Based on halogen-doped carbon dots: A review

As a kind of fluorescent carbon nanomaterial with wide application prospects, carbon dots (CDs) show excellent physical, chemical and optical properties. At present, heteroatom doping has been widely used to improve the properties of CDs. Due to the electronegativity difference between halogen atoms and carbon atom, halogen doping is considered to be an effective method to further improve the optical properties of CDs. In this review, we review the research progress of halogen-doped CDs from three aspects: different synthesis strategies, excellent physicochemical properties and applications. In particular, the different synthesis strategies of halogen-doped CDs are summarized in detail. Then the optical properties and catalytic properties are discussed. In addition, the potential applications of halogen-doped CDs in optical sensors, information security and anti-counterfeiting, catalysis, optoelectronic devices, bioimaging, and phototherapy are reviewed. Finally, we present and discuss the challenges and outlook of halogen-doped CDs.