Green Mediated Synthesis of Macroporous Hierarchical CeO2 Nanoparticles\nusing Mimosa pudica Leaf Extract for Humidity Sensing Application

Abstract

Metal oxide nanoparticles are popular candidates for chemiresistive sensors application. Cerium oxide\n(CeO2) based semiconducting gas sensors have gained rapid interest in recent years. In this study, an\nenvironment-friendly green synthesis approach was employed for the synthesis of macroporous CeO2\nnanoparticles using Mimosa pudica leaf extract. Later the performance of CeO2 nanoparticles for\nhumidity sensor is demonstrated. X-ray diffraction studies revealed the cubic fluorite crystal structure\nwith no impurities, scanning electron microscopy analysis revealed the macroporous morphology of\nCeO2 hierarchical nanoparticles. Humidity sensing properties were studied using interdigitated electrode\ncoated with CeO2 nanoparticles. The results showed the sensing response of 0.5 times for 10% RH\n(relative humidity) and seven times for 90% RH. The response and recovery times were found to be as\nlow as 12 s and 15 s, respectively. The experimental results provided an environment-friendly approach\nfor the synthesis of CeO2 particles and revealed promising results in humidity sensing application.