Optimization of iridium oxy-hydroxide films for pH monitoring of underground components of nuclear repositories

Abstract : For the long-term monitoring of the pore water of clay-based disposal systems, the development of robust all-solid pH sensors, which do not necessitate any maintenance, is required. Due to their high stability, corrosion resistance and reversible redox properties, iridium oxyhydroxides (IrOx) are widely investigated for pH sensing and can be regarded among the promising technologies to be devoted to the observation and monitoring of pH of underground components of nuclear repositories. This work aimed at in depth investigating and optimizing the IrOx coating process for pH measurements in agreement with the specific constraints related to on-site conditions. Electrochemically assisted synthesis was selected in order to control the oxidation states of IrOx redox active species in the coating