Carbon dot-based artificial light-harvesting systems with sequential energy transfer and white light emission for photocatalysis

In this work, we designed and synthesized cationic carbon dots (CDs) with a size distribution of 1.6–3.7 nm, which exhibited dark blue fluorescence in the aqueous solution. Based on its excellent luminescence properties, we used it as an energy donor to construct a sequential artificial light-harvesting system (LHS) by employing the energy-matching dyes eosin Y disodium salt (EY) and sulforhodamine 101 (SR101), which could regulate the white light emission (Commission Internationale de l'Eclairage (CIE) coordinate: (0.30, 0.31)) with the energy transfer efficiency (ΦET) of 53.9% and 20.0%. Moreover, a single-step artificial LHS with white light emission (0.32, 0.28) can be constructed directly using CDs and dye solvent 43 (SR) with ΦET and antenna effect (AE) of 48.8% and 6.5, respectively. More importantly, CDs-based artificial LHSs were firstly used in photocatalytic of α-bromoacetophenone, with a yield of 90%. This work not only provides a new strategy for constructing CDs-based LHSs, but also opens up a new application for further applying the energy harvested in CDs-based LHSs to the field of the aqueous solution photocatalysis.