Preparation and characterization of zno/cuo semiconductor and photocatalytic activity on the decolorization of direct red 80 azodye

• WALLACE J. C. DA SILVA ^[1] ; MARCELO R. DA SILVA ^[2] ; KEIKO TAKASHIMA ^[1]
  1. [1] Universidade Estadual de Londrina Departamento de Química Laboratório deProcessos de Oxidação Avançados
  2. [2] Universidade Estadual Paulista Faculdade de Engenharia Colégio Técnico Industrial
• Localización: Journal of the Chilean Chemical Society (Boletín de la Sociedad Chilena de Química), ISSN-e 0717-6309, ISSN 0366-1644, Vol. 60, Nº. 4, 2015, págs. 2749-2751
• Idioma: inglés
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• Resumen

  • Zinc oxide, an n-type semiconductor, has been used as photocatalyst for contaminated water purification by organic compounds. The addition of a p-type semiconductor as copper oxide could increase the catalytic efficiency through the p-n junction in order to decrease the electron-hole recombination. In this work, zinc and copper oxides containing 1.0, 3.0, and 5.0 % of copper were prepared by manual grinding, followed by heat treatment at 300°C during 5 h. The zinc oxide and copper oxide mixture as well as their precursors were characterized by x-ray diffraction, diffuse reflectance, scanning electron microscopy, and x-ray fluorescence. The photocatalytic efficiency was verified by the direct red 80 tetraazodye decolorization using UV radiation under pseudo-first order conditions at natural pH (7.5-8.0) and 30 °C. The highest photocatalytic activity occurred to the semiconductor containing 1.0 % copper oxide, whose decolorization rate constant was equivalent to 6.40×10-2 min-1, that is, 17.4 % larger in comparison to ZnO, 5.45×10-2 min-1.