Fig. 6

(Left panel) HRPES S 2p core-level spectra obtained after the catalytic oxidations of 180 L 2-ATP (the saturation exposure in our system) on anatase TiO₂ and 5 mol% TM-TiO₂ (a TiO₂, b Cr-TiO₂, c Mn-TiO₂, d Fe-TiO₂, e Co-TiO₂, and f Ni-TiO₂). (Right panel) g The plot for intensity ratio between S3 (− SO₃H) and S1 (− SH) of anatase TiO₂ and the five TM-TiO₂, indicating their catalytic activities in the oxidation of 2-ATP, for 180-l exposures under 365 nm UV light