Highly sensitive and selective CO gas sensor based on a hydrophobic SnO2/CuO bilayer

Abstract

Here, we have deposited bare SnO₂ and SnO₂/CuO bilayer thin films directly on porous anodic alumina (AAO) by pulsed laser deposition and then used them as a gas sensor without additional processing. The bilayer sensor shows remarkably high and selective responses to CO gas compared with bare SnO₂ in a low detection range 5–500 ppm. Sensor response, selectivity, and stability studies reveal excellent sensing of the thin films. The working principle and role of hydrophobicity behind their good performance was discussed.