Rational Design of Multi?Color?Emissive Carbon Dots in a Single Reaction System by Hydrothermal

ABSTRACT: Abstract As an emerging building unit, carbon dots (CDs) have been igniting the revolutionaries in the fields of optoelectronics, biomedicine, and bioimaging. However, the difficulty of synthesizing CDs in aqueous solution with full?spectrum emission severely hinders further investigation of their emission mechanism and their extensive applications in white light emitting diodes (LEDs). Here, the full?color?emission CDs with a unique structure consisting of sp3?hybridized carbon cores with small domains of partially sp2?hybridized carbon atoms are reported. First?principle calculations are initially used to predict that the transformation from sp3 to sp2 hybridization redshifts the emission of CDs. Guided by the theoretical predictions, a simple, convenient, and controllable route to hydrothermally prepare CDs in a single reaction system is developed. The prepared CDs have full?spectrum emission with an unprecedented two?photon emission across the whole visible color range. These full?color?emission CDs can be further nurtured by slight modifications of the reaction conditions (e.g., temperature, pH) to generate the emission color from blue to red. Finally a flexible LEDs with full?color emission by using epoxy CDs films is developed, indicating that the strategy affords an industry translational potential over traditional fluorophores. A novel multi?color?emissive carbon dots (CDs) with two?photon fluorescence are developed in aqueous solution for the first time by slight modifications of the reaction conditions. Theoretical calculations combined with experiments show that the photoluminescence mechanism of the multi?color?emissive CDs is the size change and the conversion of sp3 to sp2 hybridization.

SUBMITTER: Wang B 

PROVIDER: S-EPMC7788586 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature