“…For the past decades, transition-metal-catalyzed reaction has become a rapidly growing area of research due to the excellent properties of transition-metal ions in reversible ligation, electron transfer, light-harvesting, catalytic transformation and opening new reaction pathways [26][27][28][29]. Previous studies show that a dynamic Fe 2+ /Fe 3+ redox cycle can enhance the photodecomposition of PFOS and PFOA under UV [30][31][32] and VUV [33,34] illumination. However, Fe(H2O)6 2+ and Fe(H2O)6 3+ are only stable in very acidic conditions (pH<4).…”