SnO₂/CNTs复合体的可控制备及气敏性研究

【作者】 陈春晟；

【导师】 史克英；

【作者基本信息】 黑龙江大学 ， 材料物理与化学， 2011， 硕士

【摘要】 以简单、廉价的方法得到具有优良性能并在室温下可以稳定工作的气敏材料是目前气体传感器研究的重要方向,同时工业上也有着迫切需求。本文采用水热法制备得到具有介孔特征的二氧化锡（SnO₂）纳米晶,在羧基化修饰的碳纳米管（CNTs）基础上,通过调整沉淀剂种类、反应物比例等因素得到了二氧化锡晶粒均匀的分散在碳纳米管表面的、不同复合程度的SnO₂/CNTs复合体。对SnO₂/CNTs复合体的NO_x气敏性能进行了对比研究,结果表明:SnO₂纳米晶均匀分散的复合体具有更优异的NO气敏响应特征,这是由于均匀分散的SnO₂/CNTs复合体结构能形成有效的电子传输通道,利于得到优异的气敏响应信号。对SnO₂表面NO气体吸附行为进行了理论计算,通过吸附能及电荷转移的计算推测出可能的最适合吸附晶面为（101）晶面,并对理论计算结果进行了初步验证。采用原位聚合法制备了聚苯胺/碳纳米管（PANI/CNTs）复合体。通过控制反应物的比例得到不同形貌的核壳结构聚苯胺/碳纳米管复合体;对聚苯胺/碳纳米管复合体进行了NO_x及NH₃气敏测试。采用机械混合法将金属氧化物（Cu₂O）与SnO₂/CNTs复合体混合,得到Cu₂O与SnO₂/CNTs复合体混合材料,提出可以采用多种材料联用的方法提高气敏材料的选择性,该方法有望使一些性质并不突出的常规气敏材料得到更好的应用。更多还原

【Abstract】 Gas sensitive materials with good performances and stable properties at room temperature are urgently wanted in industry and widely studied by researchers in gas sensor area. Meso-porous tin oxide nanocrystal is prepared by a hydrothermal method in this paper. With the same method, carbonxylic muliti-walled carbon nanotubes are compound with tin oxide. Different morphologies of SnO₂/CNTs composites are obtained by adjusting the concentration of ethernol water, ratio of reactants and precipitat species. The NO_x gas sensing properties of the composites are investigated. Results show that the gas sensing properties of the composites are related to their morphologies. Possible mechanism is proposed. Based on the experimental data, a theoretical study on the adsorption of NO onto the SnO₂ surface is presented. The conclutions of the theoretical calculation are verified by an experiment.Conductive polyaniline （PANI） and PANI/CNTs are prepared through in-situ polymerization. The diameter of the PANI/CNTs composite can be controlled by changing the mass ratio of reactants. NO_x gas and NH₃ gas sensing tests of the pure PANI and PANI/CNTs composites are carried on.Cu₂O powder and SnO₂/CNTs composites are mixed by grinding and the NO_x gas and NH₃ gas sensing properties of the mixture are studied. A method to promote the selectivity of a sensing material is proposed and shows a possibility to ordinary sensing materials for better use.更多还原