Affiliation:
1. School of Chemistry and Chemical Engineering Shanxi University Taiyuan China
2. Engineering Research Center of Ministry of Education for Fine Chemicals Shanxi University Taiyuan China
3. Institute of Molecular Science Shanxi University Taiyuan China
4. State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan China
Abstract
AbstractDeveloping new photosystems that integrate broad‐band near‐infrared (NIR) light harvesting and efficient charge separation is a long‐sought goal in the photocatalytic community. In this work, we develop a novel photochemical strategy to prepare light‐active carbon dots (CDs) under room temperature and discover that the aggregation of CDs can broaden the light absorption to the NIR region due to the electronic couplings between neighboring CDs. Importantly, the dynamic non‐covalent interactions within CD aggregates can stabilize symmetry breaking and thus induce large dipole moments for charge separation and transfer. Furthermore, the weak non‐covalent interactions allow for flexible design of the aggregated degrees and the local electronic structures of CD aggregates, further strengthening NIR‐light harvesting and charge separation efficiency. As a result, the CD aggregates achieve a record apparent quantum yield of 13.5% at 800 nm, which is one of the best‐reported values for NIR‐light‐driven hydrogen photosynthesis to date. Moreover, we have prepared a series of different CDs and also observed that these CDs after aggregation all exhibit outstanding NIR‐responsive photocatalytic hydrogen production activity, suggesting the universality of aggregation‐enhanced photocatalysis. This discovery opens a new promising platform for using CD aggregates as efficient light absorbers for solar conversion.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Shanxi Province
Subject
General Medicine,General Chemistry