Preparation and performance of TiO2/ZnO humidity sensor based on TiO2

Abstract

In this study, TiO2 was selected as the primary material to prepare a humidity sensor. To enhance its sensing performance, it was doped with ZnO, and a TiO2/ZnO composite was synthesized via the hydrothermal method. Based on this composite material, a TiO2/ZnO humidity sensor was designed and fabricated. The sensor properties were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) techniques. The increase in hydroxyl and oxygen vacancy content on the surface of composite materials enhances their sensitivity to water molecules, leading to improved sensor response. The construction of ZTO3 heterojunction promotes the migration of electrons on the sensor surface to improves the performance of the sensor. Humidity sensor based on the TiO2/ZnO composite material exhibits excellent performance, with high response to water molecules, a fast response/recovery time (18/22 s), low humidity hysteresis (1.55 %), and low interference from monochromatic light. Thus, the TiO2-based humidity sensor doped with ZnO shows great potential for practical applications.