Tuning the Photoluminescence of Graphene Quantum Dots by Photochemical Doping with Nitrogen

Xiaofen Xu; Fuhua Gao; Xiaohua Bai; Fuchi Liu; Wenjie Kong; Ming Li

doi:10.3390/ma10111328

Tuning the Photoluminescence of Graphene Quantum Dots by Photochemical Doping with Nitrogen

Materials (Basel). 2017 Nov 20;10(11):1328. doi: 10.3390/ma10111328.

Authors

Xiaofen Xu¹, Fuhua Gao², Xiaohua Bai³, Fuchi Liu⁴, Wenjie Kong⁵, Ming Li⁶

Affiliations

¹ College of Physics and Technology, Guangxi Normal University, Guilin 541004, China. xiaofenxu111@163.com.
² College of Physics and Technology, Guangxi Normal University, Guilin 541004, China. 15078369629@163.com.
³ College of Physics and Technology, Guangxi Normal University, Guilin 541004, China. 18593231070@163.com.
⁴ College of Physics and Technology, Guangxi Normal University, Guilin 541004, China. liufuchi@gxnu.edu.cn.
⁵ College of Physics and Technology, Guangxi Normal University, Guilin 541004, China. wkong@gxnu.edu.cn.
⁶ College of Science, Guilin University of Technology, Guilin 541004, China. liming928@163.com.

Abstract

Nitrogen-doped graphene quantum dots (NGQDs) were synthesized by irradiating graphene quantum dots (GQDs) in an NH₃ atmosphere. The photoluminescence (PL) properties of the GQDs and the NGQDs samples were investigated. Compared with GQDs, a clear PL blue-shift of NGQDs could be achieved by regulating the irradiating time. The NGQDs obtained by irradiation of GQDs for 70 min had a high N content of 15.34 at % and a PL blue-shift of about 47 nm. This may be due to the fact that photochemical doping of GQDs with nitrogen can significantly enhance the contents of pyridine-like nitrogen, and also effectively decrease the contents of oxygen functional groups of NGQDs, thus leading to the observed obvious PL blue-shift.

Keywords: blue-shift; graphene quantum dots; nitrogen-doped graphene quantum dots; photochemical doping; photoluminescence.