Miniaturized\nElectrochemical Gas Sensor with a Functional\nNanocomposite and Thin Ionic Liquid Interface for Highly Sensitive\nand Rapid Detection of Hydrogen

Hydrogen has been widely used in industrial and commercial\napplications\nas a carbon-free, efficient energy source. Due to the high flammability\nand explosion risk of hydrogen–air mixtures, it is vital to\ndevelop sensors featuring fast-responding and high sensitivity for\nhydrogen leakage detection. This paper presents a miniaturized electrochemical\ngas sensor by elaborately establishing a nanocomposite and thin ionic\nliquid interface for highly sensitive and rapid electrochemical detection\nof hydrogen, in which a remarkable response time and recovery time\nof approximately 6 s was achieved at room temperature. A screen-printed\ncarbon electrode was modified with a reduced graphene oxide–carbon\nnanotube (rGO-CNT) hybrid and platinum–palladium (Pt–Pd)\nbimetallic nanoparticles to realize high sensitivity. To achieve miniaturization\nand high stability of the sensor, a thin-film room-temperature ionic\nliquid (RTIL) was employed as the electrolyte with a significantly\ndecreased response time. The fast-responding hydrogen sensor demonstrates\nexcellent performance with high sensitivity, linearity, and repeatability\nat concentrations below the lower explosive limit of 4 vol %. The\nengineered high-performance interface and gas sensor provide a promising\nand effective strategy for gas sensor design and rapid hazardous gas\nmonitoring.