To study the enhanced humidity-sensing performance of rGO/ZnO heterostructure compared to pure ZnO and its practical utility in contactless sensing device

The humidity sensor has gained a lot of attention from many researchers nowadays due to its vast applications including human diagnosis, contactless sensing, agriculture, and industrial processes. In this work, we synthesized ZnO nanoparticles and rGO/ZnO heterostructures via hydrothermal technique and investigated the enhanced humidity-sensing performance of rGO/ZnO heterostructure in comparison with pristine ZnO. The crystallinity, phase formation, and morphology of the synthesized nanoparticles have been examined through XRD (X-ray Diffraction) and SEM. For humidity sensing, the sensing properties of the fabricated sensors were studied within the range of 11–90% relative humidity. As compared to the pristine ZnO, the rGO/ZnO heterostructure shows a remarkable response towards humidity (R_o/R_H = 4507) with fast response and recovery time of 1.5 s and 11 s, respectively. Furthermore, rGO/ZnO heterostructure exhibits superior humidity-sensing properties, including enhanced sensitivity, faster response and recovery times, and improved stability compared to pure ZnO. This analysis signifies that rGO in ZnO contributes to the advancement of humidity-sensing technology and offers insights into the potential applications of rGO/ZnO heterostructure-based sensors in various industries, medical applications, and non-contact sensing.