The Preparation Of Carbon-Based Fluorescent Quantum Dots And Ordered Mesoporous Materials And Research On Their Performance

Fluorescent carbon quantum dots were widely applied in bioimaging, biosensing, medical diagnosis, drug delivery, catalysis and photovoltaic devices owing to their excellent properties such as high optical absorptivity, chemical stability, biocompatibility, and low toxicity. In recent years, the research in carbon quantum dots has made a great progress. But there are still some problems that need to be solved, for example how to select carbon source and synthesis methods, how to regulate color, and how to determine the luminescence mechanism.Spherical mesoporous carbon is a major breakthrough in the study of ordered mesoporous carbon materials. They benefit from advantages resulting from the remarkable and complementary property of the mesochannels and quantum effects at the nanoscale. They have large surface area and high porosity, and the mesoporous structure is perpendicular to the nucleus, which is more conducive to transport materials. These superior properties provide a promise for the applications of mesoporous carbon in adsorption, controlled drug release, intracellular transport, energy storage and catalysis. However, literatures on research in ordered mesoporous carbon spheres are a scanty few. It is of great practical significance to find a simple, efficient method for the synthesis of ordered mesoporous carbon nanospheres and expand its application areas.The purpose of this paper is to find the suitable carbon source to fabricate carbon dots with high quality by using a traditional hydrothermal synthesis route, and even to achieve the regulation in color these fluorescent carbon dots and to expand its application areas. In addition, another aim of this paper is to synthesize the ordered mesoporous carbon spheres with excellent performance by using a strategy inspired by the synthesis method of carbon quantum dots.Carbon quantum dots prepared by different vitamins have rich colors, different fluorescence intensity and a wide range of quantum yield. The carbon quantum dots can emit blue, green, yellow fluorescence, respectively. Carbon quantum dots prepared by Vitamin B6 emit strong yellow fluorescence, and the quantum yield is about 10.76%. Carbon quantum dots prepared by vitamin B9 can emit strong blue fluorescence, the fluorescence intensity is the strongest among the obtained carbon quantum dots, and the quantum yield of about 31.59% is also the highest. Through the treatment of phosphoric acid and oxalic acid of vitamin B9, we obtained carbon quantum dots with green and yellow-green fluorescence, respectively. Finally, the carbon dots prepared by vitamin B9 have been demonstrated as excellent probes for cellular imaging in cell culture experiments.We prepared FDU-15 mesoporous carbon films and mesoporous carbon nanospheres, respectively, using block copolymer F127 as a template and phenolic resin as carbon source. Ordered mesoporous carbon spheres obtained have uniform size, good morphology, ordered pores, and even they still retained many active groups, which are quite different from the inert mesoporous carbon spheres without chemical activity. This will be conducive to their further subsequent grafting and modification and to extend their application.