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Abstract Facet‐selective etching and deposition, as determined by the landscape of surface energy, represent two powerful methods for the transformation of noble‐metal nanocrystals into nanostructures with complex shapes or morphologies. This review highlights the use of these two methods, including integration of them, for the fabrication of novel monometallic and bimetallic nanostructures with enhanced properties. We start with an introduction to the role of surface capping in controlling the facet‐selective etching or deposition on the surface of Ag nanocrystals, followed by a case study of how to maneuver etching and deposition at different facets of Pd nanocrystals for the fabrication of nanoframes. We then introduce the use of galvanic replacement to accomplish selective etching and deposition on two different facets in an orthogonal manner, transforming Pd nanocubes into Pd−Pt octapods. By complementing galvanic replacement with a chemical reduction reaction, it is also feasible to control the rates of these two reactions for the conversion of Ag nanocubes into Ag@Ag−Au concave nanocubes and Ag@Au core‐shell nanocubes. These transformation methods not only greatly increase the shape diversity of metal nanocrystals but also offer nanocrystals with enhanced plasmonic and/or catalytic properties.
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Dynamically Switchable Multicolor Electrochromic Films
Abstract The dynamic optical switch of plasmonic nanostructures is highly desirable due to its promising applications in many smart optical devices. To address the challenges in the reversibility and transmittance contrast of the plasmonic electrochromic devices, here, a strategy is reported to fabricate color switchable electrochromic films through electro‐responsive dissolution and deposition of Ag on predefined hollow shells of Au/Ag alloy. Using the hollow Au/Ag alloy nanostructures as stable seeds for site‐specific deposition of Ag, elimination of the random self‐nucleation events is enabled and optimal reversibility in color switching is allowed. The hollow structure further enables excellent transmittance contrast between the bleached and colored states. With its additional advantages such as the convenience for preparation, high sensitivity, and field‐tunable optical property, it is believed that this new electrochromic film represents a unique platform for designing novel smart optical devices.
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- Award ID(s):
- 1808788
- PAR ID:
- 10462869
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- Volume:
- 15
- Issue:
- 7
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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