Impedimetric humidity sensor based on the use of SnO2-Co3O4 spheres

The article describes synthesis and sensing properties of SnO2-Co3O4 spheres composed of aggregated nanoparticles. Co3O4 was doped with pristine SnO2, and the resulting nanocomposite spheres were incorporated into a silicon adhesive. This material is shown to enable impedimetric sensing of relative humidity (RH). The impedance of the material decreases by 80% at a 1.0 kHz working frequency and by a factor of 2500 at 100 Hz. Capacitance increases by 70% at 1.0 kHz frequency and by a factor of 1509 at 100 Hz. The sensor works in the 10-90% RH range at temperatures from 10 to 80 A degrees C. SnO2-Co3O4 based humidity sensor exhibited high sensitivity which makes it suitable material for the utilization in humidity meter.