Detection properties of electrochemical acidic gas sensors using halide–halate electrolytic solutions

Amperometric sensors for the detection of acidic gases were investigated. A detection method is based on the electrode reactions of halogen liberated by the hydrogen ion generated from an acidic gas. We have compared the detection abilities of the sensors using different combinations of the halide–halate ion to detect different acidic gases, such as HF and HCl. We have found that the sensitivity of the sensors depends on the electrolytic solution composition and the acidic gases. The I−/IO3− system shows the highest sensitivity to detect HF gas, however, the Br-/BrO3− gives hardly response to HF. In the case of HCl gas detection, I−/IO3− system gives high sensitivity, and the Br−/BrO3− also adaptable to the sensing. The selectivity for acidic gas detection can be controlled by choosing the combination of the halide–halate systems.