Synthesis, Characterization Of Ferrite Nano-Powders And Its Performance

In recent years, dealing with water pollution is one of the hot spot ofenvironmental studies, the photocatalytic degradation and adsorption are bothconsidered to be effective mens of green management. Bisides, ferrite compositeoxides have widely used in various fields because of its excellent ferromagnetism.Therefore, ferrite materials with magnetic were prepared by the method which wassimple, convenient and quick in our present work, and it is of great importence toapplied it to deal with the water pollution.1. Single-crystalline YFeO3particles with the perovskite structure have beenfabricated through a facile KCl-assisted solution combustion synthesis (SSCS) route,using alanine as fuel and corresponding nitrates as oxidants. The effects of F/N andthe KCl/M ratios on the phase and microstructure of the products are studied in detailby XRD analysis, SEM, low temperature N2adsorption, UV-visible diffuse reflectionspectroscopy. It is remarkable that the introduction of KCl into the solutioncombustion synthesis (SCS) process results in a dramatic increase in surface of theobtained YFeO3. Results show that both of YFeO3nanoparticles prepared by SCS andSSCS exhibit excellent photocatalytic activity for the photodegradation of RhB in thepresence of H2O2. The photogenerated holes (h+) and OH were the main activespecies of YFeO3for RhB degradation under visible light irradiation.2. Different crystalline phases YFeO3nanopowders synthesised via sol-gelmethod using egg white as the complexing agent. By adjusting the preparationparameters in the synthesis process, which demonstrated that the amount ofcomplexing agent, calcining temperature and time have important influence on thecrystalline phase and adsorptive ability of YFeO3. Therein, the structure ofhexagonal YFeO3was mesporous, and its average pore size was21.3nm.Furthermore, the adsorption properties of YFeO3onto CR were systematically studied. It shows that nanopowder YFeO3exhibts strong adsorption ability for CR,its highest adsoption capacity could reach216.9mg/g.3. Magnetic MnFe2O4nanopowders were prepared by a KCl-assisted solutioncombustion synthesis method. The effects of the fuel-to-nitrate ion (F/N) and theKCl-to-metal ratios (KCl/M) on the phase and microstructure of the products arestudied in detail. It is remarkable that the introduction of KCl into the SCS processresults in an obvious dispersion in the obtained MnFe2O4particles. The materialshowed better adsorptive property than that of no KCl-assisted and can be used as amagnetically separatable adsobrent to treat CR solution. MnFe2O4can be easilyrecyled with external magnetic field and regeneration, it still maintained goodadsorption property after using several times.4. NiFe2O4Nanoparticles was successful prepared according to SSCS methodand the co-precipitaion route. It was found that the type and amount of fuel, theaddition of inert salt had important effect on the microstructure andcrystalline phases.The sample which was prepared with Na2CO3precipitant was nanoscale particles, itsdiameter was about50nm. In addition, the adsorption of MB and CR using differentsamples was studied reapectively, and found that samples prepared with differentmethod could selective adsorption different dyes, and recyle by external magneticfield as well.5. BiYO3photocatalysts were prepared via the co-precipitation method usingvarious precipitants, the effects of the precipitants and calcination temperature on thephotocatalytic activities and adsorptive properties of the BiYO3samples areinvestigated. BiYO3catalyst prepared with NH4OH as precipitant exhibit smallestcrystalline size and outstanding visible-light photocatalytic activities for RhB and MOdegradation in the presence of H2O2. Moreover, the sample prepared with Na2CO3precipitant displays the the highest dispersion, and the largest specific surface area.All the samples show higher adsorption capacity for CR than the other cationic dyes.