Synthesis of -MnO2 Nanomaterial from a Precursor γ -MnO2: Characterization and Comparative Adsorption of Pb(II) and Fe(III)

Mno2 nanostructure was successfully synthesized via hydrothermal treatment of a precursor γ-mno2. structure,morphology,and bet surface area were characterized using x-ray powder diffraction (xrd),scanning electron microscopy (sem),and brunauer-emmett-teller nitrogen adsorption (bet-n2 adsorption). thermal analysis result showed that -mno2 nanorods were formed from γ-mno2 at 600c. in addition,pb(ii) and fe(iii) adsorptive properties were investigated in an optimal condition. results showed that equilibrium adsorption was obtained after 60 minutes for pb(ii) at ph = 4.0 and 80 minutes for fe(iii) at ph = 3.5 with 240 rpm of shaking speed overall. experimental data was analyzed using three models: langmuir,freundlich,and sips. adsorption capacities (qm) from the langmuir isotherm models are 124.87 mg/g for pb(ii) and 30.83 mg/g for fe(iii). along with the highest corelation coefficients,it is clear that the adsorption of pb(ii) and fe(iii) ions on -mno2 surface followed sips model. kinetic studies indicated that the uptake of pb(ii) and fe(iii) occurred in the pseudo-second-order model with two stages for pb(ii) and three stages for fe(iii). � 2016 van-phuc dinh et al.