铋基、银基光催化材料的制备及其性能研究

发布时间：2018-02-05 01:37

本文关键词： 铋基半导体银基半导体复合材料可见光催化　出处：《辽宁科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着国家工业的快速发展,环境污染与能源短缺问题日益凸显,开发更为高效的新型可见光响应光催化剂势在必行。本论文利用不同方法成功制备了α-Bi2O3、Ag3PO4光催化剂,并用XRD、SEM、UV-Vis DRS等检测手段对样品的晶相结构、晶体形貌和光学性能进行分析。同时,由于Ag3PO4存在稳定性差、光腐蚀性严重、价格昂贵的问题,本文制备了Ag3PO4-BiPO4和Ag3PO4-Bi2WO6两种复合材料,并对其光催化活性和循环稳定性进行了研究。论文的主要研究内容如下:1.选用不同醇(甲醇、乙醇、异丙醇)作溶剂,采用溶剂热法制备了不同晶体形貌的α-Bi2O3光催化剂。研究结果显示,醇的种类和用量对晶体形貌具有很大影响;甲醇与水体积比的改变对晶体形貌影响最大,随着醇水比的增加,α-Bi2O3晶体形貌从斜棱柱状纳米棒逐渐演变为菱形片状结构。将菱形片状结构α-Bi2O3用于光催化降解MO,光催化降解效率达68.7%,五次循环再生后光催化降解效率仍可达到65%。2.选用不同醇(乙醇、乙二醇、丙三醇),采用醇辅助水热法制备了Ag3PO4光催化剂。研究发现,醇的种类影响Ag3PO4的晶体形貌、分散性及光学性质,进而影响其光催化性能。在可见光下降解Rh B实验显示,加入乙醇后制备的多面体Ag3PO4光催化活性最强。循环实验表明,Ag3PO4光催化剂降解性能不稳定,多面体Ag3PO4稳定性相对较好。3.采用水热法和沉淀法相结合的方法成功制备Ag3PO4-BiPO4异质结光催化剂。它由直径在300-400 nm Ag3PO4球形颗粒与宽约150 nm、长约3μm的BiPO4微米棒通过自组装形成。可见光下降解RhB实验表明,当Ag3PO4与BiPO4摩尔比为1:5时,Ag3PO4-BiPO4异质结光催化剂呈现出最高的催化活性,90 min内RhB降解效率为96%。经过五次循环实验后,降解效率仍可达到90%。4.采用溶剂热法与沉淀法相结合的方法成功制备Ag3PO4-Bi2WO6复合材料光催化剂。可见光下降解RhB实验表明,当Ag3PO4与Bi2WO6摩尔比为1:2时,光催化活性最好,70 min内降解率达98%。经过五次循环实验,90 min光催化降解RhB效率仍保持在92%,稳定性明显提高。
[Abstract]:With the rapid development of national industry, environmental pollution and energy shortage have become increasingly prominent. It is imperative to develop a more efficient photocatalyst for visible light response. In this paper, 伪 -Bi2O3Ag-3PO4 photocatalyst has been successfully prepared by different methods, and XRDX SEM has been used to prepare 伪 -Bi2O3Ag-3PO4 photocatalyst. The crystal structure, morphology and optical properties of the samples were analyzed by UV-Vis DRS. At the same time, because of the poor stability of Ag3PO4, the photocorrosion was serious. Because of the high price, Ag3PO4-BiPO4 and Ag3PO4-Bi2WO6 composites were prepared in this paper. The photocatalytic activity and cycle stability were studied. The main contents of this paper were as follows: 1. Different alcohols (methanol, ethanol, isopropanol) were selected as solvents. 伪 -Bi _ 2O _ 3 photocatalysts with different crystal morphology were prepared by solvothermal method. The change of the volume ratio of methanol to water has the greatest effect on the morphology of the crystal, with the increase of the ratio of alcohol to water. The morphology of 伪 -Bi _ 2O _ 3 crystal evolved from an oblique prismatic nanorod to a rhombohedral structure. 伪 -Bi _ 2O _ 3 was used in photocatalytic degradation of MO.The photocatalytic degradation efficiency of 伪 -Bi _ 2O _ 3 was up to 68.7%. The photocatalytic degradation efficiency of Ag3PO4 was still up to 65.2 after five cycles regeneration. Different alcohols (ethanol, ethylene glycol, glycerol) were used to prepare Ag3PO4 photocatalyst by alcohol-assisted hydrothermal method. The crystal morphology, dispersion and optical properties of Ag3PO4 were affected by the kinds of alcohols. The photocatalytic activity of polyhedron Ag3PO4 prepared by adding ethanol was the strongest, and the cyclic experiment showed that the photocatalytic activity of Ag-3PO4 photocatalyst was unstable. The stability of polyhedron Ag3PO4 is relatively good .3.The photocatalyst of Ag3PO4-BiPO4 heterojunction is successfully prepared by hydrothermal method and precipitation method. The photocatalyst is composed of 300-400 diameters. Ag3PO4 spherical particles with a width of about 150nm. BiPO4 micron rods about 3 渭 m in length were formed by self-assembly. RhB degradation experiments under visible light show that when the molar ratio of Ag3PO4 to BiPO4 is 1: 5. Ag3PO4-BiPO4 heterojunction photocatalyst showed the highest catalytic activity within 90 min. The degradation efficiency of RhB was 96%. The photocatalyst of Ag3PO4-Bi2WO6 composite was successfully prepared by the combination of solvothermal method and precipitation method. The results of RhB degradation experiments under visible light showed that the degradation efficiency was still 90%. When the molar ratio of Ag3PO4 to Bi2WO6 is 1: 2, the photocatalytic activity can reach 98% in 70 min. The photocatalytic degradation efficiency of RhB remained at 92 for 90 min, and the stability was improved obviously.
【学位授予单位】：辽宁科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O643.36

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