Photobase effect for just-in-time delivery in photocatalytic hydrogen generation
| Autor: | Fang, Jiawen, Debnath, Tushar, Bhattacharyya, Santanu, Döblinger, Markus, Feldmann, Jochen, Stolarczyk, Jacek K. |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Nature Communications, Vol 11, Iss 1, Pp 1-8 (2020) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | Carbon dots (CDs) are a promising nanomaterial for photocatalytic applications. However, the mechanism of the photocatalytic processes remains the subject of a debate due to the complex internal structure of the CDs, comprising crystalline and molecular units embedded in an amorphous matrix, rendering the analysis of the charge and energy transfer pathways between the constituent parts very challenging. Here we propose that the photobasic effect, that is the abstraction of a proton from water upon excitation by light, facilitates the photoexcited electron transfer to the proton. We show that the controlled inclusion in CDs of a model photobase, acridine, resembling the molecular moieties found in photocatalytically active CDs, strongly increases hydrogen generation. Ultrafast spectroscopy measurements reveal proton transfer within 30 ps of the excitation. This way, we use a model system to show that the photobasic effect may be contributing to the photocatalytic H2 generation of carbon nanomaterials and suggest that it may be tuned to achieve further improvements. The study demonstrates the critical role of the understanding the dynamics of the CDs in the design of next generation photocatalysts. Efficient photocatalytic hydrogen generation relies on highly choreographed delivery of protons and electrons to the reaction site such that they arrive just in time. Here, authors show that proton transport can be controlled by light with the photobase effect to increase H2 generation rate. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|