金属纳米线的可控制备及低维化研究

发布时间：2018-04-15 03:30

本文选题：多孔阳极氧化铝(PAA) + 电化学沉积　；参考：《浙江理工大学》2017年硕士论文

【摘要】：模板法操作容易,设备简单,并且可以通过调节所用模板的孔径大小和厚度来控制合成材料的直径和长度,这一特点为纳米器件的制备及应用提供了基础。本论文选用模板多孔阳极氧化铝模板与电化学沉积相结合,通过控制反应中的化学条件成功合成了保持本征特性的单晶银纳米线、铁纳米线一维材料,并研究了其形貌及结构。通过溶剂热与超声方法相结合将一维金属纳米材料转化为零维纳米颗粒,制备了具有本征特性的纳米粒子,成功实现了金属纳米线的低维化,讨论了反应时间以及反应温度等因素对所得产物形貌与结构的影响,避免了化学法合成中为了防止纳米粒子发生团聚,在反应体系中加入分散剂等表面活性剂而产生的繁杂后处理,同时保持了纳米粒子的本征特性。采用扫描电镜(SEM),透射电镜(TEM),紫外可见吸收光谱(UV-Vis),X-射线衍射(XRD)以及能谱(EDS)对一维纳米材料金属纳米线和低维化的金属纳米粒子进行了基础分析表征。本论文所做的有研究主要有以下方面的工作:银纳米线阵列的制备:首先在多孔阳极氧化铝(PAA)模板的一侧蒸镀金属(一般蒸镀金属为Ag/Au,Ag蒸镀13 min,Au蒸镀10 min)作为工作电极,然后再电化学恒电位(-0.8V)沉积银纳米线,银电解液为28.7 g/L Ag电解液,至电流急剧上升时停止沉积,沉积完成后,用物理方法打磨除去Ag工作电极,然后将样品溶解在3M NaOH中震荡溶解PAA模板,用去离子水进行离心洗涤3~5次,之后放入真空干燥器中干燥12 h,即得银纳米线阵列。铁纳米线阵列的制备:首先在PAA模板的一侧蒸镀金属(一般蒸镀金属为Ag/Au,Ag蒸镀13 min,Au蒸镀10 min)作为工作电极,然后再电化学恒电位(-0.9V)沉积铁纳米线。铁电解液:FeSO4·7H2O 120 g/L,H3BO3 45 g/L,Vc1 g/L。先沉积4 min的Ag,再沉积Fe纳米线,至电流下降至0时停止沉积,沉积完成后,用物理方法打磨除去Ag工作电极和牺牲电极银,然后将样品溶解在3M NaOH中震荡溶解PAA模板,用去离子水进行离心洗涤3~5次,之后放入真空干燥器中干燥12 h,即得铁纳米线阵列。将阳极氧化铝模板结合电化学沉积制备的纳米线利用溶剂热与超声结合的方式将纳米线低维化,首先将制备好的纳米线在设定的温度下进行电磁搅拌或者机械搅拌搅拌,自然冷却至室温后,将在设定的温度下电磁搅拌得到的样品,进行超声浴或者超声探头进行超声处理,即可将纳米线低维化处理成为纳米颗粒。该方法可以将单晶的纳米线转化为单晶的纳米粒子。结果表明,在以N-甲基吡咯烷酮为溶剂时,通过改变溶剂热反应时间、反应温度或超声时间、方式等均可生成银纳米粒子的溶胶,研究了溶剂热反应温度、反应时间,超声时间、方式等因素对纳米粒子形貌、尺寸的影响。
[Abstract]:The template method is easy to operate and the equipment is simple, and the diameter and length of the synthesized material can be controlled by adjusting the pore size and thickness of the template, which provides the basis for the fabrication and application of nanodevices.In this paper, single crystal silver nanowires and iron nanowires were successfully synthesized by using porous anodic alumina template and electrochemical deposition, and their morphology and structure were studied.One-dimensional metal nanocrystals were transformed into zero-dimensional nanoparticles by solvothermal and ultrasonic methods, and nanocrystalline nanoparticles with intrinsic properties were prepared, and the low-dimensional metal nanowires were successfully realized.The effects of reaction time and reaction temperature on the morphology and structure of the products were discussed.The complex post-treatment produced by the addition of surfactants such as dispersants in the reaction system keeps the intrinsic properties of the nanoparticles at the same time.Scanning electron microscopy (SEM), transmission electron microscope (TEM), UV-Vis absorption spectrum (UV-Vis) -X ray diffraction (XRD) and energy dispersive spectroscopy (EDS) were used to characterize one-dimensional metal nanowires and low-dimensional metal nanoparticles.The main work of this thesis is as follows: the preparation of silver nanowire array: firstly, the metal was evaporated on the side of the porous anodic aluminum oxide (PAA) template (the common metal was evaporated by Ag / Au-Ag for 13 min or 10 min) as the working electrode.The silver nanowires were deposited by electrochemical potentiostatic deposition. The silver electrolyte was 28.7 g / L Ag electrolyte. After the deposition was finished, the Ag working electrode was removed by physical method.Then the sample was dissolved in 3M NaOH and the PAA template was dissolved in 3M NaOH. The silver nanowire array was obtained by centrifugation with deionized water for 5 times and then dried in a vacuum dryer for 12 hours.Preparation of iron nanowire arrays: first, the metal was evaporated on one side of the PAA template (the general evaporation metal was Ag / Au-Ag vaporized for 13 min or 10 min) as the working electrode, and then the electrochemically constant potential (-0.9V) was used as the working electrode for the deposition of iron nanowires.Iron electrolyte: FeSO4 7H2O 120 g / L H3BO3 45 g / L Vc 1 g / L.After deposition, Ag working electrode and sacrificial electrode silver were removed by physical method, then the sample was dissolved in 3M NaOH to dissolve PAA template, and the Ag was deposited for 4 min, then Fe nanowires were deposited. After the deposition was finished, the Ag working electrode and sacrificial electrode silver were removed by physical method.Iron nanowire arrays were obtained by centrifugation with deionized water for 5 times and then dried in a vacuum dryer for 12 hours.The nanowires prepared by anodic alumina template and electrochemical deposition were prepared by solvothermal and ultrasonic methods. Firstly, the prepared nanowires were agitated by electromagnetic or mechanical stirring at a given temperature.After natural cooling to room temperature, the samples obtained by electromagnetic stirring at a given temperature were treated by ultrasonic bath or ultrasonic probe, and the nanowires were treated into nanocrystalline particles by low-dimensional treatment.This method can transform the nanowires of single crystals into single crystal nanoparticles.The results show that the sols of silver nanoparticles can be obtained by changing the solvothermal reaction time, reaction temperature or ultrasonic time when N-methylpyrrolidone is used as solvent. The solvothermal reaction temperature and reaction time are studied.The influence of ultrasonic time, mode and other factors on the morphology and size of nanoparticles.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O614.123;TB383.1

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