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唐山学院
毕业设计
设计题目:载银光催化剂Ag-TiO2的制备及光催化性能研究
系别: 环境与化学工程系
班级: 06化工(1)班
姓名:
指导教师:
2010年6月17 日
载银光催化剂Ag-TiO2的制备及光催化性能研究
摘要
半导体光催化氧化是一种新型的光化学反应方法,由于它对多种有机物具有无选择性氧化降解,对贵金属离子具有还原沉积作用,因而在化学反应、催化剂制备、水处理技术等领域具有广阔的应用前景。但是光生载流子的重新复合会影响半导体光催化的效率,在半导体表面沉积贵金属是提高半导体光催化剂活性的一种有效方法。负载在催化剂上的金属粒子能够消除电子,防止催化剂带电及电子与空穴的复合,从而提高催化剂的光催化活性。
本文通过溶胶-凝胶法制备了TiO2,并利用光化学沉积法合成了负载有贵金属银的高活性光催化剂Ag-TiO2,通过以亚甲基蓝为模型化合物对所制得的光催化剂的光催化活性进行评价,研究了制备过程中的主要因素对催化剂活性的影响。结果表明,,AgNO3溶液用量为7mL/gTiO2,AgNO3与Na2NO3的溶液体积比为2:1时,所合成的Ag-TiO2光催化剂活性最高。在相同条件下,Ag-TiO2对亚甲基蓝的降解速度明显高于TiO2。
关键词:光催化剂光化学沉积 Ag-TiO2 光降解
Preparation and Photocatalytic Performance of Ag –Loaded photocatalyst Ag- TiO2
Abstract
Semiconductor photocatalytic oxidation is a new method of photochemical reaction. Because it can degradate a variety pounds with no selective and can deposite noble metal ions , has broad application prospects in the field of Chemical reaction, catalyst preparation and water treatment. However, posite of exciton could affect the efficiency of photocatalyst. Depositing noble metal in the semiconductor surface is a effective method to improve the activity of semiconductor photocatalyst. The metal particle loaded on catalyst can dispel electron, avoid catalyst to be charged and posit of exciton, therefore it can improve the photocatalytic activity of catalyst.
In this paper, TiO2 was prepared by sol-gel and Ag-TiO2(Ag-loaded Titanium dioxide) was prepared by photocbemical precipitation. some affecting factors during the preparation were discussed in this paper. Methylene blue was used as model. Compound to determine the photocatalytic activity of the photocatalyst. The optimal condition for Ag-TiO2 was determined: the dosage of AgNO3 aqueous solution() is 7 mL/g, the ratio of AgNO3 solution volume to Na2NO3 2:1. Under the same conditon,degradation rate of Ag-TiO2 is higher than that of naked TiO2.
Key words: photocatalyst; photochemical precipitation; Ag-TiO2; photodegrade
目录
1 引言 1