Electronic charge modulation in Bi2O3/SnO2 heterostructures for enhanced NO2 gas-sensing performance

Environmental monitoring has become essential for recognizing and mitigating the effects of the increased release of hazardous gases on ecosystems and human health. NO 2 is harmful air pollutant, mainly emitted by combustion sources and is associated with respiratory problems and photochemical smog. The present investigation utilized a simple hydrothermal approach to synthesis Bi 2 O 3 /SnO 2 heterostructures designed for the detection of NO 2 gas at low concentrations. The Bi/Sn-2 heterostructure exhibited a remarkable response (R g /R a ) of 105.4 upon exposure to 50 ppm of NO 2 gas. Furthermore, the Bi/Sn-2 heterostructure exhibited significant repeatability in its performance for 8 continuous cycles while ensuring long stability for 30 days. The exceptional responsiveness and selectivity towards NO 2 gas have been attributed to the formation of a p-n junction, augmented by the combined effect of increased surface area and unique morphological characteristics. This study demonstrates a viable approach to develop metal oxides heterojunctions that can detect low concentrations of NO 2 gas.