Printed, Flexible, Ionic Liquid-Based Hydrogen Sensor via Aerosol Jet Printing of Nanomaterials

Low-cost, high-performance hydrogen sensors are highly demanded in hydrogen leakage detection. To increase the sensitivity and reliability of the hydrogen sensor, an ionic liquid (IL)-based electrochemical gas sensor is fabricated with bimetallic Platinum–Nickel (Pt-Ni) nanoparticles (NPs) with aerosol jet printing technology for continuous monitoring of hydrogen concentration. The Pt-Ni NPs covering the top surface of the metal electrodes can accelerate the catalysis and expand the sensing surface area. When hydrogen gas is sensed at room temperature, the uniquely reversible and rapid redox reactions of hydrogen at the IL/Pt electrode interface, thereby creating continuous measurement capability in a real-time manner with little signal drift. The full coverage of the sensor electrodes will increase the robustness and accuracy of the device. The fabricated sensors demonstrate excellent analytical sensing performance, reaching a limit of detection up to 19.3 ppm. The device takes advantage of an easy fabrication process, simple structure, high sensing response, and low cost, providing a promise for hydrogen sensing at room temperatures.