Environmental sensing semiconducting nanoceramics made using a continuous hydrothermal synthesis pilot plant

Room temperature vanadium dioxide–carbon nanotube gas sensors made via continuous hydrothermal flow synthesis

“…The circular arrangement of the devices around the midpoint, along with the extraction of gas behind each individual port location, ensured that each sensor was exposed to an equal flow and concentration of gas. A potentiostat setup was used to derive the room temperature sensor conductance throughout the testing run, as described previously 2 .…”

“…The synthesis of gas sensing nanomaterials at scale is important for the development of better commercial gas sensors 1,2 . Nanomaterials have shown promise for sensing of low concentrations of analyte, due to their high surface area and electronic properties that are affected by the local environment [3][4][5] .…”

“…Controlling the nanoparticle size, shape and microstructure is important for sensing applications, as these factors drastically affect the material's performance. Therefore, the CHFS method used herein, was beneficial as it allowed scalable synthesis of the nanomaterials (with some control over particle properties) that were then used for water and ammonia gas sensing 2,[44][45][46] .…”

Sustainable Transparent Conducting Oxide Nanomaterials; Aluminium- and Gallium-Co-Doped Zinc Oxide (AGZO)

“…By virtue of being a continuous process, CHFS lends itself to process intensification, which opens up the possibility of it being used for direct, scalable and continuous TCO-ceramic ink production. [19][20][21] In CHFS, the mechanism of precursor conversion to nanoparticle metal oxide in the supercritical/superheated water environment proceeds via simultaneous and rapid hydrolysis and dehydration. A schematic for the CHFS process is shown in Figure 1.…”

“…After the mixer, the newly formed aqueous nanoparticle slurry is rapidly cooled in flow before passing through a back-pressure regulator valve, where it is collected for removal of the water and residual ions. [19][20][21][22] To the knowledge of the authors, doped zinc oxide synthesis via CHFS for TCO applications has not previously been investigated, however, zinc oxides made via CHFS have been of interest for other applications on the laband pilot-scale; [20][21][22] this includes a combinatorial approach (lab-scale) to d-and f-block doped zinc oxides (0.5-1.5%) Figure 1. General schematic for the CHFS process; ambient precursor metal solution and base solution meet a stream of supercritical water, forming metal oxide nanoparticles which are collected as a slurry after cooling.…”