Electrospun ZnO hollow nanofibers gas sensors: An overview

Resistive gas sensors are used widely for the detection of toxic gases. ZnO nanofibers (NFs) with a onedimensional morphology, high electron mobility, and rough surfaces have abundant adsorption sites for gas molecules. Hence, they are considered reliable materials for sensing toxic gases. Further improvement in their sensing performance can be achieved through the synthesis of hollow ZnO NFs (HNFs), in which their surface areas are significantly higher than ZnO NFs owing to the hollowness of NFs. HNFs are produced mainly by electrospinning, a straightforward and versatile technique with high efficiency. This review paper discusses the gas -sensing properties of pristine, doped, decorated, and composite ZnO HNFs, focusing on the gas -sensing mechanism of ZnO HNFs to provide valuable information on ZnO HNFs for potential use as highly reliable gas sensors.