Long-Term Durability and Cycling of Nanoporous Materials Based Impedance NO₂ Sensors

Abstract

Nanoporous materials, including metal–organic frameworks (MOFs) and inorganic zeolites, are gaining attention as gas sensor materials due to their chemical selectivity and robustness. To advance industrial viability of these materials as sensors, long-term, variable environment testing is needed to evaluate their stability and continued chemical exposure response. Nanoporous materials-based direct electrical readout sensors were evaluated for 3 months under dry or humid conditions at 74 °C. The sensors were comprised of either Ni-MOF-74, Mg-MOF-74, or Ni-SSZ-13 zeolite. Additionally, we describe the development of multichambered sensor testing platforms that allows uninterrupted direct impedance monitoring of each sensor over long test periods. Results indicate relative stability in dry conditions for the sensors over time. In contrast, degradation of the active sensing material is evident in the humid environment. Collectively, these results demonstrate need for long-term testing of emerging nanoporous sensor materials under specific environmental conditions.

Impedance-Based Detection of NO2 Using Ni-MOF-74: Influence of Competitive Gas Adsorption

“…From this complementary set of characterizations (impedance, PXRD, SEM, HE-PXRD), it is inferred that the adsorption of the gas molecules (specifically NO 2 ) by the stable Ni-MOF-74 structure altered the electrical properties of the MOF, creating the observed changes in electrical response. While this work only considers the Ni-MOF-74 response over several hours, the reader is referred to prior work for insights on the stability of this response to a variety of aging conditions over several months …”

“…While this work only considers the Ni-MOF-74 response over several hours, the reader is referred to prior work for insights on the stability of this response to a variety of aging conditions over several months. 70 Real-Time Sensor Response Reveals Gas Competition. The changes in electrical properties of Ni-MOF-74 discussed above are after 5 h of gas exposure, sufficient time for the Ni-MOF-74 to equilibrate with the gas environment.…”

Quasicrystal Nanosheet/α-Fe2O3 Heterostructure-Based Low Power NO2 Sensors: Experimental and DFT Studies

“…In recent years, there has been an emphasis on developing highly tailored sensors. Gas sensors are often based on metal oxides for higher temperature industrial demands (>250 °C, typically 600–900 °C) . Every technology has a distinct set of advantages and drawbacks, with power consumption and source options being the key factors to consider.…”

Editorial for the Festschrift Honoring the Legacy of Babatunde A. Ogunnaike (1956–2022)

“…24 Percival et al discuss the durability and cycling of impedance NO 2 sensors based on nanoporous materials. 25 Hong et al report on the hydrothermal synthesis of a nanoflower-like Cu-ZnO catalyst for the hydrogenation of methyl acetate. 26 Michael Baldea orcid.org/0000-0001-6400-0315 Lorenz T. Biegler orcid.org/0000-0003-3875-4441 Marianthi G. Ierapetritou orcid.org/0000-0002-1758-9777…”

“…The Festschrift also includes several contributions that focus on materials science and engineering, such as the paper of Zhu et al., who report on the preparation of high-strength SBR vitrimers, Isfahani et al, reviewing the use of two-dimensional materials (such as MXenes) for membrane gas separations, and Schork, who provides a perspective on the commercialization of microemulsion technology . Percival et al discuss the durability and cycling of impedance NO 2 sensors based on nanoporous materials . Hong et al report on the hydrothermal synthesis of a nanoflower-like Cu-ZnO catalyst for the hydrogenation of methyl acetate …”