760237.fig.001a
(a)
760237.fig.001b
(b)
760237.fig.001c
(c)
760237.fig.001d
(d)
Figure 1: TEM images of nanostructured particles (a–d) with different loadings of Ce. The molar ratios of the precursor sol compositions are TEOS : EtOH : H2O : HCl : CTAB : CeCl3  =  1 : 7.7 : 24.8 : 0.00125 : 0.18 :  𝑥 , where 𝑥 = 0 , 0.06, 0.12, and 0.18, respectively, for particle samples (a)–(d).