Humidity-resistant gas sensors based on SnO2 nanowires coated with a porous alumina nanomembrane by molecular layer deposition

We report a novel route for enhancing the humidity resistance of SnO2 nanowires (NWs; widely used metal oxide semiconductor gas sensors) based on their coating with humidity-resistant nanomembrane. A conformal thin film was deposited by Molecular Layer Deposition (MLD) NWs using trimethylaluminum and ethylene glycol as precursors (100 MLD cycles), followed oxidation in air at 400 °C. In conditions increasing relative humidity, NW sensor coated microporous, 10-nm thick nanomembrane layer converted alucone obtained calcination showed remarkable response compared pristine sensor. This stable displayed good recovery times humid (30 90 % humidity). work shows benefits practical application MLD-prepared nanomaterials. original strategy applied to NW-based sensors paves way other complex 3D designs different applications that require or ion selectivity, such photocatalysts biosensors, atmosphere.