Size-selective trapping and photocatalytic degradation of PFOA in Fe-modified zeolite frameworks
Jan-Max Arana Juve, Xavier Baami González, Lu Bai, Zhiqun Xie, Yanan Shang, Ali Saad, Rafael Gonzalez‐Olmos, Michael S. Wong, Mohamed Ateia, Zongsu Wei
Abstract
Removal and destruction of perfluorooctanoic acid (PFOA) are challenging due to its extreme persistence and dilute concentrations. This study investigated dual-function adsorptive-photocatalytic zeolite materials to selectively adsorb and degrade PFOA via tuning pore structures and doping transition metals. It is found that the pore opening is critical in the size-selective trapping of PFOA, while the iron doped zeolites present excellent adsorption of PFOA (>80 mg g −1 ) combining hydrophobic and electrostatic interactions. The formation of PFOA-iron complexes has reduced bond dissociation energy of C−F, calculated from density functional theory, for favorable stepwise defluorination (over 60% defluorination in 4 hours) by superoxide radicals and ligand-to-metal charge transfer. This mechanistic investigation extends the potential of the concentrate-and-degrade concept to remove PFOA selectively and effectively from contaminated water. • Zeolites with comparable pore opening to PFOA favor its adsorption and degradation. • PFOA adsorption on Fe-BEA is driven by hydrophobic and electrostatic interactions. • PFOA molecule activation by Fe complexes decreases the decarboxylation energy. • Ligand-to-metal charge transfer and superoxide radical contribute to PFOA degradation.