2b compares the EDX spectra for samples made by various deposition time, clearly showing the successfully electrochemical deposition of Pt NPs intothe TiO2 mesoporous films. The intensity of the Pt EDX peak (atabout 2.1 keV) increased linearly with the deposition time. Thisresult agrees well with the observation of mass loading of Pt in the TiO2film in the chronoamperometric experiments for platinumdeposition (Table 1).