Metallic catalyst loaded 2D perovskite sheets for heightened surface activity for selective chemiresistive sensing

The demand for portable real-time monitoring technologies for air quality and hazardous gas detection has significantly increased due to the growing interest in healthy living. In particular, nitrogen dioxide (NO 2 ) is a major contributor to air pollution in urban areas, and its concentration can fluctuate rapidly in a short period of time due to traffic emissions and industrial activities. Therefore, it is necessary to develop an ultra-sensitive sensor with fast response and recovery at room temperature. In this study, we demonstrate an NO 2 gas sensor operated at room temperature using Ag-decorated Sr 2 Nb 3 O 10 (ASNO) nanosheets, fabricated through a simple solution-based exfoliation process. This sensor exhibits excellent structural stability and an enhanced response of 935 % to NO 2 gas due to catalytic effect of the Ag decorated surface. It demonstrates fast response and recovery characteristics, which makes it a good candidate for reliable real-time monitoring and repeated use. Room-temperature NO 2 sensing using Ag-decorated 2D nanosheets supports sensitive and selective urban air pollution monitoring.