Skip to Main Content
Figure 3 depicts the adsorption–desorption isotherm of adsorbent at the boiling point of N2. It can be clearly seen that the isotherm is of type II, as categorized by the IUPAC and Brunauer (Rouquerol et al. 2013). The isotherm is type H4 hysteresis loop, characteristic of aggregated particles with nonporous or macroporous adsorbents and unrestricted monolayer–multilayer adsorption (Rouquerol et al. 2013). The BET analysis revealed particles with SBET 4.51 m2·g−1 and pores with average volume of 0.0201 cm3/g. Similar values of specific surface area for ZnFe2O4 were obtained by Sakthivel et al. (2002). The relatively small specific area may be attributed to the large particle size (Zhang et al. 2010). The data obtained from the analysis are summarized in Table 1.
Table 1

N2 adsorption analysis data

PropertyValue
t-plot external surface area 4.5294 m2/g
BET surface area 4.5135 m2/g
Pore volume 0.0201 cm3/g
Pore size (from distribution plot) 36.0 A°
BJH adsorption size 177.76 A°
BJH desorption size 184.58 A°
PropertyValue
t-plot external surface area 4.5294 m2/g
BET surface area 4.5135 m2/g
Pore volume 0.0201 cm3/g
Pore size (from distribution plot) 36.0 A°
BJH adsorption size 177.76 A°
BJH desorption size 184.58 A°
Figure 3

(a) N2 adsorption–desorption curves of at 77 K for (x)ZnO(1 − x)Fe2O3 nanopowder. (b) Pore size distribution for (x)ZnO(1 − x)Fe2O3 nanopowder.

Figure 3

(a) N2 adsorption–desorption curves of at 77 K for (x)ZnO(1 − x)Fe2O3 nanopowder. (b) Pore size distribution for (x)ZnO(1 − x)Fe2O3 nanopowder.

Close Modal