Recent advances on the incorporation of N into zero-valent and atomic iron for contaminants transformation

The FeNx active species in Fe-N materials after the incorporation of N into zero-valent and atomic iron showed excellent performance on contaminants transformation compared with the materials before modification. However, the research of FeNx on the environmental field is still in the preliminary stage at present. In view of the enormous potential, this article emphasizes the research advances in the incorporation of N into zero-valent and atomic iron for contaminants transformation. Firstly, the synthesis of Fe-N material including synthesis methods, changes in characterization and active species as well as influence factors during the synthesis progress are introduced. Most importantly, the efficiency and mechanism of zero-valent iron after the N incorporation on dechlorination, denitrification and activation of oxidants, and the atomic iron after N incorporation on desulfurization, selective transformation and activation of oxidants are also summarized, where FeNx species play an important role. Additionally, due to the high stability, tolerance, adaptability to various contaminants and less recycling difficulty, the potential of Fe-N materials for practical environmental applications is appreciated. At length, this review discusses the challenges and overlooks in the future, looking forward to providing assistance for utilizing the Fe-N materials to handle the troublesome water contaminants.