发现NIO纳米薄膜制成的传感器对1一 10PPm的NO2气体有很好的响应。 LuyO等人45研究了NiO纳米薄膜制成的传感器对NO2气体的灵敏度，当NO2、H2S气体的浓度都为 5ppm时，它们的灵敏度分别为1.6和1.8，其NO2和H2S气体检测最佳的温度范围分别为100一125和150一162。2.3电化学性能Nee曲am和wang等人侧24 31分别对NiO纳米管和NiO多孔纳米片进行了电化学性能的检测，由于其具有大的比表面积和多孔的结构，它的平均放电电容达到为700mA与纳米颗粒的 (620mA)相比较提高了很多。马俊林等人46对纳米颗粒NiO蓄电池和普通NIO蓄电池的放电性能进行了比较，结果发现普通NIO蓄电池放电 30min后，其端电压就接近于衰竭，而纳米NIO蓄电池放电 90min以后才出现了衰竭现象。因此，加入纳米颗粒NiO的蓄电池它的放电时间会大大的延长，其放电性能也增强。Liu等人3对NiO纳米线组装的海胆结构的充放电电容进行了研究，结果表明，充放电循环次数越多，其充放电电容就越小。2.4光催化性能氧化镍是一种良好的催化剂(由于Ni2+具有3d轨道，对多电子氧具有择优吸附的倾向)。目前，对氧化镍纳米结构光催化性质的研究主要中集中在纳米颗粒上，而具有一定形貌的氧化镍纳米结构光催化性质的研究比较少。娄向东等人l4研究了不同尺寸的NiO纳米颗粒(18nm和27nm)对三种染料:活性染料B一RN蓝，活性艳兰KNR和活性B一GFF黑脱色率的比较，结果表明尺寸是18nm的NIO纳米颗粒对三种染料的脱色率可以很快的达到100%，而尺寸为27nm的NiO纳米颗粒对三种染料的脱色率相对较慢。这是由于尺寸较小的纳米颗粒的比表面积较大，与染料液的接触比较充分导致的。随后，阳霞等人148对尺寸约为11nm的NiO纳米颗粒作为催化剂降解酸性红染料进行了研究，结果发现这种小尺寸的催化剂对酸性红的降解效果非常显著。song等人49将NiO实心球、NiO纳米棒、NiO的空心微球和NiO纳米管等四种不同的形貌作为不同的催化剂，对酸性红的降解速率进行了研究，结果表明NiO的空心微球对酸性红的降解速率最快，其降解效率达到了93%。3.本课题的提出及意义设计简单、.实用和形貌可控的纳米结构的制备方法和新纳米结构的发现一直都是科学研究中最具有挑战性的问题之一。综上所述，关于NIO纳米结构，人们已经制备出了NiO纳米棒、纳米管、纳米线、纳米带、纳米片、纳米花、纳米线组装的海胆结构、纳米微球和分级结构等。然而关于NIO纳米颗粒组装的超长纳米线和NiO八面体结构至今未见报道。众所周知，氧化镍是一种非常重要的气敏传感材料，目前，气敏传感器材料的研究主要集中在NIO纳米薄膜上，但是有关一定形貌的NIO纳米结构的气敏传感性能至今还未见报道。关于有一定形貌的NIO纳米材料的光催化性能的研究报道也比较少。因此，开发简单、实用的氧化镍纳米结构的制备方法，通过改变反应的条件来控制NiO的成核和生长，以制备出形貌多样的Nio纳米结构。在此基础上，研究所制备的NiO纳米结构的气敏传感性能及光催化性能，探讨结构、尺寸和性能的内在关系，具有十分重要的科学意义和巨大的潜在应用价值。 参考文献：1张立德，牟季美，纳米材料和纳米结构，科学出版社，2001.2S.C.Tsang,Y.K.Chen,P.J.Harrris,Nature 1994,372,159.3舒万艮. 有色金属精细化工产品生产与应用M. 长沙：中南工业大学出版社，1995：211.4孙全，邵忠财，高景龙NiO 超细粉的制备及应用进展J有色矿冶，2006，22（4）：40-445陈敬中，刘剑洪. 纳米材料科学导论M. 北京：高等教育出版社，2006：90-93.6吴彬福，吴廷华，吴瑛. 纳米氧化镍的乙烷氧化脱氢催化性能研究J. 广州化工，2008，36（1）：28-30.7刘焕彬，陈小泉 . 纳米科学与技术导论M. 北京：化学工业出版社，2006：7-9.8娄向东，楚文飞，韩珺，等. 水热法制备片状纳米氧化镍及其光催化性能J. 水处理技术，2007，33（11）：23-27.9Lv Pin，Tang Zhen-A，Yu Jun，et al. Study on a micro-gas sensor withSnO2-NiO sensitive film for indoor formaldehyde detectionJ.Sensors and Actuators B，2008，132（1）：74-80.10 Bahadur J，Sen D，Mazumder S，et al. Effect of heat treatment onpore structure in nano-crystalline NiO：A small angle neutronscattering study J. Journal of Solid State Chemistry，2008，181（5）：1227-1235.Nickel xide nano structure preparation and catalytic performanceName: Chen Rong Number: 6100311243 lass: class 115 electrical information IIAbstract: the nanometer science and technology is the basis of nanostructured materials. It is the synthesis of nanometer science and technology in dispersion and coating, high surface area materials, functional nanoscale devices, such as strengthening material breakthrough point. Nanoparticles ( F1 100 nm ) with macroscopic quantum tunnel effect, quantum size effect, surface effect many unique properties, the preparation of the increasingly wide concern and attention.Nickel oxide is a kind of widely used in catalysis, electronic, battery and other areas of inorganic materials, nano nickel oxide as small grain size, large specific surface area, obvious quantum effects and surface microstructure on a nanometer scale adjustability, which is different from the traditional materials of excellent physical and chemical properties. Therefore in such as catalytic materials, electrode materials has broad application prospects. In this paper a variety of nickel oxide nano structure preparation method and catalytic performance .Key words: nickel oxide; nanometer structure NiO; solid phase method; catalytic performance; wet chemical method photocatalytic performance1 foreword : IntroductionNanometer material ( Nanomaterials ) refers to the three-dimensional space in at least one dimension at the nanometer scale range orMade up of units of material. Due to the surface and interface effect, quantum size effect, quantum tunnel effect, nanometer material is different from general materials, physical and chemical properties, the physical and chemical performance depends not only on the nanometer size but also with its appearance, at the same time the different morphologies of the nanometer structure is also constructed of nanodevices basic primitives. Therefore, the different morphology of nano structure controllable synthesis and physical and chemical properties of the research has very important scientific significance, nickel oxide ( NiO ) is a kind of important inorganic functional material, the lithium ion batteries, photovoltaic devices, gas sensors, magnetic, catalyst, glass and ceramic colorants and other raw materials and metallurgical materials it has been applied extensively. These nanostructured materials physical chemistry performance largely depends on the size and morphology of nickel oxide. So the nickel oxide nanostructures with controllable synthesis and physical chemical properties of unusually active, people have used various methods of preparation with different morphologies of nanostructures, and study the effects of different performance.This thesis is to discuss the different morphologies of nickel oxide preparation and electrochemical properties of. The nickel oxide morphology research is mainly based on the hydrothermal method for nickel oxide morphology of precursor research, studied here precursor consists of basic nickel carbonate, nickel hydrogen and nickel hydroxide carbonate.The main content of this chapter is to explore hydrothermal preparation of three kinds of different morphologies of nickel oxide precursor conditions, including thin self assembly structure of nickel oxide precursor, ball-flower shaped structure of precursor and sheet structure of nickel oxide precursor.1.1 NiO nano structure preparationPreparation of nickel oxide nano structure method: wet chemical method and solid phase method. The wet chemical methodIncluding chemical method, hydrothermal method and hydrothermal method.1.1.1 solid phase methodThe solid-phase method is generally used by low temperature solid state reaction of coordination to synthesize precursor complexes, precursor complexesThe thermal decomposition by nano nickel oxide, this method is the preparation of nano nickel oxide nano particles of the commonly used method, method is simple but the morphology of the product is not easy to control. The nanometer particle size is about 30 40nm, but the poor dispersion of particles. By NiCl2 6H2O and sodium carbonate powder mixed after grinding to get nickel carbonate precursor, and then the prepared precursor and sodium chloride and alkyl phenolsPolyoxyethylene ether ( 9) ( NP 9) mixed after grinding, the thermal decomposition are NIO nanorods, the rod length of about a dozen microns in diameter, about 30 of 80nln (see Figure 1, 1 ), solid-phase method experimental operation although is simple and convenient, but the morphology of the product is not easy to control ( due to in the low temperature solid state reaction of lapping process, the reaction speed is very fast, but the spread and growth speed is very slow, so that the reaction after nucleation crystal nucleus can not grow rapidly, causing nucleation crystal growth speed and the speed is slow, generating crystal with smaller size and homogeneous powder.1.1.2 wet chemical methodAt present people by wet chemical method has been prepared the NiO nanometer structure with different morphologies, which mainly includeNanowires, nanorods, nano, nano particle, nanometer hollow sphere, nanometer hexagonal, nano surface of the body eight,Nanometer polyhedral, nano film, nanometer, nano, nano rings, echinoid structure and nano particles assembled three-dimensional superlattice structure. In recent years, nickel oxide nano structure preparation is generally through the different preparation methods to prepare different morphology of precursor structure, and then the prepared precursor in the air through different heat treatment temperature for a certain time, get the nickel oxide nano structure. Therefore, we according to preparation of precursor of different methods of the preparation method are mainly divided into solution chemical method, microemulsion method, hydrothermal method and template method. Wet chemical method compared with the solid phase method, the synthesis temperature is low, the equipment is simple, the product structure, and high yield, easy mass production, is currently preparing cylinder laboratory nanoscale topography on the main method of structure.1.1.3 solution chemical methodThe method mainly by chemical precipitation reaction, prepared from different precursor, wherein the main precursor has nickel hydroxide, nickel, Ding two ketone malic acid nickel and nickel carbonate, precursor by thermal decomposition can be different morphologies of NiO nanometer structure.Nano belt.2 NiO nanometer structure properties study2.1 magnetic propertiesThe research is mainly on magnetic properties of nanoparticles, on other nanostructure morphology of magneticStudy on the properties of the less. Parada et al on size of about NNM NiO nanoparticles for magneticAnalysis, analysis results showed a weak ferromagnetic properties, the coercive force of about 700Oe. Ichiyanagia et al. 138 on dimensions are respectively 3, 3.1 and 5.4nm NIO nanometer particles were magnetic analysis, results show that they have a weak ferromagnetic, the coercive force of about 750Oe, at the same time, they also found with nanometer particle size increases, saturated magnetization intensity will be reduced. Park et al. 1391 the size of about 7Nm NiO nanometer particles were magnetic analysis, the results showed that at different temperatures show is super paramagnetic behavior.2.2 gas sensing propertiesIn recent years, the gas sensing properties of research mainly concentrates in the NIO nanometer thin films, also on the otherNano structure morphology of the sensing properties of. At present, with the NIO nanometer thin film sensor made of mainly NO2 sensor 40, formaldehyde sensor 41, 42 and H2 43 and Li et al. 44 sensor with hollow ball as biological sensors. Hotovy et al. 140 on NiO nanometer film sensor to NO2 gas sensitivity effect, in the test temperature of 160 C, found NIO nano thin film sensor made of 1 10PPm NO2 gas response is very good. LuyO et al. 45 on NiO nanometer film sensor to NO2 gas sensitivity, when NO2, H2S gas concentration for 5ppm, their sensitivity in respectively 1.6 and 1.8, the NO2 and H2S gas detection optimal temperature range was 100 125 and 150 162.The 2.3 electrochemical performanceNee am and Wang et al 24 31 side respectively for NiO nanotubes and NiO nanometer porous films by electrochemical performance test, due to its large specific surface area and porous structure, its average discharge of the capacitor reaches 700mA and nanoparticles ( 620mA ) compared to improve a lot. Ma Junlin et al 46 nanoparticles NiO battery and NIO battery discharge performance were compared, results found that the average NIO battery discharge 30min, its terminal voltage is close to failure, and the nanometer NIO battery discharge 90min appeared after the failure phenomenon. Therefore, adding nanometer particle NiO battery its discharge time can be greatly extended, its discharge performance enhancement. Liu et al. 3 on NiO nanometer line assembly in the sea urchin structure of the charge and discharge the capacitor were studied, the results showed that, the number of cycles of charge and discharge, the charge and discharge the capacitor is smaller.2.4 photocatalytic performanceNickel oxide is a good catalyst ( because Ni2+ 3D track, on multiple electronic oxygen has preferential adsorptionInclination ). At present, the nickel oxide nanostructures with photocatalytic properties of nanometer particles in concentrated in the main, and have certain morphologies of nickel oxide nanostructures with photocatalytic properties study. Lou Xiangdong et al l4 of different size particles of NiO nm ( 18NM and 27nm ) on three kinds of dye: B a RN blue reactive dyes, reactive brilliant blue KNR and activity of B GFF black decoloration rate comparison, the results show that size is 18NM NIO nanoparticles on three kinds of dye decolorization rate can quickly reach in 100%, while the size of 27nm particles of NiO nm upon three kinds of dye decolorization rate was relatively slow. This is due to small size of the nanometer particle has larger specific surface area, and the dye solution to contact more fully. Subsequently, Yang Xia et al 148 on size of about 11nm NiO nanoparticles as catalyst degradation of acid red dyes were studied, the results found that the small size of the catalyst on degradation of acid red very significant effect. Song, 49 NiO, NiO NiO nanorods solid ball, hollow microspheres and NiO nanotubes four different morphologies as different catalyst, acid red degradation rate were studied, the results showed that NiO hollow microspheres on acidic red degradation rate is the fastest, the degradation efficiency reached 93%.3 the paper and its significanceThe design is simple, practical and of morphology controllable nano structure preparation method and new nanostructures has been foundThe scientific research is one of the most challenging issues. To sum up, on the NIO nanometer structure, it has been prepared the NiO nanorods, nanowires, nanotubes, nano, nano sheet, nanometer, nanometer line assembly in the sea urchin structure, nanospheres and hierarchical structure. However, on the NIO nanoparticles assembled super long nanometer line and NiO eight surface structure has not been reported.As everyone knows, nickel oxide is a kind of very important gas sensing materials, at present, the gas sensor materials research mainly concentrated in the NIO films, but certain morphologies of NIO nanometer structure and gas sensing properties of was seldomreported. About a certain morphologies of NIO nanometer material photocatalysis research reports are also less. Therefore, the development of simple, practical nickel oxide nano structure preparation method