摘 要环境污染与能源短缺已成为全球普遍关注的重要课题。在半导体光催化材料 中,TiO2 具有高化学稳定性、高活性、无毒无害、较高的光电转换效率以及低成 本等优点,因此在光催化降解废水和产氢方面具有广泛的应用前景。但活性较高 的锐钛矿型 TiO2 光催化产氢效率依然较低,提高其光催化活性即产氢速率与产 氢量,是目前国内外研究关注的趋势。81709
本文采用溶胶凝胶法,利用钛酸四正丁酯、无水乙醇、钨酸铵、柠檬酸为原 料合成物质的量之比分别为 0%、1%、2%、3%、5%、8%的纳米 WO3/TiO2 复合 半导体,并对产氢效率最高的2%W/T 样品进行金属离子(Fe3+、Cu2+、Bi2+)掺 杂改性,系统研究了复合比例、金属离子掺杂对其形貌、晶型、比表面积及光催 化活性的影响。分析了 2%W/T 光解水的最佳工艺条件并进行光催化性能测试。 实验结果表明:
(1)、最佳摩尔比为 2% WO3/TiO2,最佳投加量为 100mg/L,pH 为 10,光照 时间为 1h,光催化产氢效果最好;
(2)、对 2%WO3/TiO2 掺杂金属离子(Fe3+、Cu2+、Bi2+)改性后,产氢效率 降低。由强到弱依次为 Bi2+、Fe3+、Cu2+;
(3)、用甲醇逐渐代替蒸馏水后,产氢效率随甲醇量的增多而降低。
毕业论文关键词:光催化产氢;WO3/TiO2;金属掺杂;甲醇
Abstract Environment pollution and energy shortage has become an important topic of global attention 。 Among all the semiconductor photocatalytic materials,with strong chemical stability, high-activity, poisonless and harmless, high photoelectric conversion efficiency ,low cost and so on,therefore TiO2 has a wide application prospect in the field of degrading waste water and generate hydrogen 。 But photocatalytic hydrogen production efficiency of the anatase TiO2 which shows higher activity is still low, improving the photocatalytic activity of hydrogen production rate and hydrogen production quantity are the trends which researchments are focus on domestic and overseas。
This paper used the sol-gel method to prepare different molar ratio:0%, 1%, 2%, 3%, 5%, 8% nano WO3/TiO2 composite semiconductors by using Tetrabutyl titanate,Ethanol, Ammonium tungstate hydrate, Citric acid monohydrate as raw materials , and modified the 2% W/T sample which has the highest production efficiency through doping metal ions (Fe3 +, Cu2 +, Bi2 +) into it。and reseached the influence of the photocatalytic activity about its morphology, crystal type and specific surface area systematically resulted by the composite ratio and metal ions dopant 。and analyzed the optimum process conditions for the test that 2% W/T sample splits water for hydrogen production,and at last made a list of tests for photocatalytic performance 。The experimental results show that:
(1)The best mole ratio of WO3/TiO2 is 2% , and the optimal dosing quantity is 100 mg/L, pH is 10, illumination time is one hour,which make the best photocatalytic hydrogen production ;
(2)After modificating the 2% of WO3/TiO2 though doped with metal ions (Fe3 +, Cu2 +, Bi2 +) , the production efficiency is lower。and sequence from strong to weak was followed by Bi2 +, Fe3 + ,Cu2 +;
(3)After using methanol instead of distilled water gradually,the hydrogen production efficiency reduced with the amount of methanol increased 。
Keywords: photocatalytic hydrogen production; WO3/TiO2 ; metal doping; methanol
目 录
第一章 绪 论 1
1。1 引言 1
1。2 TiO2 光催化原理 2
1。2。1 光催化反应的基本原理 2
1。3 TiO2 光催化影响因素