Síntese de Hidróxido de Índio (III) substituído parcialmente por Zn+2 com propriedades fotocatalíticas e Ag+ com propriedades bactericidas

Abstract

Currently is being investigated a new class of inorganic materials occurring as a promising option with high performance in different applications, such as photocatalytic and bactericidal. The Hydroxide of Indium (III) is a semiconductor that performs well in optical properties and have generated intense research to understand new applications. The doping of semiconductors with different elements is known to greatly affect many of their basic properties. To obtain the desired properties, currently many researchers study synthesis of pure semiconductors and doped, in a the wide variety of materials. In this work, crystal structures of pure indium hydroxide and doped zinc ions and silver ions were synthesized by hydrothermal method assisted by microwave (MAH) using hydrothermal treatment level of 30 minutes. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy, with field emission (SEM-FEG), photoluminescence (PL) and UV-visible (UV-vis). To verify the applicability were conducted on samples In1-x(OH)3Znx photocatalytic test and samples the In1-x(OH)3Agx bactericidal test. The results of X-ray diffraction confirmed the formation of cubic phase of In(OH)3 even with the maximum level of doping (0,04 Zn2+ and 0,04 Ag+). SEM pictures showed that the samples of pure In(OH)3 exhibits morphology in the form of cubes with different sizes of particles, since at the samples doped with Zn2+ and Ag+ ions were no significant changes in morphology compounds having aggregate with different sizes of particles. The photoluminescence spectra show decrease in intensity with increased concentration of Zn2+ ions in the host matrix, since the samples doped with 0,02 and 0,04 Ag+ ions have a redshift. The reflectance spectra of UV-vis indicated that doping with Zn2+ and Ag+ ions caused a decrease in the band gap with increasing doping of 0 to 0,04 Zn2+/Ag+. In the photocatalytic test sample of In1-x(OH)3Znx (x=0,04) the rhodamine dye (RhB) degraded in about 16 minutes under UV irradiation. The samples pure In(OH)3 dye degraded after 30 minutes under UV irradiation. These results indicated that even without doping, the efficiency of this semiconductor in photodegradation of rhodamine B (RhB) is high. The bactericidal activity of the sample In1-x(OH)3Agx was evaluated using Gram negative bacteria (Escherichia coli) and Gram positive (Staphylococcus aureus). The presence of a zone of inhibition clearly shows the antibacterial effect of Ag+ doped samples for both types of bacteria (E. coli and S. aureus), while samples of pure In(OH)3 show no antibacterial effect.