Research Progress in Preparation and Application of Coal-based Carbon Dots

Coal and coal derivatives have high carbon content and abundant resources, so it is of great research value to develop coal-based carbon materials and their preparation technology. As a rising star in the family of carbon nanomaterials, carbon dots (CDs) show great applications in many fields due to their excellent photoelectric properties, non-toxicity and good biocompatibility. Coal and coal derivatives are three-dimensional cross-linked network polycrystalline materials, containing rich functional groups and dangling bonds, and the aromatic structural units are connected by methylene, ether and other cross-linking bridge bonds. The bridge bonds can be destroyed by chemical, electrochemical or physical methods. Based on the structural characteristics of coal and coal derivatives, the synthesis methods of coal-based CDs and their applications in electrochemistry, photocatalysis, chemical analysis, biomedicine and photoelectric materials were reviewed, and the future development direction of coal-based CDs was prospected. The future research directions are as follows: optimizing the synthesis process to achieve the large-scale and green preparation of high-performance coal-based CDs; developing simulation, theoretical calculation and other advanced techniques to further explore the mechanism for regulating the structure and properties of coal-based CDs and their composites; expanding the application fields through the modification and assembly of coal-based CDs.