Efficient persulfate activation by CeO2 on plasma-modified nickel foam for enhanced Rhodamine B degradation

To efficiently activate persulfate (PS) for the removal of organic contaminants from water, we developed a novel integrated catalyst by loading cerium oxide onto plasma-treated nickel foam (CeO2@NF-P). The plasma treatment generated a rougher and defect-rich surface on the nickel foam (NF-P), which enhanced the dispersion and loading of CeO2. This modification further promoted the formation of a dynamic Ce3+/Ce4+ redox cycle and abundant oxygen vacancies, serving as active sites for PS activation. The CeO2@NF-P/PS system achieved complete degradation of Rhodamine B (Rh B) within 16 min, exhibiting a pseudo-first-order rate constant 3.75 times higher than that of the CeO2@NF/PS system. Quenching experiments and full-wavelength scanning elucidated the contributions of reactive species and the breakdown of the Rh B chromophore. The CeO2@NF-P catalyst demonstrated excellent reusability, maintaining a Rh B removal efficiency of 85.52% after five cycles. This work overcomes the separation and recovery limitations of conventional powder catalysts, offering a promising strategy for advanced wastewater treatment.