静电纺丝法制备CuO/SnO_2复合材料及其气敏特性研究

Preparation of CuO/SnO_2 composite materials by electrospinning and gas-sensing properties

为研究p型材料和n型材料复合时气敏特性的变化,采用静电纺丝法分别制备了CuO、SnO_2以及3种比例混合的CuO/SnO_2复合纳米纤维材料,并通过XRD及SEM对其形貌、微观结构等进行表征.测试了该5种材料对丙酮、甲醛、甲醇、乙醇、甲苯等VOC气体的敏感特性.研究表明,CuO/SnO_2=2∶1的复合材料对丙酮、甲苯和乙醇的的响应值有一定提高;CuO/SnO_2=1∶1的复合材料对丙酮具有很高响应的同时,对乙醇和甲苯的响应产生了一定的抑制作用,从而大大提高了材料的选择性.其机理是:半导体材料复合后,在复合材料的表面会有更多的氧吸附,导致更多的VOC气体在半导体材料表面发生反应,使材料的电阻值变化更加明显,提高了材料的响应值.

In order to study the change of the gas sensitive properties when the p-type and n-type material are composited,CuO,SnO2 and CuO/SnO2 composite nanofibers materials mixed by 3 kinds proportion are prepared by using the electrospinning. The morphology,microstructure of the as-prepared materials is characterized by XRD and SEM. At the same time,the sensitivity of the 5 materials to acetone,formaldehyde,methanol,ethanol,toluene and other VOC gases was tested. The results indicate that the response values for acetone,toluene and ethanol are greatly improved when the composite proportion CuO/SnO2 is 2 ∶ 1. The response value increases from 2.8 to 4.67,from 2.2 to 3.88 and from 2.93 to 3.61 separately. With a high response to acetone with CuO/SnO2 of 1 ∶ 1 and inhibiting effect to toluene and ethanol was caused to make a good selectivity of the material. The mechanism may be that,when different materials are composited,more oxygen will be adsorbed at the surface of the materials and more VOC gases will be reacted at the surface of the semiconductor material,which make the material resistance more sharp,leading to the improvement of the response.