Date of Award

Spring 2024

Document Type


Degree Name

Doctor of Philosophy (PhD)


Electrical & Computer Engineering


Electrical and Computer Engineering

Committee Director

Helmut Baumgart

Committee Member

Abdelmageed Elmustafa

Committee Member

Linda Vahala

Committee Member

Gon Namkoong

Committee Member

Yaw Obeng


The industrial revolution drove technological progress but also increased the release of harmful pollutants, posing significant risks to human health and the environment. Volatile organic compounds (VOCs), which have various anthropogenic and natural sources, are particularly concerning due to their impact on public health, especially in urban areas. Addressing these adverse effects requires comprehensive strategies for mitigation as traditional gas sensing techniques have limitations and there is a need for innovative approaches to VOC detection.

VOCs encompass a diverse group of chemicals with high volatility, emitted from various human activities and natural sources. These compounds play a crucial role in the formation of ground-level ozone and secondary pollutants, significantly impacting global climate and air quality. Anthropogenic sources dominate in urban areas, exacerbating air pollution and its associated health risks. Monitoring and controlling VOC emissions are imperative for public health, environmental sustainability, and industrial processes.

Gas sensors offer a promising solution for VOC monitoring, with advancements focusing on improving sensitivity, selectivity, and real-time detection capabilities. Broadband dielectric spectroscopy (BDS) emerges as a non-contact metrology method for probing material properties, particularly suited for gas-sensitive materials like zinc oxide (ZnO) and metal-organic frameworks (MOFs). BDS provides detailed insights into gas sensing mechanisms, enabling the development of enhanced gas sensing devices.

This thesis explores the use of ZnO and MOFs as detection elements in gas sensing applications, aiming to advance understanding and application of gas sensing technologies. Objectives include investigating ZnO's oxidization mechanism, studying metal-doped ZnO for enhanced sensing, exploring MOF films for VOC detection, and conducting a comparative analysis between ZnO and MOF sensors. Experimental setups involve BDS measurements to monitor changes in material properties and gas-sensor interactions. Experimental investigations reveal unique mechanistic insights into ZnO gas sensing behavior, particularly in detecting aliphatic alcohols like ethanol. Metal doping of ZnO nanorods alters gas sensing responses, with different metals exhibiting distinct detection mechanisms. MOF films demonstrate high sensitivity to VOCs, showcasing potential applications in gas sensing technologies. Comparative analysis highlights the advantages of MOF films over ZnO nanorods for ethanol vapor detection at low temperatures.


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