Facile Low-Temperature synthesis of novel carbon nitrides for efficient conversion of carbon dioxide into Value-Added chemicals

The interest in using carbon nitrides (CN) for CO₂ conversion has stimulated extensive research on CN synthesis. Herein, we report the synthesis of two novel CN materials using low-cost commercially available precursors at low temperatures in a short duration of time. Two CN materials, one derived from 5-amino tetrazole (named 4NZ-CN) and the other derived from 3, 5-diamino-1, 2, 4-triazole (named 3NZ-CN) precursors, are prepared by refluxing these precursors for 2 h at 100 °C. 4NZ-CN and 3NZ-CN catalysts show higher surface areas (55.80 and 52.00 m² g^-1) and more basic sites (10.05 and 5.65 mmol g^-1) than the conventional graphitic carbon nitride (g-C₃N₄) derived from melamine, for which the corresponding values are 9.20 m² g^-1 and 0.62 mmol g^-1, respectively. In addition, both CN exhibit a 3-fold higher catalytic activity for CO₂ cycloaddition to epoxides than g-C₃N₄. The structure-activity relationship was ascertained using a combination of experimental and computational studies, and a catalytic mechanism was proposed. This work provides a facile strategy for the synthesis of novel CN materials at relatively low temperatures, and the developed catalysts show remarkable performance in the conversion of CO₂ to value-added chemicals.