Preparation, Functionality, and Application of Metal Oxide‐coated Noble Metal Nanoparticles

Abstract

With their remarkable properties and wide-ranging applications, nanostructures of noble metals and metal oxides have been receiving significantly increased attention in recent years. The desire to combine the properties of these two functional materials for specific applications has naturally prompted research in the design and synthesis of novel nanocomposites, consisting of both noble metal and metal-oxide components. In this review, particular attention is given to core-shell type metal oxide-coated noble metal nanostructures (i.e., metal@oxide), which display potential utility in applications, including photothermal therapy, catalytic conversions, photocatalysis, molecular sensing, and photovoltaics. Emerging research directions and areas are envisioned at the end to solicit more attention and work in this regard.

One-pot one-step synthesis of Au@SiO2 core–shell nanoparticles and their shell-thickness-dependent fluorescent properties

“…Noble metal@oxide core-shell nanostructures have attracted much attention [1][2][3] due to their unique properties and promising applications in catalysis, 2 solar cells, 4,5 biomedical materials, 6 environmental remediation, 7 and sensors. 8 Among various noble metal@oxide core-shell nanostructures, gold@silica (Au@SiO 2 ) core-shell nanoparticles (NPs) are probably most studied because of the synergetic properties of Au NPs and silica shells.…”

Silica‐Coated Plasmonic Metal Nanoparticles in Action

“…Since the first reports on gold/silica hybrid nanoparticles were published over two decades ago, [81][82][83] a plethora of protocols for core-shell particle synthesis have been devised, granting access to almost every imaginable noble metal/metal oxide combination, as well as to many different morphologies. [3] Instead of recapturing in detail the manifold developments in this mature field, we restrict ourselves to a brief overview of the well-established synthesis strategies for the growth of both dense and porous silica shells. For a comprehensive survey of the available procedures the reader is kindly referred to recent review articles.…”

“…[2] In the context of modern 'craftsmanship', the synthesis and application of individual plasmonic colloids encapsulated in silica shells or, more general, metal oxide shells with thicknesses ranging from few nanometers to potentially over a hundred nanometers, have attracted tremendous interest during the last two decades. [3] The reason for the vast amount of research dedicated to the development of such nanohybrids is the plain and simple fact that bare metal nanoparticles are poorly suited for many practical applications: while a wide range of scalable synthetic methods are available for the preparation of well-defined plasmonic nanostructures such as spheres, [4,5] rods, [6,7] triangles, [8] stars, [9] cubes, [10] or polyhedra, [11] the harsh conditions required for many applications can severely undermine all efforts to tailor particle properties, inducing aggregation, etching, or other undesired effects. To improve the manipulation of plasmonic particles and facilitate their integration into sensors, photovoltaics cells, catalysts or other functional devices, coating with rigid shells of a chemically inert material such as silica has become a prominent approach.…”

Fabrication of Mesoporous Titania Nanoparticles with Controlled Porosity and Connectivity for Studying the Photovoltaic Properties in Perovskite Solar Cells

“…Even though there is improved interfacial contact of perovskite with highly porous TiO 2 , other factors may also play crucial roles in elevating photovoltaic performance. Thus far, efforts have been made to investigate the influence of porosity, crystallinity, morphology and size of TiO 2 nanoparticles on mesoporous film formation and related device performance.…”

“…This research provides a critical understanding in controlling morphology, size and crystallinity of mesoporous TiO 2 nanoparticles together their porosity, connectivity and conductivity in films for studying the photovoltaic properties in perovskite solar cells. In addition, the direct growth of mesoporous TiO 2 nanoparticles with plasmonic nanostructures will be an alternative way to explore more opportunity in understanding and enhancing photovoltaic performance ,…”