One-step supramolecular pre-organizational synthesis of copper-doped porous carbon nitride for high photocatalytic nitrogen fixation

Solar-driven reduction of nitrogen to ammonia is a promising green approach and is considered as a sustainable alternative to the Haber–Bosch process. Carbon nitride (g-C 3 N 4 ) is an ideal non-metallic semiconductor photocatalyst for photocatalytic N 2 reduction reaction (p-NRR). In this work, we designed a simple supramolecular self-assembly method to prepare copper-doped porous graphitic nitride (Cu@pg-C 3 N 4 ) photocatalysts. The synergistic semiconductor and metal interactions enabled the obtained Cu@pg-C 3 N 4 to achieve larger specific surface area, more efficient photogenerated carrier separation, and stronger photoreduction ability. The specific surface area of Cu@pg-C 3 N 4 increased from 5.69 to 75.76 μmol/L, exposing more active sites compared to bulk g-C 3 N 4 . The NH 4 + production rate of the obtained Cu@pg-C 3 N 4 was 150.47 μmol/L, which is 20 times higher than that of the bulk carbon nitride, exhibiting excellent N 2 photofixation ability. These findings highlight the significant progress that can be achieved by metal supramolecular network modification strategies in harnessing the potential of carbon nitride for photocatalytic reduction applications.