Photoinduced Electron Transfer Dynamics in Hybrid Quantum Dot/Molecular Catalyst Systems for Artificial Photosynthesis

Quantum dots (QD) have been gaining popularity within the highly multidisciplinary field of artificial photosynthesis research because of their unique photophysical properties. The fundamental processes that need to be coupled efficiently in artificial photosynthesis are (i) light harvesting to generate an excited state, (ii) generating a charge separated state by pairing photosensitizer and catalyst, and (iii) multielectron catalysis to split water into hydrogen and oxygen. During the past two decades, molecular catalysts, especially biomimetic complexes composed of earth-abundant elements, have been explored as pre-catalysts/catalysts for solar fuel production under photocatalytic conditions. However, very little is known about the fundamental step of such catalysis, i.e., photoinduced electron transfer. In this chapter, we investigated different multi-component systems to understand the mechanism of electron transfer pathways such that an efficient photosensitizer-catalyst assembly might be designed using quantum dots as photosensitizers. This chapter will highlight the accomplishments in the field of QD-catalyst assemblies as artificial photosynthesis systems and the contribution of our research in that direction. Direct conversion of solar energy into chemical fuels represents an ideal approach to address the globally growing energy demand in a sustainable way, and this chapter will give a summary of our current standing toward that goal.