發(fā)布時(shí)間：2018-05-26 03:59

  本文選題：模板法 + NiFe_2O_4�。� 參考：《河南師范大學(xué)》2017年碩士論文

【摘要】：光催化是處理廢水最理想的反應(yīng),不僅利用了太陽(yáng)能,并且無(wú)有害副產(chǎn)物生成。自從發(fā)現(xiàn)TiO_2光催化分解水以來(lái),人們對(duì)于半導(dǎo)體材料在光催化技術(shù)領(lǐng)域進(jìn)行了廣泛的研究。磁性鐵氧體材料的磁性有利于催化劑的回收,所以磁性鐵氧體材料被應(yīng)用到光催化技術(shù)領(lǐng)域。其中NiFe_2O_4是非常重要的尖晶石鐵氧體材料。NiFe_2O_4的帶隙能為1.7eV,作為光催化劑,吸收太陽(yáng)光中的可見(jiàn)光部分,提高了太陽(yáng)光利用率;同時(shí)NiFe_2O_4的磁性解決了光催化劑回收的難題。到目前為止,關(guān)于NiFe_2O_4光催化降解污染物的研究發(fā)現(xiàn),NiFe_2O_4直接用于光催化降解污染物時(shí),光催化降解率普遍較低。本論文中,使用模板法制備了NiO,Fe_2O_3,并進(jìn)行光催化性能研究;在不同的溫度下以棉纖維為模板制備了多孔NiFe_2O_4,研究了溫度對(duì)于NiFe_2O_4光催化性能的影響;研究了模板法,水熱法,溶膠-凝膠法對(duì)于NiFe_2O_4樣品光催化性能的影響;通過(guò)負(fù)載Bi_2O_3,嘗試優(yōu)化多孔NiFe_2O_4光催化性能;主要實(shí)驗(yàn)內(nèi)容和結(jié)果如下:1.以棉纖維為模板制備了NiO,Fe_2O_3,并進(jìn)行光催化性能研究。NiO樣品,Fe_2O_3樣品的光催化降解率分別為28%,63%。NiO樣品,Fe_2O_3樣品和吸附率分別是24%,46%。由實(shí)驗(yàn)數(shù)據(jù)知,Fe_2O_3樣品光催化效果較好。2.以棉纖維為模板制備多孔NiFe_2O_4,在不同的溫度下(400℃,500℃,600℃)煅燒得到不同樣品的光催化性能,由實(shí)驗(yàn)數(shù)據(jù)知:400℃,500℃,600℃下樣品的吸附率分別為41%,33%,29%,光催化降解率分別為63%,92%,90%,比表面積分別為9.38 m~2/g,12.61 m~2/g,7.21 m~2/g。500℃下樣品的光催化降解率較好,說(shuō)明適中的結(jié)晶度、吸附率以及比表面積可以提高光催化降解率。3.模板法制備多孔NiFe_2O_4樣品,與水熱法,溶膠-凝膠法制備的NiFe_2O_4樣品的催化性能進(jìn)行對(duì)比,由實(shí)驗(yàn)數(shù)據(jù)知,水熱法樣品,溶膠-凝膠法樣品,模板法樣品的光催化降解率分別為23%,69%,92%,吸附率分別為23%,29%,33%,比表面積分別為55.6 m~2/g,12.61 m~2/g,3.59 m~2/g;溶膠-凝膠法和模板法的到的樣品是多孔材料,而水熱法樣品的平均孔徑是12.4nm,屬于介孔材料。說(shuō)明適中的比表面積、孔徑、吸附率可以提高光催化降解率。4.直接煅燒法制備α-Bi_2O_3與多孔NiFe_2O_4復(fù)合,由實(shí)驗(yàn)數(shù)據(jù)知,并沒(méi)有將α-Bi_2O_3負(fù)載到多孔NiFe_2O_4上,純多孔NiFe_2O_4的光催化降解率(92%)較負(fù)載α-Bi_2O_3的光催化降解率(41%)高出51%;說(shuō)明較大粒徑的α-Bi_2O_3與多孔NiFe_2O_4沒(méi)有形成有效的異質(zhì)結(jié)構(gòu),導(dǎo)致光催化降解率的降低;水熱法制備較小粒徑的β-Bi_2O_3與多孔NiFe_2O_4負(fù)載,形成β-Bi_2O_3/NiFe_2O_4異質(zhì)結(jié)構(gòu)。由實(shí)驗(yàn)數(shù)據(jù)知,純多孔NiFe_2O_4的光催化降解率(92%)較負(fù)載β-Bi_2O_3的光催化降解率(42%)高出50%,;說(shuō)明較小粒徑的β-Bi_2O_3負(fù)載到多孔NiFe_2O_4的表面,使得多孔NiFe_2O_4的吸附率降低,導(dǎo)致光催化降解率降低。
[Abstract]:Photocatalysis is the most ideal reaction for wastewater treatment, which not only uses solar energy, but also produces no harmful byproducts. Since the discovery of TiO_2 photocatalytic decomposition of water, semiconductor materials have been widely studied in the field of photocatalytic technology. Magnetic ferrite materials are favorable to the recovery of catalysts, so magnetic ferrite materials have been applied to photocatalytic technology. Among them, NiFe_2O_4 is a very important spinel ferrite material. NiFeS _ 2O _ 4 has a band gap energy of 1.7 EV. As a photocatalyst, it absorbs the visible light in the solar light and improves the utilization ratio of the sunlight. Meanwhile, the magnetic properties of NiFe_2O_4 solve the problem of photocatalyst recovery. Up to now, studies on photocatalytic degradation of pollutants by NiFe_2O_4 have shown that the photocatalytic degradation rate is generally low when NiFeS _ 2O _ 4 is directly used for photocatalytic degradation of pollutants. In this thesis, we have prepared NiO- Fe _ 2O _ 3 by template method and studied its photocatalytic properties; we have prepared porous NiFeS _ 2O _ 4 with cotton fiber as template at different temperatures to study the effect of temperature on the photocatalytic performance of NiFe_2O_4; we have studied template method, hydrothermal method, The effect of sol-gel method on the photocatalytic properties of NiFe_2O_4 samples was studied. The photocatalytic properties of porous NiFe_2O_4 were optimized by loading Bikes _ 2O _ 3. The main experimental contents and results were as follows: 1. NiOG Fe2O3 was prepared by using cotton fiber as template, and the photocatalytic performance of NiO sample was studied. The photocatalytic degradation rate of Fe2O3 sample was 280.63% and NiO sample / Fe2O3 sample was 240.46%, respectively. According to the experimental data, the photocatalytic effect of FeS _ 2O _ 3 sample is better than that of Fe _ S _ 2O _ 3 sample. The porous NiFeS _ 2O _ 4 was prepared by using cotton fiber as template, and calcined at different temperatures (400 鈩，

本文編號(hào)：1935851