Construction of WO3 coatings with micro-nano hybrid structures by liquid precursor flame spray for enhanced sensing performances to sub-ppm ozone

WO 3 coatings with tunable micro-nano hybrid structures were fabricated by liquid precursor flame spraying. The coatings consisting of the sole component of monoclinic WO 3 show porous topographical morphology with grains of ∼20   nm and pores of ∼4–8   μm. Assessment of gas sensing performances of the coatings to ozone reveals their optimum operating temperature of 150   °C, and sensor response of 3.9 and 46.7 to ozone concentration of 0.5   ppm and 2.0   ppm respectively. The results shed light on construction of ceramic coatings with tunable hybrid structures by the precursor flame spray technical route for functional applications.