*5.3.2 Gas sensors*

Gas sensors have widely been explored in recent years to monitor and rapidly detect flammable, explosive, and toxic gases in an environment. The most important factors in determining the gas-sensing performance of these sensors are sensitivity, working temperature, response/recovery time, and also the selectivity. Thus, significant research has been focused on exploring various methods to lower the working temperature, increase the sensitivity, shorten the response/ recovery time, and also to improve the selectivity of metal oxide semiconductor based sensors. In the last decades, In2O3 [77] based gas sensors have been extensively studied because of the facile material synthesis and their high response to target gases. Among different metal oxide semiconductors, In2O3 is found to be an important and most promising gas-sensing material owing to its good electrical conductivity and high chemical stability. Till date, various nanostructures based on In2O3 for high-performance gas-sensing material in the form of thin films [78], nanowires [79], nanocrystals [80], and hollow microspheres have been developed [81].

*Indium Oxide Based Nanomaterials: Fabrication Strategies, Properties, Applications, Challenges… DOI: http://dx.doi.org/10.5772/intechopen.94743*
