Zhu Shoujun, Shao Jieren, Song Yubin, Zhao Xiaohuan, Du Jianglin, Wang Lei, Wang Haiyu, Zhang Kai, Zhang Junhu, Yang Bai
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Nanoscale. 2015 May 7;7(17):7927-33. doi: 10.1039/c5nr01178g.
A universal route to GQDs is developed based on "solution phase-based scissor" methods. The PL centers of the GQDs are systematically studied and are proved to be the surface state. This is related to the hybridization structure of the edge groups and the connected partial graphene core. Through experiment and analysis, we have preliminarily proved that the efficient edge groups for green emission are mainly carboxyl, carbonyl and amide. This is indicated by the following three factors: firstly, the PL of GQDs is enhanced by UV exposure, during which partial -OH groups are converted into carboxyl groups; secondly, the PL properties of GQDs can be further improved by one-step solvothermal treatment, in which partial carboxyl groups are converted to amide groups and the surface state of the GQDs is enhanced; thirdly, reduced m-GQDs possess more -OH groups compared with reduced GQDs, resulting in more blue PL centers (the carboxyl, carbonyl and amide-based green centers are converted to -OH-based blue centers). The present work highlights a very important direction for the understanding of the PL mechanism of GQDs and other related carbon-based materials.
基于“溶液相剪刀”方法开发了一种制备石墨烯量子点（GQDs）的通用途径。对GQDs的光致发光（PL）中心进行了系统研究，并证明其为表面态。这与边缘基团和相连的部分石墨烯核心的杂化结构有关。通过实验和分析，我们初步证明了对绿色发射有效的边缘基团主要是羧基、羰基和酰胺基。这由以下三个因素表明：首先，通过紫外线照射增强了GQDs的PL，在此过程中部分-OH基团转化为羧基；其次，通过一步溶剂热处理可进一步改善GQDs的PL性质，其中部分羧基转化为酰胺基且GQDs的表面态得到增强；第三，与还原的GQDs相比，还原的m-GQDs具有更多的-OH基团，导致更多的蓝色PL中心（基于羧基、羰基和酰胺基的绿色中心转化为基于-OH的蓝色中心）。目前的工作突出了理解GQDs和其他相关碳基材料PL机制的一个非常重要的方向。
