Electrospun Ceramic Nanofibers and Hybrid-Nanofiber Composites for Gas Sensing

Over the past few years, there has been a huge demand for developing sensors capable of monitoring and quantifying volatiles related to food quality analysis, medical diagnosis, and environmental monitoring. Sensors designed for such applications are required to present simultaneously high selectivity, low power consumption, fast response/recovery rate, low humidity dependence, and a low detection limit, which pose great challenges to be overcome in the development of suitable transducer nanomaterials for gas sensing. The nanostructure dimensionality certainly plays a key role for efficient gas detection. Thanks to the advantages derived from the nanoscaled size and the large surface-to-volume ratio, electrospun ceramic nanofibers (ECNs) have demonstrated great potential for the design of gas-sensing devices during the most recent years. Recently, studies have shown that the sensitivity, selectivity, and other important sensing parameters of ceramic nanofibers can be improved by designing heterojunctions at the nanoscale. As a consequence, outstanding composite and hybrid materials with unprecedented features have been recently reported for the detection of hazardous gases. In view of the importance and the potential impact of these results, here we review the latest findings and progress reported in the literature on the factors that influence the gas-sensing characteristics, as well as their application as gas sensors for monitoring various volatiles. This review will help researchers and engineers to understand the recent evolution and the challenges related to electrospun ceramic-based gas sensors and also further stimulate interest in the development of new gas-sensing devices.