Hydroxyl radical

Catalysis

Adsorption

Photochemistry

Reactive oxygen species

Nuclear physics

Biochemistry

Electron transfer

Fenton reaction

Singlet oxygen

Physics

Organic chemistry

Oxygen

Singlet state

Radical

Excited state

Chemistry

Selectivity

Proceedings of the National Academy of Sciences

Significance In the bulk phase, hydroxyl radical from the one-electron transfer and high-valent iron-oxo species from the O-atom transfer compete to be the reactive intermediates in the Fenton and related reactions. In the confined space at a nanoscale, however, the behavior of the Fenton reaction is elusive. Herein, we report an unprecedented singlet oxygen mediated Fenton’s reaction occurred inside carbon nanotube with inner diameter of ∼7 nm, showing exotic catalytic activities, unforeseen adsorption-dependent selectivity, and pH stability for the oxidation of organic compounds. Our results suggest the use of Fenton’s reaction in more scenarios than ever explored.

Singlet oxygen mediated iron-based Fenton-like catalysis under nanoconfinement