Daniel Zhou
Thermoelectric materials, or materials that can convert waste heat into electricity are promising sources for renewable energy. For a thermoelectric material to be efficient, it must have low thermal conductivity and high electrical conductivity. Prime candidates for these materials are Zintl phases which are semiconductors that can exhibit metallic conductivity due to the contributions of ionic and covalent character. Both the cationic and anionic sites of these compounds can be manipulated to tune the electronic and thermal properties. The Velian group has developed redox-active nanoclusters that can be tuned electronically with the addition of different transition metals. I plan on linking these nanoclusters with inorganic...
Ying Xia
The focus of my research will be interface-assisted solution-synthesis of two-dimensional metal-porphyrin monoatomic layers (2D-PML), which are of great interest due to the tunability of their properties. I will use two methods to synthesize metal-porphyrin monoatomic layer structures, one is the hydrothermal method, the other is the water-oil interface assisted method. AFM will be the main characterization method to analyze nucleation and growth mechanisms during the synthesis procedure. Then clean energy applications such as catalysts for hydrogen evolution and electrical capacitance will be studied. Advisor: Jim De Yoreo and Jun Liu - Materials Science & Engineering...
Xingyi Wang
Semiconductor crystals that behave exactly as researchers expect are rare, if nonexistent in nature or in lab. Local environment within crystals like defects or surface discontinuities may dominate the properties of semiconductor materials, and often these intractable local impurities limit the performance of clean energy harvest or generation devices like solar cells or LEDs. As part of a collaboration, my project takes a step towards understanding photon generation and loss mechanisms bottom-up by isolating and directly observing single defects within ZnO nanoparticles at atomic level, and correlating their optical properties with theoretical calculations based upon the local environment of single defects. If the observed...
Eden Tzanetopoulos
Lighting accounts for 15% of annual global energy consumption. Due to mounting concerns arising from anthropogenic climate change, there is an increased demand for lighting technologies with higher efficiencies and greater longevity. My research will focus on synthesizing colloidal nanocrystals of Mn4+-doped A2MF6 (A = K, Na, Cs; M = Ti, Ge, Zr) lattices to be used as red-emitting phosphors. These activator-host materials can act as an efficient red component of white LEDs due to their narrow-band ~630 nm emission. Mn4+-doped fluorides have recently been utilized in next-generation lighting technologies, but the nanoscale regime that affords synthetic tunability and narrow emission bandwidth has yet to...
Kathleen Snook
Electrically conductive metal–organic frameworks (MOFs) are important due to their applications in electrocatalysis, energy storage, and electronic devices. However, their synthesis is often poorly developed, resulting in small crystal sizes and a limited understanding of their physical properties. I hypothesize that a critical barrier to their synthesis is uncontrolled ligand oxidation, as conductive MOFs often contain air-sensitive catechol, o-phenylenediamine, and dithiolene building units. During this award period, I will examine the synthesis of π–d conjugated 2D frameworks, an important family of conductive MOFs, via controlled chemical oxidation in an inert atmosphere. I will optimize my synthetic parameters using a design of experiments approach, in...
Ricardo Rivera-Maldonado
Electrocatalysis is a promising means to reduce the climate impacts of the chemical industry by combining renewable electricity, abundant feedstocks, and catalysts made of earth-abundant materials. The study of the surface of electrocatalytic materials is essential for the advancement of the field since all inner-sphere reactions occur at the surface and the surface modulates charge transfer and outer-sphere interactions with solvents, electrolytes, and substrates. Nanoscale catalysts enable these studies due to their high surface-to-bulk atom ratio. My research involves studying transition metal phosphide (TMP) nanoparticles. TMPs have been shown to be excellent catalysts for hydroprocessing and hydrogen evolution, which provide a foundation for developing...
Sebastian Krajewski
My research is centered on the synthesis and design of atomically defined nanoclusters that act as clean energy catalysts. The aim is to study the catalyst-support interface in catalytic systems by utilizing metal chalcogenide clusters that feature transition metal edge sites. This serves as a model for heterogeneous catalysts, which themselves are resistant to precise characterization and mechanistic elucidation. I will synthesize and study compounds that feature a cobalt selenide core with pendant organic ligands, aiming to construct a pocket on the surface of the cluster where transition metals may bind. Studying the behavior of earth-abundant metals such as iron and cobalt in this system via methods...
Ashlyn Kamin
Examples of electrically conductive metal–organic frameworks (MOFs) are rare, yet they show incredible promise for applications in electrocatalysis, advanced energy storage, and chemical sensing. My research focuses on combining the high conductivity, tunability, and porosity of these MOFs with the solution-processability of liquid crystals. To do this, we synthesize planar, π–d conjugated macrocycles that are equivalent to a single hexagonal pore in a conductive MOF. By simultaneously tuning the macrocycle’s core and periphery, we hope to stabilize liquid-crystalline phases that preserve the extremely high through-space conductivity (from π-π stacking) whilst introducing fluidity and stimuli-responsiveness. Advisor: Dianne Xiao - Chemistry...
Micaela Homer
Photocatalysis is valuable to clean energy research because it allows the storage of solar energy in stable, energy dense chemical bonds. Solution processability and ease of chemical modification make semiconductor nanostructures ideal candidates for applications in photoredox catalysis. The rate of charge transfer is an important benchmark in evaluating such a system. Spectroscopic measurements of charge transfer (picoseconds) are incommensurate with the timescale of typical photocatalytic reactions (minutes). Electrochemical experiments will be an attractive alternative for screening of photocatalytic systems when coupled with electrochemical modeling. Advisor: Brandi Cossairt - Chemistry...
John Cenker
Two-dimensional van der Waals crystals hold great promise for future devices due to their atomically thin nature and the consequent unique emergent physics. Furthermore, their pristine crystal lattices should make them extraordinarily robust to external stresses such as strain. My research focuses on developing new ways to apply strain to 2D materials to drive phase transitions which can be harnessed for future device applications. For example, applying strain to atomically thin magnets to drive magnetic phase transitions. This research could enable energy-efficient, ultrathin memory bits which can be written purely by an applied voltage to the strain cell. Advisor: Xiaodong Xu - Physics...
Matthew Golder
Research in the Golder lab is centered around the creation of cutting-edge organic materials. We are interested in new synthetic methodologies that enable the design of large macrocycles with potential utility in organic electronics and gas transport. We ultimately design catalysts and then study their application in the development of conjugated cyclic polymers and other novel porous polymeric materials....
Eleftheria Roumeli
Assistant Professor, Materials Science & Engineering The Roumeli group creates sustainable polymer nanocomposite materials from renewable resources, and specifically from plant and algae cells. We develop processing methods to transform the biomass to new biodegradable and multifunctional nanocomposites and study their structure-property relationships. Future applications for these materials and structures include critical material capturing and packaging. Email | Website | LinkedIn ...