Banca de QUALIFICAÇÃO: WALLONILSON VERAS RODRIGUES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: WALLONILSON VERAS RODRIGUES
DATA: 09/03/2020
HORA: 14:30
LOCAL: Auditório do PPGQ
TÍTULO: Structural reorganization of CuO/Cu2[Fe(CN)6] nanocomposite: characterization and electrocatalitic effect for the hydrogen peroxide reduction
PALAVRAS-CHAVES: nanocomposite, Prussian blue analogue, supramolecular properties, hydrogen peroxide.
PÁGINAS: 25
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Inorgânica
ESPECIALIDADE: Físico Química Inorgânica
RESUMO:

The investigation of the structural, spectroscopic and electrochemical properties of new nanocomposites opens perspectives for the development of new functional devices for nanomedicine applications. In this work, we report a comprehensive study for CuO/Cu₂[Fe(CN)₆] nanocomposite formation, which was obtained from copper oxide nanoparticles (CuO NPs) and Prussian Blue precursors species. The UV-vis analysis indicated that Cu²⁺ ions are released from CuO NPs (in excess) and Fe^{3 +} species were adsorbed on the crystal structure of CuO, due to the high increase in zeta potential (of -30 to 0 mV) after formation of the Cu₂[Fe(CN)₆] complex. The EDS spectrum also confirmed that Fe³⁺ species trapped in the CuO NPs structure. The CuO/Cu₂[Fe(CN)₆] nanocomposite exhibited the monoclinic and face-centred cubic phases that correspond to the CuO and Cu₂[Fe(CN)₆] components. Based on the TEM results, CuO/Cu₂[Fe(CN)₆] nanocomposite presented a polydisperse distribution with well-defined CuO rods and Cu₂[Fe(CN)₆] spherical shpaes. Cyclc voltammetry for nanocomposite modified electrode revealed two well-defined redox couples at - 0.073 ((E_1/2)₁) and 0.664 mV ((E_1/2)₂) attributed to the conversion of the Cu²⁺ to Cu⁺ and CuFe²⁺ to CuFe³⁺ pairs, respectively, which are similar to those of CuO and Cu₂[Fe(CN)₆] components. The catalytic activity toward hydrogen peroxide (H₂O₂) in nanocomposite was also investigated using cyclic voltammetry, where reduction of H₂O₂ led to increased currents for the electrochemical process associated with the first redox pair, while for isolated materials (CuO NPs and Cu₂[Fe(CN)₆]) only a slight effect for both redox pairs was observed.

MEMBROS DA BANCA:
Interno - 1998602 - EVERSON THIAGO SANTOS GERONCIO DA SILVA
Interno - 1714171 - JANILDO LOPES MAGALHAES
Interno - 794.918.553-87 - REGINALDO DA SILVA SANTOS - UESPI
Presidente - 1508806 - WELTER CANTANHEDE DA SILVA