Self-assembled metalloporphyrin-carbon nitride heterointerface promotes fenton-like activity to purify high-salinity phenolic wastewater

Abstract

Developing a Fenton-like peroxymonosulfate (PMS) activator capable of producing ¹O₂ is beneficial for treating high-salinity wastewater. Herein, the FeTCPP-CN catalyst was synthesized by self-assembling iron (Ⅲ) tetrakis(4-carboxyphenyl)porphyrin (FeTCPP) molecule with lamellar carbon nitride (CN) polymer. The formed hydrophilic-hydrophobic heterointerface enhanced the adsorption potential with pollutants, and the hydrogen bonding and π-π interactions between interfaces constructed an efficient electron transfer channel, while the highly dispersed Fe-N₄ moiety promoted atomic utilization efficiency. In the FeTCPP-CN/PMS system, 2,4-dichlorophenol (2,4-DCP) could be efficiently degraded under high concentration (200 mM) of inorganic salts, and the excellent degradation performance could be maintained over 10 cycles in a continuous flow device. During the reaction, the O₂^·- and ¹O₂ were identified as the main active species, where *SO₅^·- was the crucial intermediate to selectively generate ¹O₂. This work offers insights into the construction of efficient catalysts for the treatment of high-salinity phenolic wastewater.