Síntese, caracterização e atividade fotocatalítica do compósito NiWO4-paligorsquita na fotodegradação da pirazinamida sob irradiação policromática

Abstract

In this work, NiWO4 nanocomposites and NiWO4-Pal nanocomposites (2, 6 and 10%) were obtained by the coprecipitation method of treatment followed by treatment, photodegradation of the antibiotic antibiotic (PZA) pyrazinamide under polychromatic irradiation. X-ray diffraction (XRD) analysis associated with Rietveld refinement showed that NiWO4 nanocrystals and NiWO4-Pal nanocomposites (2, 6 and 10%) revealed a Wolframite-like monoclinic structure with the P2 / c space group. The active vibrational modes related to the characteristic groups of the samples were identified using Raman and Fourier Transform Infrared (FT-IR) spectroscopy. The morphology was identified by Scanning Electron Microscopy (SEM), obtaining an average particle size of NiWO4 nanocrystals of 20.83 nm. The photoluminescence spectrum (PL) revealed that NiWO4 and NiWO4-Pal (2%) present the highest recombination rate of the e-/h+ pair, and the contribution of the green component, which indicates a greater contribution of deep energy levels to the PL profile. Diffuse reflectance spectroscopy in the UV-Visible region indicated that NiWO4 nanocrystals have indirect band-gap energy (EBG) 2.63 eV, NiWO4-Pal (2, 6 and 10%) 2.61, 2.69, 2 .70 eV, and Pal 2.80 eV, respectively. The catalytic tests showed that the NiWO4-Pal nanocomposites (2%), under polychromatic radiation, present greater efficiency in photodegradation at 110 min, with a yield of 98.5%, respectively. In the study of reactive oxygen species, the results showed that all reactive PZA species play a similar role in PZA photodegradation.