發(fā)布時(shí)間：2019-02-26 08:01

【摘要】：納米材料是一種由尺寸介于1至100 nm之間的粒子組成的物質(zhì),具有較大的比表面積,以及擁有異于普通材料的特殊性能及較高的催化活性,成為20世紀(jì)末21世紀(jì)初科研工作者的研究焦點(diǎn)之一。有目的的按照人們的需要將兩種或兩種以上具有不同性質(zhì)的納米粒子復(fù)合在一起形成具有特殊性質(zhì)的復(fù)合材料是納米科學(xué)的研究熱點(diǎn)。本文以Zn O和Ti O2為研究對(duì)象,通過(guò)不同的實(shí)驗(yàn)方法分別在Zn O和Ti O2上負(fù)載在可見(jiàn)光區(qū)域活性較強(qiáng)的貴金屬和聚合物,通過(guò)三者之間的協(xié)同作用可以很好的提升Zn O和Ti O2的活性。本文的主要研究?jī)?nèi)容如下:1.在乙二醇與水的混合溶劑中用預(yù)先合成的Ag納米粒子作種子,聚乙烯吡咯烷酮(PVP)作表面活性劑,通過(guò)乙酸鋅和六次甲基四胺(HMT)之間的快速反應(yīng)合成了花生狀的Zn O-Ag異質(zhì)結(jié)構(gòu)。分散在Zn O粒子表面的Ag納米粒子增加了Zn O在催化降解甲基藍(lán)時(shí)的活性,而且經(jīng)實(shí)驗(yàn)證明在Zn O-Ag表面再覆蓋一層聚吡咯(PPy)薄膜可以進(jìn)一步增加其催化活性。原因有兩點(diǎn):一方面,PPy的存在保護(hù)了Zn O表面上的Ag粒子在紫外光與可見(jiàn)光照射下不被氧化以及丟失;另一方面,PPy在可見(jiàn)光下可以吸收光子增加樣品在催化降解過(guò)程中的光吸收率。2.首先在30℃的恒溫下,Ti Cl4經(jīng)過(guò)簡(jiǎn)單的水解反應(yīng),不同的時(shí)間段內(nèi)產(chǎn)生不同形貌的Ti O2,且不同形貌的產(chǎn)物產(chǎn)量不同,實(shí)驗(yàn)發(fā)現(xiàn)處于花狀或棒狀的Ti O2的產(chǎn)量最多。結(jié)合花狀產(chǎn)物的合成時(shí)間相對(duì)較短,我們最終選擇花狀Ti O2作為研究對(duì)象進(jìn)行復(fù)合。將預(yù)先合成的Ti O2粉末分散在乙醇中,與同樣分散在乙醇中的Au粒子混合,超聲生成Ti O2-Au復(fù)合粒子。再經(jīng)過(guò)原位聚合的方法在Ti O2-Au粒子表面覆蓋一層聚苯胺(PANI)薄膜,成功的合成出了Ti O2-AuPANI三元復(fù)合材料。
[Abstract]:A nano-material is a substance consisting of particles between 1 and 100 nm in size, having a large specific surface area, as well as special properties and high catalytic activity different from those of ordinary materials. It has become one of the research focuses of researchers in the end of 20th century and the beginning of 21st century. It is a research hotspot of nano-science to combine two or more kinds of nano-particles with different properties to form composite materials with special properties according to the needs of people. In this paper, Zn O and Ti O 2 were taken as research objects, and precious metals and polymers with strong activity in visible light region were loaded on Zn O and Ti O 2 by different experimental methods, respectively. The activities of Zn O and Ti O 2 can be enhanced by the synergistic action among them. The main contents of this paper are as follows: 1. In the mixed solvent of ethylene glycol and water, pre-synthesized Ag nanoparticles were used as seeds and polyvinylpyrrolidone (PVP) as surfactant. Peanut-like Zn O-Ag heterostructures were synthesized by the rapid reaction between zinc acetate and hexamethylenetetramine (HMT). The Ag nanoparticles dispersed on the surface of Zn O particles increased the activity of Zn O in the catalytic degradation of methyl blue, and it was proved by experiments that another layer of polypyrrole (PPy) film on the surface of Zn O-Ag could further increase its catalytic activity. There are two reasons for this: on the one hand, the existence of PPy protects the Ag particles on the Zn O surface from oxidation and loss under UV and visible light irradiation; On the other hand, PPy can absorb photons in visible light to increase the photoabsorptivity of the sample in the process of catalytic degradation. 2. At the constant temperature of 30 鈩，

本文編號(hào)：2430587