A Miniaturized Electrochemical Gas Sensor Utilizing Ionic Liquid/Polymeric Ionic Liquid-Based Solid-State Electrolyte

Due to its non-volatility and excellent electrochemical properties, ionic liquid has emerged as a promising alternative to traditional aqueous electrolytes in electrochemical hydrogen gas sensors. However, the fluidic nature of ionic liquids poses challenges to the lifespan and integration of sensors. To address this issue, this study introduced polymeric ionic liquid to the ionic liquid, solidifying it to form a stable solid electrolyte membrane on the electrode surface, while retaining high electrical conductivity. Different types and proportions of ionic liquids and polymeric ionic liquids were mixed to form solid-state electrolyte membranes. These membranes were then integrated with Pt-Pd nanoparticle-modified screen-printed carbon electrodes, resulting in a highly sensitive electrochemical hydrogen gas sensor. It demonstrates high sensitivity, linearity, stability, and repeatability at concentrations below the lower explosive limit of 4 vol-% H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> . The miniaturized electrochemical hydrogen gas sensor, based on ionic liquid/polymeric ionic liquid solid-state electrolyte membrane, offers a simple manufacturing process and excellent performance, showcasing promising prospects for diverse applications.