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In this research, the effect of temperature and concentration of bismuth nitrate mole on structural, magnetic and photocatalytic properties of the bismuth ferrite nanoparticles prepared by nitrate-citrate method have been investigated. The structural and magnetic properties were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and vibrating-sample magnetometer at room temperature. An important role in the synthesis of pure bismuth ferrite is played by temperature and excess bismuth oxide. Analysis of XRD patterns and FTIR data indicate that to obtain the pure bismuth ferrite, a stoichiometric amount of bismuth nitrate mole in solution and sintering at temperature 650 °C is needed. The magnetic and photocatalytic results have showed that the presence of the impurity phases led to strong ferromagnetic behavior in samples, but has a negative effect on the photocatalytic properties of bismuth ferrite.

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Bahramtaj Pb-Zn deposit is located about 90 km NW of Yazd, central Iran. The area has been located in Central Iran geotectonic zone and hosted in dolomitic limestone of Paleozoic age. The purpose of this research is to investigate Zincian-dolomite as one of the important effects of the alteration process. Zincian-dolomite as a non-sulfide zinc mineral is characterized by a different amount of Zn, as well as lower amounts of Pb,Cu, and rarely Cd. Characterization of Zn-bearing dolomite, using differential thermal analysis, shows a drop in temperature of the first endothermic reaction of dolomite decomposition with increasing Zn contents in dolomite. The substitution of dolomite by zincian-dolomite supergene is known as a part of a multi-stage mineralization process in Bahramtaj, which begins with the development of the zincian-dolomite process and continues with the dolomitization of the previous dolomites, and finally results formation of zinc non-sulfide minerals such as smithsonite and hemomorphite.

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This study have been developed BiFeO₃/reduced graphene oxide (BFO/RGO) nanocomposites by introduction of RGO in the structure of BFO nanoparticles in a short term ultrasonic treatment. The X-ray diffraction pattern and Fourier-transform infrared spectroscopy analysis reveal that the BFO/RGO composites were successfully synthesized. UV-visible absorption show that the introduction of RGO can effectively reduce the recombination of photo-generated electron and hole pairs and the lower band gap energies were also identified for BFO/RGO composites as compared to 1.97 eV for BFO. The photocatalytic performance of BFO/RGO nanocomposites is stable and exhibit considerably higher photocatalytic ability over the pristine BFO for the degradation of methyl orange solution under visible light irradiation. The possible mechanism behind the superior photocatalytic performance of BFO/RGO nanocomposite has been critically discussed.