Chapter 19 - Functionalized nanofibers for gas and volatile organic compound sensing

Abstract

Gas sensors that are exceptionally sensitive and discriminating, with low power consumption and shrinking capability, are required for applications needing real-time gas monitoring. The challenge is to develop low-cost sensing units that are affordable enough to be widely deployed, which can only be done via the use of effective materials and manufacturing techniques. Nanofibers have the potential for next-generation gas sensors, customized pore sizes, high stacking density, and ease of surface modification, resulting in excellent sensitivity, selectivity, quick reaction and recovery, and good reversibility, thanks to their large surface-area-to-volume ratio. However, it has been impossible to fulfill all of the demand for perfect sensors using single-component nanofibers. These restrictions have been addressed by the use of techniques like doping with different oxides, UV irradiation, as well as noble metal decoration. These can enhance the oxygen vacancy and active sites. In this chapter, the first part of covers the nanofiber-based gas sensor's assessment criteria, application domains, and sensing mechanism (ionosorption and oxygen-vacancy model). Then, we discussed the need for efficient gas sensors in safety systems for heating, ventilation, and air conditioning (HVAC), as well as online monitoring of industrial processes and to name a few. Moreover, another large part of the chapter consists of the different synthesis methods for functionalized nanofibers, their characterization, sensor selectivity, responsiveness, and recovery on the exposure of gas. This chapter might see the continued growth and evolution of functionalized nanofiber-based sensors for detecting a variety of analytes.