Recent developments in electrospun ZnO nanofibers: A short review

Especially for the potential use as sensors, but also in all other applications in which an interaction with the environment occurs, nanofibrous materials are advantageous due to their large specific surface area. An interesting material for electrospinning is the semiconductor zinc oxide (ZnO) which is often used in photoelectric or sensory applications. Nanofibers containing ZnO can be produced, for example, by electrospinning polyvinylpyrrolidone/zinc nitrate from a dimethylformamide/ethanol solution, followed by calcination to remove the organic phase. Alternatively, the polymer/semiconductor blended nanofibers can be used which are often less brittle, but on the other hand offer less contact between ZnO and the environment. Finally, decorating a nanofiber mat with ZnO offers another possibility to prepare nanofibers with ZnO surface. Possible applications of electrospun ZnO nanofibers or nanofiber mats include gas sensing, microwave absorption, photocatalytic degradation or enhancement of supercapacitor electrodes. This short review gives an overview of the most recent electrospinning and after-treatment techniques to create pure and blended ZnO nanofibers and presents the broad variety of possible applications of this well-known semiconductor with some still surprising properties.