Preparation of Improved p-n Junction NiO/TiO₂ Nanotubes for Solar-Energy-Driven Light Photocatalysis

Figure 4

(a) Raman spectra of photocatalysts (a: TNTs; b: 0.5 M NiO/TNTs; c: 2.5 M NiO/TNTs) and (b) enlarged region of Raman shift range 100–200 cm⁻¹.

(a)

(b)