Fig. 3From: Ag Nanoparticles Located on Three-Dimensional Pine Tree-Like Hierarchical TiO2 Nanotube Array Films as High-Efficiency Plasmonic PhotocatalystsSEM images of three-dimensional pine tree-like hierarchical TiO2 nanotube arrays deposited with Ag by different deposition times: a 10 s, b 20 s, c 30 s, and d 40 s, and the set one is the corresponding magnified imageBack to article page