Structural investigations of Au-Ni aerogels: morphology and element distribution

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

Abstract

The physical properties of nanomaterials are determined by their structural features, making accurate structural control indispensable. This carries over to future applications. In the case of metal aerogels, highly porous networks of aggregated metal nanoparticles, such precise tuning is still largely pending. Although recent improvements in controlling synthesis parameters like electrolytes, reductants, or mechanical stirring, the focus has always been on one particular morphology at a time. Meanwhile, complex factors, such as morphology and element distributions, are studied rather sparsely. We demonstrate the capabilities of precise morphology design by deploying Au-Ni, a novel element combination for metal aerogels in itself, as a model system to combine common aerogel morphologies under one system for the first time. Au-Ni aerogels were synthesized via modified one- and two-step gelation, partially combined with galvanic replacement, to obtain aerogels with alloyed, heterostructural (novel metal aerogel structure of interconnected nanoparticles and nanochains), and hollow spherical building blocks. These differences in morphology are directly reflected in the physisorption behavior, linking the isotherm shape and pore size distribution to the structural features of the aerogels, including a broad-ranging specific surface area (35-65 m2 g-1). The aerogels were optimized regarding metal concentration, destabilization, and composition, revealing some delicate structural trends regarding the ligament size and hollow sphere character. Hence, this work significantly improves the structural tailoring of metal aerogels and possible up-scaling. Lastly, preliminary ethanol oxidation tests demonstrated that morphology design extends to the catalytic performance. All in all, this work emphasizes the strengths of morphology design to obtain optimal structures, properties, and (performances) for any material application.Novel Au-Ni aerogels have been successfully synthesized in common metal aerogel morphologies: alloys, heterostructures and hollow spheres. The morphological features and structural trends were related to the physicochemical and catalytic properties.

Details

OriginalspracheEnglisch
Seiten (von - bis)5487-5498
Seitenumfang12
FachzeitschriftNanoscale advances
Jahrgang5 (2023)
Ausgabenummer20
Frühes Online-Datum15 Sept. 2023
PublikationsstatusVeröffentlicht - 10 Okt. 2023
Peer-Review-StatusJa

Externe IDs

PubMed 37822903
Scopus 85172216453

Schlagworte

Schlagwörter

  • Oxygen reduction, Gold nanoparticles, Metallic aerogels, Core-shell, Ethanol electrooxidation, Hollow nanoparticles, Dielectric-constants, Catalytic-activity, Nitrogen sorption, Nickel