Brazilian Archives of Biology and Technology (Jul 2020)

Photocatalytic Degradation of Textile dye Orange-122 Via Electrospray Mass Spectrometry

  • Luiz Eduardo Nochi de Castro,
  • Eduardo César Meurer,
  • Helton José Alves,
  • Marco Aurélio Reis dos Santos,
  • Erika de Castro Vasques,
  • Leda Maria Saragiotto Colpini

DOI
https://doi.org/10.1590/1678-4324-2020180573
Journal volume & issue
Vol. 63

Abstract

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Abstract This work reports the study of the potential application of Zn/TiO2 catalysts, obtained by the sol-gel method, in processes of environmental decontamination through the reactions of photodegradation of textile dye, followed by electrospray mass spectrometry. The catalysts synthesis was performed according to a 2² factorial design with repetition at the central point. The characterization techniques used were: N2 adsorption measurements (BET method), scanning electron microscopy with energy dispersive X-ray (MEV/EDS), X-ray diffraction and point of zero charge (PZC). The photocatalytic tests were performed in batch in the presence of sunlight, and to evaluate the degradation kinetics study, a rapid direct injection electrospray mass spectrometry (DI-ESI-MS) method has been developed. By the photocatalytic tests, the calcination temperature of 400 °C has shown the best results of discoloration for the reactive Orange-122 dye (99.76%) in a reaction time of 2h. The discoloration kinetics were a pseudo-first order, and a statistical analysis was performed to investigate the effects of the variables and to optimize the conditions of discoloration to the dye. After the reactional time of 2 h, an ion of m/z 441.5 was detected by ESI-MS, indicating that the photocatalytic process was effective for the degradation of the dye to secondary compounds.

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