Modification of One-Dimensional TiO₂ Nanotubes with CaO Dopants for High CO₂ Adsorption

Figure 3

FESEM top view image of nanotubes subjected to wet impregnation of 1.2 M calcium nitrate solution for (a) 24 hours, (b) 48 hours, and (c) 72 hours and subsequent annealing at 673 K in Ar gas for 4 hours.

(a)

(b)

(c)