Síntese de nanopartículas magnéticas de Fe3O4@TiO2-Nd para degradação fotocatalítica de cloridrato de propranolol em meio aquoso

Abstract

Propranolol hydrochloride is a drug widely used for the treatment of hypertension, arrhythmias, ischemic heart disease and migraines. Due to the fact that this drug has potential for toxicity and has been detected in rivers and sea water, processes for the removal of this contaminant are being developed and evaluated. Advanced Oxidative Processes (AOPs) hold great promise in providing treatment alternatives to reduce pharmaceutical residue concentrations and meet acceptable limitations. Heterogeneous photocatalysis involves the presence of semiconductors capable of promoting the complete oxidation of both organic (rhodamine B and methylene blue) and inorganic (chloride, nitrate and sulfate ions) species, due to the production of highly reactive chemical species, when semiconductors are induced by solar or ultraviolet radiation. In this sense, the objective of this work was to synthesize Fe3O4@TiO2-Ndx% core-shell nanoparticles, with different concentrations of neodymium (0.00 to 1.00%), at lower concentrations it can decrease the recombination of the electron/hole pair and to reduce the band gap energy of titanium dioxide, extending its use in the visible region, in order to apply it in the degradation of propranolol hydrochloride in aqueous media, using a photocatalytic process with UV and visible radiation. The characterizations performed (XRD, FTIR, VIBRANT SAMPLE MAGNETOMETRY, EPR, UV-Vis DRS, MEV-EDS and HRTEM). The XRD results showed that the co-precipitation and hydrothermal methods were able to form nanometric clusters consisting mainly of the crystalline phases of magnetite, goethite for the Fe3O4 core and anatase for the TiO2 shell. In addition, the samples showed higher magnetization measurements in the particles containing Fe3O4 and lower intensity in the samples coated with TiO2, as well as changes in the band gap of the nanoparticles when in the presence of TiO2. Photocatalytic tests under radiation in the UV region led to complete drug degradation in 60 min, while in studies in the visible light region, the contaminant degradation reached 52% when Fe3O4@TiO2-Nd 0.10% nanoparticles were used.