Hydrothermally engineered WO₃ nanosheets as potential NO₂ gas sensor

Tungsten oxide (WO₃) has gained importance in the gas sensing field, particularly for NO₂ gas monitoring. The NO₂ is a toxic gas that has a severe impact on the human health and the environment. In the present study, WO₃ nanosheets were synthesized hydrothermally at a relatively low temperature, i.e. 100°C and characterized via FTIR, XRD, FESEM, BET and UV–VIS spectroscopy techniques. The WO₃ nanosheet-based gas sensor was fabricated for NO₂ gas monitoring. The NO₂ sensing analysis showed that the WO₃ nanosheet-based gas sensor exhibited a maximum response value of 38% for 50 ppm NO₂ at 150°C operating temperature with response and recovery time of 85 s and 315 s, respectively. The detection limit of the sensor was observed up to 1 ppm of NO₂. These findings highlight the potential of WO₃ nanosheets for monitoring NO₂ gas for the development of efficient gas sensors for sustainable environmental protection.