中文摘要：

采用SnCl2溶液法制备二氧化锡包覆多壁碳纳米管（SnO2 coated multi-wall carbon nanotubes,SnO2/MWCNTs）,研究了SnO2/MWCNTs的室温氢敏性能。SEM和TEM形貌观察表明：粒径5nm的SnO2均匀包覆在MWCNTs表面,并形成连续的包覆层。氢敏性能测试表明：SnO2/MWCNTs材料具有室温氢敏性能,可以实现体积浓度0.01%氢气的检测。在对0.1%氢/氩混合气的室温氢敏测试中发现,当通入空气后出现电流反向波动的现象,这是由于空气中的O2与样品周围的H2生成H2O并吸附在SnO2表面,降低了SnO2/MWCNTs的电阻,随后由于O2的竞争吸附,H2O又脱附所导致。这一电流反向波动现象暗示SnO/MWCNTs具有室温湿敏性能。

英文摘要：

A SnCl2 solution was used to prepare SnO2-coated multi-walled carbon nanotubes （SnO2/MWC- NTs）, and their hydrogen sensing properties at room temperature was studied. SEM and TEM observations indicate that SnO2 nanoparticles with a size of 5 nm are uniformly coated on the MWCNTs, forming a continuous SnO2 coating. The SnO2/MWCNTs are sensitive to 10-4 hydrogen at room temperature. During the sensing measurement at room temperature for 10-3 hydrogen mixed with argon gas, the current change with gas concen- tration is reversed after the mixed gas is switched to air. This can be ascribed to the reaction between 02 in air and residual H2 around the SnO2/MWCNTs to form adsorbed H20 and the subsequent desorption of H2O by sub- stitution adsorption of 02 in air. The H20 adsorption may lead to a decrease of the electric resistance of SnO2/ MWCNTs and thus an increase of current measured. The reversal of current implies that the SnO2/MWCNTs may possess a good sensitivity to humidity at room temperature.