Arsenic Trioxide Nanostructures for Selective Detection of NO Gas at Room Temperature

Detection of nitric oxide (NO) is very important as the permissible exposure limit is 25 ppm for 8 h. while exposure at 100 ppm is immediately dangerous to life. However, its detection at a trace level is due to its existence as a free radical rather than a molecule. In this article, we report arsenic trioxide (As2O3) nanostructures prepared by pulverization of arsenic in liquid media by subjecting it to ultrasonic waves. The device has been found to be selective for NO gas at room temperature efficiently. The device responded in a range of 200 ppb–2.75 ppm of NO gas with reasonable (7%–90%) response at room temperature with low hysteresis ( $\sim $ 8%) with a linear sensitivity and fast response/recovery time (< 1 min). The insights on the interfacial interactions between the As2O3 and NO gas molecules were also understood based on the first principle density functional theory calculations. This work will be crucial in designing and developing new selective receptors for the detection of toxic gases.