Three-dimensional assemblies of carbon nitride tubes as nanoreactors for enhanced photocatalytic hydrogen production

Abstract

The three-dimensional character of carbon nitride can endow it with a larger specific surface area and more catalytic active sites, which are beneficial for charge and mass transfer to enhance photocatalytic hydrogen production reactions. Herein, we reported the direct assembly of three-dimensional structured carbon nitride from the thermal polymerization of 3-amino-1,2,4-triazole (AT) and melamine molecules. The 3D C₃N₄ consisted of one-dimensional thick tubes with numbers of thin tubes grown uniformly on their surfaces. It was noted that the assembly was decorated with triazole ring groups that generated a special nitrogen-rich structure, further broadening the visible-light response range. Furthermore, the nitrogen-rich carbon nitride had a large surface area of 71 m² g⁻¹, leading to a significant increase in the number of catalytic active sites. Thus, the photocatalytic hydrogen production rate reached 7.1 mmol g⁻¹ h⁻¹, 11.2 times higher than that of bulk C₃N₄. This work may provide a new strategy to controllably synthesize three-dimensional carbon nitride assemblies for photocatalytic applications.