文献类型：期刊文献

英文题名：Preparation of carbon nanodots from single chain polymeric nanoparticles and theoretical investigation of the photoluminescence mechanism

作者：Zhu, Benchuan[1];Sun, Shiyuan[1];Wang, Youfu[1];Deng, Sheng[1];Qian, Guannan[1];Wang, Meng[1];Hu, Aiguo[1]

机构：[1]E China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai Key Lab Adv Polymer Mat, Shanghai 200237, Peoples R China

年份：2013

卷号：1

期号：3

起止页码：580

外文期刊名：JOURNAL OF MATERIALS CHEMISTRY C

收录：;EI(收录号：20131916308041);WOS:【SCI-EXPANDED(收录号:WOS:000314802200030)】；

基金：The authors gratefully acknowledge financial support from National Natural Science Foundation of China (20874026), Shanghai Shuguang Project (07SG33) and Shanghai Leading Academic Discipline Project (B502). A.H. thanks Prof. Zheng Huang, Prof. Lingyong Zhu and Dr Zhen Liu for their valuable comments on this work.

语种：英文

外文关键词：Surface chemistry - Density functional theory - Living polymerization - Graphitization - Photoluminescence - Nanodots - Microstructure - Chains

摘要：Even after several years of research, controlled synthesis of photoluminescent carbon nanodots (C-dots) still constitutes a major challenge, and investigation of their photoluminescence (PL) mechanism remains elusive. Various top-down and bottom-up approaches have been reported lately. However, these methods usually suffer from limited control over the major factors that dictate the PL behaviour of these fascinating carbon materials. To this end, we discover a new approach to prepare C-dots from size-tunable single chain polymeric nanoparticles. Taking advantage of the state of the art living radical polymerization technique and unique features of Bergman cyclization, narrowly dispersed C-dots are prepared in a straightforward manner. PL study shows that the optimal emission wavelength of C-dots red-shifts when the size of C-dots decreases, which is different from the trends typically found in semiconductor quantum dots and C-dots prepared from graphitized materials. To clarify the PL mechanism of C-dots prepared from different sources, a theoretical study based on density functional theory is performed. Two series of model compounds, fused aromatic rings and cyclo-1,4-naphthylenes, are chosen for C-dots with different microstructures. The calculation data indicate that PL energy of C-dots is dictated by the size and microstructure of the sp(2) carbon core. For a C-dot with a graphitized core, the smaller the size of the core, the higher the PL energy, while for a C-dot with an amorphous core, an inverse trend is revealed. Surface reduction experiments further show that the quantum yield of C-dots is controlled by the surface chemistry.