Enhanced self-regenerating CPNs@ZIF-8/polyacrylic acid/chitosan hydrogel catalyst for synergistic adsorption and fenton-like degradation of erythromycin

Abstract

Erythromycin (ERY) is a commonly used antibiotic whose overuse poses threats to ecosystems and human health, and its effective removal is a great challenge. A novel Coupling Adsorption-Catalysis (CAC) process was developed using a dual-functional copper peroxide nanoparticles@ZIF-8/polyacrylic acid/chitosan (CPNs@ZIF-8/PA/CS) hydrogel Fenton-like catalyst. The CAC process combines the adsorption capabilities of active functional groups on CPNs@ZIF-8/PA/CS with the catalytic activity of the encapsulated CPNs@ZIF-8. This synergistic approach enables efficient adsorption and degradation of ERY. Specifically, CPNs@ZIF-8/PA/CS exhibits an adsorption efficiency four times higher than that of CS alone and a degradation efficiency twice that of CPNs@ZIF-8 alone. Notably, the coordinated incentive mechanism in the CAC system arises from enhanced adsorption sites in CPNs@ZIF-8/PA/CS and hydrogen bonding with ERY molecules (confirmed by DFT calculations), which enhances ERY adsorption. Additionally, the shorter distance between adsorbed ERY and active species, along with improved mass transfer efficiency, ensures the feasibility of creating environmental value from ERY in aquatic environments through CAC. Moreover, CPNs@ZIF-8/PA/CS demonstrates significant advantages in recyclability and stability. The robust mechanical properties enable sustained catalytic degradation of ERY, ensuring high performance even after five cycles.