Preparation of macroporous SnO2 films using PMMA microspheres and their sensing properties to NOx and H2
Preparation of macroporous SnO2 films using PMMA microspheres and their sensing properties to NOx and H2
复制标题
DOI：
10.1016/j.snb.2004.07.024
复制
发表时间：
2005-05-13
影响因子：
8.4
通讯作者：
Egashira, M
中科院分区：
文献类型：
--
作者：
Hyodo, T;Sasahara, K;Egashira, M
以聚甲基丙烯酸甲酯（PMMA）微球（n = 800、400、250和150 nm）为模板，SnCl 2为锡源，采用改进的溶胶-凝胶法制备了大孔SnO 2（mp-SnO 2（P-n）; P为PMMA，n为PMMA微球直径）厚膜气敏元件。mp-SnO 2薄膜的形貌明显依赖于SnCl 2浓度和PMMA微球的直径。特别是SnO 2壁厚与空心SnO 2微球直径的比值似乎随着所用PMMA微球直径的减小而增加。在所制备的薄膜中，mp-SnO 2（P-250）在225 ° C下对空气中的NO和NO2表现出最大的响应，但其响应瞬态相对较慢，表明SnO 2表面上带负电荷的化学吸附的NOx物质的低吸附和解吸速度。另一方面，mp-SnO 2（P-800）在高于400 ℃的温度下显示出传感器中最大的H-2响应。结果表明，SnO 2厚膜的厚度和多孔结构是决定其对NO2和H2-敏感性能的重要因素。(c)2004 Elsevier B. V.保留所有权利。
Macroporous SnO2 (mp-SnO2(P-n); P means polymethylmethacrylate (PMMA) and n = diameter of PMMA microsphere) thick film gas sensors were fabricated by a modified sol-gel method by employing PMMA microspheres (n = 800, 400, 250 and 150 nm) as a template and SnCl2 as a tin source. Morphology of mp-SnO2 films was markedly dependent on the SnCl2 concentration and the diameter of PMMA microspheres. Especially, the ratio of the thickness of the SnO2 wall to the diameter of the hollow SnO2 microsphere seems to increase with decreasing the diameter of PMMA microspheres used.Among the films prepared, mp-SnO2(P-250) exhibited the largest response to NO and NO2 in air at 225 degrees C, whereas its response transients were relatively slow, indicating low adsorption and desorption speeds of negatively charged chemisorbed NOx species on the SnO2 surface. On the other hand, mp-SnO2(P-800) showed the largest H-2 response among the sensors at temperatures higher than 400 degrees C. It has been revealed that the thickness and porous structure of the SnO2 thick films are important factors to determine the sensing properties to NO2 and H-2. (c) 2004 Elsevier B.V. All rights reserved.