Regulación del fósforo de desplazamiento al rojo de puntos de carbono mediante la introducción de cloruro de magnesio

Achieving the multicolor phosphorescence of carbon dots (CDs), particularly with controllable wavelengths, remains a challenging yet desirable goal. Herein, we designed and prepared phosphorescent CDs (CDs@Al₂O₃ and CDs@MgAl₂O₄) using an in situ synthesis strategy. The oxygen vacancies in CDs stabilized the triplet excitons, thus enabling the long-lived and strong phosphorescence of these CDs. Importantly, CDs@MgAl₂O₄ exhibited obviously red-shifted phosphorescence (552 nm) compared to CDs@Al₂O₃ (525 nm) owing to increased conjugation and a narrowed bandgap, with the narrowed gap derived from coordination between magnesium and C[double bond, length as m-dash]O. These CDs showed excitation-dependent phosphorescence, which was tunable from cyan to red by varying excitation wavelengths. Additionally, we synthesized a series of phosphorescent CDs by employing different carbon sources, among which the magnesium-doped CDs consistently displayed red-shifted phosphorescence, thus proving the universality of this strategy and providing an innovative approach for regulating the phosphorescence of CDs.