Strategy of constructing D-A structure and accurate active sites over graphitic carbon nitride nanowires for high...

Constructing photocatalysts for the stable and efficient production of NH₃ is of excellent research significance and challenging. In this paper, the electron acceptor 5-amino-1,10-phenanthroline (AP) is introduced into the electron-donor graphitic carbon nitride (CN) framework by a simple heated copolymerization method to construct a donor-acceptor (D-A) structure. Subsequently, the phenanthroline unit is coordinated with transition metal Fe³⁺ ions to obtain the photocatalyst Fe(III)-0.5-AP-CN with better nitrogen fixation performance, and the average NH₃ yield can reach 825.3 μmol g^-1 h^-1. Comprehensive experimental results and theoretical calculations show that the presence of the D-A structure can induce intramolecular charge transfer, effectively separating photogenerated electrons and holes. The Fe active sites can improve the chemisorption energy for N₂, enhance the N-Fe bonding, and better activate the N₂ molecule. Therefore, the synergistic effect between the construction of the D-A structure and the stably dispersed Fe active sites can enable CN to achieve high-performance N₂ reduction to produce NH₃.