Metal ion-doped SnO₂ ordered porous films and their strong gas sensing selectivity

Based on a sol-gel technique and the colloidal monolayer template, ion-doped SnO₂ ordered porous films were fabricated, and the corresponding gas-sensing properties were studied. The sensitivity to the given test gases strongly depends on the doping species and doping amount. Importantly, when the doping amount is 1% M, the Cr⁺³ and Pd ⁺² doped porous films demonstrate a greatly enhanced sensitivity and strong selectivity to ethanol and ammonia, respectively. The improved sensing properties are attributed to the doping-induced surface modification of the films. Such ion-doped porous films are expected to bring new opportunities for application of future porous film-based gas sensors.