masterThesis
Síntese de ferrita de níquel por coprecipitação com deposição simultânea em vidro e desenvolvimento de reator fotocatalítico
Fecha
2020-08-14Registro en:
LOUREDO, Gustavo Henrique. Síntese de ferrita de níquel por coprecipitação com deposição simultânea em vidro e desenvolvimento de reator fotocatalítico. 2020. 123f. Dissertação (Mestrado em Engenharia Química) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2020.
Autor
Louredo, Gustavo Henrique
Resumen
The search for new routes for sustainable fuel production that reduce
dependence on fossil fuels, are environmentally friendly, and are economically profitable has
fostered studies on photocatalytic processes that enable the production of hydrogen on a large
scale and in a safe way, with a high conversion rate and the lowest possible cost. In this
context, this work was conducted around the theme seeking to develop a low-cost
photocatalytic system and, simultaneously, to understand the process of production and
simultaneous deposition of nickel ferrite (NiFe2O4) on soda-lime glass. For this, the
coprecipitation method was chosen with simultaneous deposition during the drying and
calcination step, which took place at 600 ° C. The 2³ central composite experimental design
was to assess the influence of synthesis parameters on the characteristics of the catalyst. The
statistical analysis was developed around the independent variables nickel concentration in
the reactive solution (1: 2 of Ni: Fe), time at the isotherm of calcination and heating rate, and
being analyzed the response variables: crystallite size and microdeformation, obtained
through XRD analysis, and optical band gap, of which only the first presented statistical
significance through the F test, with the concentration and heating rate having a positive and
negative effect on the crystallite size, respectively. The crystallite sizes were calculated
considering three equations: Scherrer, Halder-Wagner-Langford, and Williamson-Hall, of
which the second had the best R² (0.9847 ± 0.0166) with sizes ranging from 17.40 nm to
28.33 nm, while the optical band gap varied between 1.9644 eV and 2.2374 eV. The
macroscopic analysis of the images of the produced photocatalytic plates demonstrated
greater homogeneity and quantity of material in those produced in higher concentrations (0.4
mol Ni) when compared to the others, while by scanning electron microscopy the images
demonstrated that the crystals apparently have a spherical morphology and the cluster in
quadratic structures of a certain height and with a flat surface. The photoreaction system
showed functionality in the process for hydrogen production, with the need for improvements
in the sealing system, gas extraction and quantification of these.