Ordered array of Ag–In2O3 composite nanorods with enhanced gas-sensing properties

Here we present a sensitive formaldehyde (HCHO) gas sensor based on an ordered array of Ag–In2O3 composite nanorods, which is synthesized via the nanocasting route by directly using the solvent-extracted mesoporous silica as a hard template. Incorporation of metallic Ag nanoparticles in the nanorod array significantly improves its gas-sensing properties. The response of the ordered array of Ag–In2O3 composite nanorods to 85 ppm HCHO is 4.5 times higher than that for a pure In2O3 nanorod array without Ag.