Fig. 4

HRPES results for Fe 2p, Ti 2p, and O 1s core level spectra of Fe@TiO₂ nanoparticles with various doping levels. a, d, g Core level spectra from 1 wt.% Fe@TiO₂. b, e, h Those from 3 wt.% Fe@TiO₂. c, f, i Those from 5 wt.% Fe@TiO₂. HRPES results corresponding to the S 2p core level spectrum obtained after photocatalytic oxidation of 2-aminothiophenol on j 1, k 3, and l 5 wt.% Fe@TiO₂ nanoparticles