Kim Hyeonghun, Kim Woochul, Cho Sungjun, Park Jiyoon, Jung Gun Young
School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea.
ACS Appl Mater Interfaces. 2020 Jun 24;12(25):28616-28623. doi: 10.1021/acsami.0c05369. Epub 2020 Jun 10.
Semiconductor sensors equipped with Pd catalysts are promising candidates as low-powered and miniaturized surveillance devices that are used to detect flammable hydrogen (H) gas. However, the following issues remain unresolved: (i) a sluggish sensing speed at room temperature and (ii) deterioration of sensing performance caused by interfering gases, particularly, carbon monoxide (CO). Herein, a bilayer comprising poly(methyl methacrylate) (PMMA) and zeolitic imidazolate framework-8 (ZIF-8) is utilized as a molecular sieve for diode-type H sensors based on a Pd-decorated indium-gallium-zinc oxide film on a p-type silicon substrate. While the PMMA effectively blocks the penetration of CO gas molecules into the sensing entity, the ZIF-8 improves sensing performances by modifying the catalytic activity of Pd, which is preferable for splitting H and O molecules. Consequently, the bilayer-covered sensor achieves outstanding CO tolerance with superior sensing figures of merit (response/recovery times of <10 s and sensing response of >5000% at 1% H).
配备钯催化剂的半导体传感器有望成为用于检测易燃氢气（H）的低功耗、小型化监测设备。然而，以下问题仍未得到解决：（i）室温下传感速度缓慢；（ii）干扰气体，特别是一氧化碳（CO）导致传感性能下降。在此，由聚甲基丙烯酸甲酯（PMMA）和沸石咪唑酯骨架-8（ZIF-8）组成的双层被用作基于p型硅衬底上钯修饰的铟镓锌氧化物薄膜的二极管型氢气传感器的分子筛。虽然PMMA有效地阻止了CO气体分子渗透到传感实体中，但ZIF-8通过改变钯的催化活性来提高传感性能，这有利于氢分子和氧分子的分解。因此，双层覆盖的传感器具有出色的抗CO能力，具有优异的传感品质因数（在1%氢气浓度下响应/恢复时间<10秒，传感响应>5000%）。
