Electronic, structural, optical, and photocatalytic properties of graphitic carbon nitride

Abstract

Graphitic carbon nitride (g-C3N4)-based materials exhibit an organized layered porous structure and a band position optimum for the development of various optoelectronic devices and photocatalysts.

Elucidating the structure of the graphitic carbon nitride nanomaterials via X-ray photoelectron spectroscopy and X-ray powder diffraction techniques

“…5b). The structure of fully-condensed carbon nitride is described by the hexagonal cell 63,64 and space group P6m2, 65 whereas the linear structure of melon-type by the orthorhombic cell and space group P2 1 2 1 2 proposed by Lotsch et al 36 Fina et al 66 and by Seyfarth et al 67 In Fig. 6 the X-ray diffraction pattern of carbon nitride prepared by us at 600 o C was juxtaposed with theoretical models calculated for unit cells P6m2 and P2 1 2 1 2 and intensities and positions of reflections determined theoretically for ideal unit cells of hexagonal P6m2 (187) and orthorhombic P2 1 2 1 2 (18) systems.…”

Enhanced Photocatalytic and Photoluminescence Properties Resulting from Type-I Band Alignment in the Zn2GeO4/g-C3N4 Nanocomposites

“…As shown in Figure 1c, the bands observed in Fourier transform infrared spectroscopy (FTIR) measurements for the range 1236 cm −1 to 1555 cm −1 are usually attributed to C-N bonds of the heterocycles, and the 1640 cm −1 band is characteristic of the stretching of C=N bonds in g-C 3 N 4 . The sharp peak at 807 cm −1 is characteristic of the tri-s-triazine ring [31,[38][39][40]. Other bands observed in the range of 3000 cm −1 to 3500 cm −1 correspond to the O-H and N-H stretching of adsorbed water molecules and free amino groups, respectively [31,[38][39][40].…”

“…The sharp peak at 807 cm −1 is characteristic of the tri-s-triazine ring [31,[38][39][40]. Other bands observed in the range of 3000 cm −1 to 3500 cm −1 correspond to the O-H and N-H stretching of adsorbed water molecules and free amino groups, respectively [31,[38][39][40]. Moreover, small peaks that show up only in the composites, at approximately 530 cm −1 and 750 cm −1 , are attributed to the O-Zn-O and O-Ge-O stretching vibrations, respectively, of Zn 2 GeO 4 [41][42][43].…”

“…Many of these limitations, however, may be circumvented from a theoretical point of view. Among the computational tools for the theoretical understanding of solid materials' properties, in particular, the density functional theory (DFT) method under periodic conditions is one of the most used for obtaining a highly accurate prediction of their bandgap energy, the density of states, Fermi energy level, dielectric constants, effective mass, binding energy, structural, vibrational, and thermodynamic parameters, and others [21][22][23][24][25][26][27][28][29][30][31]. In this way, we highlight that these computational methodologies have played a growing role in developing sustainable next-generation advanced materials and is typically at the forefront of modern scientific research.…”

g-C3N4 synthesized from NH4SCN in a H2 atmosphere as a high performance photocatalyst for blue light-driven degradation of rhodamine B

“…As a metal-free photocatalyst, g-C 3 N 4 offers many unique advantages, including a fascinating graphite-like phase layer structure, a suitable band gap of approximately 2.7 eV, excellent stability, nontoxicity, and facile synthesis. 33,34 In addition, g-C 3 N 4 products with different morphology structure, polymerization degrees, photoelectric properties and photocatalytic activities can be easily obtained by adding or doping other substances, [35][36][37][38] changing preparation conditions, [39][40][41] and coupling with other semiconductors. 5,42,43 Based on the previous research regarding the pyrolysis of mixed salts obtained from evaporation and concentration of desulfurization waste liquid (rich in ammonium thiocyanate) and the pyrolysis of ammonium thiocyanate in H 2 atmosphere, 44 the following work was carried out.…”