Pulsed UV Light Activated Gas Sensing in Tungsten Oxide Nanowires

Abstract The present work shows a new way to analyze transient responses of MOX sensors under Pulsed-UV light, that can improve response dynamics and mitigate drift. In particular, we focus on the gas response analysis of tungsten oxide (WO 3-x ) nanoneedles when exposed to NO 2 . It is known that temperature modulation is useful for extracting more information about the pollutant gases, so we have modulated UV source (325nm) in order to study the transients of oxidation (when UV is Off for 30 s) and transients of surface reduction or cleaning (UV On for 30 s). Using pulsed UV light activated sensing allows us to obtain responses, even at room temperature, and significantly reduce power consumption.