SnO_2/C复合材料的制备及NO_x气敏研究

摘要

为制备在室温条件下对NOx的检测具有低检测线、响应迅速、灵敏度高的材料,通过高压静电纺丝法制备了多孔SnO2/C复合材料,采用TEM、SEM、XRD等手段研究了复合材料形貌及结构.研究表明：SnO2/C复合材料表面存在丰富的微孔、介孔和大孔,且以10 nm左右的介孔居多.室温下（16～18℃）对SnO2/C复合材料NOx气敏性的检测研究发现,SnO2/C复合材料对NOx有很好的气敏响应,最低检测体积分数可达0.97×10-7.放置48 h后再重复进行相同浓度的气敏性检测时,复合材料的气敏响应重复性较好.复合材料的气敏机理研究表明,空气中的氧气吸附于多孔SnO2/C复合材料表面,形成的氧负离子有助于提高NOx气敏性能.%To study and prepare the material possessing low detection level,fast response and high sensitivity to NOx at room temperature,SnO2/C is synthesized by electrospunning method.The characteristics and morphology of the material are studied by SEM,TEM,XRD.The results show that the surface of the material possesses a wealth of microporous,mesoporous and macroporous,and the majority of the mesoporous is about 10 nm.At room temperature（16~18 ℃）,NOx gas sensor test reveals that the composite material which is composed of PS/SnCl2 nanofibers has better sensitivity of NOx than pure SnO2 after calcinations.The volume fraction of the lowest detection is 0.97×10-7,and after 48 h,the reproducibility is also better.The mechanism of gas sensor indicates that O2 in air is adsorbed on the surface of SnO2/C composite,then O-is formecl.It causes that the sensitivity of SnO2/C is improved.