物理学报2016，Vol.65Issue(6)：148-155,8.DOI:10.7498/aps.65.064206
纳米ZnO-SiO2自清洁增透薄膜的制备及其性能∗
Preparation and characterization of self-cleaning and anti-reflection ZnO-SiO2 nanometric films
摘要
Abstract
Unlike the general anti-reflection and self-cleaning film such as SiO2 and TiO2-SiO2, the ZnO-SiO2 nanometric film used as a substrate of excellent transparency in visible region and effective photo-catalytic self-cleaning under UV illumination is seldom studied in the application as a substrate; however, it has a lot of advantages including high transmittance and low refractivity. In this paper, a self-cleaning and anti-reflection ZnO-SiO2 nanometric film is successfully fabricated by using a sol-gel dip-coating method. The morphology, crystal structure, surface microstructure and light transmittance of the obtained products are characterized by techniques such as TEM, SAD, XRD, SEM, DTA and UV-vis. Photo-catalytic degradation of the methylene blue (MB) in aqueous solution is used as probe reaction to evaluate the photo-catalytic activity of ZnO-SiO2 nanometric film. The TEM images reveal that the as-prepared ZnO nanoparticles are spherical grains with diameters of 12–20 nm, the average grain diameter is about 14.51 nm. ZnO nanoparticles obtained are of hexagonal wurtzite structure revealed by XRD pattern and there exist no other diffraction peaks. Furthermore, the SAD results show that ZnO microstructurs have good crystallinity. In addition, the ZnO grain size is about 14.41 nm by using the Scherrer formula calculation, which is consistent with the TEM results by the Gauss simulation. The UV-vis spectra reveal that the ultraviolet characteristic absorption peak of ZnO-SiO2 composite films is located at 368 nm and 375 nm after annealing at different temperatures such as 300 ◦C and 450 ◦C, corresponding to the band gaps of 3.37 eV and 3.31 eV, respectively. It is highly consistent with that obtained from pure ZnO nanoparticles. Increasing the annealing temperature results in a lower refractive index and the increases of the porosity in of the ZnO-SiO2 composite films. It has a uniformly refractive index value about 1.23–1.25 and a high porosity value about 50.3%–54.7%when the annealing temperature is 450 ◦C. Experimental results show that the ZnO-SiO2 composite film can enhance the light transmittance of the quartz substrate, due to its lower reflective index and higher porosity. Compared with the quartz substrate, the average optical transmission rate of the quartz glass coated with ZnO-SiO2 composite films is increased by about 4.17%at 400–800 nm, which favors greatly anti-reflection characteristics in a wide spectrum range. Meanwhile, the ZnO-SiO2 composite films are found to be efficient for photo-catalytically degradation of methylene blue dye under UV illumination, which favors greatly the self-cleaning function.关键词
纳米ZnO/SiO2薄膜/溶胶-凝胶/光催化Key words
nano ZnO/SiO2 film/sol-gel/photo-catalytic引用本文复制引用
郭昭龙,赵海新,赵卫..纳米ZnO-SiO2自清洁增透薄膜的制备及其性能∗[J].物理学报,2016,65(6):148-155,8.基金项目
陕西省科学技术研究发展计划(批准号：S2014GY2700)、陕西省科技统筹创新工程计划(批准号:2015KTCQ01-63)和西安市科技计划(批准号：GX14021-05)资助的课题.* Project supported by the Science and Technology Research and Development of Shaanxi Province, China (Grant No. S2014GY2700), the Science and Technology Plan of Innovation of Shaanxi Province, China (Grant No.2015KTCQ01-63), and the Science and Technology Project of Xi’an, China (Grant No. GX14021-05) （批准号：S2014GY2700）
