發(fā)布時(shí)間：2018-03-13 06:38

  本文選題：碳質(zhì)材料　切入點(diǎn)：金屬氧化物　出處：《青島科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：重金屬污染給生態(tài)環(huán)境和人類生存帶來了嚴(yán)重威脅。本文制備了碳質(zhì)材料與金屬氧化物的復(fù)合材料,如α-Fe_2O_3/碳球、Bi_2Fe_4O_9/生物質(zhì)炭、TiO_2/石墨烯,采用吸附和光催化方法對(duì)其去除水中重金屬離子的性能進(jìn)行了考察,并詳細(xì)討論了其對(duì)水中重金屬離子鉻和銅的去除機(jī)制,具體研究內(nèi)容如下:(1)以葡萄糖為碳源,(NH_4)_2Fe(SO_4)·6H_2O)為鐵源,二次水為溶劑,水熱法合成了α-Fe_2O_3/碳球復(fù)合吸附劑,用SEM、TEM和XRD對(duì)其結(jié)構(gòu)進(jìn)行表征,考察了其對(duì)水中Cr(Ⅵ)的吸附性能。結(jié)果發(fā)現(xiàn),Cr(Ⅵ)在α-Fe_2O_3/碳球上的吸附在4h內(nèi)達(dá)到平衡,去除率高達(dá)到88%,分別是α-Fe_2O_3和碳球的2.99倍和4.88倍。動(dòng)力學(xué)擬合表明:該吸附過程符合準(zhǔn)一級(jí)速率方程所描述的規(guī)律,主要為物理吸附;吸附等溫線研究表明:Langmuir等溫模型能夠更好地表述該吸附行為,為典型的單分子層吸附,其最大吸附量為18.7 mg·g-1;吸附熱力學(xué)研究表明該過程為一個(gè)自發(fā)進(jìn)行的吸熱反應(yīng);α-Fe_2O_3/碳球重復(fù)使用5次后吸附能力的下降僅為7.8%,表明此吸附劑可以重復(fù)使用。(2)以硝酸鉍(Bi(NO_3)_3·5H_2O)和硝酸鐵(Fe(NO_3)_3·9H_2O)為原料,采用水熱法合成Bi_2Fe_4O_9納米片。將原位生長的Bi_2Fe_4O_9與以松樹葉粉末為原料的生物質(zhì)炭復(fù)合,制備Bi_2Fe_4O_9/生物質(zhì)炭復(fù)合吸附劑,并用于水中Cu(Ⅱ)的吸附去除。制備的Bi_2Fe_4O_9和Bi_2Fe_4O_9/生物質(zhì)炭吸附劑比表面積分別為13.35 m2·g-1和17.51 m2·g-1;在pH=5時(shí)對(duì)Cu(Ⅱ)的吸附效果最佳;動(dòng)力學(xué)擬合表明:該吸附過程適合于用準(zhǔn)二級(jí)吸附動(dòng)力學(xué)模型進(jìn)行描述,為物理化學(xué)吸附過程;對(duì)熱力學(xué)參數(shù)(Ea、ΔG、ΔH和ΔS)的分析表明:該吸附劑對(duì)Cu(Ⅱ)的吸附為自發(fā)的放熱過程;Bi_2Fe_4O_9和Bi_2Fe_4O_9/生物質(zhì)炭的最大吸附量分別為42.7 mg·g-1和61.61mg·g-1;溶液中共存的Cl~-,NO_3~-和SO_4~(2-)對(duì)Cu(Ⅱ)的吸附過程基本沒有影響,而PO_4~(3-)則會(huì)起促進(jìn)作用。Bi_2Fe_4O_9和Bi_2Fe_4O_9/生物質(zhì)炭重復(fù)使用5次后吸附能力下降分別為7.3%和11.5%,表明這兩種吸附劑可以重復(fù)使用。(3)以Hummers改性法制備的石墨烯和鈦酸四丁酯為原料,采用一步水熱法合成TiO_2/GO光催化劑,并用于吸附/光催化協(xié)同去除水中Cr(Ⅵ)的研究。通過SEM、XRD、BET、DRS和FTIR等手段對(duì)材料進(jìn)行表征和分析。復(fù)合光催化劑中的TiO_2為銳鈦礦型二氧化鈦,呈規(guī)則方塊狀的二氧化鈦顆粒均勻地分散在石墨烯表層,兩者有效的結(jié)合在一起。制備的TiO_2和TiO_2/GO樣品的比表面積分別為179.1和149.74 m2·g-1;最佳的降解實(shí)驗(yàn)條件為催化劑濃度為4.0g/L,溶液pH值為2.0;在最優(yōu)條件下,TiO_2/GO吸附去除率為65.7%,光催化去除率成為33.1%,總?cè)コ蕿?8.8%;TiO_2/GO光催化還原降解Cr(Ⅵ)的過程主要是通過超氧自由基·O_2-和空穴h+來實(shí)現(xiàn)的。相較于TiO_2而言,TiO_2/GO光催化降解Cr(Ⅵ)的性能得到了有效改善。
[Abstract]:Heavy metal pollution poses a serious threat to the ecological environment and human survival. In this paper, composite materials of carbon materials and metal oxides, such as 偽 -Fe _ 2O _ 3 / C _ 2O _ 3 / C _ 2O _ 3 / Bi2Fe4O _ 9 / biomass carbon tio _ 2 / graphene, have been prepared. The removal of heavy metal ions in water was investigated by adsorption and photocatalysis. The removal mechanism of chromium and copper ions in water was discussed in detail. The specific contents of the study were as follows: 1) taking glucose as carbon source, NH _ 4S _ 4) 路6H _ 2O) as Tie Yuan. 偽 -Fe _ 2O _ 3 / carbon sphere composite adsorbent was synthesized by hydrothermal method with secondary water as solvent. The structure of 偽 -Fe _ 2O _ 3 / carbon sphere was characterized by XRD and TEM. The adsorption properties of 偽 -Fe _ 2O _ 3 / carbon sphere on 偽 -Fe _ 2O _ 2O _ 3 / carbon sphere were investigated. The results showed that the adsorption of 偽 -Fe _ 2O _ 3 / carbon sphere on 偽 -Fe _ 2O _ 2O _ 3 / carbon sphere reached equilibrium within 4 hours. The removal rate is up to 88, which is 2.99 times and 4.88 times of 偽 -Fe _ 2O _ 3 and carbon sphere respectively. The kinetic fitting shows that the adsorption process accords with the law described by the quasi-first-order rate equation, mainly physical adsorption. The adsorption isotherm study shows that the isotherm model of 1: Langmuir can better describe the adsorption behavior and is a typical monolayer adsorption. The maximum adsorption capacity was 18.7 mg 路g ~ (-1); the adsorption thermodynamics showed that the process was a spontaneous endothermic reaction; the adsorption capacity of 偽 -Fe _ 2O _ 3 / carbon sphere decreased only 7.8 after repeated use of 偽 -Fe _ 2O _ 3 / carbon sphere for 5 times, indicating that the adsorbent could be reused with bismuth nitrate. Bigno _ 3s _ _ _. Bi_2Fe_4O_9 nanoparticles were synthesized by hydrothermal method. The in situ growth of Bi_2Fe_4O_9 was combined with biomass carbon from pine leaf powder to prepare Bi_2Fe_4O_9/ composite adsorbent. The specific surface areas of Bi_2Fe_4O_9 and Bi_2Fe_4O_9/ were 13.35 m2 路g ~ (-1) and 17.51 m ~ (2) 路g ~ (-1), respectively, and the adsorption efficiency of Cu (鈪，

本文編號(hào)：1605207