@article{prasetya2024investigation,

title = {Investigation of the Free-Base Zr-Porphyrin MOFs as Humidity Sensors for an Indoor Setting},

author = {Nicholaus Prasetya and Salih Okur},

url = {https://chemrxiv.org/engage/chemrxiv/article-details/6608e3c466c138172950e040},

doi = {https://doi.org/10.26434/chemrxiv-2024-1jwr7},

year  = {2024},

date = {2024-04-01},

urldate = {2024-04-01},

abstract = {Maintaining optimal relative humidity is paramount for human comfort. Therefore, the utilization of quartz crystal microbalance (QCM) as a humidity sensor platform holds significant promise due to its cost-effectiveness and high sensitivity. This study explores the efficacy of three free-base Zr porphyrin metal-organic frameworks (MOFs) - namely MOF-525, MOF-545, and NU-902 - as sensitive materials for QCM-based humidity sensors. Our extended experimental findings reveal that these materials exhibit notable sensitivity, particularly within relative humidity ranges of 40% to 100%. However, we observe potential irreversible adsorption sites within the MOF-545 framework, hindering its ability to revert to its initial state after prolonged exposure. In light of this observation, we conduct periodic cycling experiments at relative humidity levels of 40-70% to evaluate the measurement repeatability and feasibility of these sensors for indoor applications. Interestingly, the periodic cycling study demonstrates that MOF-545 shows promising repeatability, positioning it as a strong contender for indoor humidity sensing. In contrast, MOF-525 may necessitate extended desorption time, and NU-902 displays diminished sensitivity at low relative humidity levels. Nevertheless, a preliminary treatment of the MOF-545 QCM sensor may be necessary to address irreversible adsorption sites and uphold measurement repeatability, as only reversible adsorption sites are currently accessible. This study underscores the potential of MOF-based QCM sensors for effective humidity monitoring in indoor environments, thus facilitating improved comfort and environmental control.},

keywords = {Adsorption, humidity, openQCM, QCM, QCM sensor, Zr-porphyrin metal organic frameworks},

pubstate = {published},

tppubtype = {article}

}