本文選題：空心雙層微球　切入點：吸附　出處：《大連理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：空心微球具有大比表面積、低密度、形貌可控等優(yōu)點,在污水處理、納米反應(yīng)器、催化、藥物緩釋、超級電容器、光電等領(lǐng)域有很好的應(yīng)用前景。而空心多層微球與空心單層微球相比具有更大的比表面積、更好的結(jié)構(gòu)穩(wěn)定性和優(yōu)異的功能,在相關(guān)應(yīng)用上具有更多的優(yōu)勢。目前空心多層微球的制備主要采用多次化學(xué)沉積、層層自組裝等方法,過程復(fù)雜耗時,且難以回收再利用。因此,如何用簡單有效的方法合成易回收的空心多層微球成為了人們的研究熱點。本論文采用一步氣溶膠法合成了兩殼層組分不同的磁性空心雙層微球,并研究了該微球的相關(guān)性能。論文首先用一步氣溶膠法及溶解-再生長機理合成了磁性空心C/SiO2雙層微球,該微球內(nèi)層為C殼,外層為SiO2殼,且兩層間有約50nm的空隙,磁性物質(zhì)均勻分布在殼層中。該微球擁有較大的比表面積和孔體積(分別為226.3m2/g和0.51cm3/g),利于對分子的吸附,研究了其對亞甲基藍(MB)和金屬離子Pb2+、Ag+的吸附性能。結(jié)果表明,該微球?qū)B的最大飽和吸附量可達到171.2mg/g高于SiO2單層微球的最大飽和吸附量(150.0mg/g)。在重復(fù)使用5次后,對MB的去除率仍能達到95%以上。磁性微球?qū)B的吸附符合Langmuir模型。磁性雙層微球?qū)b2+、Ag+的最大飽和吸附量可分別達到216.5 mg/g和283.1 mg/g高于SiO2單層微球的最大飽和吸附量(189.8mg/g和213.4mg/g),重復(fù)使用5次后,雙層微球?qū)b2+、Ag+的最大飽和吸附量仍能達到180 mg/g和245 mg/g。另外,在吸附過程中可通過外加磁場對磁性微球進行有效回收。將磁性空心C/SiO2雙層微球作為載體制備了磁性空心C/SiO2-Au微球和C/Au/C微球并考察了它們對對硝基苯酚(4-NP)的催化性能。實驗結(jié)果表明磁性空心C/SiO2-Au微球?qū)?-NP具有很好的催化性能,C/Au/C微球與C/SiO2-Au微球相比具有更好的穩(wěn)定性,且催化性能良好。兩種微球均可通過外加磁場進行回收。最后以該磁性空心C/SiO2雙層微球作為模板制備了空心C/C雙層微球,該微球具有較大的比表面積(482.0m2/g)和孔體積(0.92cm3/g)是一種較理想的超級電容器電極材料。測試結(jié)果表明,其在電流密度為0.1A/g時電極的比電容達到251F/g。在電流密度為1A/g時,經(jīng)過5000次的循環(huán)實驗電極的比電容減少了5.4%,說明空心C/C雙層微球電極具有優(yōu)異的電極循環(huán)穩(wěn)定性能。
[Abstract]:Hollow microspheres have many advantages, such as large specific surface area, low density, controllable morphology, etc., in sewage treatment, nanoreactor, catalysis, drug release, supercapacitor, etc. The hollow multilayer microspheres have more specific surface area, better structural stability and better function than hollow monolayer microspheres. There are more advantages in related applications. At present, the hollow multilayer microspheres are prepared by chemical deposition and self-assembly, the process is complicated and time-consuming, and it is difficult to recover and reuse. How to synthesize hollow multilayer microspheres which are easy to be recovered by simple and effective method has become a hot topic. In this paper, the magnetic hollow bilayer microspheres with different components of two shell layers were synthesized by one-step aerosol method. The properties of the microspheres were also studied. Firstly, the magnetic hollow C / Sio _ 2 bilayer microspheres were synthesized by one-step aerosol method and solution-regrowth mechanism. The microspheres were C-shell in inner layer and SiO2 shell in outer layer, with a gap of about 50 nm between the two layers. The magnetic material is uniformly distributed in the shell. The microsphere has a large specific surface area and pore volume (226.3 m2 / g and 0.51cm ~ (-3) / g / g respectively, which is favorable for the adsorption of molecules. The adsorption properties of the microspheres for methylene blue MBs) and metal ion Pb2 (Ag) have been studied. The maximum saturated adsorption capacity of the microspheres to MB was 171.2 mg / g higher than that of SiO2 monolayer microspheres. The removal rate of MB can still reach more than 95%. The adsorption of MB on magnetic microspheres accords with Langmuir model. The maximum saturated adsorption capacity of magnetic bilayer microspheres for Pb2 + Ag can reach 216.5 mg/g and 283.1 mg/g respectively, which is higher than that of SiO2 monolayer microspheres. It's 189.8 mg / g and 213.4mg / g, and it's been reused for five times. The maximum saturated adsorption capacity of the double layer microspheres for Pb2 Ag can still reach 180 mg/g and 245 mg / g. Magnetic hollow C / Sio _ 2-Au microspheres and C / au / C microspheres were prepared by magnetic hollow C / Sio _ 2 bilayer microspheres and their catalytic properties for p-nitrophenol 4-NPs were investigated. The experimental results show that the magnetic hollow C / SiO2-Au microspheres have good catalytic performance for 4-NP. The C / au / C microspheres have better stability than C / SiO2-Au microspheres. The two kinds of microspheres can be recovered by external magnetic field. Finally, hollow C / C bilayer microspheres were prepared by using the hollow C / SiO2 bilayer microspheres as template. The microspheres with a large specific surface area of 482.0 m2 / g) and pore volume of 0.92cm3 / g) are ideal electrode materials for supercapacitors. The test results show that the specific capacitance of the electrode reaches 251F / g when the current density is 0.1Ag. When the current density is 1 / g, the specific capacitance of the electrode is 251F / g. The specific capacitance of the electrode is reduced by 5.4 after 5000 cycles, which indicates that the hollow C / C double layer microsphere electrode has excellent cycling stability.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：O613.72;TB383.1

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相關(guān)碩士學(xué)位論文 前1條

1 王萌;碳球與SnO_2空心球的制備及其電化學(xué)性能研究[D];大連理工大學(xué);2013年

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本文編號：1617940