Alkali-assisted mild aqueous exfoliation for single-layered and structure-preserved graphitic carbon nitride nanosheets.
Single-layered g-C3N4nanosheets have been fabricated by delaminating directly its bulk counterpart in an alkaline solution. According to the theoretical modeling, the interaction of OH-with terminal NH2or bridged NH group of the triazine units within bulk g-C3N4crystal structure could result in decreased bonding energy between layers and promote the total delamination. The resulting g-C3N4nanosheets colloid has a relatively high concentration (12g/L) compared with the traditional ultrasonic assistant exfoliation method. The delaminated nanosheets are revealed by atomic force microscopy to show a lateral size of a hundred nanometers and a thickness of about 0.4nm, which provides a direct evidence for the total exfoliation of g-C3N4crystals into their single sheets. More importantly, the X-ray diffraction measurement confirms that the g-C3N4nanosheets could be re-assembled with well-preserved original crystal structure. The exfoliation mechanism was also confirmed by the DFT calculation.
Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
Gengnan
G
Li
Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China. Electronic address: liliang@ecust.edu.cn.
Liang
L
Li
State Key Laboratory of Chemical Engineering Center for Computational Chemistry and Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, China.
Haiyang
H
Yuan
State Key Laboratory of Chemical Engineering Center for Computational Chemistry and Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, China.
Haifeng
H
Wang
Information Materials and Devices Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
Huarong
H
Zeng
Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China; State Key Laboratory of High Performance Ceramic and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China. Electronic address: jlshi@mail.sic.ac.cn.
Jianlin
J
Shi
Alkali solution; Exfoliation; Graphitic carbon nitride; Nanosheets