Multi-metal functionalized tungsten oxide nanowires enabling ultra-sensitive detection of triethylamine

Sensitization of metal oxide semiconductors is crucial for developing high performance electronic gas sensors. Herein, a unique dual sensitization protocol is proposed to boost the sensing performances of metal oxide nanowires. As a proof-of-concept, W18O49 nanowires are selected as the host materials, and Ag, N nanoparticles are loaded on W18O49 by an in-situ redox reaction to fabricate the novel Ag/Pt/W18O49 hybrid nanowires. Gas sensing tests demonstrate the superiority of the ternary nanowires in detecting triethylamine vapor against the binary Ag/W18O49 and Pt/W18O49 nanowires. The sensor based on Ag/Pt/W(18)O(49 )nanowires manifests fast response and recovery features and very high response over a wide concentration of 0.1-50 ppm, as well as good selectivity and stability. An ultrahigh sensitivity of 1.13 ppm(-1) is registered by the Ag/Pt/W18O49 nanowires and a low detection limit of 71 ppb is obtained. The excellent performances are attributed to the dual sensitization mechanism, i.e., a synergy of both electronic and chemical interactions derived from the Ag and N functionalization. This work establishes a new strategy for constructing multi-metal functionalized nanowires and their utilization in functional nanodevices with enhanced performances.