Sebastian Hentschel
Photo: Hans Werners
PhD student
RG Mews
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Key aspects of activity
- Phase transfer of nanostructures from unpolar to polar phases
- Photocatalysis in aqueous solution using semiconductor/metal hybrid nanostructures
- Cyclic voltammetry on nanostructures for determining the respective band gap energy
Research Topic
Sebastian is investigating semiconductor/metal hybrid nanostructures (e.g. Pt-tipped Type I and Type II Dotrods from Mareike) with respect to their ability to produce hydrogen from illuminated aqueous solutions. For this purpose, he uses a flow reactor with water cooling and a mass spectrometer specifically designed for gases. To get the nanoparticles dispersed in aqueous phases, it requires ligand exchange from the nonpolar phase to the aqueous polar phase. Hence, different types of ligands are investigated with respect to their stabilization of the nanoparticles on the one hand and their influence on hydrogen synthesis on the other. In addition, cyclic voltammetry will be used to investigate the band edge energies of the semiconductor materials of the hybrid structures, as this is an essential property of a photocatalyst.
1D - Catalysis
Figure 1: Band scheme of Pt-tipped Type I Dotrods. Photoexcitation leads to electron-hole pairs which tend to dissociate leaving electrons in the Pt-tip whereas the holes stay in the CdSe core facilitating the respective reductive and oxidative reaction.