Tunneling Electron Transport in ZnO Nanograins Prepared by Electrospinning Method: An Ethyl Acetate Vapour Sensor by Chemiresistive Method

In this work, Polyvinyl alcohol (PVA) based ZnO nanofibers were deposited by the electrospinning method. ZnO nanofibers obtained through this method have an average diameter of 514 nm. The average diameter of ZnO nanograins that was acquired by calcination of ZnO nanofibers was found to be 32 nm and shows a one-dimensional structure. The structural studies had demonstrated that ZnO nanograins are polycrystalline. XPS surface studies confirmed the presence of ZnO in the nanograins. The prepared ZnO nanograins exhibited good sensing properties towards the ethyl acetate vapour at 350 °C operating temperature. ZnO had shown rapid response and recovery time of 36 and 25 s, respectively, towards 9 ppm of ethyl acetate. The obtained ZnO nanograins demonstrate the vapour detecting mechanism through tunneling electron transport.