Advanced Spectroscopic Methods for Photochemical and Electrochemical Systems

Switching from non-renewable fossil fuels to sustainable options like light and electricity is essential for reducing global greenhouse gas emissions and mitigating the atmospheric CO2 levels. But this transition requires a detailed mechanistic understanding of the catalyst and intermediates that facilitates the efficient conversion of light (photocatalysis) and electricity (electrocatalysis) into chemical fuels. This thesis highlights the power of advanced spectroscopic tools to directly observe transient intermediates and further elucidate their roles, providing mechanistic insights for the rational design of next-generation energy conversion materials. Case of Electrocatalyst: Synergistic effects in cheaper Mixed-metal oxides (MMO) can overcome the traditional, expensive electrocatalysts, such as Pt/Pd/Ir. Here, we investigate a bifunctional MMO electrocatalyst composed of Cu, Co, and W for water splitting. The specific role of each metal element under catalytic conditions and the presence of a synergetic effect were revealed using Operando X-ray spectroscopy. Case of Photocatalyst: Plants are home to one of the oldest natural photocatalysts, which harvest solar energy and convert it into chemical energy through photosynthesis. The solar light harvested is efficiently transferred to the reaction center via a photochemical symmetry-breaking charge-transfer (SBCT) process in a few hundred picoseconds. To mimic natural photosynthesis, we explore SBCT in Alice-MOF and demonstrate that solvent polarity tunes the competition between charge separation and other pathways using time-resolved spectroscopy. Lastly, Iodo-azides are an energetic class of molecules that can dissociate even under slight perturbations, such as light, shock, or heat. Here, we employed time-resolved spectroscopy coupled with computational calculations to map the process of photo-induced homolytic I-N bond dissociation and subsequent radical reaction.

Author dc:creator

• Nikita Gupta (3386030)

• Chemistry, Radiation
• Chemistry, Physical
• chemistry

Statement dc:rights

• In Copyright
• Open Access after 2028-05-01

DOI dc:identifier

https://doi.org/10.25417/uic.32995220.v1

OAI identifier oai:identifier

oai:figshare.com:article/32995220