Surface chemical engineering towards efficient and bright chemiluminescent carbon nanodots

Abstract

Carbon nanodots (CDs) are emerging as low toxic chemiluminescent (CL) materials for new-generation cold lighting and bioimaging technology due to their tunable and efficient emissions. Nevertheless, continuous progress and efforts are still needed to improve the luminance and lifetime of the CL CDs. Here, CL quenching is observed in the CD-peroxyoxalate-hydrogen peroxide system, resulting from the water-induced aggregation and blocking effect of the electron exchange between the CDs and energetic intermediate produced in the CL reaction. A surface chemical regulation strategy is first introduced to improve the CL performance of CDs. Optimized the capped ligand species and chain length, the CDs modified by n-butylamine exhibit a CL quantum yield of 1.15 × 10–2 einsteins mol−1 and maximal luminance of 5.11 cd m−2, which is about 5- and 13-fold higher than the initial CDs and comparable with commercially available Rhodamine B. The enhanced performance can be explained by the decreased electron capture from water molecules generated due to the decomposition of hydrogen peroxide in the CL process.