MOF-SMO hybrids as a H2S sensor with superior sensitivity and selectivity

Abstract

The detection of H2S is essential due to its dangerous toxicity and extensive existence in the oil and gas industries. Zeolitic imidazolate framework-8 (ZIF-8) particle-loaded ZnO nanorod hybrid is designed and fabricated as a gas sensor, which exhibits a superior sensitivity and selectivity for H2S at room temperature. ZIF-8 plays a key role in improving the sensitivity and selectivity of ZIF-8/ZnO nanorod sensor. The loading of porous ZIF-8 particles on the ZnO surfaces provides larger surface areas and more oxygen vacancies and reacts with H2S. Thus, ZIF-8/ZnO nanorod sensor has a better H2S adsorption function and transduction function compared to raw ZnO nanorod sensor. Remarkably, the response of ZIF-8/ZnO nanorod sensor to 10 ppm H2S is 52.1% even at 25 °C, which is 15 times higher than that of raw ZnO nanorod sensor. ZIF-8/ZnO nanorod sensor is able to detect H2S at a level down to 50 ppb. Moreover, it shows an excellent selective sensitivity for H2S over other reducing gases. High-performance H2S sensor is realized by the integration of metal-organic frameworks (MOFs) with semiconductor metal oxides (SMOs).