Different bonding modes modulate the structure and properties of g-C3N4-Based materials

Composite precursors with hydrogen bonding interactions (Fe(OH)3/DCDA) and chemical bonding interactions (Fe(OH)3/PA/DCDA) were constructed by simple hydrothermal method, respectively, and then the corresponding photocatalysts (Fe2O3/g-C3N4 and Fe2O3/C/g-C3N4) were calcined under N2 atmosphere to study the effect of different bonding types of precursors on the structure and performance of the photocatalysts. It is shown that the strong chemical bonding interaction between -CHO in Fe(OH)3/PA and -NH2 in DCDA causes the calcined Fe2O3/C/g-C3N4 to exhibit a lower density of terminal amino defects compared to the weak hydrogen bonding interaction, which greatly facilitates the photogenerated electron-hole separation. In addition, the strong chemical bonding interactions in the precursors would also cause incomplete polymerization during calcination, leading to the formation of porous structures in the catalyst Fe2O3/C/g-C3N4, which increases the specific surface area on the one hand and enhances the photoavailability on the other. Therefore, the prepared Fe2O3/C/g-C3N4 has good photocatalytic activity and can degrade 51.28 % of MB solution after 60 min of continuous irradiation under visible light, which is 2.8 times higher than that of g-C3N4.

Automated summary

Composite precursors with hydrogen bonding and chemical bonding interactions were synthesized and calcined to obtain photocatalysts. The photocatalyst with strong chemical bonding interactions exhibited better photocatalytic activity due to the lower density of terminal amino defects, and the porous structure formed during calcination increased the specific surface area and photoavailability.