Dependence of electronic structure of g-C3N4 on the layer number of its nanosheets: A study by Raman spectroscopy coupled with first-principles calculations

• Published in: Carbon (New York) Vol. 80; pp. 213 - 221
• Main Authors: Jiang, Jizhou, Ou-yang, Lei, Zhu, Lihua, Zheng, Anmin, Zou, Jing, Yi, Xianfeng, Tang, Heqing
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-12-2014; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electron states; Exact sciences and technology; Lattice dynamics; Methods of electronic structure calculations; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Phonon states and bands, normal modes, and phonon dispersion; Phonons and vibrations in crystal lattices; Physics; Raman spectra; Deformation; Nanosheet; Spectral properties; Prediction; Raman spectroscopy; Exfoliation; Electronic structure; Functional material; Correlations; Vibrational modes; Density functional method; Carbon nitrides
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2014.08.059

Graphitic carbon nitride (g-C3N4) has attracted worldwide attention, because of its promising potential applications and theoretical prediction of its unique properties. Herein, 1-, 2- and 4-layer g-C3N4 nanosheets were synthesized in a well-crystallized form by controlling the intercalation time in a simple intercalation–exfoliation process. The electronic structures of the nanosheets were captured in their Raman spectra that clearly evolved with the layer number of the nanosheets for the first time. A clear correlation between the spectral properties and the layer number of the nanosheets was clarified by combining Raman spectra and the first-principles calculations. Raman vibrational modes of g-C3N4 were assigned. The layer–layer deformation vibrations and related in-plane twisting vibrations or symmetrical stretching vibrations reflected the change in the electronic structure of the nanosheets with different layers. The results may shed light on brand-new opportunities for significant improvements in the synthesis, structure, electronic and optical properties of single-layer and ultrathin g-C3N4 nanosheets toward desirable functional materials.