Table 3 Comparisons of some selected Fabricating strategies of g-C3N4 synthesis
Techniques | Comparisons | References | |
|---|---|---|---|
Characteristics | Previous studies | ||
1. Supramolecular pre-assembly | a. Molecules adopt a well-defined arrangement into stable aggregates by non-covalent bonds under equilibrium conditions b. Hydrogen bonding is highly essential in arranging the structure of supramolecular aggregates due to the directionality and specificity of this kind of inter-actions. c. The precursor melamine can link with triazine derivatives, such as cyanuric acid, into supramolecular aggregates through hydrogen bonds | a. The use of melamine–cyanuric acid (CM) complex as starting materials was reported by Thomas and coworkers and Antonietti and coworkers. It was found that the CM morphologies depend on the used solvent for melamine–cyanuric acid molecular assembly, leading to various well-organized g-C3N4 with different morphologies | |
2. Molten salt strategy | a. Salt-melt synthesis usually acts as a solvent for high-temperature materials synthesis including many organic and inorganic reactions | a. Zou et al. successfully synthesized a carbon nitride intercalation compound by heating the melamine with a low melting point eutectic mixed salts under air and ambient pressure. Interestingly, g-C3N4 nanotubes were produced. The resultant g-C3N4 nanotubes are very stable and active for solar H2 production (Fig. 8b). | |
3. Ionic strategy | a. This strategy possesses high chemical and thermal stability, small vapor pressure, and the liquid nature at ambient. b. Makes ionic liquid to be used as solvents in many fields | a. Reported the usage of 1-butyl-3 methylimidazolium tetrafluoroborate (BmimBF4) ambient ionic liquid as soft template and dicyandiamide (DCDA) as precursor to synthesize the boron- and fluorine-containing mesoporous-g-C3N4. Very interestingly, no micropores are present in obtained g-C3N4 | [32] |