Improved ethanol, acetone and H2 sensing performances of micro-sensors based on loose ZnO nanofibers

Both one-dimensional nanostructures and porous nanostructures are benefit to the sensing enhancement of semiconducting functional materials. The present paper shows an effective route to combining the advantages of these two nanostructures for a novel type of ZnO nanomaterials. Basically, a pore-forming material is employed in an electrospinning method, and the products are characterized by X-ray powder diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The obtained materials are loose ZnO nanofibers, which own both porous and one-dimensional nanostructures. Micro-sensors are fabricated by sputtering and etching techniques, and the as-prepared nanofibers are used as the functional materials in them. The sensors show improved sensing properties both in sensitivity and response-speeds. The sensitivity is enhanced from 4 to 8 and the response time is shortened from 14 to 10 s when the sensors are exposed to 100 ??L/L ethanol at 260°C. Similar results are also observed in acetone and H₂ sensing tests. These enhancements are based on the one-dimensional and porous nanostructures of the nanofibers.