Wearable electrochemical gas sensor for methanol leakage detection

To ensure worker and environmental safety in daily work, it is an urgent need in industrial safety field to construct wearable sensing devices for volatile organic compounds (VOCs) leakage detection in chemical production. In this work, methanol gas was selected as the research object, and the wearable gas sensor has been constructed on a flexible substrate for systematically investigating the sensing process and performance, as well as practicality of leak detection. Electrochemical measurements demonstrated the constructed sensor possessed obvious electrocatalytic capability at 0.6 V, good linearity in the detection range of 20–100 ppm, 200–3000 ppm and 4000–30,000 ppm, and low limit of detection (3.3 ppm). This methanol gas sensor also exhibited high reproducibility, lifetime, and stable sensitivity according to the continuous repeated and long-time stability measurement results. High gas-sensitive selectivity to methanol under multiple interference gases, such as acetone, toluene, xylene, methylene chloride, acetonitrile had been demonstrated, and the response change under selectivity test was less than 16%. Significantly, it also displayed detectability in actual methanol gasoline sample, and the response time was less than 16 s. Moreover, experimental results also have proved higher content of platinum (20%) with better theoretical CO-tolerance capacity and sensing sensitivity. When maintaining a platinum content of 20%, the introduction of support materials with high specific surface area and conductivity in place of activated carbon will ensure that all sites are catalytically active, further improve the sensing sensitivity and be extended to the design of other VOCs sensors.