本文選題：金屬氧化物　切入點：金屬硫化物　出處：《安徽工業(yè)大學》2017年碩士論文

【摘要】：隨著人口的增長和經濟的發(fā)展,大量染料及重金屬離子排放到水中造成環(huán)境污染,如何克服環(huán)境污染已然成為人們急需解決的問題。文中圍繞重金屬、有機染料污染現狀危害以及常見的處理方式進行了簡要介紹,特別是對光催化降解技術進行了重點闡述,繼而開展了金屬氧化物、硫化物復合材料的制備及其應用研究工作。具體研究內容如下:首先采用溶劑熱法合成g-C3N4/SnS2@SnO2納米復合材料,并以此考察對Cr(VI)的光催化還原性能。SEM、TEM、DRS等測試表明,六角結構的SnS2@SnO2覆蓋在多孔的二維g-C3N4表面,其禁帶寬度為2.35~2.60 eV。對合成溫度、時間、比例、光催化條件等參數進行優(yōu)化時發(fā)現,當SnS2@SnO2與g-C3N4比例為3:1時,其光催化反應速率常數(k=0.04092 min-1),分別是g-C3N4和SnS2@SnO2的39.7倍及5.9倍;而加0.2 mol L-1的乙醇能夠有效捕捉空穴,進而促進光催化還原反應的進行。其次利用水熱和高溫煅燒法制備SrTiO3@Bi2O3,并分別研究了在紫外和可見條件下其對不同染料的降解效率。多種分析技術顯示,該材料具有多孔結構和較窄的禁帶寬度(2.1~3.1 eV)。當Bi2O3質量分數為30%,于600℃下煅燒5 h時,所獲得的復合材料在420 nm Xe燈照射下,能夠100%催化降解50 mg L-1羅丹明B(40min)。在365nm紫外條件下,180 min可以達成100%降解50 mg L-1甲基橙;當向反應體系添加羅丹明B后,甲基橙降解速率可提升1倍,推測其機理可能與染料敏化有關。最后探討了鈦前驅體等因素對TiO2光催化性能的影響。數據表明鈦酸正丁酯(Ti(OBu)4)和四氯化鈦(TiCl4)為原料時,均能夠100%降解10 mg L-1羅丹明B(60min以內),而相同條件下四異丙醇鈦(TTIP)僅為20%。光催化還原20 mg L-1Cr(VI)時,三種前驅體則沒明顯區(qū)別。此外不同前驅體時,合成溫度對材料性能影響規(guī)律也不同。
[Abstract]:With the increase of population and the development of economy, a large number of dyes and heavy metal ions have been discharged into the water to cause environmental pollution. How to overcome the environmental pollution has become a problem that people need to solve urgently.In this paper, the present situation of heavy metal and organic dyes pollution and the common treatment methods are briefly introduced, especially the photocatalytic degradation technology, and then metal oxides are developed.Preparation and Application of Sulfide Composites.The main contents are as follows: firstly, g-C3N4/SnS2@SnO2 nanocomposites were synthesized by solvothermal method, and the photocatalytic reduction properties of CrVI were investigated. The results showed that the hexagonal SnS2@SnO2 was covered on the porous two-dimensional g-C3N4 surface, and its band gap was 2.35 ~ 2.60 EV.When the synthesis temperature, time, ratio and photocatalytic conditions were optimized, it was found that when the ratio of SnS2@SnO2 to g-C3N4 was 3:1, the rate constant of photocatalytic reaction was 0.04092 min-1 ~ (-1), which was 39.7 times and 5.9 times of that of g-C3N4 and SnS2@SnO2, respectively.The addition of 0.2 mol L-1 ethanol could effectively capture the holes and promote the photocatalytic reduction reaction.Secondly, SrTiO3- @ Bi2O3 was prepared by hydrothermal and high temperature calcinations, and the degradation efficiency of different dyes under UV and visible conditions was studied.A variety of analytical techniques show that the material has a porous structure and a narrow band gap of 2.1 ~ 3.1 EV ~ (-1).When the mass fraction of Bi2O3 was 30 and calcined at 600 鈩，

本文編號：1718596