The novel method, which uses aerosol assisted chemical vapour deposition, is demonstrated to be effective both for incorporating metal nanoparticles (NPs) into nanostructured materials, resulting in a useful way of tuning functionality in metal oxides, and for directly integrating these materials with devices.
By adding metal NPs to the nanostructures materials, in this case tungsten oxide nanorods, the electronic and sensing properties of the nanostructure are altered making them ideal for the fabrication of selective gas microsensor arrays.
In this instance, the addition of gold or platinum NPs affects the ability of the nanorod to effectively discriminate analytes that are present in proton-exchange fuel cells. For example, improved sensing characteristics, in particular to H2, are observed at 250 °C when platinum NPs are added, whereas without these, the nanorods show responses to low concentrations of CO at low temperatures.
Differences in the sensing characteristics of these nanostructures are attributed to the different reactivities of metal NPs, and to the degree of electronic interaction at the nanostructure and NP interface.
The method presented in this work has advantages over other methods of integrating nanomaterials and devices, of having fewer processing steps, relatively low processing temperature, and no requirement for substrate pre-treatment.