Símonarson Gunnar, Lotsari Antiope, Palmqvist Anders E C
Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Molecules. 2022 Jan 4;27(1):303. doi: 10.3390/molecules27010303.
A low-temperature spray deposition synthesis was developed to prepare locally hexagonally ordered mesoporous titania films with polycrystalline anatase pore walls in an evaporation-induced self-assembly process. The titania film preparation procedure is conducted completely at temperatures below 50 °C. The effects of spray time, film thickness, synthesis time prior to spray deposition, and aging time at high relative humidity after deposition on the atomic arrangement and the mesoorder of the mesoporous titania were studied. We find the crystallite size to depend on both the synthesis time and aging time of the films, where longer times result in larger crystallites. Using the photocatalytic activity of titania, the structure-directing agent is removed with UV radiation at 43-46 °C. The capability of the prepared films to remove the polymer template increased with longer synthesis and aging times due to the increased crystallinity, which increases the photocatalytic efficiency of the titania films. However, with increasingly longer times, the crystallites grow too large for the mesoorder of the pores to be maintained. This work shows that a scalable spray coating method can be used to prepare locally ordered mesoporous polycrystalline titania films by judiciously tuning the synthesis parameters.
开发了一种低温喷雾沉积合成方法，以在蒸发诱导自组装过程中制备具有多晶锐钛矿孔壁的局部六方有序介孔二氧化钛薄膜。二氧化钛薄膜制备过程完全在50℃以下的温度下进行。研究了喷雾时间、薄膜厚度、喷雾沉积前的合成时间以及沉积后在高相对湿度下的老化时间对介孔二氧化钛原子排列和介观有序性的影响。我们发现微晶尺寸取决于薄膜的合成时间和老化时间，时间越长，微晶越大。利用二氧化钛的光催化活性，在43 - 46℃下用紫外线辐射去除结构导向剂。由于结晶度增加，制备的薄膜去除聚合物模板的能力随着合成和老化时间的延长而提高，这提高了二氧化钛薄膜的光催化效率。然而，随着时间越来越长，微晶生长得太大，无法维持孔的介观有序性。这项工作表明，通过明智地调整合成参数，可扩展的喷雾涂层方法可用于制备局部有序的介孔多晶二氧化钛薄膜。
