Electrochemical and Capacitive Properties of Carbon Dots/Reduced Graphene Oxide Supercapacitors.
There is much recent interest in graphene-based composite electrode materials because of their excellent mechanical strengths, high electron mobilities, and large specific surface areas. These materials are good candidates for applications in supercapacitors. In this work, a new graphene-based electrode material for supercapacitors was fabricated by anchoring carbon dots (CDs) on reduced graphene oxide (rGO). The capacitive properties of electrodes in aqueous electrolytes were systematically studied by galvanostatic charge-discharge measurements, cyclic voltammetry, and electrochemical impedance spectroscopy. The capacitance of rGO was improved when an appropriate amount of CDs were added to the material. The CD/rGO electrode exhibited a good reversibility, excellent rate capability, fast charge transfer, and high specific capacitance in 1 M H₂SO₄. Its capacitance was as high as 211.9 F/g at a current density of 0.5 A/g. This capacitance was 74.3% higher than that of a pristine rGO electrode (121.6 F/g), and the capacitance of the CD/rGO electrode retained 92.8% of its original value after 1000 cycles at a CDs-to-rGO ratio of 5:1.
College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, No. 58 Yanta Road, Xi'an 710054, China. ddyqng@163.com.
Yong-Qiang
YQ
Dang
College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, No. 58 Yanta Road, Xi'an 710054, China. renshaozhao@126.com.
Shao-Zhao
SZ
Ren
College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, No. 58 Yanta Road, Xi'an 710054, China. liuguoyangxust@126.com.
Guoyang
G
Liu
College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, No. 58 Yanta Road, Xi'an 710054, China. caijiangtao11@gmail.com.
Jiangtao
J
Cai
College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, No. 58 Yanta Road, Xi'an 710054, China. zhangyt@xust.edu.cn.
Yating
Y
Zhang
State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, Dalian University of Technology, No. 2 Ling Gong Road High Technology Zone, Dalian 116024, China. jieshanqiu@gmail.com.
Jieshan
J
Qiu
carbon dots; graphene; supercapacitors