纳米二氧化锡基异质结薄膜及其光电化学性能
发布时间：2019-05-22 21:15
【摘要】：二氧化锡是一种重要的功能材料，在传感器、太阳能电池等方面有着重要的应用前景。纳米二氧化锡溶胶除了保留二氧化锡粒径小、气敏性能优异、电子迁移率高等优异性能等优点外，还具备了块体材料无法比拟的多界面特性及易复合性，对于纳米器件的构筑具备更加广泛的应用价值。 制备二氧化锡溶胶的方法主要有微乳液法、溶胶-凝胶法、水热法。本论文以湿化学法得到的水合二氧化锡为原料，通过沉淀-解胶法制备优异的分散性和稳定性的二氧化锡水溶胶。水溶胶不含表面活性剂，，pH值接近中性，适合在多种基材上制备SnO2基薄膜。论文的主要工作有： （1）将干燥后的溶胶经煅烧处理获得二氧化锡纳米粉体，通过制作气敏浆料、涂覆、烧结、焊接、陈化等步骤制备出二氧化锡纳米薄膜型气敏元件。其对甲醛、乙醇、甲醇、氨气等气体表现出了较高的灵敏性并且具有优于商业粉体二氧化锡气敏元件的灵敏度和选择性。 （2）通过“自下而上”的方法，将二氧化锡水溶胶作为基元，与二氧化钛水溶胶交替自组装法制备了全纳米SnO2/TiO2异质结薄膜。制备过程无需聚电解质，且薄膜厚度均匀可控。两种半导体纳米颗粒所形成的异质结有效避免光生载流子的复合，提高光电效率。其光电流比相同厚度的TiO2薄膜提高了2倍左右，层数为15层的薄膜电极表现出了最佳的光电催化活性。以葡萄糖等为模拟污染物，将其作为传感器用于COD的检测，最终获得的COD检测范围为0 120mg·L 1，最低检测限为1.0mg·L 1。 （3）用还原法制备晶粒尺寸为5nm的金溶胶，将Au纳米颗粒以静电吸附的方法均匀地沉积SnO2/TiO2异质结薄膜上，并且将其应用于染料敏化太阳能电池（Dye-sensitized solar cells，DSSCs）的阻挡层。含6层的Au-SnO2/TiO2复合薄膜阻挡层的DSSC的光电转换效率最终效率达到了7.12%，较常用的TiCl4稀溶液处理的改性工艺（6.06%）相比表现出了更好的改性效果。因此，层层自组法制备的异质结薄膜可有效代替传统的TiCl4处理工艺，有较好的应用前景。
[Abstract]:Tin dioxide is an important functional material, which has an important application prospect in sensors, solar cells and so on. Nano-tin dioxide sol not only retains the advantages of small particle size of tin dioxide, excellent gas sensing properties, high electron mobility and other excellent properties, but also has incomparable multi-interface characteristics and easy compounding properties of bulk materials. It has more extensive application value for the construction of nano-devices. The main methods of preparing tin dioxide sol are microemulsion method, sol-gel method and hydrothermal method. In this paper, tin dioxide hydrosol with excellent dispersion and stability was prepared by precipitation-ungelation method from hydrated tin dioxide obtained by wet chemical method. Hydrosol does not contain surfactants and pH value is close to neutral, so it is suitable to prepare SnO2 based thin films on a variety of substrate. The main work of this paper is as follows: (1) the dried sol is calcined to obtain tin dioxide nanometer powder, which is coated, sintered and welded by making gas sensitive slurry. Tin dioxide nano-thin film gas sensor was prepared by aging and other steps. It has high sensitivity to formaldehyde, ethanol, methanol, ammonia and other gases, and has better sensitivity and selectivity than commercial powder tin dioxide gas sensor. (2) all-nanometer SnO2/TiO2 Heterojunction thin films were prepared by alternating self-assembly of tin dioxide hydrosol and titanium dioxide hydrosol by "bottom-up" method. The preparation process does not need polyelectrolytes, and the thickness of the films is uniform and controllable. The heterojunction formed by two kinds of semiconductor nanoparticles can effectively avoid the recombination of photogenerated carriers and improve the photoelectric efficiency. The photocurrent of TiO2 thin film with the same thickness is about 2 times higher than that of the film with the same thickness, and the thin film electrode with 15 layers shows the best photocatalysis activity. Glucose and other simulated pollutants were used as sensors for the detection of COD. The final detection range of COD was 0 鈮
本文编号：2483265
[Abstract]:Tin dioxide is an important functional material, which has an important application prospect in sensors, solar cells and so on. Nano-tin dioxide sol not only retains the advantages of small particle size of tin dioxide, excellent gas sensing properties, high electron mobility and other excellent properties, but also has incomparable multi-interface characteristics and easy compounding properties of bulk materials. It has more extensive application value for the construction of nano-devices. The main methods of preparing tin dioxide sol are microemulsion method, sol-gel method and hydrothermal method. In this paper, tin dioxide hydrosol with excellent dispersion and stability was prepared by precipitation-ungelation method from hydrated tin dioxide obtained by wet chemical method. Hydrosol does not contain surfactants and pH value is close to neutral, so it is suitable to prepare SnO2 based thin films on a variety of substrate. The main work of this paper is as follows: (1) the dried sol is calcined to obtain tin dioxide nanometer powder, which is coated, sintered and welded by making gas sensitive slurry. Tin dioxide nano-thin film gas sensor was prepared by aging and other steps. It has high sensitivity to formaldehyde, ethanol, methanol, ammonia and other gases, and has better sensitivity and selectivity than commercial powder tin dioxide gas sensor. (2) all-nanometer SnO2/TiO2 Heterojunction thin films were prepared by alternating self-assembly of tin dioxide hydrosol and titanium dioxide hydrosol by "bottom-up" method. The preparation process does not need polyelectrolytes, and the thickness of the films is uniform and controllable. The heterojunction formed by two kinds of semiconductor nanoparticles can effectively avoid the recombination of photogenerated carriers and improve the photoelectric efficiency. The photocurrent of TiO2 thin film with the same thickness is about 2 times higher than that of the film with the same thickness, and the thin film electrode with 15 layers shows the best photocatalysis activity. Glucose and other simulated pollutants were used as sensors for the detection of COD. The final detection range of COD was 0 鈮
本文编号：2483265
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