UC San Diego

Chapter 1. This section introduces the research motivations driving the investigations pursued in this dissertation. Likewise, it discusses research fields of interest to the work conducted herein, such as electrochemistry, Photoelectrochemistry, H2 generation, semiconductors, 2D nanomaterials, and confinement catalysis.

Chapter 2. Oxide growth on the surface of semiconductors during device operation induces charge carrier recombination and photodegradation, which limit the operation lifetime of photoelectrochemical devices. Likewise, their commercialization is hindered by the use of expensive precious metal catalysts to enhance hydrogen evolution kinetics. This work demonstrates how drop casting Zn 1T-MoS2 onto SiNWs generates an interface that overcomes these challenges.

Chapter 3. Active sites are atomic sites within catalysts that drive reactions and are essential to catalysis. Spatially confining guest metals within active site microenvironments has been predicted to improve catalytic activity by altering the electronic states of active sites. Using HER as the model reaction, we show that intercalating Zn SAs into 1T-MoS2 enhances HER performance by decreasing the overpotential, charge transfer resistance, and the kinetic barrier.

Chapter 4. SACs have the ability to enhance reaction kinetics and the activity, stability, and selectivity of catalysts. Yet, investigations of the aspects of the SA that induce such desirable results fall short. In this work, we address this knowledge gap by comparing the performance d10 guest metals spatially confined within layers of 1T-MoS2 to the performance of d0 guest metals under similar confinement using Zn and Sc SAs, respectively.

Chapter 5. Primary driving factors that influence interactions between the guest metal and active sites include guest metal oxidation state, local coordination geometry, and electronic occupation of valence states. Although the guest metal’s spin state has the ability to alter its electronic structure, the impact it has under 1D confinement on catalysis is poorly understood. In this work, the electrochemical HER performance of HS and LS Mn SAs confined within 1T-MoS2 nanosheets are compared in acidic conditions.

Chapter 6. The focus of this chapter is to briefly describe the future directions of this dissertation which involve studying the catalytic effects of confining chiral molecules within the interlayer spacing of 2D materials.