Wo3 Based Nanostructures for Highly Sensitive and Selective No2 Gas Detection

Abstract

In the last few decades, the modern environment has been polluted by the presence of numerous harmful gases such as Sulfur dioxide (SO2), Ammonia (NH3), Nitrogen dioxide (NO2), Nitrous oxide (N2O), Hydrogen sulfide (H2S), etc. Among them, nitrogen dioxide is considered as a prime hazardous gas in the current environmental status. The majority of NO2 gas emissions has been received from the combustion of fossil fuel and nuclear power plant. A lower concentration (in ppm) of NO2 inhalation could cause serious problems in humans and environmental concerns. To solve these issues, transition metal oxides semiconductor has received significant attention to detect harmful gases via appropriate gas sensors owing to its nanostructure dependent an adsorption and catalytic properties. In the metal oxide family, tungsten trioxide (WO3) based nanostructured thin film exhibits relatively great sensitivity towards sensing the more poisonous gases such as CO, NO2, SO2, NH3, and H2S. Similarly, WO3 nanostructured thin film has promising gas sensing ability for practical sensor applications. However, the WO3-based gas sensor demonstrated limited sensitivity along with poor stability under ambient conditions, which limits their commercialization process. To overcome these demerits of WO3-based gas sensors, numerous strategies have been employed in recent decades. In the present thesis work, the noble metal decorated (Au)/doped (Ag) and rare earth metals (Gd, Y) doped WO3 nanostructures are promising approaches to develop efficient gas sensor devices. Moreover, the structural, morphological, chemical composition, surface analysis, and gas sensing properties of prepared samples are systematically investigated in detail newline