Abstract
In this paper we proposed a rapid and continuous process for the production of nanoporous coatings for functional applications. Experiments following two statistical designs were implemented to screen and investigate the spraying parameters’ effects on coating crystallinity and porosity to gain a better understanding. The spraying stand-off distance, solution flow rate and arc current were identified as having significant effects on coating porosity and crystallinity. The investigation yielded a microstructure comprised of interpenetrating pores and layered structures with embedded nanopores. A deposition mechanism was postulated to explain this peculiar microstructure. Gas sensors constructed from the coatings had ethanol sensitivities at room temperature comparable to those reported in the literature for conventional thick-film coatings and a maximum sensitivity near 200°C.
