Synthesis of mesoporous carbon nitride via a novel detemplation method and its superior performance in base-catalyzed reactions

Abstract

A series of mesoporous graphitic carbon nitride materials have been synthesized using dicyandiamide as a precursor by a nanocasting method through a new detemplation process. Alkaline solutions could effectively eliminate hard siliceous templates, and ordered mesostructures have been well retained over the final synthesized CND materials. Fourier transform infrared and X-ray photoelectron spectroscopy characterization revealed that the employment of alkaline solution during the synthesis of the CND samples facilitated the condensation of tri-s-triazine fragments and thus enhanced the amount of bridging N species. According to the profiles of CO₂ temperature programmed desorption and elemental analysis, the detemplating agent could not only preserve the original basic sites but also improve the overall basic intensity of the mesoporous CND samples. In base-catalyzed reactions, represented by Knoevenagel condensation and transesterification reactions, the mesoporous CND materials demonstrated excellent and stable catalytic performance, which is especially much higher than that of the mesoporous sample detemplated by traditional HF solution.