Nonconventional Photothermal and Photocatalytic Processes
Modern anthropogenic activity, related mainly to energy sourcing and consumption, has led to dire climatic consequences and an ever so growing demand for cleaner and sustainable alternatives. Consequently, energy demanding processes for key societal chemicals are also moving towards sustainable approaches. Thus, the employ of solar light, a seemingly unlimited energy source that is readily available, has attracted great interest and effort towards deployment of such technologies.
Our research interests lie in the following areas:
- on one hand, the implementation of novel photocatalytic systems that overcome the three main bottlenecks associated with solar transducers: insufficient light harvesting capabilities, fast recombination of photogenerated transient species and thermodynamic limitations. Considering this endeavor, design of hybrid molecule-semiconductor assemblies is a strategy tackling all three aforementioned limitations, mainly through introduction of electronic states compatible with different light contributions, modulated electron transfer towards substrates and beneficial band-structure alignments.
- Secondly, photothermal catalysis, a process best described as the thermalization of incident photons, lies at the boundary between classical heterogeneous catalysis and photocatalysis. Mechanistically, substrate turn-over occurs in a similar fashion as in thermochemical conditions, yet significant enhancements may occur due to generated hot electrons. This photon thermalization effect can be tweaked through strategies such as cumulative heating of optically coupled nanoparticles, photothermal confinement or by introducing charge recombination centers, all approaches that are of great interest in our research.
Considering both research lines, the main catalytic applications that are of interest to our group are: hydrogenation of aliphatic/aromatic substrates and of CO2, capture and valorization of CO2 via carboxylation of organic media and chemical upgrading of biomass fractions. Mechanistic understanding of such processes is done through ex-situ, in-situ and operando monitoring of both material and reaction media.