Síntese, caracterização e efeito da atividade fotocatalítica de nanocristais de óxido de zinco dopado com cobre e nanocompósitos de óxido de zinco dopado com cobre/óxido de cobre na degradação do 17-α-Metiltestosterona em meio aquoso

Abstract

The presence of hormones in water bodies creates health problems in humans, disturbs the ecosystem and pollutes groundwater. With the high cost of wastewater treatment with emerging pollutants (EPs), the development of capable and efficient technologies for the treatment of these pollutants is necessary. In this context, the present work evaluated the photocalytic action of Zinc Oxide (ZnO) doped with Copper (Cu), in different proportions, in the removal of 17-α- Methyltestosterone hormone, used in fish farming for sexual inversion of fish. To this end, four materials of mixed ZnO/Cu composition were synthesized. Factors such as doping concentration (ZnO:0.1Cu, ZnO:0.4Cu, ZnO:1.0Cu and ZnO:4.0Cu), mass (0.01, 0.02 and 0.04 g) and hydrogen peroxide (H2O2) (0.05, 0.1, 0.5 and 1.0 mmol) were evaluated. Among the parameters analyzed, all showed that a lower doping/mass/H2O2 achieves a significant efficiency in the final results. For the mass the fact was associated with the 'protective' effect created in the solution, through the particles, preventing the penetration of the ultraviolet (UV) light irradiation; In the H2O2 evaluation the higher the concentration, the lower the efficiency, which was explained by an excess caused in the medium, where parallel reactions, capture of • OH and production of radicals less reactive than hydroxyl radicals, are favored. In doping effects, possibly, the fact of reduced crystallinity for higher concentrations affected the efficiency of the reactions. Thus, a 92.54% removal percentage of 17-α-Methyltestosterone hormone degradation was obtained using ZnO:0.1Cu with mass of 0.01 g and 0.05 mmol of H2O2 in the reaction medium.