Another P25-Au film sample was irradiated with 16 mW laser power for TEM imaging. The Au-P25 mixture from a large scan area was separated from the silicon substrate and then transferred to the TEM grid for transmission imaging. A TEM image (Figure . The average size of gold NPs increased to 80 nm, and TiO2 NPs after phase transition increased to a few hundred nanometers through the aggregation of adjacent NPs (Figures and).