Room temperature acetone gas sensing performance of ZnS-NiO nanocomposite sensor enhanced by UV activation for diabetes detection

Metal oxide semiconductors are popular in gas sensor applications.Current metal oxide-based acetone sensors struggle to deliver ppb-level acetone sensing at low temperatures for biological use. This study synthesizes 4mol% ZnS combined with NiO for acetone sensing. Nanoparticles were studied using FE-SEM, XPS, XRD, and UV-Vis spectroscopy. Mixed ZnS and NiO resulted in rapid gas channel movement and n-p heterojunction development, which increased acetone sensitivity. ZnS-NiO showed a gas sensing response of 163% for 20 ppm acetone at room temperature under UV irradiation, which is 2.3 times higher than pristine NiO (70% at 180 ∘C). ZnS improves sensor selectivity. Heterojunction sensor reaction and recovery times were 20 and 14 seconds, respectively. The composite sensor detection limit was 0.1 ppm. The increased sensitivity validates the n-p heterojunction. The sensor's higher response values and lower detection limit point to breath analyzer applications such as diabetes detection.