Selective H 2 Gas Sensing Using ZIF-71/In-SnO 2 Bilayer Sensors: A Size-Selective Molecular Sieving Approach

作者：Dominik Baier, Laureen Kieke, Sven Voth, Marvin Kloß, Marten Huck, Hans‐Georg Steinrück, Michael Tiemann · 发表于：ACS Sensors · 年份：2025 · DOI：10.1021/acssensors.5c00770 · 被引用次数：3 · 研究领域：Gas Sensing Nanomaterials and Sensors、Analytical Chemistry and Sensors、Advanced Chemical Sensor Technologies

A universal method for creating selective hydrogen (H 2 ) gas sensors through the integration of microporous zeolitic imidazolate framework (ZIF) filter layers on metal oxide sensing layers is presented. The sensor design consists of an indium-modified tin oxide (In-SnO 2 ) layer as the gas-sensitive component, topped by a size-selective ZIF filter layer. The ZIF layer is generated by first depositing zinc oxide (ZnO) of variable thickness (20–48 nm) onto the In-SnO 2 layer, followed by in situ conversion to either ZIF-8 or ZIF-71 through solvothermal methods. The resulting bilayer structures are characterized using scanning electron microscopy (SEM), grazing incidence X-ray diffraction (GIXRD), and N 2 physisorption analysis. Gas sensing measurements at 180 °C reveal that a 57-nm-thick ZIF-71 filter layer enhances the sensor response to H 2 while simultaneously suppressing interference from carbon monoxide (CO) through molecular sieving, as the kinetic diameter of H 2 is significantly smaller than that of CO. The sensor maintains stable performance under varying humidity conditions (25–75% relative humidity). This work demonstrates a promising approach for achieving selective H 2 detection through rational design of microporous filter layers with defined pore apertures.