Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 53: Energy materials (other than photovoltaics)

HL 53.6: Vortrag

Freitag, 16. März 2018, 10:45–11:00, EW 202

Activating CO₂ for photocatalytic reduction at the semiconductor surface — •Veronika König, Peter Budweiser, Jacek Stolarczyk, and Jochen Feldmann — Chair for Photonics and Optoelectronics, Department of Physics, Ludwig-Maximilians-Universität, Munich, Germany

In modern photocatalysis sunlight is used to convert water or carbon dioxide into solar fuels like molecular hydrogen or methane. Semiconductor materials thereby serve as the catalyst and reaction site. They absorb the sunlight, separate electron-hole pairs and transfer the charges to the respective molecules triggering electrochemical reactions that ultimately lead to the formation of the desired solar fuels.

Compared to water splitting CO₂ reduction is even more challenging due to the high stability of the CO₂ molecule. The reduction potential for the initial placement of an electron on the CO₂ is much more negative than the potential of the conduction band edges of most known semiconductor materials, making appropriate catalysts rare.

Copper (I) compounds such as Cu₂S have been found to be promising candidates for CO₂ reduction^[1] and were shown by our group to produce CH₄ and CO^[2]. Here, we use Cu₂O nanocrystals ranging from 10 to 100 nm in size in combination with ZnO for better charge separation. We investigate ways to increase the efficiency of photocatalytic CO₂ reduction by activation of the CO₂ molecule at the nanocrystal surface to lower the barrier for the initial one-electron reduction.

^[1] Habisreutinger, S., et al. Angew. Chem. Int. Ed. 2013, 52, 7372

^[2] Manzi, A., et al. J. Am. Chem. Soc. 2015, 137, 14007