DETECTION OF SUB-PPM H2S CONCENTRATIONS BY MEANS OF SNO2(PT) THIN-FILMS, GROWN BY THE RGTO TECHNIQUE
DETECTION OF SUB-PPM H2S CONCENTRATIONS BY MEANS OF SNO2(PT) THIN-FILMS, GROWN BY THE RGTO TECHNIQUE
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DOI：
10.1016/0925-4005(93)85032-6
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发表时间：
1993-08-01
影响因子：
8.4
通讯作者：
CAMANZI, A
中科院分区：
文献类型：
--
作者：
SBERVEGLIERI, G;GROPPELLI, S;CAMANZI, A
本文介绍了用RGTO（rheotaxial growth and thermal oxidation）技术生长的SnO_2薄膜对低浓度H_2S（100 ppb-10 ppm）的敏感特性。RGTO方法允许我们制备具有褶皱表面的薄膜，其适合于以小簇形式分散金属催化剂。本文研究了沉积在薄膜表面的铂对硫化氢吸附的催化作用。在573 K下，这些膜对1 ppm H2S的最大灵敏度DELTAG/G等于30，而响应和恢复时间分别等于20和80 s。此外，随着铂层的沉积，相对于所测试的其它气体（H-2、CO、CH 4、n-C4 H 10、乙醇、NO（x）和SO 2），对H2S的选择性增加。我们提出了一个调查的薄膜表面所作的STM和SEM和结构分析所获得的薄膜的X射线粉末衍射仪。这些结果与传感器的电响应与存在于膜表面上的铂簇的尺寸相关。讨论了H2S与薄膜表面的相互作用机理。
In this paper the sensing properties of SnO2 thin films, grown by the RGTO (rheotaxial growth and thermal oxidation) technique, towards low concentrations of H2S (100 ppb-10 ppm) are described. The RGTO method allows us to prepare thin films with a wrinkled surface, which is suitable for the dispersion of a metal catalyst in the form of small clusters. The catalytic effect of Pt, deposited on the film surface, towards the adsorption of hydrogen sulfide is examined in this paper. The maximum sensitivity DELTAG/G of these films towards 1 ppm of H2S is equal to 30 at 573 K, while the response and recovery times are equal to 20 and 80 s, respectively. Moreover, the selectivity towards H2S with respect to the other gases tested (H-2, CO, CH4, n-C4H10, ethyl alcohol, NO(x) and SO2) was increased with the deposition of the platinum layer. We present an investigation of the film surface made with STM and SEM and the structural analysis of the film obtained with an X-ray powder diffractometer. These results are correlated with the electrical responses of the sensor versus the dimension of the platinum clusters present on the film surface. The interaction mechanisms between H2S and the thin film surface are also discussed.