Search for: All records

Controlled growth of islands on plasmonic metal nanoparticles represents a novel strategy in creating unique morphologies that are difficult to achieve by conventional colloidal synthesis processes, where the nanoparticle morphologies are typically determined by the preferential development of certain crystal facets. This work exploits an effective surface-engineering strategy for site-selective island growth of Au on anisotropic Au nanostructures. Selective ligand modification is first employed to direct the site-selective deposition of a thin transition layer of a secondary metal, e.g., Pd, which has a considerable lattice mismatch with Au. The selective deposition of Pd on the original seeds produces a high contrast in the surface strain that guides the subsequent site-selective growth of Au islands. This strategy proves effective in not only inducing the island growth of Au on Au nanostructures but also manipulating the location of grown islands. By taking advantage of the iodide-assisted oxidative ripening process and the surface strain profile on Au nanostructures, we further demonstrate the precise control of the islands’ number, coverage, and wetting degree, allowing fine-tuning of nanoparticles’ optical properties. 

The nonradiative conversion of light to heat by plasmonic nanostructures, the so‐called plasmonic photothermal effect, has attracted enormous attention due to their widespread potential applications. Herein, the perspectives on the design and preparation of plasmonic nanostructures for light to heat or photothermal conversion are provided. The general principle of plasmonic photothermal conversion is first introduced, and then, the strategies for improving efficiency are discussed, which is the focus of this field. Then, five typical application types are used, including solar energy harvesting, photothermal actuation, photothermal therapy, laser‐induced color printing, and high‐temperature photothermal devices, to elucidate how to tailor the nanomaterials to meet the requirements of these specific applications. In addition to the photothermal effect, other unique physical and chemical properties are coupled to further explore the application scenarios of plasmonic photothermal materials. Finally, a summary and the perspectives on the directions that may lead to the future development of this exciting field are also given.

 

Engineering the nucleation and growth of plasmonic metals (Ag and Au) on their pre‐existing seeds is expected to produce nanostructures with unconventional morphologies and plasmonic properties that may find unique applications in sensing, catalysis, and broadband energy harvesting. Typical seed‐mediated growth processes take advantage of the perfect lattice match between the deposited metal and seeds to induce conformal coating, leading to either simple size increases (e.g., Au on Au) or the formation of core–shell structures (e.g., Ag on Au) with limited morphology change. In this work, we show that the introduction of a thin layer of metal with considerable lattice mismatch can effectively induce the nucleation of well‐defined Au islands on Au nanocrystal seeds. By controlling the interfacial energy between the seed and the deposited material, the oxidative ripening, and the surface diffusion of metal precursors, we can regulate the number of islands on the seeds and produce complex Au nanostructures with morphologies tunable from core‐satellites to tetramers, trimers, and dimers.

 

Engineering the nucleation and growth of plasmonic metals (Ag and Au) on their pre‐existing seeds is expected to produce nanostructures with unconventional morphologies and plasmonic properties that may find unique applications in sensing, catalysis, and broadband energy harvesting. Typical seed‐mediated growth processes take advantage of the perfect lattice match between the deposited metal and seeds to induce conformal coating, leading to either simple size increases (e.g., Au on Au) or the formation of core–shell structures (e.g., Ag on Au) with limited morphology change. In this work, we show that the introduction of a thin layer of metal with considerable lattice mismatch can effectively induce the nucleation of well‐defined Au islands on Au nanocrystal seeds. By controlling the interfacial energy between the seed and the deposited material, the oxidative ripening, and the surface diffusion of metal precursors, we can regulate the number of islands on the seeds and produce complex Au nanostructures with morphologies tunable from core‐satellites to tetramers, trimers, and dimers.

 

Solar steam generation technologies have gained increasing attention due to their great potential for clean water generation with low energy consumption. The rational design of a light absorber that can maximize solar energy utilization is therefore of great importance. Here, the synthesis of Ni@C@SiO₂core–shell nanoparticles as promising light absorbers for steam generation by taking advantage of the plasmonic excitation of Ni nanoparticles, the broadband absorption of carbon, and the protective function and hydrophilic property of silica is reported. The nanoparticle‐based evaporator shows an excellent photothermal efficiency of 91.2%, with an evaporation rate of 1.67 kg m⁻² h⁻¹. The performance can be further enhanced by incorporating the nanoparticles into a polyvinyl alcohol hydrogel to make a composite film. In addition, utilizing the magnetic property of the core–shell particles allows the creation of surface texture in the film by applying an external magnetic field, which helps increase surface roughness and further boost the evaporation rate to as high as 2.25 kg m⁻² h⁻¹.