Construction Of One Dimensional Nano Gas Sensors Based On Electrospinning Technology

Recently, gas sensors are related to our life closely. We have witnessed the hugeprogress in fabricating ultra-sensitive chemiresistors driven by their practicalapplications in air quality control, environmental monitoring and healthcare, etc. Sothe modern society puts forward for the accuracy, stability and selectivity of gassensors with higher requirement. Prepared with the excellent performance of the gassensors which can detect the flammable, explosive and toxic gases rapidly andaccurately have become an indispensable prerequisite for social development. Forhigh-efficient sensing performances of semiconductor-based chemiresistors, a generalroute is to construct chemiresistors with one-dimensional1D semiconductingnanostructures as sensing element. Electrospinning technique is a method of preparingone-dimensional materials which contain polymers, metal semiconductors,organic/inorganic composite nanofibers. Nanofibers prepared with electrospinningtechnology have many benefits include large surface area, uniform and controllablediameter, changeful components and crystal structure, high aspect ratio,three-dimensional open structure. Owing to the1D nanostructure can facilitate fastmass transfer of the target molecules to and from the interaction region and owing to their continuous length, which can easily transport the sensing electronic signalsbetween the working electrodes and result in enhanced sensing performances.Nanofibers prepared with electrospinning technology can reduce the consumption ofthe electrical signal in the transmission process, thereby improving theresponse-recovery time and the sensitivity. So it is possible to build high-efficiencygas sensors.In present work, we fabricated trace ions doped/metal oxide composite nanofiberand conducting polymers/metal oxide composite nanofiber by electrospinning andevaluated the application for gas sensor. At the same time, we systematicallyinvestigated the gas sensing performances based on two representative systems. Thereare two parts:（1） Different doping level of CuO/SnO₂nanofibers were prepared andthe gas sensing performances exhibited that2%Cu²⁺/SnO₂composite nanofiber hadthe best performance for C2H2. The sensor sensitivity is6.5when C2H2concentrationis100ppm, the response and recover time are4s. By investigating the gas sensingperformances, we study that trace ions doped impact on the n-type metal oxide. Therelationship between the gas sensing performances and the crystal structures of thesemiconductors is established. It is a direction to prepare high-performance for thefuture.（2） PPy/TiO₀2and PPy/TiO₂/Au nanofibers are prepared. PPy/TiO₂/Aunanofibers present excellent performances. The sensor sensitivity is3.2when NH3concentration is20ppb. By investigating the gas sensing performances, we explorethe relationship between the gas sensing performances and p-n junction and study themechanism.