The demand for energy keeps increasing worldwide. The current energy scenario relies heavily on non-renewable fossil fuels, which release greenhouse gases causing climate change. It is imperative that new clean and renewable fuels are developed. Hydrogen gas (H₂) is a promising fuel for the future, producing nearly three-times more energy than conventional fossil fuels and releasing only water as byproduct. Solar-produced H₂ comes from photocatalytic water splitting, where the sun light energy is converted directly into chemical fuel, a promising method that avoids multi-step energy conversion processes. However, water splitting is a kinetically challenging process that requires the simultaneous management of four electrons and four protons, limiting the efficiency of most current photocatalysts. CdS quantum dots (QDs) have been extensively studied as photocatalysts and sensitizers for visible-light driven water reduction because of the favorable band structure and size-tunable properties, but single dots are insufficient to drive the multiphoton process. Accordingly, the Brock lab is investigating metal chalcogenide QD gel frameworks for photocatalytic water reduction due to their high surface area and ability to combine multiple photosensitizers feeding electrons to active catalysts.
The synthesis of CdS QDs aerogels-based photocatalysts, incorporating either Ni₂P or Pt nanoparticles (NPs), will be described and their catalytic activity for Hydrogen Evolution Reaction under visible-light irradiation in the presence of sacrificial electron donors (sulfide/sulfite) will be reported. Structural and photophysical techniques will be employed to evaluate their efficiency towards charge separation, electron transfer kinetics and hydrogen production. Both co-catalyst NPs will be explored targeting different sizes, seeking to determine optimal Schottky junction, as well as their mass loadings into gels. Our results will be compared to state-of-the-art CdS-based photocatalysts for water splitting and evaluated towards H₂ production and stability.

Cole Premtaj

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