We will discuss the ultrafast electron phenomena taking place in metal-semiconductor hybrid nanocrystals composed of linearly stacked ZnSe, CdS, and Pt domains, which underpins the photocatalytic activity of these colloids. First, we will demonstrate that the production of hydrogen on the Pt site of ZnSe/CdS/Pt nanocomposites can be enhanced by using electron-donating molecules as surface ligands on the semiconductor counterpart. These surfactants appear to be of key importance in enabling an efficient and stable reduction of water by CdS-based photocatalysts as they fill the vacancy in the valence band of the semiconductor domain, preventing its degradation. The second part of the presentation will discuss the ultrafast dynamics of photoinduced charges in ZnSe/CdS/Pt heterostructured nanocrystals, measured by means of femtosecond transient absorption spectroscopy. This technique allows determining the rates of inter-domain and semiconductor-to-ligand charge transfer processes, and therefore provides important insights into the mechanism of energy dissipation in these hybrid systems.

Ultrafast dynamics of electron-hole pairs underlying hydrogen production in heteronanocrystal photocatalysts

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.