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Artigo Produção Nacional Revisado por pares
BIBTEX RIS

Fast and efficient green synthesis of CaWO4 NPs using eggshells as a biogenic calcium source: Structure, optical property, and morphology

2023; Elsevier BV; Volume: 439; Linguagem: Inglês

10.1016/j.jphotochem.2023.114589

ISSN

1873-2666

Autores

Francisco Xavier Nobre, O.C. Mendes, A.P.J. da Silva, J.L.S. Junior, Marcus Valério Botelho do Nascimento, Wanison A.G. Pessoa, Lizandro Manzato, Ayrton de Sá Brandim, José Milton Elias de Matos, Walter Ricardo Brito, Paulo Rogério da Costa Couceiro, Y. Leyet,

Tópico(s)

Crystal Structures and Properties

Resumo

In summary, we report a fast, easy, and low-cost green synthesis approach to obtain calcium tungstate nanoparticles (CaWO4NPs_GS) using eggshells as a source of calcium by the sonochemistry method at room temperature. These nanomaterials were structurally characterized by X-ray diffraction (XRD) and Rietveld refinement analysis, where a pure phase with very close structural parameters with calcium tungstate nanoparticles was synthesized at the conventional route (CaWO4NPs_CS). All vibrational Raman active modes characteristic of symmetry point C4h6 were confirmed. An optical band gap value (Egap = 3.92(2) eV) for CaWO4NPs_GS lower than for CaWO4NPs_CS (Egap = 3.92(2) eV) was archived, and that is associated with the intermediate electronic levels due to the oxygen vacancy and micro-strain effect. Field Emission Scanning Electron Microscopy (FE-SEM) images show several nanoparticles with a particle size of 62.7 ± 1.3 nm for CaWO4NPs_CS and 48.7 ± 1.2 nm for CaWO4NPs_GS, where all elements characteristic of calcium tungstate (Ca, W, and O) were appointed by Energy Dispersive X-ray (EDX) analysis. While the photocatalytic performance of CaWO4NPs_GS was 2.5 times faster than CaWO4NPs_CS in the photodegradation of Rhodamine B (RhB) dye in an aqueous solution under UV light in 120 min. Therefore, confirming that chicken eggshell is a promissory raw material as a biogenic source of calcium ions for synthesizing calcium tungstate with promissory photocatalytic properties.

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