Sulphur doping: a facile approach to tune the electronic structure and optical properties of graphene quantum dots.
Sulphur-doped carbon-based materials have attracted a great deal of interest because of their important applications in the fields of oxygen reduction reactions, hydrogen storage, supercapacitors, photocatalysts and lithium ion batteries. Here, we report a new member of sulphur-doped carbon-based materials, i.e. sulphur doped graphene quantum dots (S-GQDs). The S-GQDs were prepared by a hydrothermal method using fructose and sulphuric acid as source materials. Absorption and photoluminescence investigations show that inter-band crossings are responsible for the observed multiple emission peaks. The incorporation of ∼1 at% of S into the quantum dots can effectively modify the electronic structure of the S-GQDs by introducing S-related energy levels between π and π* of C. The additional energy levels in the S-GQDs lead to efficient and multiple emission peaks.
Solar Energy Research Institute, Yunnan Normal University, Kunming 650092, P. R. China. pzhyang@hotmail.com.
Xueming
X
Li
Shu Ping
SP
Lau
Libin
L
Tang
Rongbin
R
Ji
Peizhi
P
Yang