Development of an IoT-enabled aqueous Sulphur sensor
This thesis presents research in relation to the development of a low-cost sensor capable of real-time detection of Sulphur ions within aqueous mediums, with the future potential of detection of Hydrogen Sulfide (H2S) in potable and wastewater systems. H2S is a toxic gas that can be harmful to humans at low concentrations and also cause significant damages to wastewater infrastructure. There currently remains a large interest in developing a low-cost sensor capable of detecting H2S in liquid phase. The synthesis of a graphene-based polymer composite coating for Sulphur ion absorption is detailed and characterized. Electrochemical impedance spectroscopy is utilized alongside a novel interdigital capacitive sensor for detection. Sampled Sulphur measurements are conducted through using the sensor in combination with a selective coating of Reduced Graphene Oxide (rGO) coated with Silver nanoparticles (AgNPs). The sensitivity curve was developed for concentrations ranging from 0.5 to 40 ppm, highlighting the promising initial results and strong potential for detection of liquid H2S. A portable IoT-based wireless sensing system is also presented for use alongside the sensor to allow for detection of Sulphur at any location at any time, with the obtained data being uploaded to the internet and stored to allow for further analysis.
