Investigation of the Fe-Mo electrodeposition from sorbitol alkaline bath and characterization of the films produced

Autor(es)

Zacarin, Maria G. ^[1] ; de Brito, Matheus M. ^[1] ; Barbano, Elton P. ^[1] ; Carlos, Rose M. ^[1] ; Mastelaro, Valmor R. ^[2] ; Carlos, Ivani A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Chem, CP 676, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Inst Phys Sao Carlos, CP 369, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Alloys and Compounds; v. 750, p. 577-586, JUN 25 2018.
• Citações Web of Science: 2

Resumo

The electrodeposition of Fe-Mo alloys from an alkaline solution containing sorbitol as the complexing agent for Fe(III) ions was studied. XRD analysis of the film produced by reduction of {[}MoO4](2-) anions at a copper substrate showed the formation of MoO2. The presence of the intermediate Fe(II) species was detected by electrolysis from an Fe-Mo solution and Visible spectroscopy of the final solution in the presence of 1,10-phenanthroline. The Visible spectrum showed a broad absorption (lambda(max) = 514 nm) typical of the {[}Fe(phen)(3)](2+) complex. Under our conditions, the Fe-Mo alloy was formed from reduction of {[}Fe(OH)(2)(C6H12O6)(2)](3-) to {[}Fe(OH)(2)(C6H12O6)(2)](4-), reduction of {[}MoO4](2-) to molybdenum (IV) oxide/hydroxide and its further reduction to Mo-0 concomitant with {[}Fe(OH)(2)(C6H12O6)(2)](4-)ads to Fe-0. Photomicrographs of the Fe-Mo electrodeposits produced with q(d) 5.30Ccm(-2) showed that they were smooth or contained cracks, depending on the deposition potential (E-d). Chemical composition analysis by EDXS of Fe-Mo electrodeposits (q(d) 5.30Ccm(-2)) showed that deposits containing 5.5 at% (18.8 wt%) Mo could be produced at E-d -1.40 V and similar values were obtained at more negative potentials. X-Ray diffraction indicated that the Fe-Mo coatings were composed of Fe3Mo and Fe2MoO4 phases, regardless of Ed. The presence of the Fe2MoO4 phase on the sample surface could explain the observation of Fe2+ and Mo4+ states by XPS, although the occurrence of others crystalline oxide phases, such as FeMoO4 and Fe-2(MoO4)(3) could not be discarded. The crystal size value varied from similar to 47 nm to similar to 37 nm, when Ed changed to more negative values. (C) 2018 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 08/57652-1 - Estudos eletroanalíticos do processo de eletrodeposição da liga Cu-Sn obtida a partir de banho não cianetado: caracterização morfológica, química e estrutural dos eletrodepósitos
• Beneficiário: Ivani Aparecida Carlos
• Modalidade de apoio: Auxílio à Pesquisa - Regular