發(fā)布時(shí)間：2018-03-10 19:15

  本文選題：親水性　切入點(diǎn)：羧基化碳納米管　出處：《天津工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：二氧化鈦是一種安全無毒、化學(xué)活性高、價(jià)格低廉、容易合成的納米材料,尤其是其優(yōu)異的催化活性,可以作為水環(huán)境的凈化處理,受到了人們的廣泛關(guān)注,所以,納米TiO_2是目前最合適的催化劑之一。但是,由于實(shí)驗(yàn)室所制備的TiO_2可能會(huì)有顆粒分布不均,分散性較差,易團(tuán)聚,而且TiO_2是一種半導(dǎo)體復(fù)合物,其電子-空穴對極容易復(fù)合,其禁帶寬度大,只能用紫外光激發(fā),不能有效地利用可見光和太陽能。這些都會(huì)導(dǎo)致TiO_2的催化效率降低。許多研究指出可以添加金屬或非金屬元素對TiO_2做出改性處理。本文主要通過溶膠-凝膠法,以鈦酸丁酯為原料,制備了純TiO_2光催化劑。利用親水性多壁碳納米管(oCNTs)對納米TiO_2進(jìn)行了改性處理,制備了羧基化碳納米管負(fù)載納米二氧化鈦(TiO_2/oCNTs)復(fù)合光催化劑,并對TiO_2/oCNTs復(fù)合光催化劑進(jìn)行了催化性能的研究和分析;通過過渡金屬Fe對TiO_2/oCNTs復(fù)合光催化劑進(jìn)行了摻雜研究分析。而且,通過TiO_2光催化劑、TiO_2/oCNTs復(fù)合光催化劑和Fe-TiO_2/oCNTs復(fù)合光催化劑對模擬污染物甲基橙的光催化降解效果評價(jià)了光催化劑催化活性的高低。(1)羧基化的多壁碳納米管經(jīng)過超聲震蕩處理后,比原始碳管在有機(jī)溶劑中的分散性要更好,團(tuán)聚的較少,互相纏結(jié)也比較少,易于與鈦酸丁酯結(jié)合;(2)通過 TEM、XRD、XPS、FT-IR、UV-vis 等表征手段對 oCNTs 和TiO_2/oCNTs進(jìn)行測試分析,證明oCNTs是官能化的,并且oCNTs的表面負(fù)載上了納米TiO_2粒子;(3)納米TiO_2光催化劑對模擬污染物甲基橙的光催化降解效果的評價(jià),證實(shí)了 TiO_2光催化劑降解甲基橙的最佳條件是:納米TiO_2的煅燒溫度為450℃,TiO_2光催化劑的濃度為0.8 g/L,甲基橙溶液的濃度為20mg/L,甲基橙溶液的pH值為3.64;(4)oCNTs相對于納米TiO_2為3wt%,可以有效地提高TiO_2/oCNTs復(fù)合材料的光催化性能,而oCNTs在低含量時(shí),在一定程度上促進(jìn)納米TiO_2的負(fù)載,提升TiO_2/oCNTs復(fù)合材料光催化性能;oCNTs高含量時(shí),會(huì)因團(tuán)聚纏結(jié),降低TiO_2/oCNTs復(fù)合材料的光催化活性。其中,TiO_2/oCNTs復(fù)合材料的光催化利用率可達(dá)到95%;(5)通過Fe~(3+)對TiO_2/oCNTs復(fù)合材料的摻雜改性,發(fā)現(xiàn)Fe~(3+)可以置換TiO_2中的Ti4+,進(jìn)而破壞TiO_2的晶格結(jié)構(gòu),光照下減少TiO_2中電子—空穴對的復(fù)合,提高復(fù)合材料的光催化活性。Fe~(3+)的最佳添加量為6wt%。
[Abstract]:Titanium dioxide is a kind of safe and non-toxic, high chemical activity, low cost, easy to synthesize nanomaterials, especially its excellent catalytic activity, which can be used as purification treatment of water environment. Nanocrystalline TiO_2 is one of the most suitable catalysts at present. However, the TiO_2 prepared in the laboratory may have uneven particle distribution, poor dispersion and easy agglomeration. Moreover, TiO_2 is a semiconductor complex, and its electron-hole pair is very easy to recombine. The band gap is so wide that it can only be excited by ultraviolet light. It is pointed out that TiO_2 can be modified by adding metal or non-metallic elements. Pure TiO_2 photocatalyst was prepared by using butyl titanate as raw material, and modified by hydrophilic multiwalled carbon nanotubes (MwCNTs) to prepare carboxylated carbon nanotubes (CNTs) supported nano-TiO _ 2 / TIO _ 2 / TIO _ 2 composite photocatalyst. The catalytic performance of TiO_2/oCNTs composite photocatalyst was studied and analyzed, and the doping of TiO_2/oCNTs composite photocatalyst was studied by transition metal Fe. The photocatalytic degradation of methyl orange, a simulated pollutant, was evaluated by the photocatalytic degradation of TiO-2 / TiOCNTs composite photocatalyst and Fe-TiO_2/oCNTs photocatalyst. The carboxylated multi-walled carbon nanotubes (MWCNTs) were treated by ultrasonic shock. The dispersity of carbon tubes in organic solvents is better than that of original carbon tubes, the agglomeration is less, the entanglement is less, and it is easy to bind with butyl titanate. (2) oCNTs and TiO_2/oCNTs are characterized by means of TEM, XRDX, XPSN, FT-IR, UV-vis, and so on. The results show that oCNTs is functionalized. The photocatalytic degradation of methyl orange, a simulated pollutant, was evaluated by nanometer TiO_2 photocatalyst supported on the surface of oCNTs. The optimum conditions for degradation of methyl orange by TiO_2 photocatalyst are as follows: the calcination temperature of nanometer TiO_2 is 450 鈩，

本文編號：1594695