Humidity Sensing with PVA-Doped ZnO Nanocrystals: Synthesis, Characterization, and Performance Evaluation

The Synthesis, characterisation, and performance assessment of zinc oxide (ZnO) nanocrystals doped with polyvinyl alcohol (PVA) for use in humidity sensing are presented in this work. Sol-gel synthesis was used to create ZnO nanocrystals, which were then doped with different PVA concentrations to improve their hydrophilic characteristics and sensor responsiveness. Using scanning electron microscopy (SEM), and X-ray diffraction (XRD), the structural and morphological properties of the nanocrystals were investigated in detail. It was discovered that the addition of PVA affected the optical bandgap, surface morphology, and crystallinity of ZnO nanocrystals. Evaluations of the humidity detecting capabilities throughout a broad range of relative humidity (RH) levels (40–80%) demonstrated the PVA-doped ZnO sensors' increased sensitivity, quicker response/recovery times, and better repeatability when compared to their undoped counterparts. According to our results, PVA doping successfully modifies the surface characteristics of ZnO, which makes it a viable approach for creating effective and reasonably priced humidity sensors for industrial and environmental monitoring applications.