發(fā)布時(shí)間：2018-06-22 05:07

  本文選題：ZnO + 復(fù)合薄膜��； 參考：《北京化工大學(xué)》2010年碩士論文

【摘要】： 本論文針對(duì)氧化鋅在實(shí)際應(yīng)用中尚存在不足,如光催化效率低、光譜吸收范圍窄和粉末回收困難等問(wèn)題,提出采用在LDHs層板上引入過(guò)渡金屬的三元類(lèi)水滑石(LDHs)為前驅(qū)體,再經(jīng)涂敷熱分解法制備得到改性的ZnO復(fù)合薄膜材料。采用X-射線衍射(XRD)、紫外-可見(jiàn)吸收光譜(UV-Vis)、傅立葉變換紅外光譜(FT-IR)、熱重-差熱分析(TG-DTA)、比表面-孔徑分析(BET)、場(chǎng)發(fā)射掃描電鏡-能量散射譜分析(SEM-EDS)等測(cè)試手段對(duì)所得改性Zn0復(fù)合材料進(jìn)行結(jié)構(gòu)、組成、形貌以及性能等進(jìn)行表征,并分別以甲基橙和亞甲基藍(lán)作為目標(biāo)降解物,考察其在紫外光和可見(jiàn)光下的光催化活性,對(duì)其改性效果進(jìn)行評(píng)價(jià)。具體研究結(jié)果如下： (1)制備了不同投料比的銅鋅鋁層狀前體,并考察了不同焙燒溫度對(duì)三元ZnO復(fù)合薄膜的結(jié)構(gòu)及催化性能的影響,結(jié)果表明,煅燒溫度為500℃時(shí),[Cu2+]/[Zn2+]/[Al3+]投料比為1/6/2的三元ZnO復(fù)合薄膜的光催化能力最強(qiáng)；在此條件下,在6h內(nèi)在紫外光和可見(jiàn)光照射下,對(duì)甲基橙和亞甲基藍(lán)的降解率可分別達(dá)到92.6%和92.5%。分析結(jié)果表明,最優(yōu)條件下制備的三元ZnO復(fù)合薄膜由于ZnO高度均勻分散在其它基質(zhì)金屬氧化物相中,從而使整體組成和結(jié)構(gòu)高度均勻,有利于催化性能的提高；同時(shí)由于Cu2+對(duì)ZnO的改性,使得ZnO的帶隙寬度隨Cu2+含量的增加而減小,增強(qiáng)了ZnO的可見(jiàn)光催化降解能力。 (2)制備了不同比例鈷鋅鋁層狀前體,考察了不同焙燒溫度對(duì)三元ZnO復(fù)合薄膜的結(jié)構(gòu)和性能的影響,發(fā)現(xiàn)焙燒溫度越高,制得的三元ZnO復(fù)合薄膜就越致密,但是隨著焙燒溫度的升高,其催化活性漸降低。最佳制備條件下(500℃焙燒,[Co2+]/[Zn2+]/[Al3+]投料比為1/6/2)制得的氧化鋅復(fù)合薄膜具有最強(qiáng)的光催化能力,在紫外光和可見(jiàn)光照射下,6h對(duì)甲基橙和亞甲基藍(lán)的降解率可分別達(dá)到93.6%和84.0%。而900℃焙燒得到的薄膜沒(méi)有光催化能力。分析結(jié)果表明,最優(yōu)條件下制備的三元ZnO復(fù)合薄膜由于Co2+在可見(jiàn)光范圍內(nèi)具有較強(qiáng)的響應(yīng),同時(shí)還能使ZnO復(fù)合薄膜的光吸收帶邊向可見(jiàn)光區(qū)域擴(kuò)展,因此,隨著Co2+含量的增加,ZnO的可見(jiàn)光催化降解能力逐漸增強(qiáng)。
[Abstract]:In order to solve the problems of zinc oxide in practical application, such as low photocatalytic efficiency, narrow spectrum absorption range and difficulty in powder recovery, the ternary hydrotalcite (LDHs) which introduced transition metal into LDHs laminates was proposed as the precursor. The modified ZnO composite films were prepared by thermal decomposition method. X-ray diffraction (XRD), UV-Vis absorption spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric differential thermal analysis (TG-DTA), specific surface pore size analysis (BET), field emission scanning electron microscopy (SEM) and energy scattering spectroscopy (SEM-EDS) were used to improve the results. The structure of Zn0 composite, The composition, morphology and properties of methyl orange and methylene blue were characterized. The photocatalytic activity of methyl orange and methylene blue were investigated under UV and visible light, respectively, and the modification effect was evaluated. The results are as follows: (1) the layered precursors of copper, zinc and aluminum with different feed ratios were prepared, and the effects of calcination temperature on the structure and catalytic performance of ZnO composite films were investigated. The photocatalytic activity of [Cu _ 2] / [Zn _ 2] / [Al3] composite films with the ratio of [Cu _ 2] / [Zn _ 2] / [Al3] was the strongest at 500 鈩，

本文編號(hào)：2051710