Catalyst‐Free Vapor‐Phase Method for Direct Integration of Gas Sensing Nanostructures with Polymeric Transducing Platforms

Abstract

Tungsten oxide nanoneedles (NNs) are grown and integrated directly with polymeric transducing platforms for gas sensors via aerosol-assisted chemical vapor deposition (AACVD) method. Material analysis shows the feasibility to grow highly crystalline nanomaterials in the form of NNs with aspect ratios between 80 and 200 and with high concentration of oxygen vacancies at the surface, whereas gas testing demonstrates moderate sensing responses to hydrogen at concentrations between 10 ppm and 50 ppm, which are comparable with results for tungsten oxide NNs grown on silicon transducing platforms. This method is demonstrated to be an attractive route to fabricate next generation of gas sensors devices, provided with flexibility and functionality, with great potential in a cost effective production for large-scale applications.

Cerium Oxide-Tungsten Oxide Core-Shell Nanowire-Based Microsensors Sensitive to Acetone

“…SEM imaging of the microsensors after AACVD of the gas sensitive structures showed uniform deposited films that covered the electrodes integrated into the micromachined membrane (Figure 2a). A close view of the non-modified tungsten oxide wires ( W ) showed bare and even surfaces as noticed previously for other AACVD tungsten oxide structures [21]. In contrast, a close view of the cerium oxide-tungsten oxide core-shell wires ( Ce / W ) displayed the presence of a rugged thin film covering the wire surface (Figure 2b,c), similarly to that observed when depositing non-modified cerium-based films ( Ce ) from a Ce (acac) 3 methanolic solution via AACVD (Figure 2d).…”

Sensitivity of Mesoporous CoSb2O6 Nanoparticles to Gaseous CO and C3H8 at Low Temperatures

“…In recent years, nanoscience and nanotechnology have had a huge impact on many fields of scientific research. New materials with nanometric sized particles (1 nm = 10 −9 m) show interesting physical and chemical properties for different applications, including gas sensors [1][2][3][4][5][6][7][8][9][10].…”

Aerosol assisted chemical vapour deposition of gas sensitive SnO2 and Au-functionalised SnO2 nanorods via a non-catalysed vapour solid (VS) mechanism

“…The formation of nanostructures via a vapour-solid (VS) mechanism, in contrast, avoids the use of catalyst seeds and facilitates device fabrication, but the synthesis of tin oxide nanostructures via a VS mechanism has so far required the use of very high temperatures in the range of 850 °C and 1150 °C 10 11 13 14 25 , or the use of plasma systems to reduce the deposition temperature, both of which can damage fragile substrates 26 . Recently, however, we have recognised that aerosol assisted (AA)CVD (a variant of traditional CVD which uses aerosol droplets to transport the precursor solution to the heated reaction zone) can lead to the formation of tungsten oxide nanostructures via a VS mechanism at relatively low onset temperatures, attributed to formation of reactive intermediates during deposition 27 . This method, which works at atmospheric pressure and relies on a solution-based delivery approach, is advantageous over traditional CVD as it allows for a wider range of precursors to be utilised 28 .…”