Zinc-based metal-organic framework nanofibers membrane ZIF-65/PAN as efficient peroxymonosulfate activator to degrade aqueous ciprofloxacin

A novel peroxymonosulfate (PMS) catalyst, zinc-based metal-organic framework electrospinning (ES) nanofibers membrane (short for ZIF-65/PAN) was firstly fabricated and used for the degradation of aqueous ciprofloxacin (CIP). Physicochemical properties, catalytic performance, stability, reusability, and the regeneration of ZIF-65/PAN was observed and conducted. Influence of various parameters including ZIF-65 loading content, reaction temperature, initial pH, and competitive organic molecules on CIP degradation was investigated. Reactive active species and degradation intermediates that involved in ZIF-65/PAN/PMS/CIP process were identified. Corresponding reaction mechanisms were speculated. The results indicate that the easy-separation ZIF-65/PAN nanofibers exhibit high efficiency for PMS activation, 89.2 % of CIP was degraded within 60 min, with up to 87.5 % of PMS utilization efficiency. ZIF-65/PAN was renewable through simple layer-by-layer self-assembly, thus shows good prospect in future applications. 26.4 % of surface Zn2+ of ZIF-65/PAN exists in the form of + III oxidation state after activation, indicating the role of zinc catalytic site. Through activation, oxidative active species SO4 center dot-, center dot OH, and O-1(2) was generated, CIP was thus degraded through mainly-three pathways. This study provides novel ideas for the application of MOF-based membrane on PMS based advanced oxidation processes.