發(fā)布時間：2018-01-29 19:28

  本文關(guān)鍵詞： 鐵氧體/LDH復(fù)合材料 光催化 產(chǎn)氫 電鍍廢水 酸洗廢液　出處：《上海大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：本研究在課題組前期工作的基礎(chǔ)上,通過溶膠凝膠法成功制備了三種尖晶石型鐵氧體Cu Fe2O4、Ni Fe2O4和Zn Fe2O4;選擇光催化性能最優(yōu)的Cu Fe2O4作為磁性前驅(qū)體,采用微波水熱法將其負(fù)載在層狀雙金屬氫氧化物上制備新型鐵氧體/LDH磁性復(fù)合材料(Cu Fe2O4/Zn2Cr-LDH);并以電鍍廢水和酸洗廢液作為原材料,通過兩步微波水熱法制備廢物基鐵氧體和廢物基磁性復(fù)合材料(CFL),同時凈化重金屬廢水中的金屬離子。在模擬可見光照射的條件下,測試了此類材料的光催化裂解水產(chǎn)氫性能,并研究了不同因素對其產(chǎn)氫性能的影響以及廢物基磁性復(fù)合材料的最優(yōu)合成條件。研究工作得到了以下主要結(jié)論:(1)通過溶膠凝膠法制備的Cu Fe2O4具有粒徑小、分散性好、結(jié)構(gòu)邊緣平滑清晰可見、磁性強(qiáng)的優(yōu)點(diǎn),其粒徑為20 nm左右、飽和磁化強(qiáng)度為18.16 emu/g。光催化產(chǎn)氫實(shí)驗(yàn)表明:Cu Fe2O4具有優(yōu)秀的可見光響應(yīng)性能,在6h內(nèi)的總產(chǎn)氫量為791.9μmol·g-1,并表現(xiàn)出良好的光催化穩(wěn)定性。最適宜的催化劑投加量為0.8 g/L,最適宜的犧牲劑為乙醇,犧牲劑投加量為溶液體積分?jǐn)?shù)的10%。(2)通過溶膠凝膠-微波水熱法聯(lián)用制備磁性復(fù)合材料Cu Fe2O4/Zn2Cr-LDH,其飽和磁化強(qiáng)度為8.47 emu/g,在6h內(nèi)的總產(chǎn)氫量為1567.7μmol·g-1,幾乎是純Cu Fe2O4或Zn2Cr-LDH的一倍以上。在復(fù)合材料的內(nèi)部存在電子由鐵氧體向LDH部分遷移的現(xiàn)象,有助于可見光激發(fā)的空穴和電子對分離,提高其光催化性能。單因素試驗(yàn)表明磁性復(fù)合材料光催化裂解水產(chǎn)氫的最優(yōu)反應(yīng)條件為:合成p H值為7、Cu Fe2O4負(fù)載量為0.20 g、Cu Fe2O4/Zn2Cr-LDH投加量為1.0 g/L、犧牲劑投加量為溶液體積分?jǐn)?shù)的10%。該磁性復(fù)合材料至少可以重復(fù)利用三次并保持較穩(wěn)定的結(jié)構(gòu)和光催化性能。(3)通過微波水熱法制備廢物基鐵氧體可有效凈化重金屬廢水,堿性環(huán)境有助于鐵氧體晶格結(jié)構(gòu)的形成。實(shí)驗(yàn)表明在p H=7~10、合成時間t=15~40 min、合成溫度T=100~180 oC的范圍內(nèi),通過兩步微波水熱法合成廢物基CFL對廢水中的重金屬去除率可達(dá)到90%以上。廢物基CFL光催化產(chǎn)氫性能略優(yōu)于廢物基Cu Fe2O4,在4h內(nèi)的總產(chǎn)氫量為343.9μmol·g-1。受到重金屬廢水中復(fù)雜成分的影響,廢物基CFL的光催化性能與純藥劑合成材料存在明顯差距。在連續(xù)光照后廢物基CFL的結(jié)構(gòu)仍然保持完整、重金屬離子的釋放量低,說明其作為光催化劑的穩(wěn)定性能較好。通過單因素試驗(yàn)研究不同合成條件對材料光催化性能的影響,并根據(jù)響應(yīng)曲面法模擬CFL的最優(yōu)合成條件。
[Abstract]:Based on the previous work of our research group, three kinds of spinel ferrite Cu Fe 2O 4 Ni Fe2O4 and Zn Fe 2O 4 have been successfully prepared by sol-gel method. Cu Fe2O4, which has the best photocatalytic activity, is chosen as the magnetic precursor. A new type of ferrite / LDH magnetic composite, CuFe2O4 / Zn2Cr-LDHN, was prepared by microwave hydrothermal method on layered bimetallic hydroxides. Waste ferrite and waste magnetic composite (CFL) were prepared by two-step microwave hydrothermal method using electroplating wastewater and pickling waste liquid as raw materials. At the same time, the metal ions in heavy metal wastewater were purified. Under the condition of simulated visible light irradiation, the photocatalytic cracking of aquatic hydrogen was tested. The effects of different factors on the hydrogen production properties and the optimum synthesis conditions of the waste based magnetic composites were studied. The main conclusions are as follows: 1). The Cu Fe2O4 prepared by sol-gel method has small particle size. It has the advantages of good dispersion, smooth structure edge and strong magnetic properties, and its particle size is about 20 nm. The saturation magnetization is 18.16 emu / g. The photocatalytic hydrogen production experiments show that the Fe2O4 has excellent visible light response. The total hydrogen production was 791.9 渭 mol 路g -1 in 6 h, and showed good photocatalytic stability. The optimum dosage of catalyst was 0.8 g / L, and the most suitable sacrificial agent was ethanol. A magnetic composite Cu Fe2O4/Zn2Cr-LDH was prepared by sol-gel microwave-hydrothermal method in which the dosage of sacrificial agent was 10% of the volume fraction of the solution. The saturation magnetization is 8.47 emu / g, and the total hydrogen production is 1 567.7 渭 mol 路g ~ (-1) in 6 h. The electron migration from ferrite to LDH is observed in the composite material, which is almost twice as large as that of pure Cu Fe2O4 or Zn2Cr-LDH. The single factor experiment showed that the optimum reaction conditions for the photocatalytic cracking of aquatic hydrogen with magnetic composites were as follows: the pH value was 7. The loading amount of Cu Fe2O4 is 0.20 g / L Cu Fe2O4/Zn2Cr-LDH is 1.0 g / L. The dosage of the sacrificial agent is 10 parts of the volume fraction of the solution. The magnetic composite can be reused at least three times and maintain a stable structure and photocatalytic performance. Waste ferrite prepared by microwave hydrothermal method can effectively purify heavy metal wastewater. The alkaline environment contributes to the formation of the lattice structure of ferrite. The experimental results show that the synthesis time is 1540 min, the synthesis time is 1540 min, and the synthesis temperature is 100 鈩，

本文編號：1474172