Synthesis and Characterization of Hierarchical Structured TiO₂ Nanotubes and Their Photocatalytic Performance on Methyl Orange

Figure 1

FESEM images of as-prepared TiO₂ nanotube arrays (a) and hierarchical structured TiO₂ fabricated after different ball milling time: (b) 0.5 h, (c) 5 h, and (d) 10 h. TEM investigation of 0.5 h (e) and 5 h (f) milled samples.

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