| Oxygen sensors possess great prospect of implication such as industrial production, environmental monitor and medical chemistry etc. In recent years, photochemical oxygen sensors are more attractive than conventional amperometric devices due to the following advantages: faster response time, higher sensitivity and selectivity, no O2 consumption, no poison and no requirement for a reference electrode. Unfortunately, there are significant drawbacks when using conventional systems for oxygen sensors because only weak physical interactions exist between the dopants and the matrix, including inhomogeneous distribution of both organic/inorganic components, leaching of dopants, and poor flexibleness.In order to overcome the above-mentioned drawbacks, here we present a strategy to prepare novel sol-gel derived oxygen sensing materials based on covalently grafting the Ru(II) complex to the backbone of silica networks via Si-CH2 covalent bonds. The 2, 2′-bipyridyl covalently grafted to 3-aminopropyltriethoxysilane was used as not only one of the sol-gel precursors but also the second ligand of Ru(bpy)2Cl2?2H2O complex to prepare the sol-gel derived silicates for oxygen sensors, and found that the covalently grafting strategy presented in this dissertation can be used for developing oxygen sensors. Another further investigation indicats that the presence of pores inside the matrics which facilitate the diffusion of gaseous molecules can improve the oxygen sensing property, so we applied surfactant as reagent of oriented structure in the sol-gel process and obtained further improved mesoporouse oxygen sensing materials. In addition we studied the covalently grafted Ru/MSU-3 oxygen sensing materials prepared at different temperature and found that the sample prepared at low temperature in which the nanospheres were formed possessed the best sensing property. This conclusion may set a basis for the choice of the sensing materials'shape in the future research. |
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