Synthesis of solid-state multicolor fluorescent calcium carbonate by controlled defect degree of (110)/(104) crystal plane and atomic order

Abstract

Multicolor fluorescent calcium carbonate materials have significant applications in many fields such as papermaking, pigments, white light illumination and biological imaging, etc. In this work, blue (B-cal), yellow (Y-cal), and orange (O-cal) fluorescent calcium carbonates were synthesized using calcium gluconate and urea as substrates. The synthesis involved regulating the degree of (110)/(104) crystal plane defects and atomic order by adjusting temperature and time in the hydrothermal process. The luminescence mechanism was investigated through TEM, XRD and other characterizations. The result shows that there is an increase in atomic order and a decrease in the degree of lattice defects with red shift of the emission wavelength. The lattice defects in B-cal and Y-cal are mainly observed in the (110)/(104) crystal planes, while O-cal predominantly exhibits defects in the (104) crystal planes. Moreover, the first-principle calculation result shows that their fluorescences are caused by molecular packing or aggregation. Finally, the films were made using the different fluorescence calcium carbonates and exhibit the corresponding and favorable fluorescence and biomimetic enzyme properties.