Preparation And Application Of One-dimensional SnO₂Nanomaterials By Electrospinning

S11O2is a n-type semiconductor with excellent physical and chemicalproperties, which attracts a lot of attentions in lithium ion battery and gassensor applications. S11O2is a kind of potential anode material for lithiumion batteries with theoretical capacity of782mAh/g，which is twicecapacity of graphite. However, the practical application of S11O2ishampered by the drastic specific volume change （about360%），which leadsto poor cyclability. While S11O2as the gas sensing material, the sensitivityand selectivity of the gas sensor need to be further improved. Manyresearches show that the performances of the lithium ion battery and gassensor have been improved by one-dimensional nanostructure due to highspecific surface area. At present, electrospinning is a simple technique forpreparing one-dimensional nanomaterials. In the electrospinning process,the nanofibers with different morphologies can be obtained by controllingthe process parameters.In chapter2，we discussed that the electrospinning process wasinfluenced by the PVP concentration, the voltage, the curing distance andthe calcination temperature, etc. The experiments showed that the resultsfor the optimal parameters: PVP concentration was8wt%, the voltage was10kV，the curing distance was20cm，and the calcination temperature was500。C.In chapter3，aim at poor cyclability, the porous S11O2nanowires withthe diameter of60nm were prepared by electrospinning. S11O2nanofiberscan provide much more Li-intercalation sites and the porous structure isfavorable for lithium ion diffusion, which can improve the performance ofthe lithium ion batteries. As anode material for lithium ion batteries, at thecurrent density of70mA/g，the first discharge capacity was18O₂mAh/gand the reversible capacity retained350mAh/g after50cycles.In chapter4，to improve the gas sensing properties of S11O2，porousNi0-SnO₂nanotubes were prepared by electrospinning. The response was25to50ppm ethanol at300°C and the response time and recovery time were3s and10s，respectively. Compared with pure S11O2nanotubes, porous Ni0-SnO₂nanotubes based sensor exhibited high sensitivity and fastresponse and recovery. The excellent sensing performance was related to theporous hollow structure with high surface-to-volume ratio and theformation of p-n heterojunctions by NiO-doping.