The invention discloses a
zirconium oxide film coating liquid and a method for preparing a
zirconium oxide film type sensor. Slowly dropwise adding 31-49 parts of
metal salt solution into 50-68 parts of
oxalic acid solution, and continuously and quickly stirring for 2 hours to obtain blue transparent
sol; 0.2-0.3 part of
acetylacetone is added into the blue transparent
sol to serve as a
sol stabilizer, 0.7-0.8 part of 5 wt%
polyvinyl alcohol 1788 low-
viscosity PVA solution is added to serve as a complexing agent, continuous stirring is conducted for 1 h, and
coating liquid for
zirconium oxide film coating is obtained; fixing an Al2O3 substrate on a table type spin coater, dripping 100 microliters of
coating liquid on the Al2O3 substrate, and forming a YSZ film on the surface of the Al2O3 substrate by adopting a
spin coating method; drawing a
platinum strip as a
reference electrode at one end of the YSZ film by using a pen
brush, drawing a
platinum point at the other end of the YSZ film, and adhering a
platinum wire as a
signal conduction wire at the
reference electrode and the platinum point; drawing an M-shaped platinum wire on the back surface of the Al2O3 substrate by using a pen
brush; after
sintering, the platinum strip forms a
reference electrode, the platinum wire forms a heating
resistor, and the platinum point forms a platinum point
electrode; uniformly
coating the surface of a platinum point
electrode with a pen
brush to form a strip-shaped NiO strip; the sintered NiO strip forms a sensitive
electrode; and
welding the Al2O3 substrate on the hexagonal tube seat to complete the manufacturing of the
zirconium oxide film type sensor. The invention has the advantages of lower impedance, lower
working temperature, lower preparation temperature and better
ionic conductivity.