Strategy of constructing D-A structure and accurate active sites over graphitic carbon nitride nanowires for high efficient photocatalytic nitrogen fixation
Donghui Cui, Xue Yang, Yu Liu, Ting Ou, Xiangyi Kong, Yali Zhang, Jiangwei Zhang, Fengyan Li
Abstract
Constructing photocatalysts for the stable and efficient production of NH 3 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 Fe 3+ ions to obtain the photocatalyst Fe(III)-0.5-AP-CN with better nitrogen fixation performance, and the average NH 3 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 N 2 , enhance the N -Fe bonding, and better activate the N 2 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 N 2 reduction to produce NH 3 .