A Novel Solar Driven Photocatalyst: Well-Aligned Anodic WO₃ Nanotubes

Figure 1

FESEM images of anodic WO₃ nanostructures obtained in 1 M Na₂SO₄ electrolyte containing 0.5 wt% NH₄F for different anodization times at 40 V: (a) pure W foil before anodization; (b) 2 min; (c) 5 min; (d) 10 min; (e) 15 min; (f) cross-sectional view for 15 min anodization; (g) 30 min; (h) cross-sectional view for 30 min anodization; (i) 60 min; (j) cross-sectional view for 60 min anodization. Insets show the higher magnification of the surface morphology.

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