Figure 11.

(Color online) Changes in the Ce 3d XPS spectra collected as a function of time for (a) particles formed in an aqueous solution, containing some amount of organic (toluene) (after Ref. 81), or (b) particles synthesized in a solution with no added organic. The 3–5 nm diameter particles produced in the solution with toluene (a) tended to become reduced upon x-ray exposure, while 10–14 nm particles formed in aqueous solution without added organics (b) tended to become oxidized upon x-ray exposure.