Roya Maboudian (Advisor)

Metal oxide semiconducting gas sensors are one of the most widely used gas sensing devices due to their low cost, high reliability, solid-state, and high response. While they have been employed for the detection of various gases and in many applications, several issues remain including their limited selectivity and humidity interference. As the core part of a semiconducting gas sensor, sensing materials play the key role in determining the sensing performance of the device, with the materials’ microstructure and surface properties being the dominant factors. Thus the primary...

A classic challenge in chemical sensing is selectivity. Metal-organic frameworks (MOFs) are an exciting class of materials because they can be tuned for selective chemical adsorption. Adsorption events trigger work-function shifts, which can be detected with a chemical-sensitive field-effect transistor (power ≈microwatts). In this work, several case studies were used towards generalizing the sensing mechanism, ultimately towards our metal-centric hypothesis. HKUST-1 was used as a proof-of-principle humidity sensor. The response is thickness independent, meaning the response is...

Carbon dioxide (CO2) has been shown to contribute to human health consequences indoors, such as shortness of breath, nasal and optic irritation, dizziness, and nausea. In this work, we explore the potential of metal–organic frameworks (MOFs) as highly-porous, crystalline sorbents for sensitive colorimetric CO2 detection. In particular, the zeolitic imidazolate framework (ZIF-8) is chosen as the sorptive material due to its chemical stability and tunable CO2 affinity. The colorimetric gas sensor is developed in methanol with three components: (i) MOF ZIF-8 as a high surface area adsorbent...

With the rising demands for small, lightweight, and long-lasting portable electronics, the need for energy storage devices with both large power and large eneergy densities become vitally important. From their usage in hybrid electric vehicles to wearable electronics, supercapacitors, and rechargeable batteries have been the focus of many previous works. Electrode materials with large specific surface areas can enhance the charning speed and total amount of stored energy. To this end, vertically self-aligned conductivities as well as high mechanical stregth and large specific surface areas...