Synthesis Of Nano-zinc Ferrite Via Hydrothermal Synthesis Route And Study On Their Photocatalytic Properties

Spinel Nano-zinc ferrite has potential applications in many areas, such as magneticmaterials, high temperature materials, gas sensing materials and semiconductor photocatalysts,beacause of its unique physical and chemical properties.Pure spinel ZnFe2O4nanoparticles with different structures and different specific surfaceareas have been synthesized via hydrothermal synthesis route in the presence of differentorganic carboxylic acids as additives. The as-prepared samples were characterized by FT-IR,powder X-ray diffraction, UV-visible diffuse reflectance spectroscopy, energy dispersiveX-ray spectroscopy, X-ray photoelectron spectroscopy, nitrogen adsorption-desorption,scanning transmission electron microscopy and transmission electron microscopy. The resultsshowed that spinel ZnFe₂O₄could be prepared at180°C for48h with mesoporous structure.The ZnFe₂O₄samples have particle sizes of8.4-15.9nm and surface areas of44.5-99.6m2/gin pure phase.Photocatalytic properties of the selected three different ZnFe₂O₄materials with differentsurface areas were investigated to determine their visible-light induced degradation ofrhodamin B. The influences of reaction conditions such as initial concentration of rhodaminB, and catalyst dosage have important effect on the degradation efficiency of rhodamin B.When rhodamin B with its initial concentration of10mg/L and the catalysts with1.50g/L,the catalysts showed good catalytic properties. The ZnF₂O₄sample with specific surface areaof60.5m²/g and particle size of12.8nm showed the degradation of rhodamin B with97.5%efficiency in40min, which was better than the catalyst with surface area of91.0m2/g andparticle size of10.2nm. The photocatalytic performance of the ZnFe2O4materials wasattributed to the synergetic effects of the particle size, crystallinity, porosity, and thevariations of local structures.Further studies revealed that these three selected ZnFe₂O₄samples have great catalyticstability and reproducibility, indicating from the good catalytic performance （>95%） ofdegradation of rhodamine B after repeated use for three times. The results from our studysuggest that the ZnFe₂O₄with suitable particle size, pore size distribution and specific surfaceareas will have potentially application for treatment of the organic dyes in pollution water.