Figure 4

High resolution XPS results of (a) TiO2 (Ti 2p), (b) Nb2O5 (Nb 3d), (c) Ta2O5 (Ta 4f), (d) ZrO2 (Zr 3d), (e) O (O 1s) and (f) Ag° (Ag 3d) with C1s peak as calibration.

High resolution XPS results of (a) TiO2 (Ti 2p), (b) Nb2O5 (Nb 3d), (c) Ta2O5 (Ta 4f), (d) ZrO2 (Zr 3d), (e) O (O 1s) and (f) Ag° (Ag 3d) with C1s peak as calibration.