Transition metal/carbon composite catalysts can effectively activate persulfate (PMS) to degrade organic pollutants. In the present study, a simple pyrolysis technique was used to effectively transform a composite hydrogel adsorbent loaded with Cu (Ⅱ) into a zerovalent copper/carbon composite catalyst (C-Cu), which efficiently activated PMS and rapidly degraded 2,4-dichlorophenol (2,4-DCP). Under conditions of pH=5, a C-Cu dosage of 5 mg, and PMS concentration of 0.20 g/L, 2,4-DCP (0.1 mmol/L) was completely removed within 5 minutes, with a reaction kinetic constant as high as 3.4342 min^-1, which was 3 orders of magnitude higher than those of reported metal oxides. In compliance with the Integrated Wastewater Discharge Standard (GB 8978—1996) Grade I, C-Cu could stably operate for 81.3 hours in a dynamic column reactor. Under the coexistence conditions of pH=5-9, conventional inorganic salts, and natural organic matter, the degradation of 2,4-DCP in the C-Cu/PMS system was not significantly inhibited, demonstrating good environmental tolerance. Moreover, the C-Cu/PMS system showed superior removal performance for various chlorophenol pollutants. Quenching experiments of active species and EPR results consistently indicated that zerovalent copper acts as the active site for PMS activation, generating a large amount of ¹O₂ and ·O₂^-. LC-MS analysis results suggested that 2,4-DCP underwent processes such as dechlorination and ring-opening to achieve degradation and mineralization.

The low intrinsic activity of Fenton catalytic site and high demand for light-energy input inhibit the organic-pollution control efficiency of photo-Fenton process. Here, through structural design with density functional theory (DFT) calculations, Ce is predicted to enable the construction of coordinatively unsaturated metal centers (CUCs) in Prussian blue analogue (PBA), which can strongly adsorb H₂O₂ and donate sufficient electrons for directly splitting the O–O bond to produce ^·OH. Using a substitution-co-assembly strategy, binary Ce-Fe PBA is then prepared, which rapidly degrades sulfamethoxazole with the pseudo-first-order kinetic rate constant exceeding reported values by 1–2 orders of magnitude. Meanwhile, the photogenerated electrons reduce Fe(Ⅲ) and Ce(Ⅳ) to promote the metal valence cycle in CUCs and make sulfamethoxazole degradation efficiency only lose 6.04% in 5 runs. Overall, by introducing rare earth metals into transition metal–organic frameworks, this work guides the whole process for highly active CUCs from design and construction to mechanism exploration with DFT calculations, enabling ultrafast and stable photo-Fenton catalysis.