Acid Ammonium Salt of 12-Phosphotungstic Acid and Calixarene Composite Solid Electrolytes for Potentiometric H2 and CO Sensors

The work is focused on the analysis the impact of the composition of a composite electrolyte comprising a disubstituted ammonium salt of phosphotungstic acid and sulfonated calixarene on the characteristics of solid-state potentiometric sensors for hydrogen and carbon monoxide, including their simultaneous detection in air. The response time of the CO sensors is shown to be independent of the composition of the composite electrolyte, with a value of approximately two minutes for 0.1 vol %. The study also observed two types of open circuit voltage, depending on the electrolyte composition. The sensors demonstrated selectivity for CO, detecting it in the H2–CO–air atmosphere at concentrations comparable to H2 concentrations.