Efficient Visible Light Photocatalytic Oxidation of NO on F- and N-Codoped Spherical TiO₂ Synthesized via Ultrasonic Spray Pyrolysis

Figure 3

SEM images of fluorine- and nitrogen-codoped TiO₂ with different amount urea in the precursor solution: (a) FT; (b) FNT-1; (c) FNT-5; (d) FNT-10. The scale bar in the figure is 1 μm.

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