To further analyze and quantify the pore structure and surface
area of the obtained samples, the N2 adsorption–desorption iso-therms were carried out and shown in Fig. 3A. 0CTAB sample
shows a type II isotherm with a big H3hysteresis loop in theP/Po
range of 0.9–1.0 (Fig. 3A, linea). Since H3hysteresis loop did not
show any adsorption isotherm plateau atP/Po1, the formation
of slit-shaped pores as secondary pores in the aggregates of nano-particles which a pore size distribution extending to the macropore
range is suggested [28]. Two other samples prepared with CTAB
(2.2CTAB and 2.9CTAB) possess dual hysteresis loops. The big
one, similar to that of 0CTAB (P/Po0.8–1.0), confirms the forma-tion of slit-shaped large pores, due to the aggregation of the nano-plate-like particles, whereas the small one (P/Po0.3–0.8)
indicates the presence of mesopore (Fig. 3A, linescandd) [29].
In contrast, 1.5CTAB sample shows characteristic behavior of type
IV isotherm with a H3hysteresis loop (P/Po0.3–1.0) revealing the
formation of mesoporous structure (Fig. 3A, lineb). For all samples