Enhanced HMDSO Resistance in CeO₂-rGO/Pd/ZnO Gas Sensor

Hexamethyldisiloxane (HMDSO) presents a significant challenge to the reliability of metal-oxide-semiconductor (MOS) gas sensors due to its deactivation properties, posing risks to environmental and daily life safety. This study enhances the performance of MOS gas sensors by developing an anti-poisoning sensor (APS) with a composite CeO₂-rGO (Cerium Oxide-reduced Graphene Oxide) layer on Pd/ZnO nanoparticles. The APS improves resistance to HMDSO poisoning during hydrogen (H₂) detection and extends the sensors’ lifespan. Previous work was referenced for this study, and experimental sensing results demonstrate that the APS sensor shows a notable 1.25% change in resistance/conductivity when exposed to air and HMDSO (10 ppm) at 250℃, surpassing both Pd/ZnO and ZnO sensors. Surface modifications with CeO₂-rGO effectively mitigate HMDSO-induced deactivation mechanisms, inhibiting the formation of organosilicon compounds, silicates, and a SiO₂ layer on metal/metal-oxide surfaces that typically reduce sensor sensitivity over time. CeO₂ supplies oxygen, influencing surface chemical reactions, while rGO acts as a barrier preventing HMDSO infiltration, thereby protecting the sensing layer’s integrity. The aim of these APS a material system is to enhance the lifespan and reliability of electrochemical sensors (ECS) for future applications in the detecting of food spoilage gases in refrigerator environments.