Optical gas sensing by semiconductor nanoparticles or organic dye molecules hosted in the pores of mesoporous siliceous MCM-41
Optical gas sensing by semiconductor nanoparticles or organic dye molecules hosted in the pores of mesoporous siliceous MCM-41
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DOI：
10.1039/b308139g
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发表时间：
2003-11
影响因子：
3.3
通讯作者：
M. Wark;Yven Rohlfing;Yucel Altindag;H. Wellmann
中科院分区：
文献类型：
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作者：
M. Wark;Yven Rohlfing;Yucel Altindag;H. Wellmann
通过使用用金属氧化物簇或染料分子改性的分子筛来光学检测不同气体气氛的存在。用原位漫反射（DR）UV/维斯光谱研究了镶嵌在介孔硅质MCM-41孔道中的二氧化锡团簇在还原性和氧化性气氛（CO、H2、NH3、O2）中的可逆氧化还原行为。通过用Sn前体浸渍，由于氧化锡物质与MCM-41基质的硅烷醇基团的强相互作用，在MCM-41的内孔壁上形成SnO 2簇毯。托管的二维SnO 2层的CO通过光学检测的登记的响应时间是短的和浓度下降到20 ppm的CO在空气中和50 ppm的H2或NH3在空气或Ar中，分别可以被监测。吸附在硅质MCM-41的孔中的烃改变，取决于它们的链长，介孔基质的光散射。由于气体吸附取决于碳氢化合物的分压，因此这种效应可用于检测碳氢化合物，并在嵌入的光吸收客体的帮助下监测其浓度。然而，这种感测只有在粉末样品的情况下才有可能，并且根据Kubelka-Munk形式主义通过漫反射测量。在气体气氛中的SO2的浓度可以从锚定在硅质MCM-41的孔中的罗丹明染料分子的荧光的猝灭推断。
The presence of different gas atmospheres is optically detected by use of molecular sieves modified with metal oxide clusters or dye molecules. The reversible redox behaviour of tin dioxide clusters, embedded in the regular pores of mesoporous siliceous MCM-41 in reducing and oxidizing atmospheres (CO, H2, NH3, O2) is studied by in-situ diffuse reflectance (DR) UV/Vis spectroscopy. By impregnation with Sn precursors a carpet of SnO2 clusters is formed on the inner pore walls of the MCM-41 due to strong interactions of the tin oxide species with the silanol groups of the MCM-41 matrix. The response time of hosted two-dimensional SnO2 layers for the registration of CO by optical detection is short and concentrations down to 20 ppm CO in air and 50 ppm of H2 or NH3 in air or Ar, respectively, can be monitored. Hydrocarbons adsorbed in the pores of siliceous MCM-41 alter, depending on their chain length, the optical scattering of the mesoporous matrix. Since the gas adsorption depends on the partial pressure of the hydrocarbons this effect can be used to detect hydrocarbons and to monitor their concentration with the help of embedded light absorbing guests. This sensing, however, is only possible with powdered samples and by measuring in diffuse reflectance according to the Kubelka–Munk formalism. The concentration of SO2 in a gas atmosphere can be deduced from the quenching of the fluorescence of rhodamine dye molecules anchored in the pores of siliceous MCM-41.