title: Facile synthesis of N-rich carbon quantum dots by spontaneous polymerization and incision of solvents as efficient bioimaging probes and advanced electrocatalysts for oxygen reduction reaction.
abstract: In this study, uniform nitrogen-doped carbon quantum dots (N-CDs) were synthesized through a one-step solvothermal process of cyclic and nitrogen-rich solvents, such as N-methyl-2-pyrrolidone (NMP) and dimethyl-imidazolidinone (DMEU), under mild conditions. The products exhibited strong light blue fluorescence, good cell permeability and low cytotoxicity. Moreover, after a facile post-thermal treatment, it developed a lotus seedpod surface-like structure of seed-like N-CDs decorating on the surface of carbon layers with a high proportion of quaternary nitrogen moieties that exhibited excellent electrocatalytic activity and long-term durability towards the oxygen reduction reaction (ORR). The peak potential was -160 mV, which was comparable to or even lower than commercial Pt/C catalysts. Therefore, this study provides an alternative facile approach to the synthesis of versatile carbon quantum dots (CDs) with widespread commercial application prospects, not only as bioimaging probes but also as promising electrocatalysts for the metal-free ORR.
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Collaborative Innovation Center of Polymers and Polymer Composite Materials, Department of Macromolecular Science and Laboratory for Advanced Materials, Fudan University, Shanghai 200433, China. peiyiwu@fudan.edu.cn.
authors.forename: Zhouyue
authors.initials: Z
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Collaborative Innovation Center of Polymers and Polymer Composite Materials, Department of Macromolecular Science and Laboratory for Advanced Materials, Fudan University, Shanghai 200433, China. peiyiwu@fudan.edu.cn.
authors.forename: Shengjie
authors.initials: S
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Collaborative Innovation Center of Polymers and Polymer Composite Materials, Department of Macromolecular Science and Laboratory for Advanced Materials, Fudan University, Shanghai 200433, China. peiyiwu@fudan.edu.cn.
authors.forename: Jiaxun
authors.initials: J
authors.lastname: Wan
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Collaborative Innovation Center of Polymers and Polymer Composite Materials, Department of Macromolecular Science and Laboratory for Advanced Materials, Fudan University, Shanghai 200433, China. peiyiwu@fudan.edu.cn.
authors.forename: Peiyi
authors.initials: P
authors.lastname: Wu
mesh_terms: D002244:Carbon / Q000737:chemistry*; D055664:Electrochemical Techniques; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D061848:Optical Imaging / Q000379:methods*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*; D011728:Pyridones / Q000737:chemistry; D045663:Quantum Dots / Q000737:chemistry*
chemical_list: D011728:Pyridones; D002244:Carbon; C000604889:N-methyl-2-pyridone; D010100:Oxygen