共查询到18条相似文献,搜索用时 93 毫秒
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采用蒸发诱导自组装工艺制备了Pd-SnO2介孔金属氧化物薄膜。采用静态配气法,研究了Pd掺杂量对SnO2元件气敏性的影响,并通过测定电化学阻抗谱,分析了介孔金属氧化物的气敏机理。结果表明:Pd掺杂降低了SnO2元件对氢气初始响应温度,并提高了元件对氢气灵敏度;Pd掺杂量为0.5%时,SnO2元件对氢气的气敏性最好;温度为175℃时,0.5%Pd-SnO2对体积分数为1 000×10-6氢气灵敏度为22.6;阻抗分析表明,通入还原性气体后,氧化物的晶界电阻明显减小。 相似文献
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用模板法合成了介孔二氧化硅SBA-15,为了改善其湿敏特性进行了金属盐掺杂.通过扫描电子显微镜(SEM)和XRD对纯质介二氧化硅SBA-15以及不用金属盐掺杂材料的形貌和结构进行了表征.在11 %RH到95 %RH的范围内研究了纯SBA-15和不同金属盐掺杂SBA-15材料的湿敏特性.结果表明:适量的金属盐掺杂能很好的提高了介孔硅SBA-15材料的湿敏特性.不同金属盐掺杂SBA-15材料的响应恢复时间也比较迅速,响应时间都在60 s以内,而恢复时间都在180 s以内,能够满足湿度传感器的应用需要. 相似文献
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新《环境空气质量标准》已经出台,其中的PM2.5指标已被列入相关的国标,并纳入各省市强制监测范畴,作为导致PM2.5主要因素的汽车尾气控制势在必行。本文创新性地使用“前置装置”,即将稀土-铝纳米复合材料,通过油路上的1个滤网,以缓释的方式添加到汽油中,利用纳米材料的特性,对汽油催化助燃,并促使其充分燃烧,从燃烧源头上削减尾气中PM2.5的产生,克服以往单纯依靠“后处理装置”无法有效防治PM2.5产生的问题。拟通过微观调控及优化组装,研发催化助燃效果良好的稀土-铝有序介孔纳米复合材料,分析评定其降低PM2.5尾气排放的功效。本研究可丰富纳米微观基础理论,促进纳米环保交叉学科的发展;同时,对解决全球关注的环境保护问题及生态文明建设,也具有重要的现实意义,体现了纳米材料的时代效应。 相似文献
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采用溶胶-凝胶法,结合旋转涂膜法,制备了六种稀土掺杂光催化抗菌薄膜(Ce/TiO2,Pr/TiO2,Gd/TiO2,Dy/TiO2,Y/TiO2,Eu/TiO2),研究了影响薄膜光催化抗菌性能的因素,确定了最佳制备工艺条件.、除Ce掺杂TiO2薄膜含有极少量金红石型TiO2外,其余全部由单一锐钛矿型TiO2构成,薄膜表面均存在缺陷.RE/TiO2光催化抗菌薄膜对大肠杆菌平均杀菌率皆在90%以上,与纯TiO2的杀菌率34%相比有明显提高.稀土元素掺杂显著提高了光催化薄膜对可见光的响应.经反复使用和高温、高压、冲刷等处理,薄膜完整不脱落,始终有很高的杀菌率和稳定性.稀土掺杂TiO2具有良好的实用价值和应用前景. 相似文献
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Hallegot 《Journal of microscopy》1999,195(2):147-149
Backscattered electron (BSE) imaging was used to study ultrafine TiO2 crystals distribution in a test cream. The cream was fast frozen, cryofractured and observed uncoated at low temperature. The BSE detector was a microchannel plate. The results demonstrate that up-to-date photoprotective preparations can be investigated by this technique. 相似文献
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G. Rdegran J. Lausmaa L. Mattsson U. Rolander B. Kasemo 《Microscopy research and technique》1991,19(1):99-106
Using submerged jet electropolishing, extremely thin (<10 nm), continuous, thermal oxide “windows” have been prepared on poly crystalline titanium (Ti). The preparation technique is described in detail. It has allowed a systematic investigation of the structure of thermal surface oxide layers on Ti in the thickness range 6–40 nm, corresponding to oxidation temperatures 100–450°C. Auger electron spectroscopy was used for oxide characterization and for depth profiling to determine oxide thickness. The thinnest oxides, < 10 nm, are amorphous, morphologically homogeneous, and with essentially no contrast in the transmission electron microscopy (TEM) pictures. As the oxide thickness is increased up to 40 nm, a texture corresponding to the grain structure of the oxidized metal becomes gradually more visible. At the same time the oxide becomes increasingly more crystalline. The results are compared with previously published corresponding results for thicker anodic oxides on Ti. 相似文献
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In this study, a comparative topography analysis of titanium (Ti) surfaces was performed using two‐ (2D) and three‐dimensional (3D) profilometers. Ti samples were either only sandblasted (SB) using Al2O3 particles or were SB and received an additional chemical treatment using a solution of 4% HF (SLA). Samples with no treatment were used as a control group (C). Therefore, three different surfaces were evaluated: SB, SLA and C. The Ti surface topographies were evaluated by scanning electron microscopy. An Ra roughness measurement was performed on each Ti sample by 2D and 3D profilometers. Surface roughness was also characterized using amplitude, spatial and hybrid 3D parameters. 2D and 3D profilometer analyses produced very close results. Mean Ra values range from 0.19 to 0.25 (C, p<0.05), 0.84 to 0.99 (SLA, p<0.05) and 0.98 to 1 µm (SB, p>0.05). The statistically different Ra values depending on the surface studied may be explained by methodological and technical differences. Also, 3D profilometer seems to be the more appropriate analytical method for measuring the roughness of Ti surfaces because it also describes surface organization. SCANNING 31: 174–179, 2009. © 2009 Wiley Periodicals, Inc. 相似文献