熔融盐法制备几种碳膜负载的纳米粒子及其性能研究
发布时间：2018-07-17 15:01
【摘要】：单分散性纳米材料因其均一的尺寸分布、表面性质的可控性、量子尺寸效应而表现出特殊的物理化学性质。构建具有功能特性的纳米材料在催化、高密度信息存储、生物荧光标记、核磁共振成像等领域已表现出潜在的应用前景。目前,在制备单分散纳米材料的方法中不可避免的要使用油酸(OA)或油胺(OAm)等长碳链有机分子作为表面活性剂来调控粒子的尺寸和形貌。而当这些单分散纳米粒子被应用于催化、气敏、电化学等领域时,包裹在粒子表面的长碳链有机分子往往会成为阻碍。为克服纳米粒子应用上的缺陷,本论文以Na2SO4作为导热剂采用熔融盐焙烧法,通过调整不同的实验参数制备出Bi-Bi2O3/C纳米材料,CoO/C纳米材料和Ni/C纳米材料。并对所合成的材料在光催化,电化学及气敏方面的应用进行了初步探究。主要研究内容与结论如下:Bi-Bi2O3/C纳米材料的制备和光催化性能研究:以Bi(OH)3@OA为前驱体,在Ar气氛中以无机盐Na2SO4作为牺牲模版,通过调节惰性气体的流速并采用不同的焙烧温度得到Bi-Bi2O3/C纳米复合材料。采用X射线粉末衍射(XRD)技术,透射电子显微镜(TEM)和扫描电子显微镜(SEM)对其进行物相、尺寸、形貌等微观结构的表征。结果表明:不同焙烧温度条件下得到产物为碳膜上负载的尺寸在20-60 nm之间的Bi-Bi2O3纳米球。并考察了四种Bi-Bi2O3/C纳米材料对亚甲基蓝(MB),甲基橙(MO)和罗丹明B(RhB)染料溶液的光催化降解能力。光催化结果表明:在100 W汞灯光照下,400℃焙烧得到的Bi-Bi2O3/C纳米材料在3.5 h内使10 mg/L的MB,MO,RhB染料溶液降解完全。CoO/C纳米材料的制备和电化学性能研究:以Co(OH)2@OA为前驱体,在Ar气氛中以无机盐Na2SO4作为牺牲模版,考察不同的焙烧温度对CoO/C和Co/C纳米材料的物相和电化学性能影响。结果表明,350℃,400℃和500℃焙烧得到碳膜上负载的CoO纳米颗粒,600℃焙烧则得到碳膜上负载的单质Co纳米颗粒,且CoO和单质Co纳米颗粒尺寸均在7-12 nm之间。材料电化学测试结果表明:400℃下合成的材料,在电流密度为70 mA·g-1时,首次放电容量达1139.1mAh·g-1,经50圈循环后放电容量为642.1 mAh·g-1,容量保持率为95%。Ni/C纳米材料的制备和气敏性能研究:以Ni(OH)2@OA为前驱体,在Ar气氛中以无机盐Na2SO4作为牺牲模版,通过调控温度发现,当焙烧温度为400℃时,得到尺寸和形貌分布均匀的Ni/C纳米材料。将此材料采用不同温度和时间利用Kirkendall effect氧化时可得到尺寸在20-70 nm之间的中空结构NiO球。通过对得到的NiO纳米材料进行气敏性能的初步研究。结果表明:在氧化条件为500℃,4 h时得到的NiO材料对正丁醇表现出优异的选择性和较高的响应性(1000 ppm,Rg/Ra=9.0)。
[Abstract]:Monodisperse nanomaterials exhibit special physical and chemical properties due to their uniform size distribution, controllable surface properties and quantum size effect. The fabrication of functional nanomaterials has shown potential applications in the fields of catalysis, high density information storage, bioluminescence labeling, magnetic resonance imaging and so on. At present, it is inevitable to use long chain organic molecules such as oleic acid (OA) or oleamine (OAM) as surfactants to control the size and morphology of nanoparticles in the preparation of monodisperse nanomaterials. However, when these monodisperse nanoparticles are applied in the fields of catalysis, gas sensitivity, electrochemistry and so on, the organic molecules with long carbon chains on the surface of the particles often become obstacles. In order to overcome the defects in the application of nano-particles, Bi-Bi2O3 / C nanomaterials and Ni / C nanomaterials were prepared by using Na _ 2SO _ 4 as heat conduction agent by molten salt roasting method and by adjusting different experimental parameters. The applications of the synthesized materials in photocatalysis, electrochemistry and gas sensitivity were also discussed. The main contents and conclusions are as follows: the preparation and photocatalytic properties of Bi-Bi _ 2O _ 3 / C nanomaterials were studied: using Bi (OH) _ 3SO _ 3 as precursor and inorganic salt Na _ 2SO _ 4 as sacrificial template in ar atmosphere. Bi-Bi _ 2O _ 3 / C nanocomposites were prepared by adjusting the flow rate of inert gas and using different calcination temperatures. X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM) were used to characterize the phase, size and morphology. The results showed that Bi-Bi2O3 nanospheres with the size of 20-60 nm were obtained under different calcination temperature. The photocatalytic degradation of methylene blue (MB), methyl orange (MO) and rhodamine B (RhB) dyes by four Bi-Bi _ 2O _ 3 / C nanomaterials was investigated. The photocatalytic results showed that Bi-Bi _ 2O _ 3 / C nanomaterials calcined at 400 鈩，
本文编号：2130021
[Abstract]:Monodisperse nanomaterials exhibit special physical and chemical properties due to their uniform size distribution, controllable surface properties and quantum size effect. The fabrication of functional nanomaterials has shown potential applications in the fields of catalysis, high density information storage, bioluminescence labeling, magnetic resonance imaging and so on. At present, it is inevitable to use long chain organic molecules such as oleic acid (OA) or oleamine (OAM) as surfactants to control the size and morphology of nanoparticles in the preparation of monodisperse nanomaterials. However, when these monodisperse nanoparticles are applied in the fields of catalysis, gas sensitivity, electrochemistry and so on, the organic molecules with long carbon chains on the surface of the particles often become obstacles. In order to overcome the defects in the application of nano-particles, Bi-Bi2O3 / C nanomaterials and Ni / C nanomaterials were prepared by using Na _ 2SO _ 4 as heat conduction agent by molten salt roasting method and by adjusting different experimental parameters. The applications of the synthesized materials in photocatalysis, electrochemistry and gas sensitivity were also discussed. The main contents and conclusions are as follows: the preparation and photocatalytic properties of Bi-Bi _ 2O _ 3 / C nanomaterials were studied: using Bi (OH) _ 3SO _ 3 as precursor and inorganic salt Na _ 2SO _ 4 as sacrificial template in ar atmosphere. Bi-Bi _ 2O _ 3 / C nanocomposites were prepared by adjusting the flow rate of inert gas and using different calcination temperatures. X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM) were used to characterize the phase, size and morphology. The results showed that Bi-Bi2O3 nanospheres with the size of 20-60 nm were obtained under different calcination temperature. The photocatalytic degradation of methylene blue (MB), methyl orange (MO) and rhodamine B (RhB) dyes by four Bi-Bi _ 2O _ 3 / C nanomaterials was investigated. The photocatalytic results showed that Bi-Bi _ 2O _ 3 / C nanomaterials calcined at 400 鈩，
本文编号：2130021
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