Nanoparticles of FeNbO₄ Produced by Microwave Assisted Combustion Reaction: a Potential Technology for the Treatment of Wastewater

Iron(III) niobate, FeNbO4, was synthesized for the first time by microwave-assisted combustion reaction between Fe(NO3)(3).9H(2)O and NH4[NbO(C2O4)(2)(H2O)(2)](H2O) in the presence of NH4NO3 and Urea {O=C(NH2)(2)}. Experiments of X-ray powder diffraction revealed a small crystallite size for this material, 16 nm, and the results of MEV showed that it forms agglomerates with diameters between 80 and 180 nm with spherical shapes. HRTEM images revealed that the material is formed by clusters of particles with a diameter near 20 nm. A surface area of 40 m(2)g(-1) was determined by experiments of specific surface area (SSA). The FeNbO4 induced the decomposition of H2O2, forming radicals that, in turn, discoloured Indigo dye Carmine (IC) a solution. The results showed that this niobate was able to degrade 55% of the initial solution in the presence of H2O2 after 360 minutes of reaction time.