基于硅藻土多孔陶瓷衬底制备SnO2纳米线及其低温H2S气敏性能

Low-temperature H2S sensing properties of SnO2 nanowiresgrown on diatomite-based porous ceramic substrate

采用热蒸发法在镀金硅藻土多孔陶瓷衬底表面合成出SnO2纳米线,通过XRD、SEM、TEM和XPS等检测手段对SnO2纳米线的微观形貌、晶体结构及元素组成进行分析,探讨硅藻土多孔陶瓷衬底对SnO2纳米线生长的影响。结果表明:该衬底上所获产物为具有四方相晶体结构的SnO2纳米线,直径为53~170 nm,长度为10μm^1 mm。该硅藻土陶瓷衬底的多孔特性增加材料的成核位点,有利于Sn蒸气与Au液滴的高概率融合并快速饱合析出,从而促使SnO2纳米线具有高产率和高长径比。气敏检测结果表明,在较低工作温度条件下,基于所获SnO2纳米线的气体传感器对浓度为5×10^−7~1×10^−5(体积分数)的H2S具有优异的气敏特性,同时具有良好的稳定性及选择性。

SnO2 nanowires(SNWs)were grown on Au-coated diatomite-based porous substrate by a thermal evaporation method.The obtained SNWs were characterized by XRD,SEM,TEM and XPS to investigate their morphology,crystallization and composition.The effect of the diatomite-based porous substrate on the growth of SNWs was discussed.It demonstrates that the obtains SNWs with tetragonal rutile structure are 53−170 nm in diameter and 10μm−1 mm in length.The porous ceramic substrate not only increases the nucleation sites of the SNWs,but also enhances the sticking probability between Sn vapors and Au droplets as well as rapid saturation precipitation,which raises the high yield and large length-to-diameter ratio of SNWs.The sensing measurements illustrate that the gas sensor based on SNWs shows excellent gas sensing properties to the volume fraction of 5×10^−7−1×10^−5 H2S at low operating temperatures.Moreover,the obtained SNWs show good stability and high selectivity.