Humidity sensing performance of hybrid nanorods of polyaniline-Yttrium oxide composite prepared by mechanical mixing method.

In this work, polyaniline (PANI) synthesized by in-situ polymerization was mechanically mixed with different feeding mass ratios of Y2O3 to form four Polyaniline/Yttrium oxide (PYO) composites. Among them, the PYO-4 composite acquiring nanorod structure with high aspect ratio confirmed from its TEM image and consequent maximum enhancement in its humidity sensing response discussed in comparison with those of PANI and other composites. The interaction of PANI with Y2O3 in the composite confirmed from FTIR studies. The increase in defects and vacancies in all the composites, being maximum in PYO-4 composite nanorods compared to those of PANI confirmed from XRD studies. Maximum increase in the porosity of PYO-4 composite nanorods as compared to those of PANI and other composites confirmed from SEM studies. The humidity sensing studies revealed that, PYO-4 composite nanorods showed a maximum sensing response of 99.99% with a dynamic response and recovery time of 3 s and 4 s respectively. The PYO-4 composite nanorods having acquired comparatively good sensing characteristics such as low real sensitivity and limit of detection (LOD), negligible hysteresis, best linearity and perfect stability as against those of PANI and other composites established which were also correlated with the calculated physical parameters such as porosity, water content and degree of swelling.