Humidity Sensing Application Of One Dimension Nano-material Based On Eletrospinning

The development and application of nanomaterials is a great renovation in material science. Compared with traditional material, nanomaterial has a higher surface-to-volume ration. Nanomaterial always costs low and has a stable chemical characteristic. Among them, the nanomaterials based on metal oxide are popular in sensing field. The performance of a sensor can be greatly influenced by the difference in structure, size and preparation. In this paper, one dimension metal oxide nanomaterial was made by electrospinning and mainly improved in structure and size. The results demonstrated that one dimens ion nanomaterials based on metal oxide prepared by electrospinning has a great improvement in sensing property, such as response and recovery time, sensitivity and stability. Our main work is as these following aspects.Electrospinning has enormous advantage in making one dimension nanomaterial. Followed by annealing at high temperature, the as-prepared nanomaterial can form nanofiber or nanotube. These one dimension structures has huge surface-to-volume ratio which can enhance the performance of nanomateri al. The special structure and small size is good to sensitivity, rapid response and recovery.In Chapter 3, the preparation process, testing and response mechanism of G/SnO_x/CF were dicussed in detail. SnO₂ nanotube and SnO_x/CFs nanofiber was synthesized by using tin dichloride dehydrate, ethanol, N, N-Dimethylformamide（DMF） and polyvinyl pyrrolidone（PVP）. SEM and TEM testing results demonstrate that the surface of SnO₂ nanotube is roughly, the tube wall is consisted of Sn O 2 crystal. Humidity sensor based on G/SnO_x/CFs has higher sensitivity and faster response and recovery property. The addition of graphene improved the sensitivity efficiently, the highest sensitivity is 6.22.In Chapter 4, ZnFe₂O₄ nanotube was prepared successfully by electrospinning. The as-synthesized products exhibited hollow s tructure with thin walls which are consisted of tiny nanocrystals and the average diameter is 80 nm. The sensitivity is as high as 85.03 when the sensor switched between 75%RH and 95%RH. By accurate calculated, the response time is 5.60 s for RH change from 35% to 75%, which is much faster than the same type humidity sensor.