Activation of molecular oxygen by triplet states of S,N-doped carbon dots

S,N-doped carbon dots were synthesized and they were considered as activators of molecular oxygen, as evi-denced by the observed phosphorescence of singlet oxygen upon excitation of solutions in the absorption band of carbon dots. The process of singlet-triplet annihilation develops when O-2((3)Sigma(-)(g)) molecules were added to the solution, the efficiency of which depends on the ratio of concentrations of triplet carbon dots and O-2((1)Delta(g)) singlet molecules. In the presence of plasmonic nanoparticles of Au the phosphorescence of singlet oxygen was increased.