Facile green synthesis of CoFe2O4 nanoparticles using hibiscus extract and their application in humidity sensing properties

Current work describes eco-friendly synthesis of cobalt ferrite (CoFe2O4) nanoparticles utilizing the flower and leaves extract of Hibiscus rosa-sinensis by chemical co-precipitation method and explored the behavior of CoFe2O4 nanoparticles on humidity sensing for humidity range 15% to 98% at room temperature. The cubic spinel structure of synthesized CoFe2O4 nanoparticles suggests a porous complex shape with an average crystalline size of 23.85 nm. Elemental analysis reveals no signs of impurity. Thermogravimetric analysis and differential thermal analysis showed that the material experienced a transformation toward thermal stability. CoFe2O4 nanoparticles as sensing medium were found to have a practical sensitivity of 40% relative humidity in the atmosphere and a response/recovery time of 5.31/7.75 seconds, respectively. CoFe2O4 nanoparticles are stable over time, according to the findings. CoFe2O4 nanoparticles humidity sensing performance demonstrates their suitability for room temperature-based humidity sensors.