Najbliższe Konwersatorium Fizyczne OK PTF odbędzie się w dniu 18 marca 2021r. o godz. 16:15, online na platformie MS TEAMS.

Dr Jacek Stolarczyk (Photonics and Optoelectronics Group, Department of Physics and Nano-Institute Munich, Ludwig-Maximilians-Universität München, Königinstr. 10, 80799 Munich, Germany) wygłosi referat: „Solar fuels: Photocatalytic water splitting on semiconductor nanocrystals”.

Streszczenie:
Renewable sources provide more than a quarter of global electricity supply, while in several countries this share already exceeds 50%. However, the actual output is highly variable due to annual and diurnal cycles as well as weather changes, stressing the importance of large-scale storage of excess energy. Storage in a form of chemical fuels, such as hydrogen, methanol or methane is an appealing solution, because of high gravimetric energy densities, two orders of magnitude higher than present day batteries.

In my presentation, I will talk about using semiconductor nanocrystals to photocatalytically harvest energy of incident (solar) photons to drive energetically up-hill reactions such as water splitting. The key to an efficient generation of hydrogen and oxygen lies in understanding (or lack thereof) the charge transfer mechanisms in the nanostructures.[1] I will talk about using ultrafast transient absorption and time-resolved photoluminescence spectroscopies to study the charge transfer dynamics in photocatalytic water splitting on metal chalcogenide nanocrystals [2-3] and on carbon dots[4-5]. We demonstrate that nearly 100% quantum efficiency of hydrogen production can be achieved.[2-5] Utilizing the nanorod morphology to separate the reduction and oxidation sites, we further show that combining the semiconductor nanocrystals with molecular catalyst enables complete water splitting into hydrogen and oxygen on a single CdS nanocrystal. We also show how light can be used to control proton transfer to overcome a limiting step in water splitting. This demonstrates that anisotropic nanocrystals and careful management of charge carrier transfer pathways provide an effective pathway for visible-light driven photocatalytic water splitting.

References:
1. J.K. Stolarczyk et al., ACS Catalysis 2018, 8, 3602–3635
2. T. Simon et al., Nature Mater. 2014, 13, 1013-1018
3. C.Wolff et al., Nature Energy 2018, 3, 862-869.
4. S. Bhattacharyya et al.. Nature Commun. 2017, 8, 1401.
5. J. Fang et al.. Nature Commun. 2020, 11, 5179.

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Dołącz do spotkania.