SnO₂based nanostructures for gas sensor application: a review

In recent years, atmospheric pollution has been increasing day by day due to the rapid growth of industrialization, urbanization and motor vehicles. As a result, a large number of pollutants containing harmful and toxic gases like NO₂, NH₃, H₂, H₂S and C₃H₆O etc. are being released into the environment. This detrimental increase can cause adverse effects on human life, necessitating monitoring and safety measures. Gas sensors play a crucial role in this regard by monitoring and alerting when pollutant levels exceed permissible limits. Metal oxide semiconductor (MOS) gas sensors have gained much popularity due to their good stability, tunable chemical properties, simple fabrication process and cost effectiveness. SnO₂is the most widely used MOS material for detecting various toxic and hazardous gases, owing to its excellent physical and chemical properties, high reliability and short adsorption and desorption times. In this review, we elevated the role of SnO₂in detecting various toxic and hazardous gases and highlighting different synthesis methods with various structural and morphological modifications are summarized. By reviewing the latest advancements, this paper proposes several future research directions for SnO₂-based gas sensors.