Desenvolvimento de materiais do tipo LaCoO3, La0,7Sr0,3CoO3 e SrCoO3 pelo método proteico modificado para remoção do corante vermelho Bezaktiv em solução

Abstract

Mixed oxides with perovskite structure are widely known due to their redox, catalytic, magnetic and electrical properties and are applied in various sectors. Were synthesized in the present work LaCoO3, SrCoO3 and La0,7Sr0,3CoO3 perovskites through the modified protein method using gelatin as a chelating agent and subjected to calcination at 900 ºC. The materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FTIR), scanning electron microscopy (SEM), zero charge point (ZCP) and N2 adsorption at 77K techniques. The results showed the formation of the perovskite phase in the calcined samples, with the presence of some secondary phases in the materials, whereas FTIR spectra indicated that gelatin bands are not present in the samples calcined at 900 ºC. The modified protein method was efficient in obtaining materials with relatively high surface areas, compared to other synthesis methods. The dye was subjected to characterization techniques such as FTIR and CHN, the result of which was possible to identify bands related to reactive dyes and obtain the content of the amount of carbon, hydrogen and nitrogen present in the sample. The materials showed removal efficiency above in the range 47% to 93%. The experimental data were applied to the kinetic models pseudo first order, pseudo second order and variable constants and Langmuir and Freundlich adsorption isotherms. In the studies for reuse of adsorbents it has been proven that the perovskite structure remained, signaling its stability after adsorption and recovery conditions.