论文标题:溶胶凝胶纳米氧化锌薄膜的制备、改性及光催化性能研究
The Preparation, Modification and Photocatalytic Properties of Nanocrystalline Zinc Oxide (ZnO) Thin Films by Sol-gel
论文作者 王英连
论文导师 孙汪典,论文学位 硕士,论文专业 凝聚态物理
论文单位 暨南大学,点击次数 192,论文页数 63页File Size2528k
2005-05-01论文网 http://www.lw23.com/lunwen_31862597/ 纳米ZnO薄膜;溶胶-凝胶;光催化;掺杂改性
ZnO thin films; Sol-gel; Photocatalysis; doping modify
本实验采用溶胶-凝胶镀膜的方法,成功地制备了纳米ZnO薄膜,并通过XRD、AFM和UV-Vis吸收光谱对薄膜的结构及形貌进行了表征;考察了基底、退火温度、降解温度、溶液初始浓度和空气流量对ZnO薄膜光催化活性的影响;探讨了ZnO薄膜掺杂改性的原理和依据,分别采用金属离子掺杂、表面贵金属沉积和离子注入三种方法,对ZnO薄膜的光催化活性进行改性试验,并对其失活与再生进行了分析和尝试。结果表明,纯ZnO薄膜光催化活性最优的条件是:石英基底,退火温度300℃,降解温度在25℃～40℃之间,空气流量为40ml/min,溶液起始浓度越低,降解效果越显著;改性后ZnO薄膜的吸收限向可见光方向移动,光催化活性有不同程度的提高;用H_2O_2清洗的ZnO薄膜的光催化活性可再生,基本可满足重复性实验的需要。ZnO薄膜固载在基片上,无二次污染,便于回收再利用,催化效果显著。
Highly photoactive nanocrystalline ZnO thin films were prepared by sol-gel process. Structural features, surface morphologies and UV absorption spectra were studied by XRD, AFM and UV-Vis-Nir scanning spectrophotometer. The influence of substrates, annealing temperatures, degradation temperatures, original concentration of phenol and air flux on photocatalytic activity have also been studied. The principles and methods for enhancing nano-ZnO photocatalystic activity were discussed. The effective approaches were metal ion-doping, precious metal deposition and ion-implanting. Furthermore, the loss and regeneration of photocatalytic activity were attempted as well. And the results show the best conditions, the substrate is quartz, annealing temperature is 300℃, degradation temperature is between 25℃ and 40℃, air flux is 40ml/min, the lower original concentration, the higher degradation rates. The doping modified ZnO photocatalysts" absorbing bounds moved to visible light, and their photocatalytic activities were enhanced with different degree. For photocatalysts having lost activity, washing with H_2O_2 can resume the activity and satisfy the repeatable experiments. Excellent adhesion as well as recyclable and efficient degradation in phenol of ZnO thin films were found in this experiment.
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