Room temperature CO sensor fabricated from Pt-loaded SnO2 porous nanosolid

Highly sensitive room temperature carbon monoxide (CO) gas sensor was prepared by Pt-loaded SnO2 porous nanosolid (SnO2:Pt PNS). The effects of preparation conditions on sensor response were studied and the highest response to 100 ppm CO at room temperature reached a value of 64.5, which is actually high compared with previous reports. In addition, SnO2:Pt PNS sensor showed a good CO selectivity against H2. Hall effect measurement was conducted to analyze the sensing mechanism, which reveals that SnO2 PNS is highly depleted after Pt-loading and the high response of our sensors depends on the change of both electron concentration and mobility upon exposing to CO gas. The sensor response is also favored by the highly porous, interconnected small-grain structure of SnO2 PNS.