Carbon Nitride Supported High-Loading Fe Single-Atom Catalyst for Activation of Peroxymonosulfate to Generate 1 O2 with 100 % Selectivity.

Singlet oxygen (1 O2 ) is an excellent active species for the selective degradation of organic pollutions. However, it is difficult to achieve high efficiency and selectivity for the generation of 1 O2 . In this work, we develop a graphitic carbon nitride supported Fe single-atoms catalyst (Fe1 /CN) containing highly uniform Fe-N4 active sites with a high Fe loading of 11.2 wt %. The Fe1 /CN achieves generation of 100 % 1 O2 by activating peroxymonosulfate (PMS), which shows an ultrahigh p-chlorophenol degradation efficiency. Density functional theory calculations results demonstrate that in contrast to Co and Ni single-atom sites, the Fe-N4 sites in Fe1 /CN adsorb the terminal O of PMS, which can facilitate the oxidization of PMS to form SO5 .- , and thereafter efficiently generate 1 O2 with 100 % selectivity. In addition, the Fe1 /CN exhibits strong resistance to inorganic ions, natural organic matter, and pH value during the degradation of organic pollutants in the presence of PMS. This work develops a novel catalyst for the 100 % selective production of 1 O2 for highly selective and efficient degradation of pollutants.