A bioinspired iron-peroxy species of feroxyhyte for micropollutants oxidation with ultrahigh peroxymonosulfate utilization efficiency.

By systematically regulating the Fe-O coordination number of feroxyhyte (δ-FeOOH), we disclosed the structure–activity relationship and developed a highly efficient Fenton-like catalyst. [Display omitted] • Coordination number of Fe atoms were regulated through tuning δ-FeOOH thickness. • 5-coordinated Fe sites accelerate the rate-limiting step and facilitate the PMS activation. • The PMS utilization efficiency achieved as high as 78.40%. • The catalytic mechanism of low coordination Fe sites were proposed. • Fe-O 5 nanosheets were assembled into laminar membrane for micropollutants treatment. Efficient purification of water is essential to remove organic micropollutants for human and environmental health. The development of catalysts with high activity and peroxymonosulfate (PMS) utilization efficiency for removal of organic micropollutants remains challenging. Inspired by natural enzymes, we designed δ-FeOOH nanosheets with abundant 5-coordinated iron sites, which are responsible for the formation of iron-peroxy (FeIII-O-O-FeIII) species with PMS. The iron-peroxy species can directly oxidize and degrade electron-rich micropollutants (e.g. BPA) with an ultra-high PMS utilization efficiency of 78.4%. A laminar membrane constructed from a stack of δ-FeOOH nanosheets, replete with an abundance of 5-coordinated iron sites. The laminar membrane can degrade multiple micropollutants by almost 100% due to nonlinear transport between the δ-FeOOH nanolayers, compared with the dispersed catalyst. This work would motivate the community to focus more on the diversified behavior of the coordination number of active centers in the design of efficient catalysts for water purification. [ABSTRACT FROM AUTHOR]