Performance Study of Heterogeneous Photo‐Fenton Degradation of p ‐Nitrophenol by CuCo 2 S 4 Nanoparticles Loaded on MIL‐53(Fe)

ABSTRACT Rapid industrial development has led to wastewater discharge containing refractory toxic organics, posing a severe threat to aquatic ecosystems and water security. As a typical recalcitrant pollutant, p ‐nitrophenol (PNP) is hard to degrade due to its stable benzene ring and electron‐withdrawing nitro group, demanding efficient removal methods. This study synthesized a MIL‐53(Fe)/CuCo 2 S 4 composite (MCCS‐15, ‐20, ‐25, and ‐30) via hydrothermal method and constructed a heterogeneous photo‐Fenton system (composite/visible light/H 2 O 2 ) for PNP degradation. Among samples, MCCS‐25 exhibited the highest degradation performance, achieving a rate constant of 0.08613 min −1 , which is 9.06 and 23.03 times greater than that of MIL‐53(Fe) and CuCo 2 S 4 , respectively. Photoelectrochemical measurements revealed that the loading of CuCo 2 S 4 not only broadened the visible light absorption range of MIL‐53(Fe), but also significantly improved the separation efficiency of photogenerated electron‐hole pairs. Scavenger experiments and EPR analyses confirmed that hydroxyl radical (OH) and superoxide radical (O 2 − ) were the predominant reactive species in the degradation process. The possible degradation mechanism was proposed based on the band structures of MIL‐53(Fe) and CuCo 2 S 4 . The MIL‐53(Fe)/CuCo 2 S 4 /visible light/H 2 O 2 system demonstrates promising application potential for efficient degradation of PNP.