Advancing Optical Strategies for In-situ and In-operando Studies of Electrochemical Processes in Green Energy Applications
DescriptionOptical characterization techniques operating in the UV-Vis-NIR spectral range offer great potential to design powerful and affordable in-situ and in-operando (ISIO) strategies that can be of use, for example, to better understand the complex dynamic processes in green energy applications such as rechargeable batteries, fuel cells, catalysis, and others. However, despite much consensus on their advantages and opportunities, so far optical ISIO techniques remain underused and underdeveloped. We will use the synergetic and complementary expertise of the research team to overcome this stalemate by developing sensitivity-enhancing strategies for optical ISIO techniques based on optical cavity, plasmonic, and nanostructured effects. These sensitivity-enhancing strategies will then be applied to correlated spectroscopic ellipsometry (SE) and Raman spectroscopy (RS) as synergetic and complimentary optical techniques to study the evolution of the electrode–electrolyte interface in electrochemical processes. Furthermore, we will apply the knowledge generated to advanced optical strategies such as imaging, ultrafast (100 fs) and vacuum UV (6-35 eV) SE enabling detail information to unravel, for example, the reaction pathway selectivity in catalytic applications. Short-range chemical order can be identified from the vibrational spectrum signature of materials measured by RS, to unravel the chemical phase evolution of bulk phases and interfaces. Meanwhile, SE measures changes in the polarization of light after being reflected from a sample. Because ellipsometry is phase-sensitive and self-referenced, it is capable of high-precision measurements of, for example, thickness changes of a fraction of a monolayer. SE measurements thus determine the thickness evolution and spectral optical properties, (n,k) as function of wavelength, which are sensitive to several material properties including, for example, composition, density, and phase. The correlation of SE with RS is thus highly synergetic: RS provides additional information on chemical phases, which assist in the development of the SE optical models, while the SE models help to elucidate the location (i.e., depth) of the phases identified with RS. The correlated ISIO RS-SE to be developed will provide important insights on the processes that occur at electrochemical interfaces, such as changes in structure, composition, and morphology, phase transitions, and surface chemical state evolution including adsorption and interface formation. They are intensively used in a wide range of scientific and industrial fields (e.g., medicine, pharmacology, food, bioengineering). In the medium to short term, we foresee that multidisciplinary efforts will be able to take advantage of the developed strategies, e.g., in artificial photosynthesis, protein film voltammetry, and transparent battery materials.
|Effective start/end date||1/01/22 → …|