Metal Oxide Nanostructures for Gas Sensing Applications

Abstract

Air quality is one of the major concerns in the modern world. The day-by-day increase in air pollution and the increasing industrial activities have noticeably depleted the air quality. This could bring about a surge in the use of gas sensors. Nowadays, gas sensors are widely used in the fields of flammable detection, explosive detection, and environmental control. Gas sensors could be used widely to detect/warn the presence of toxic and harmful gases. Nanostructured materials, due to their size effect on their physical properties and high surface-to-volume ratio attracted high scientific interest. Engineered nanostructures form compact nanosized arrays that dramatically increase the active surface area and have found vast technological applications including sensors, catalysis, energy, and so on. Moreover, approaching the nanometer regime changes the properties of the materials, which could be tuned by controlling the size, when compared to the bulk. Gas sensors fabricated with Metal-oxide (MO) nanostructured are preferred because of their relatively easy synthesis, simple supportive electronics and high sensing efficiency owing to their nanoscopic advantages. This chapter is mostly focused on the different types of nanostructures of metal oxide gas sensors and understanding their mechanism of gas sensing.