【摘要】：二氧化錫是一種重要的功能材料，在傳感器、太陽(yáng)能電池等方面有著重要的應(yīng)用前景。納米二氧化錫溶膠除了保留二氧化錫粒徑小、氣敏性能優(yōu)異、電子遷移率高等優(yōu)異性能等優(yōu)點(diǎn)外，還具備了塊體材料無(wú)法比擬的多界面特性及易復(fù)合性，對(duì)于納米器件的構(gòu)筑具備更加廣泛的應(yīng)用價(jià)值。 制備二氧化錫溶膠的方法主要有微乳液法、溶膠-凝膠法、水熱法。本論文以濕化學(xué)法得到的水合二氧化錫為原料，通過(guò)沉淀-解膠法制備優(yōu)異的分散性和穩(wěn)定性的二氧化錫水溶膠。水溶膠不含表面活性劑，，pH值接近中性，適合在多種基材上制備SnO2基薄膜。論文的主要工作有： （1）將干燥后的溶膠經(jīng)煅燒處理獲得二氧化錫納米粉體，通過(guò)制作氣敏漿料、涂覆、燒結(jié)、焊接、陳化等步驟制備出二氧化錫納米薄膜型氣敏元件。其對(duì)甲醛、乙醇、甲醇、氨氣等氣體表現(xiàn)出了較高的靈敏性并且具有優(yōu)于商業(yè)粉體二氧化錫氣敏元件的靈敏度和選擇性。 （2）通過(guò)“自下而上”的方法，將二氧化錫水溶膠作為基元，與二氧化鈦水溶膠交替自組裝法制備了全納米SnO2/TiO2異質(zhì)結(jié)薄膜。制備過(guò)程無(wú)需聚電解質(zhì)，且薄膜厚度均勻可控。兩種半導(dǎo)體納米顆粒所形成的異質(zhì)結(jié)有效避免光生載流子的復(fù)合，提高光電效率。其光電流比相同厚度的TiO2薄膜提高了2倍左右，層數(shù)為15層的薄膜電極表現(xiàn)出了最佳的光電催化活性。以葡萄糖等為模擬污染物，將其作為傳感器用于COD的檢測(cè)，最終獲得的COD檢測(cè)范圍為0 120mg·L 1，最低檢測(cè)限為1.0mg·L 1。 （3）用還原法制備晶粒尺寸為5nm的金溶膠，將Au納米顆粒以靜電吸附的方法均勻地沉積SnO2/TiO2異質(zhì)結(jié)薄膜上，并且將其應(yīng)用于染料敏化太陽(yáng)能電池（Dye-sensitized solar cells，DSSCs）的阻擋層。含6層的Au-SnO2/TiO2復(fù)合薄膜阻擋層的DSSC的光電轉(zhuǎn)換效率最終效率達(dá)到了7.12%，較常用的TiCl4稀溶液處理的改性工藝（6.06%）相比表現(xiàn)出了更好的改性效果。因此，層層自組法制備的異質(zhì)結(jié)薄膜可有效代替?zhèn)鹘y(tǒng)的TiCl4處理工藝，有較好的應(yīng)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

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