Highly porous SnO2 fibers by electrospinning and oxygen plasma etching and its ethanol-sensing properties

Highly porous fibers are of great benefit to many applications, such as filtration, biomaterial devices and sensing materials. The current work is focused on preparing highly porous fibers. It demonstrates the feasibility of preparing porous SnO2 fibers through electrospinning of poly(vinyl alcohol) (PVA)/SnCl4·5H2O composite and oxygen plasma etching. The process parameters of oxygen plasma etching, including etching power and etching time, were investigated. The morphology and crystal structure of the electrospun fibers were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD), and the ethanol-sensing properties of the porous fibers were tested. It is found that porous SnO2 fibers are composed of many nano-size fibrils which are perpendicular to fiber axis. The porous fibers exhibit large response, low detection limit (<1 ppb) to ethanol.