鐵氧體納米復(fù)合材料的可控制備及其催化性能研究
發(fā)布時(shí)間：2018-07-30 07:15
【摘要】：納米復(fù)合材料兼具不同材料的多功能性,越來(lái)越引起科技工作者們的廣泛關(guān)注。納米材料的微觀結(jié)構(gòu)往往對(duì)其性能有著巨大的影響,并且多階納米復(fù)合材料的制備中也存在著選擇性生長(zhǎng)的問(wèn)題。本論文主要研究Ag-MxFe3-xO4(M=Co,Mn)納米復(fù)合材料的可控制備及形變,通過(guò)對(duì)不同結(jié)構(gòu)復(fù)合材料催化性能分析,探索納米復(fù)合材料的結(jié)構(gòu)與性能之間的關(guān)系,并采用硫化形變的方法摸索多階納米復(fù)合材料的選擇性生長(zhǎng)規(guī)律。主要研究?jī)?nèi)容如下:(1)采用種晶生長(zhǎng)法制備出Ag@MxFe3-xO4核殼納米顆粒,通過(guò)導(dǎo)電炭黑負(fù)載制備得到Ag@MxFe3-xO4/C,進(jìn)而利用納米銀內(nèi)核在飽和氯化鈉溶液中的氧化溶出制備得到空心MxFe3-xO4/C。通過(guò)不同材料在堿性溶液中的氧還原反應(yīng)(ORR)催化性能分析,發(fā)現(xiàn)Ag@MxFe3-xO4/C的催化活性和導(dǎo)電性都明顯優(yōu)于空心MxFe3-xO4/C。由此推理,納米銀內(nèi)核不僅可以提高納米復(fù)合材料的導(dǎo)電性,而且其協(xié)同作用有利于增強(qiáng)過(guò)渡態(tài)金屬鐵氧體的ORR催化性能。(2)采用種晶生長(zhǎng)法制備出Ag-MFe2O4異質(zhì)納米顆粒,通過(guò)導(dǎo)電炭黑負(fù)載制備得到Ag-MFe2O4/C,進(jìn)而利用納米銀在飽和氯化鈉溶液中的氧化溶解制備得到MFe2O4/C、Ag+MFe2O4/C。通過(guò)不同材料在堿性溶液中的ORR和析氧反應(yīng)(OER)催化性能分析,發(fā)現(xiàn)Ag-MFe2O4/C的催化活性明顯優(yōu)于Ag/C、MFe2O4/C和Ag+MFe2O4/C。由此推理,Ag和MFe2O4納米晶之間的直接耦合和電子轉(zhuǎn)移有助于增強(qiáng)過(guò)渡態(tài)金屬鐵氧體的電催化活性。此外,Ag-MFe2O4/C也表現(xiàn)出良好的循環(huán)穩(wěn)定性和抗甲醇毒性。因此,Ag-MFe2O4/C可以作為一種優(yōu)異的雙功能性非Pt/C電催化劑。(3)通過(guò)分析Ag-CoFe2O4核殼和異質(zhì)納米顆粒的硫化形變過(guò)程,探究多階納米復(fù)合材料的選擇性生長(zhǎng)規(guī)律。針對(duì)硫化產(chǎn)物,結(jié)合軟硬酸堿理論對(duì)其形成機(jī)理進(jìn)行分析,并對(duì)其磁學(xué)性能和光學(xué)性能進(jìn)行了表征。結(jié)果發(fā)現(xiàn),CoS/Ag2S-空心Fe2O3納米復(fù)合材料在常溫下兼具超順磁性和近紅外熒光性能。
[Abstract]:Nanocomposites, with the versatility of different materials, have attracted more and more attention of science and technology workers. The microstructure of nanomaterials often has a great influence on their properties, and there is also a problem of selective growth in the preparation of multi-order nanocomposites. In this paper, the controllable preparation and deformation of Ag-MxFe3-xO4 nanocomposites are studied. The relationship between the structure and properties of the nanocomposites is explored by analyzing the catalytic properties of the composites with different structures. The selective growth of multi-order nanocomposites was studied by means of vulcanization deformation. The main research contents are as follows: (1) Ag@MxFe3-xO4 core-shell nanoparticles were prepared by seed crystal growth method. AgMxFe3-xO4 / C was prepared by conducting carbon black loading, and then hollow MxFe3-xO4 / C was prepared by oxidation dissolution of the nano-silver core in saturated sodium chloride solution. The catalytic activity and conductivity of (ORR) for oxygen reduction reaction of different materials in alkaline solution were analyzed. It was found that the catalytic activity and conductivity of Ag@MxFe3-xO4/C were better than that of hollow MxFe3-xO4 / C. Therefore, the nano-silver core can not only improve the electrical conductivity of the nanocomposites, but also enhance the ORR catalytic performance of the transition metal ferrite. (2) the heterogeneous Ag-MFe2O4 nanoparticles were prepared by seed crystal growth method. Ag-MFe _ 2O _ 4 / C was prepared by conducting carbon black loading, and then prepared by oxidation dissolution of nano-silver in saturated sodium chloride solution to obtain MFe _ 2O _ 4 / C _ (10) Ag. By analyzing the catalytic properties of ORR and (OER) in alkaline solution, it is found that the catalytic activity of Ag-MFe2O4/C is better than that of Ag / C / MFE _ 2O _ 4 / C and Ag / M _ Fe _ 2O _ 4 / C respectively. It is concluded that direct coupling and electron transfer between Ag and MFe2O4 nanocrystals can enhance the electrocatalytic activity of transition metal ferrites. In addition, Ag-MFe _ 2O _ 4 / C also showed good cycling stability and anti-methanol toxicity. Therefore, Ag-MFe _ 2O _ 4 / C can be used as an excellent double-functional non-Pt/C electrocatalyst. (3) the selective growth of multi-order nanocomposites is investigated by analyzing the vulcanization deformation process of Ag-CoFe2O4 core-shell and heterogeneous nanoparticles. The formation mechanism of the vulcanized product was analyzed with the theory of hard and soft acid-base. The magnetic and optical properties of the vulcanized product were characterized. The results show that CoS- / Ag2S- hollow Fe2O3 nanocomposites have both superparamagnetic and near infrared fluorescence properties at room temperature.
【學(xué)位授予單位】：青島科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB383.1;O643.36
本文編號(hào)：2154249
[Abstract]:Nanocomposites, with the versatility of different materials, have attracted more and more attention of science and technology workers. The microstructure of nanomaterials often has a great influence on their properties, and there is also a problem of selective growth in the preparation of multi-order nanocomposites. In this paper, the controllable preparation and deformation of Ag-MxFe3-xO4 nanocomposites are studied. The relationship between the structure and properties of the nanocomposites is explored by analyzing the catalytic properties of the composites with different structures. The selective growth of multi-order nanocomposites was studied by means of vulcanization deformation. The main research contents are as follows: (1) Ag@MxFe3-xO4 core-shell nanoparticles were prepared by seed crystal growth method. AgMxFe3-xO4 / C was prepared by conducting carbon black loading, and then hollow MxFe3-xO4 / C was prepared by oxidation dissolution of the nano-silver core in saturated sodium chloride solution. The catalytic activity and conductivity of (ORR) for oxygen reduction reaction of different materials in alkaline solution were analyzed. It was found that the catalytic activity and conductivity of Ag@MxFe3-xO4/C were better than that of hollow MxFe3-xO4 / C. Therefore, the nano-silver core can not only improve the electrical conductivity of the nanocomposites, but also enhance the ORR catalytic performance of the transition metal ferrite. (2) the heterogeneous Ag-MFe2O4 nanoparticles were prepared by seed crystal growth method. Ag-MFe _ 2O _ 4 / C was prepared by conducting carbon black loading, and then prepared by oxidation dissolution of nano-silver in saturated sodium chloride solution to obtain MFe _ 2O _ 4 / C _ (10) Ag. By analyzing the catalytic properties of ORR and (OER) in alkaline solution, it is found that the catalytic activity of Ag-MFe2O4/C is better than that of Ag / C / MFE _ 2O _ 4 / C and Ag / M _ Fe _ 2O _ 4 / C respectively. It is concluded that direct coupling and electron transfer between Ag and MFe2O4 nanocrystals can enhance the electrocatalytic activity of transition metal ferrites. In addition, Ag-MFe _ 2O _ 4 / C also showed good cycling stability and anti-methanol toxicity. Therefore, Ag-MFe _ 2O _ 4 / C can be used as an excellent double-functional non-Pt/C electrocatalyst. (3) the selective growth of multi-order nanocomposites is investigated by analyzing the vulcanization deformation process of Ag-CoFe2O4 core-shell and heterogeneous nanoparticles. The formation mechanism of the vulcanized product was analyzed with the theory of hard and soft acid-base. The magnetic and optical properties of the vulcanized product were characterized. The results show that CoS- / Ag2S- hollow Fe2O3 nanocomposites have both superparamagnetic and near infrared fluorescence properties at room temperature.
【學(xué)位授予單位】：青島科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB383.1;O643.36
【參考文獻(xiàn)】
相關(guān)期刊論文 前3條
1 何曉燕,俞梅;納米銀粒子的化學(xué)法制備及其表征[J];蘭州交通大學(xué)學(xué)報(bào);2005年03期
2 姚素薇,劉恒權(quán),張衛(wèi)國(guó),王宏智,鄭長(zhǎng)峰;在線性殼聚糖膜內(nèi)原位還原制備銀納米粒子及銀單晶體[J];物理化學(xué)學(xué)報(bào);2003年05期
3 梁海春,容敏智,章明秋,曾漢民;微乳液法制備納米銀粒子的結(jié)構(gòu)及其熒光現(xiàn)象研究[J];物理學(xué)報(bào);2002年01期
，本文編號(hào)：2154249
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