6 documents found, page 1 of 1
UV-assisted anchoring of gold nanoparticles into TiO2 nanotubes for oxygen elec...
Maltanava, Hanna; Mazheika, Semyon; Starykevich, Maksim; Gaevskaya, Tatiana; Konakov, Artem; Ferro, Marta; Tedim, João; Poznyak, SergeyGold nanoparticles (AuNPs) have been deposited on titania nanotubular layers (TNT) via photocatalytic deposition, and the activity of the obtained AuNPs-TNT systems toward oxygen electroreduction reaction (ORR) in an alkaline medium has been studied and compared with the activity of AuNPs TNT composites prepared from Au colloidal solutions. Two photodeposition methods were utilized for anchoring of AuNPs: direc...
Colloidal dendritic nanostructures of gold and silver for SERS analysis of wate...
Fernandes, Tiago; Fateixa, Sara; Ferro, Marta; Nogueira, Helena I. S.; Daniel-da-Silva, Ana L.; Trindade, TitoSurface-Enhanced Raman Scattering (SERS) using colloidal metal (Ag, Au) nanoparticles has been regarded as a powerful method for detecting organic pollutants at vestigial levels. Although less investi- gated, the controlled synthesis of binary nanostructures comprising two metals provides an alternative route to SERS platforms with tuned surface plasmon resonances. Here, we demonstrate that the use of dendrimer...
A general route for growing metal sulfides onto graphene oxide and exfoliated g...
Lopes, Joana L.; Estrada, Ana C.; Fateixa, Sara; Ferro, Marta; Trindade, TitoGraphene-based materials are elective materials for a number of technologies due to their unique properties. Also, semiconductor nanocrystals have been extensively explored due to their size-dependent properties that make them useful for several applications. By coupling both types of materials, new applications are envisaged that explore the synergistic properties in such hybrid nanostructures. This research r...
Photoluminescent Nanocrystals in a Multicomponent Aluminoborosilicate Glass
Ruivo, Andreia; Ferro, Marta; Andrade, Suzana M.; Rocha, Joao; Pina, Fernando; Laia, Cesar A. T.In this study, stable and nonexpensive aluminoborosilicate glasses with different photoluminescence colors were synthesized by doping with Pb(II), Ba(II) and sodium halides. While glasses with NaF and NaCl exhibit no (or very low) luminescence, glasses doped with NaBr and NaI display room-temperature photoluminescence at 435 and 530 nm, respectively. The observed room-temperature photoluminescence is attributed...
Synthesis and characterization of reduced graphene oxide/spiky nickel nanocompo...
Salimian, Maryam; Ivanov, Maxim; Deepak, Francis Leonard; Petrovykh, Dmitri Y.; Bdikin, Igor; Ferro, Marta; Kholkin, Andrei; Titus, Elby; Goncalves, GilThe surface modification of graphene oxide (GO) sheets with Ni nanoparticles has been a subject of intense research in order to develop new preeminent materials with increased performance for different application areas. In this work, we develop a new hydrothermal one-step method for the simple and controllable synthesis of reduced GO/nickel (GO/Ni) nanocomposites. Different reaction parameters have been invest...
The visible image is not always correct: the differentiation of layers by optic...
Barata, Carolina; Cruz, António João; Ferro, MartaThe stratigraphic characterization of polychrome surfaces in works of art is frequently done through the observation of cross-section samples by optical microscopy (OM). Three examples that show some limits to this method are presented here. In samples where at first only one layer was visible, several strata were detected through electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). These an...