Preparation And Phootcatalytic Pefrormance Of Iron Doped Perovskite Manganese Oxide

Perovskite style oxides (ABO3) have unique electromagnetic properties and redoxcatalytic activities. Acceptor doping ABO3(A二La, B=Mn，Fe, Co, Ni) has high scaleconductivity, is commonly used as solid oxygen fuel cell cathode. Few studies of its photocatalytic can be found. How to improve separation efifciency, enhance response to visiblelight of the heterogeneous photocatalytic systems using powdered semiconductors is now aifeld of great interest, encouraging new fundamental investigations into the chemicalreactions.Perovskite style oxides structure, preparation method, application feature, adsorbentand catalytic characteristics are reviewed in this paper. Series of powder samples ofLaMni.Je^Os and Lao.67Sro.33Mn1.^Fcompounds have been prepared through a solidphase reaction process at temper temperature, and heat treated at70(TC according to theresults of TG experiment. The phase structure and morphology were characterized byusing X-ray diffraction (XRD), scanning electron microscopy (SEM). The results of XRDand TEM show that the samples are single orthogonal phase and grain size is about onemicron.Photodecomposition experiment reaults of methylene blue dye shows that both seriesof catalyst possess excellent catalytic performance. This illustrate that the determine sectorof photo generated electron hole has slow rate of recombination and high catalytic activityis not caused by particle size and specific surface area. Other factors also affect catalyticactivity of the catalyst, such as surface structure, crystallinity and surface morphology. Byanalyzing the reflectance image，pure phase and doping powder both have strong visiblelight absorption in visible band.Degradation of methylene blue by the LaoS.67ro.33Mni.^Fejt03samples was detail study,including such factors as exposure time，the amount of catalyst and dye concentration. Atthe optimization degradation condition, atfer6h reaction, Degradation ratio is about 95.95%. Degradation appears one class dynamic equation obviously as-AciAt=Q.52^c/h. Multiple recovery experiment shows that the catalyst can sustainable beused at least10times with less lost of activity. The catalyst has high catalytic activity todegrade the methyl orange with the highest degradation ratio about94.28%.Although powders are obviously too fine in size, they lack the advantage of havinglarge surface, but separation in the space between the oxidation and reduction sites found isstill efficient compared to those found in TiCh particles photochemical reactions system，where the products of the ch^ge transfer reaction are in close proximity.