Study On Synthesis And Application Of Iron Oxide Nano Materials

Fe²⁺ was extracted from pyrite cinder by reduction roasting method and transformed into FeSO₄ as a precursor to prepare α-FeOOH. The crystal nucleus of α-FeOOH was prepared in a neutral solution (pH: 6-7) of FeSO₄ (0.15-0.25 mol/L) and Na₂CO₃ (n_Na2CO3 :n_FeSO4 =1:1). In order to maintain a properoxidizing rate of Fe²⁺, the pH value of the solution was controlled in the range of 4-5 by dropping Na₂CO₃ solution. A uniform needle crystal of α-FeOOH was obtained with width 30⁴0nm and length about 250nm. α-Fe₂O₃ was prepared by roasting α-FeOOH.The band gap of α-Fe₂O₃ is smaller than TiO₂. α-Fe₂O₃ possesses a stronger ability of photoelectrons acceptance in visible area and higher photo-electro-catalytic activities. The results of voltammetry test indicated that the photo-electronic current of α-Fe₂O₃-TiO₂ was enhanced significantly. Methylene blue was degraded and decolorized by UV irradiating on nano α-Fe₂O₃ -TiO₂ crystal coated at the glass substrates.Surface" structure and catalytic activities of the films of α-Fe₂O₃/SA, TiO₂/SA and α-Fe₂O₃ -TiO₂/SA were characterized by FTIR, XRD, PL, TEM and I-V techniques. The results showed that α-Fe₂O₃ enhanced their photo-decolorized-activities by doping 15% TiO₂. The detail quantitive examination was carried out to investigate the decolorization effect of methylene blue. The experiment results demonstrated that the degradation of methylene blue with a novel multiple-semiconductor embedded in the natural-degradation sodium alginate films, was photo-electro-catalytic-oxidative mechanism. The environmentally friendly material α-Fe₂O₃ -TiO₂/SA possessed favorableprospective application in environmental treatment.