Graphitic Carbon Nitride: Synthesis, Properties, and Applications in Catalysis

Abstract

Graphitic carbon nitride, g-C3N4, is a polymeric material consisting of C, N, and some impurity H, connected via tris-triazine-based patterns. Compared with the majority of carbon materials, it has electron-rich properties, basic surface functionalities and H-bonding motifs due to the presence of N and H atoms. It is thus regarded as a potential candidate to complement carbon in material applications. In this review, a brief introduction to g-C3N4 is given, the methods used for synthesizing this material with different textural structures and surface morphologies are described, and its physicochemical properties are referred. In addition, four aspects of the applications of g-C3N4 in catalysis are discussed: (1) as a base metal-free catalyst for NO decomposition, (2) as a reference material in differentiating oxygen activation sites for oxidation reactions over supported catalysts, (3) as a functional material to synthesize nanosized metal particles, and (4) as a metal-free catalyst for photocatalysis. The reasons for the use of g-C3N4 for such applications are also given, and we expect that this paper will inspire readers to search for further new applications for this material in catalysis and in other fields.

Pore confinement effects and stabilization of carbon nitride oligomers in macroporous silica for photocatalytic hydrogen production

“…[18,20,22] and the powder pattern is consistent with a structural model of melon recently proposed. [29] This structure comprises buckled chains of tris-s-triazine moieties idealized as 3 (Fig.…”

“…[11][12][13][14][15][16][17] In addition, metalfree graphitic carbon nitride (g-C3N4) has been reported as a photocatalyst for the sacrificial production of dihydrogen from water, although typically metal co-catalysts are also required. [18,19] The idealized structure of g-C3N4 is not realized when using the most common synthetic procedures involving hydrogen-containing precursors. [18,[20][21][22][23][24][25][26] Synthesis is typically achieved via thermal decomposition of molecular precursors such as cyanamide, dicyanamide, melamine or urea.…”

“…[18,19] The idealized structure of g-C3N4 is not realized when using the most common synthetic procedures involving hydrogen-containing precursors. [18,[20][21][22][23][24][25][26] Synthesis is typically achieved via thermal decomposition of molecular precursors such as cyanamide, dicyanamide, melamine or urea. For example cyanamide (1) (Fig.…”

“…The local and long-range structure can lead to similar analytical data from common methods of characterization, and hence establishing the true composition and structure necessitates application of a broad range of techniques. [18,[20][21][22]30] Nevertheless, g-C3N4 and carbon nitride (CN) are used as descriptors for a range of compositions, which differ in their extent of condensation, CHN composition, and possibly oxygen content. [24] Indeed it has been shown that using hydrogen containing precursors such as cyanamide, the resulting 'carbon nitride' product synthesized above 500 o C is predominantly melon (3), which also has several potential structures, [22,28,31] and that continued heating leads to carbonization in addition to further polymerisation.…”

Direct Exfoliation of g-C3N4 with Addition of NaOH for Enhanced Photocatalytic Cr(Ⅵ) Reduction

“…It is nontoxic, stable, and easy synthesized from rich and cheap CN-containing precursor [1]. In addition, it has been proved to have photocatalytic activity responsive to visible light in many chemical reactions [2][3][4][5][6][7].…”