The invention provides a long-
afterglow silicon dioxide nanosphere as well as a preparation method and application thereof, and belongs to the technical field of inorganic nano materials. In order to solve the problems that an existing
room temperature phosphorescence (RTP) material depends on
metal or organic fluorophores, the light stability is poor, the biotoxicity is high and the like, the long
afterglow silicon dioxide nanospheres free of the
metal and the organic fluorophores are prepared through a
silicon source copolycondensation and
calcination defect
engineering strategy. According to the material, a silicon source precursor and a
silane coupling agent are used as raw materials,
polysaccharide-assisted copolycondensation is performed to form a
triple bond Si-O-network, and then high-temperature
calcination is performed to generate optical activity defects related to
carbon impurities in a
silicon dioxide matrix, so that long-life room-temperature
phosphorescence (the
afterglow life reaches 1.852 s) is realized. The material has the characteristics of excellent light stability, low biotoxicity and no
autofluorescence interference, is suitable for anti-counterfeiting device imaging, and breaks through the defects of low luminous efficiency and poor stability of the traditional RTP material.