Plasmon-assisted spin transition in gold nanostar@spin crossover heterostructures

Aquí presentamos el diseño de nanopartículas core@shell formadas por un núcleo de nanoestrella de Au metálico y una capa cruzada de espín basada en el polímero de coordinación [Fe(Htrz)2(trz)](BF4). Este procedimiento es general y se ha extendido a otras morfologías metálicas (nanovarillas, nanotriángulos). Gracias al efecto fototérmico derivado de las propiedades plasmónicas de la nanoestrella de Au, el 60 % de los centros de hierro experimentan una transición de espín térmico dentro de la histéresis térmica provocada por una irradiación de baja intensidad con un láser de 808 nm. En comparación con otras morfologías de Au, la gran ventaja de la forma de nanoestrella surge de los puntos cal…

The design of magneto-plasmonic nanostructures formed by magnetic Prussian Blue-type nanocrystals decorated with Au nanoparticles.

Abstract: We have developed a general protocol for the preparation of hybrid nanostructures formed by nanoparticles (NPs) of molecule-based magnets based on Prussian Blue Analogues (PBAs) decorated with plasmonic Au NPs of different shapes. By adjusting the pH, Au NPs can be attached preferentially along the edges of the PBA or randomly on the surface. The protocol allows tuning the plasmonic properties of the hybrids in the whole visible spectrum.

Hybrid nanostructures based on gold nanoparticles and functional coordination polymers: Chemistry, physics and applications in biomedicine, catalysis and magnetism

During the last decade, the scientific community has become interested in hybrid nanomaterials, especially the ones that combine gold nanoparticles with a second functional component. In this context, coordination polymers are materials that possess potential advantages over conventional inorganic nanomaterials and organic compounds such as chemical versatility, easy processability, high specific area, low toxicity, biodegradability and electronic and magnetic functionalities to name a few. In this manner, the wise integration of Au nanoparticles with coordination polymers in different types of nanostructures has allowed extending the scope of properties and applications of these systems, a…

Improving the onset potential and Tafel slope determination of earth-abundant water oxidation electrocatalysts

To date, a plethora of electrocatalysts for the Oxygen Evolution Reaction (OER) have been proposed. For evaluating their electrocatalytic behavior the determination of the onset potential in each studied electrolyte is a key parameter. Nevertheless, this evaluation becomes particularly problematic for first- transition metal catalysts as well as by the use of electroactive collectors ( e.g. Ni foams) whose redox peaks overlap the onset potential. A usual solution to detect the onset potential requires the availabil- ity of in-situ mass spectrometric determination of the generated oxygen. In this work, we present fast and easier available cyclic voltammetry and coulovoltammetric responses to…

Design of Bistable Gold@Spin‐Crossover Core–Shell Nanoparticles Showing Large Electrical Responses for the Spin Switching

<p>A simple protocol to prepare core-shell gold@spin-crossover (Au@SCO) nanoparticles (NPs) based on the 1D spin-crossover [Fe(Htrz)<sub>2</sub>(trz)](BF<sub>4</sub>) coordination polymer is reported. The synthesis relies on a two-step approach consisting on a partial surface ligand substitution of the citrate-stabilized Au NPs followed by the controlled growth of a very thin layer of the SCO polymer. As a result, colloidally stable core@shell spherical NPs of 19 nm in size exhibiting a narrow distribution in sizes have been obtained, revealing a switchable SCOshell of <i>ca.</i>4 nm. Temperature-dependent charge transport measurements of an electri…

Core–Shell Nanoparticles: Design of Bistable Gold@Spin‐Crossover Core–Shell Nanoparticles Showing Large Electrical Responses for the Spin Switching (Adv. Mater. 27/2019)

Enhancing the electrocatalytic activity and stability of Prussian blue analogues by increasing their electroactive sites through the introduction of Au nanoparticles

Prussian blue analogues (PBAs) have been proven as excellent Earth-abundant electrocatalysts for the oxygen evolution reaction (OER) in acidic, neutral and alkaline media. Further improvements can be achieved by increasing their electrical conductivity, but scarce attention has been paid to quantify the electroactive sites of the electrocatalyst when this enhancement occurs. In this work, we have studied how the chemical design influences the specific density of electroactive sites in different Au-PBA nanostructures. Thus, we have first obtained and fully characterized a variety of monodisperse core@shell hybrid nanoparticles of Au@PBA (PBA of NiIIFeII and CoIIFeII) with different shell siz…