Three-Dimensional Polyacrylonitrile Nanofibrous Sponge with In Situ Grown ZIF-67 for Activating Peroxymonosulfate to Degrade Organic Contaminants

Abstract

Metal–organic frameworks (MOFs)-based advanced oxidation processes show great potential in wastewater treatment, while large-scale application is limited by their particle agglomeration and poor recyclability. Herein, a novel three-dimensional (3D) ZIF-67/PAN nanofibrous sponge (ZIF-67/PAN NFS) was successfully fabricated by a convenient method based on a combination of liquid-assisted collection electrospinning, in situ growth and freeze-drying. It was an efficient catalyst for the activation of peroxymonosulfate (PMS). The obtained ZIF-67/PAN NFS exhibited excellent catalytic performance toward the degradation of methylene blue (MB) (99.25% within 30 min). Several influencing factors, such as PMS concentration, temperature, initial pH, and initial MB concentration, were systematically investigated for the degradation of MB. Moreover, the radical quenching experiments proved that ${\text{SO}}_{4}^{ \cdot - }$ was the predominant reactive species instead of $\cdot {\text{OH}}$ for the degradation of MB. Besides, the ZIF-67/PAN NFS showed excellent reusability and the degradation efficiency remained above 94.36% after five consecutive cycles. This strategy is feasible for the fabrication of novel and efficient catalysts for remediation of organic wastewaters.