Ion-exchange membranes are critical to electrolyzers, fuel cells, artificial photosynthetic systems, and electrodialysis devices, by providing a barrier to fuel crossover and maintaining pressure differentials while still affording rapid ion conduction. If the membranes could also generate electrochemical potential energy through sunlight absorption, they would boost the power output and efficiency of these devices, as well as enable game-changing solar desalination innovations. The Ardo Group is characterizing excited-state ion-transfer photochemistry and photophysics and functionalizing ion-exchange materials with photoacid dyes for this purpose.
If several photon absorption events could be efficiently coupled to multiple-charge-transfer catalysis in donorchromophoreacceptor complexes, light-driven reactions to form stable chemical products would be possible. Although individual electron-transfer and energy-transfer events are efficient, successful integration into a functioning system remains elusive. The Ardo Group is evaluating various integrated geometries to demonstrate sunlight-driven charge accumulation, which is projected to enable a >20% efficiency for solar energy conversion to electricity.
Hybrid organicinorganic leadhalide perovskite solar cells have reached >20% sunlight-to-electrical energy conversion efficiency using small laboratory-scale devices. However, for commercialization, the materials need to be made more robust and lead should be replaced with more environmentally friendly alternatives. The Ardo Group is chemically modifying the organic moiety from a monovalent cation to a divalent cation with the goal of increasing thermal and moisture stability of one-dimensional and two-dimensional metalhalide perovskite materials.
Scalable technologies for solar-energy conversion and storage must be efficient, robust, and inexpensive to manufacture. Recent techno-economic analyses of solar water splitting reactors suggest that colloidal-particle-based suspensions would be cost competitive with current forms of H2 generation. Moreover, it is projected that the first major large-scale photovoltaic installations will utilize silicon, or an inexpensive easy-to-deposit material. The Ardo Group is exploring alternative fuel-forming chemistries, materials, and designs for disruptive innovations in grid-scale solar-energy conversion, storage, and use.
Fuel cells and solar fuels devices each require electrocatalysts and ion-exchange membranes that are stable in a single electrolyte. State-of-the-art ion-exchange membranes are highly acidic, yet most scalable and inexpensive electrocatalysts are unstable in acidic conditions. The Ardo Group is leveraging materials synthesis and engineering to overcome this incompatibility.
Materials Characterization: atomic force microscopy (AFM), scanning electron microscopy (SEMEDS), transmission electron microscopy (TEM), x-ray and ultraviolet photoelectron spectroscopy (XPS/UPS), x-ray diffraction (XRD), etc.
Computational Modeling: finite-element device physics simulations, Monte Carlo simulations, charge-transport mechanisms, etc.
Device Fabrication and Evaluation: electrochemical cells, small-scale model reactors, prototype devices, etc.