Transient co-tuning of atomic Fe and nanoparticle facets for self-relaying Fenton-like catalysis

Fenton-like catalysts are important materials for degrading refractory organic pollutants, however, they still suffer from limited oxidizing ability. Although single atoms and nanoparticles with high-index facets are commonly used in catalysis, their high surface energy hinders controllable synthesis. Here, we construct an iron-based material containing both isolated single atoms and high-index faceted nanoparticles by carbon-assisted Flash Joule heating for organic pollutant remediation. The current-induced thermal shock benefits the excitation of iron atoms and subsequent trapping by graphene defects. At ultrahigh temperatures, the thermodynamic limitations are overcome, leading to nanoparticles with high-index facets. Density functional theory calculations indicate that hydroxyl radical production can be enhanced by self-relay catalysis via the ensemble effect between single atoms and high-index facet nanoparticles. The derived materials exhibit dramatically improved performance in terms of antibiotic removal and medical micropolluted water. Thus, this method presents an effective strategy for designing smart materials for organic wastewater purification.