1
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Shi Y, Elnabawy AO, Gilroy KD, Hood ZD, Chen R, Wang C, Mavrikakis M, Xia Y. Decomposition Kinetics of H2O2 on Pd Nanocrystals with Different Shapes and Surface Strains. ChemCatChem 2022. [DOI: 10.1002/cctc.202200475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yifeng Shi
- Georgia Institute of Technology Chemical and Biomolecular Engineering UNITED STATES
| | - Ahmed O Elnabawy
- University of Wisconsin-Madison Chemical and Biological Engineering UNITED STATES
| | - Kyle D Gilroy
- Georgia Institute of Technology The Wallace H. Coulter Department of Biomedical Engineering UNITED STATES
| | - Zachary D Hood
- Georgia Institute of Technology Chemistry and Biochemistry UNITED STATES
| | - Ruhui Chen
- Georgia Institute of Technology Chemistry and Biochemistry UNITED STATES
| | - Chenxiao Wang
- Georgia Institute of Technology Chemistry and Biochemistry UNITED STATES
| | - Manos Mavrikakis
- University of Wisconsin-Madison Chemical and Biological Engineering UNITED STATES
| | - Younan Xia
- Georgia Institute of Technology Biomedical Engineering 901 Atlantic DriveMoSE 3100J 30332 Atlanta UNITED STATES
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2
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Qiu J, Xie M, Lyu Z, Gilroy KD, Liu H, Xia Y. General Approach to the Synthesis of Heterodimers of Metal Nanoparticles through Site-Selected Protection and Growth. Nano Lett 2019; 19:6703-6708. [PMID: 31449753 DOI: 10.1021/acs.nanolett.9b03167] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Heterodimers of metal nanoparticles are widely sought for applications in photonics, sensing, and catalysis. In this work, we demonstrate a general approach to the fabrication of heterodimers of metal nanoparticles by leveraging the concept of site-selected growth under the protection of an inert material. When styrene is polymerized in the presence of Au nanoparticles, the resultant polystyrene (PS) can be controlled to grow from only one portion of the surface of a nanoparticle. Free of PS, the remaining portion can serve as an active site for the heterogeneous nucleation and growth of the second metal. After dissolving the PS component, we obtain heterodimers of metal nanoparticles with tunable elemental compositions and controllable physical dimensions. The contact area between the two metals can also be maneuvered by adjusting the concentration of divinylbenzene used for copolymerization with styrene. Using this method, we have prepared Au-Ag, Au-Pd, and Au-Pt heterodimers and further investigated their plasmonic properties. The capability of this approach should be extendible to the fabrication of heterodimers with a broader range of compositions and properties.
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Affiliation(s)
- Jichuan Qiu
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University , Atlanta , Georgia 30332 , United States
- State Key Laboratory of Crystal Materials , Shandong University , Jinan , Shandong 250100 , P. R. China
| | - Minghao Xie
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Zhiheng Lyu
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University , Atlanta , Georgia 30332 , United States
| | - Hong Liu
- State Key Laboratory of Crystal Materials , Shandong University , Jinan , Shandong 250100 , P. R. China
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University , Atlanta , Georgia 30332 , United States
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
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3
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Rodrigues TS, Zhao M, Yang TH, Gilroy KD, da Silva AGM, Camargo PHC, Xia Y. Corrigendum: Synthesis of Colloidal Metal Nanocrystals: A Comprehensive Review on the Reductants. Chemistry 2019; 25:11791. [PMID: 31490012 DOI: 10.1002/chem.201903421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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4
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Zhao M, Hood ZD, Vara M, Gilroy KD, Chi M, Xia Y. Ruthenium Nanoframes in the Face-Centered Cubic Phase: Facile Synthesis and Their Enhanced Catalytic Performance. ACS Nano 2019; 13:7241-7251. [PMID: 31145858 DOI: 10.1021/acsnano.9b02890] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Owing to their highly open structure and a large number of low-coordination sites on the surface, noble-metal nanoframes are intriguing for catalytic applications. Here, we demonstrate the rational synthesis of Ru cuboctahedral nanoframes with enhanced catalytic performance toward hydrazine decomposition. The synthesis starts from Pd nanocubes, which quickly undergo truncation at the corners as a consequence of oxidative etching caused by Br- ions. Afterward, the galvanic replacement reaction between Pd and Ru(III) ions dominates, leading to the selective deposition of Ru atoms on the corners and edges and thereby the fabrication of Pd@Ru core-frame cuboctahedra. Significantly, the deposited Ru atoms are crystallized in a face-centered cubic (fcc) phase instead of the hexagonal close-packed (hcp) structure typical of bulk Ru. Upon the removal of Pd remaining in the core via chemical etching, we obtain Ru cuboctahedral nanoframes. By varying the amount of the Ru(III) precursor, the ridge thickness of the nanoframes can be tuned from a few atomic layers up to 10. Both the frame structure and fcc crystal phase of the Ru cuboctahedral nanoframes can be well preserved up to 300 °C. When compared with hcp-Ru nanoparticles, the fcc-Ru nanoframes displayed substantial enhancement in terms of H2 selectivity toward hydrazine decomposition. This work offers the opportunity to engineer both the morphology and crystal phase of Ru nanocrystals for catalytic applications.
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Affiliation(s)
- Ming Zhao
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Zachary D Hood
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Madeline Vara
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University , Atlanta , Georgia 30332 , United States
| | - Miaofang Chi
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Younan Xia
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University , Atlanta , Georgia 30332 , United States
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5
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Sil D, Lane C, Glor E, Gilroy KD, Sylla S, Barbiellini B, Markiewicz R, Hajfathalian M, Neretina S, Bansil A, Fakhraai Z, Borguet E. Synthesis and Properties of Au Hydride. ChemistrySelect 2019. [DOI: 10.1002/slct.201900925] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Devika Sil
- Department of Chemistry Temple University Philadelphia, Pennsylvania 19122 USA
| | - Christopher Lane
- Northeastern University Physics Department 360 Huntington Ave. 111 Dana Research Center Boston, MA 02115 USA
| | - Ethan Glor
- Department of Chemistry University of Pennsylvania 231 S. 34th Street Philadelphia, PA 19104 USA
| | - Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta, GA 30332 USA
- College of Engineering Temple University Philadelphia, PA 19122 USA
| | - Safiya Sylla
- Department of Chemistry Temple University Philadelphia, Pennsylvania 19122 USA
| | - Bernardo Barbiellini
- Northeastern University Physics Department 360 Huntington Ave. 111 Dana Research Center Boston, MA 02115 USA
- Department of Physics School of Engineering Science, LUT University FI-53850 Lappeenranta Finland
| | - Robert Markiewicz
- Northeastern University Physics Department 360 Huntington Ave. 111 Dana Research Center Boston, MA 02115 USA
| | | | - Svetlana Neretina
- College of Engineering University of Notre Dame Notre Dame, IN 46556 USA
| | - Arun Bansil
- Northeastern University Physics Department 360 Huntington Ave. 111 Dana Research Center Boston, MA 02115 USA
| | - Zahra Fakhraai
- Department of Chemistry University of Pennsylvania 231 S. 34th Street Philadelphia, PA 19104 USA
| | - Eric Borguet
- Department of Chemistry Temple University Philadelphia, Pennsylvania 19122 USA
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6
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Hood ZD, Kubelick KP, Gilroy KD, Vanderlaan D, Yang X, Yang M, Chi M, Emelianov SY, Xia Y. Photothermal transformation of Au-Ag nanocages under pulsed laser irradiation. Nanoscale 2019; 11:3013-3020. [PMID: 30698179 DOI: 10.1039/c8nr10002k] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Pulsed laser irradiation has emerged as an effective means to photothermally transform plasmonic nanostructures after their use in different biomedical applications. However, the ability to predict the products after photothermal transformation requires extensive ex situ studies. Here, we report a systematic study of the photothermal transformation of Au-Ag nanocages with a localized surface plasmon resonance at ca. 750 nm under pulsed laser irradiation at different fluences and a pulse duration of 5 ns. At biologically relevant laser energies, the pulsed laser transforms Au-Ag nanocages into pseudo-spherical, solid nanoparticles. The solid nanoparticles contained similar numbers of Au and Ag atoms to the parent Au-Ag nanocages. At increased laser fluences (>16 mJ cm-2) and number of pulses (>150), the average diameter of the resulting pseudo-spherical particles increased due to the involvement of Ostwald ripening and/or attachment-based growth. The changes in optical properties as a result of the transformation were validated using simulations based on the discrete dipole approximation method, where the spectral profiles and peak positions of the initial and final states matched well with the experimentally derived data. The results may have implications for the future use of Au-Ag nanocages in biomedicine, catalysis, and sensing.
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Affiliation(s)
- Zachary D Hood
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
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7
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Yan Y, Du JS, Gilroy KD, Yang D, Xia Y, Zhang H. Intermetallic Nanocrystals: Syntheses and Catalytic Applications. Adv Mater 2019; 31:e1806746. [PMID: 30667140 DOI: 10.1002/adma.201806746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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8
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Rodrigues TS, Zhao M, Yang T, Gilroy KD, da Silva AGM, Camargo PHC, Xia Y. Frontispiece: Synthesis of Colloidal Metal Nanocrystals: A Comprehensive Review on the Reductants. Chemistry 2018. [DOI: 10.1002/chem.201886462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Thenner S. Rodrigues
- The Wallace H. Coulter Department of Biomedical EngineeringGeorgia Institute of Technology and Emory University Atlanta Georgia 30332 USA
- Departamento de Química FundamentalInstituto de QuímicaUniversidade de São Paulo Av. Prof. Lineu Prestes, 748 05508-000 São Paulo-SP Brazil
| | - Ming Zhao
- School of Chemistry and BiochemistryGeorgia Institute of Technology Atlanta Georgia 30332 USA
| | - Tung‐Han Yang
- The Wallace H. Coulter Department of Biomedical EngineeringGeorgia Institute of Technology and Emory University Atlanta Georgia 30332 USA
| | - Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical EngineeringGeorgia Institute of Technology and Emory University Atlanta Georgia 30332 USA
| | - Anderson G. M. da Silva
- The Wallace H. Coulter Department of Biomedical EngineeringGeorgia Institute of Technology and Emory University Atlanta Georgia 30332 USA
- Departamento de Química FundamentalInstituto de QuímicaUniversidade de São Paulo Av. Prof. Lineu Prestes, 748 05508-000 São Paulo-SP Brazil
| | - Pedro H. C. Camargo
- Departamento de Química FundamentalInstituto de QuímicaUniversidade de São Paulo Av. Prof. Lineu Prestes, 748 05508-000 São Paulo-SP Brazil
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical EngineeringGeorgia Institute of Technology and Emory University Atlanta Georgia 30332 USA
- School of Chemistry and BiochemistryGeorgia Institute of Technology Atlanta Georgia 30332 USA
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9
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Zhao M, Wang X, Yang X, Gilroy KD, Qin D, Xia Y. Hollow Metal Nanocrystals with Ultrathin, Porous Walls and Well-Controlled Surface Structures. Adv Mater 2018; 30:e1801956. [PMID: 29984540 DOI: 10.1002/adma.201801956] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/25/2018] [Indexed: 06/08/2023]
Abstract
Recent developments of a novel class of catalytic materials built on hollow nanocrystals having ultrathin, porous walls, and well-controlled surface structures are discussed, with a focus on platinum and the oxygen reduction reaction (ORR). An introduction is given to the critical role of platinum in the proton exchange membrane fuel cells, and the pressing need to develop a strategy for achieving cost-effective and sustainable use of this precious metal. How to maximize the mass activity of ORR catalysts based on platinum by rationally engineering the surface structure while increasing the utilization efficiency of atoms is then discussed. After reporting on the synthetic methods involving galvanic replacement and seed-mediated growth followed by etching, respectively, a number of examples to demonstrate the enhancement in activity and durability for this new class of catalytic materials are showcased. The feasibility to have the methodology extended from platinum to other precious metals such as gold and ruthenium is highlighted. In conclusion, some of the remaining issues and emerging solutions are examined.
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Affiliation(s)
- Ming Zhao
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Xue Wang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Xuan Yang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Dong Qin
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Younan Xia
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
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10
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Zhou S, Huo D, Goines S, Yang TH, Lyu Z, Zhao M, Gilroy KD, Wu Y, Hood ZD, Xie M, Xia Y. Enabling Complete Ligand Exchange on the Surface of Gold Nanocrystals through the Deposition and Then Etching of Silver. J Am Chem Soc 2018; 140:11898-11901. [DOI: 10.1021/jacs.8b06464] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Shan Zhou
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Da Huo
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Sondrica Goines
- Honors College, College of Charleston, Charleston, South Carolina 29424, United States
| | - Tung-Han Yang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Zhiheng Lyu
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ming Zhao
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Yiren Wu
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Zachary D. Hood
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Minghao Xie
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Younan Xia
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
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11
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Rodrigues TS, Zhao M, Yang TH, Gilroy KD, da Silva AGM, Camargo PHC, Xia Y. Synthesis of Colloidal Metal Nanocrystals: A Comprehensive Review on the Reductants. Chemistry 2018; 24:16944-16963. [PMID: 29923247 DOI: 10.1002/chem.201802194] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 06/13/2018] [Indexed: 01/13/2023]
Abstract
There is a growing interest in controlling the synthesis of colloidal metal nanocrystals and thus tailoring their properties toward various applications. In this context, choosing an appropriate combination of reagents (e.g., salt precursor, reductant, capping agent, and stabilizer) plays a pivotal role in enabling the synthesis of metal nanocrystals with diversified sizes, shapes, and structures. Here we present a comprehensive review that highlights one of the key reagents for the synthesis of metal nanocrystals via chemical reduction: the reductants. We start with a brief introduction to the compounds commonly employed as reductants in the colloidal synthesis of metal nanocrystals by showing their oxidation half-reactions and the corresponding oxidation potentials. Then we offer specific examples pertaining to the controlled synthesis of metal nanocrystals, followed by some fundamental aspects covering the general mechanisms of metal ion reduction based on the Marcus Theory. Afterwards, we present a case-by-case discussion on a wide variety of reductants, including their major properties, reduction mechanisms, and additional effects on the final products. We illustrate these aspects by selecting key examples from the literature and paying close attention to the underlying mechanism in each case. At the end, we conclude by summarizing the highlights of the review and providing some perspectives on future directions.
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Affiliation(s)
- Thenner S Rodrigues
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332, USA.,Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000, São Paulo-SP, Brazil
| | - Ming Zhao
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA
| | - Tung-Han Yang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332, USA
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332, USA
| | - Anderson G M da Silva
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332, USA.,Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000, São Paulo-SP, Brazil
| | - Pedro H C Camargo
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000, São Paulo-SP, Brazil
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332, USA.,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA
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12
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Gilroy KD, Yang X, Xie S, Zhao M, Qin D, Xia Y. Shape-Controlled Synthesis of Colloidal Metal Nanocrystals by Replicating the Surface Atomic Structure on the Seed. Adv Mater 2018; 30:e1706312. [PMID: 29656471 DOI: 10.1002/adma.201706312] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/05/2017] [Indexed: 05/25/2023]
Abstract
Controlling the surface structure of metal nanocrystals while maximizing the utilization efficiency of the atoms is a subject of great importance. An emerging strategy that has captured the attention of many research groups involves the conformal deposition of one metal as an ultrathin shell (typically 1-6 atomic layers) onto the surface of a seed made of another metal and covered by a set of well-defined facets. This approach forces the deposited metal to faithfully replicate the surface atomic structure of the seed while at the same time serving to minimize the usage of the deposited metal. Here, the recent progress in this area is discussed and analyzed by focusing on the synthetic and mechanistic requisites necessary for achieving surface atomic replication of precious metals. Other related methods are discussed, including the one-pot synthesis, electrochemical deposition, and skin-layer formation through thermal annealing. To close, some of the synergies that arise when the thickness of the deposited shell is decreased controllably down to a few atomic layers are highlighted, along with how the control of thickness can be used to uncover the optimal physicochemical properties necessary for boosting the performance toward a range of catalytic reactions.
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Affiliation(s)
- Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Xuan Yang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Shuifen Xie
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Ming Zhao
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Dong Qin
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
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13
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Zhao M, Xu L, Vara M, Elnabawy AO, Gilroy KD, Hood ZD, Zhou S, Figueroa-Cosme L, Chi M, Mavrikakis M, Xia Y. Synthesis of Ru Icosahedral Nanocages with a Face-Centered-Cubic Structure and Evaluation of Their Catalytic Properties. ACS Catal 2018. [DOI: 10.1021/acscatal.8b00910] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Ming Zhao
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Lang Xu
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Madeline Vara
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ahmed O. Elnabawy
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Zachary D. Hood
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Shan Zhou
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Legna Figueroa-Cosme
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Miaofang Chi
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Manos Mavrikakis
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Younan Xia
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
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14
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Figueroa-Cosme L, Gilroy KD, Yang TH, Vara M, Park J, Bao S, da Silva AGM, Xia Y. Synthesis of Palladium Nanoscale Octahedra through a One-Pot, Dual-Reductant Route and Kinetic Analysis. Chemistry 2018; 24:6133-6139. [DOI: 10.1002/chem.201705720] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Legna Figueroa-Cosme
- School of Chemistry and Biochemistry; Georgia Institute of Technology; Atlanta Georgia 30332 USA
| | - Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering; Georgia Institute of Technology and Emory University; Atlanta Georgia 30332 USA
| | - Tung-Han Yang
- The Wallace H. Coulter Department of Biomedical Engineering; Georgia Institute of Technology and Emory University; Atlanta Georgia 30332 USA
| | - Madeline Vara
- School of Chemistry and Biochemistry; Georgia Institute of Technology; Atlanta Georgia 30332 USA
| | - Jinho Park
- School of Chemistry and Biochemistry; Georgia Institute of Technology; Atlanta Georgia 30332 USA
| | - Shixiong Bao
- The Wallace H. Coulter Department of Biomedical Engineering; Georgia Institute of Technology and Emory University; Atlanta Georgia 30332 USA
| | - Anderson G. M. da Silva
- The Wallace H. Coulter Department of Biomedical Engineering; Georgia Institute of Technology and Emory University; Atlanta Georgia 30332 USA
| | - Younan Xia
- School of Chemistry and Biochemistry; Georgia Institute of Technology; Atlanta Georgia 30332 USA
- The Wallace H. Coulter Department of Biomedical Engineering; Georgia Institute of Technology and Emory University; Atlanta Georgia 30332 USA
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta Georgia 30332 USA
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15
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Ligon C, Latimer K, Hood ZD, Pitigala S, Gilroy KD, Senevirathne K. Electrospun metal and metal alloy decorated TiO2 nanofiber photocatalysts for hydrogen generation. RSC Adv 2018; 8:32865-32876. [PMID: 35547708 PMCID: PMC9086326 DOI: 10.1039/c8ra04148b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/18/2018] [Indexed: 11/21/2022] Open
Abstract
Photocatalytic hydrogen generation by electrospun TiO2 nanofibers decorated with various co-catalysts (Pt2Pd, PtCu, Cu, Pt, Pd) was explored.
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Affiliation(s)
- Courtney Ligon
- Department of Chemistry
- Florida A&M University
- Tallahassee
- USA
| | | | - Zachary D. Hood
- School of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
- Center for Nanophase Materials Sciences
| | | | - Kyle D. Gilroy
- Wallace H. Coulter Department of Biomedical Engineering
- Georgia Institute of Technology
- Emory University
- Atlanta
- USA
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16
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Yang TH, Gilroy KD, Xia Y. Reduction rate as a quantitative knob for achieving deterministic synthesis of colloidal metal nanocrystals. Chem Sci 2017; 8:6730-6749. [PMID: 29147498 PMCID: PMC5643889 DOI: 10.1039/c7sc02833d] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/15/2017] [Indexed: 01/29/2023] Open
Abstract
Despite the incredible developments made to the synthesis of colloidal metal nanocrystals, it is still challenging to produce them in a reproducible and predictable manner. This drawback can be attributed to the fact that the protocols continue to be built upon qualitative observations and empirical laws. Because of the vast number of intricately entangled experimental parameters in a synthesis, it is almost impossible to predict and control the outcome by knowingly alternating these parameters. In this Perspective article, we discuss the recent efforts in pushing nanocrystal synthesis towards a deterministic process based upon quantitative measurements. In particular, we focus on how the reduction rate of a salt precursor can be used as a quantitative knob for predicting and controlling the outcomes of both nucleation and growth. We begin with a brief introduction to the techniques that have been used to extract the kinetic information of a synthesis and then discuss how the reduction rate is correlated with the defect structure, shape/morphology, and elemental distribution of the resultant nanocrystals. We conclude by highlighting some of the recent advances related to in situ probing of nanocrystal synthesis, with an emphasis on the real-time, quantitative aspects with regard to both nucleation and growth.
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Affiliation(s)
- Tung-Han Yang
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University , Atlanta , Georgia 30332 , USA .
- Department of Materials Science and Engineering , National Tsing Hua University , Hsinchu , 30013 , Taiwan
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University , Atlanta , Georgia 30332 , USA .
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering , Georgia Institute of Technology and Emory University , Atlanta , Georgia 30332 , USA .
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332 , USA
- School of Chemical and Biomolecular Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , USA
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17
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Yang M, Wang W, Gilroy KD, Xia Y. Controlling the Deposition of Pd on Au Nanocages: Outer Surface Only versus Both Outer and Inner Surfaces. Nano Lett 2017; 17:5682-5687. [PMID: 28777579 DOI: 10.1021/acs.nanolett.7b02578] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
When a metal precursor is reduced in the presence of Au nanocages with a hollow interior and porous walls, in principle the resultant metal atoms can be deposited onto both the outer and inner surfaces or just the outer surface. Here we demonstrate that these two different scenarios of metal deposition can be deterministically achieved by controlling the reduction kinetics of the precursor. Specifically, if PdCl42- is employed as the precursor, its fast reduction kinetics favors the solution reduction pathway, in which the resultant Pd atoms are deposited only onto the outer surface for the generation of Au@Pd double-shelled nanocages. When the precursor is switched to PdBr42- to slow down the reduction, the precursor can readily diffuse into the interior of the Au nanocages prior to its reduction to elemental Pd. As such, both the outer and inner surfaces of the nanocages become coated with Pd for the generation of Pd@Au@Pd triple-shelled nanocages. This study not only offers a new synthetic approach to metal nanocages with diverse compositions and structures but also demonstrates the necessity of controlling the relative rates of reduction and bulk diffusion of a metal precursor when nanostructures with a hollow interior and porous walls are used for seed-mediated growth.
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Affiliation(s)
- Miaoxin Yang
- School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Wenxia Wang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
- School of Light Industry and Food Sciences, South China University of Technology , Guangzhou, Guangdong 510640, People's Republic of China
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
| | - Younan Xia
- School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
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18
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Yang X, Gilroy KD, Vara M, Zhao M, Zhou S, Xia Y. Gold icosahedral nanocages: Facile synthesis, optical properties, and fragmentation under ultrasonication. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.01.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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19
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Gilroy KD, Puibasset J, Vara M, Xia Y. On the Thermodynamics and Experimental Control of Twinning in Metal Nanocrystals. Angew Chem Int Ed Engl 2017; 56:8647-8651. [DOI: 10.1002/anie.201705443] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 USA
| | - Joël Puibasset
- Interfaces, Confinement, Matériaux et Nanostructures (ICMN) UMR 7374 CNRS et Université d'Orléans 1b rue de la Férollerie 45071 Orléans cedex 02 France
| | - Madeline Vara
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 USA
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
- School of Chemical and Biomolecular Engineering Georgia Institute of Technology Atlanta GA 30332 USA
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20
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Affiliation(s)
- Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 USA
| | - Joël Puibasset
- Interfaces, Confinement, Matériaux et Nanostructures (ICMN) UMR 7374 CNRS et Université d'Orléans 1b rue de la Férollerie 45071 Orléans cedex 02 France
| | - Madeline Vara
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 USA
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
- School of Chemical and Biomolecular Engineering Georgia Institute of Technology Atlanta GA 30332 USA
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21
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Gilroy KD, Elnabawy AO, Yang TH, Roling LT, Howe J, Mavrikakis M, Xia Y. Thermal Stability of Metal Nanocrystals: An Investigation of the Surface and Bulk Reconstructions of Pd Concave Icosahedra. Nano Lett 2017; 17:3655-3661. [PMID: 28448153 DOI: 10.1021/acs.nanolett.7b00844] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Despite the remarkable success in controlling the synthesis of metal nanocrystals, it still remains a grand challenge to stabilize and preserve the shapes or internal structures of metastable kinetic products. In this work, we address this issue by systematically investigating the surface and bulk reconstructions experienced by a Pd concave icosahedron when subjected to heating up to 600 °C in vacuum. We used in situ high-resolution transmission electron microscopy to identify the equilibration pathways of this far-from-equilibrium structure. We were able to capture key structural transformations occurring during the thermal annealing process, which were mechanistically rationalized by implementing self-consistent plane-wave density functional theory (DFT) calculations. Specifically, the concave icosahedron was found to evolve into a regular icosahedron via surface reconstruction in the range of 200-400 °C, and then transform into a pseudospherical crystalline structure through bulk reconstruction when further heated to 600 °C. The mechanistic understanding may lead to the development of strategies for enhancing the thermal stability of metal nanocrystals.
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Affiliation(s)
- Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
| | - Ahmed O Elnabawy
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Tung-Han Yang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
| | - Luke T Roling
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Jane Howe
- Hitachi High-Technologies Canada, Toronto, Ontario M9W 6A4, Canada
| | - Manos Mavrikakis
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
- School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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22
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Yan Y, Du JS, Gilroy KD, Yang D, Xia Y, Zhang H. Intermetallic Nanocrystals: Syntheses and Catalytic Applications. Adv Mater 2017; 29:1605997. [PMID: 28234403 DOI: 10.1002/adma.201605997] [Citation(s) in RCA: 223] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/11/2017] [Indexed: 05/21/2023]
Abstract
At the forefront of nanochemistry, there exists a research endeavor centered around intermetallic nanocrystals, which are unique in terms of long-range atomic ordering, well-defined stoichiometry, and controlled crystal structure. In contrast to alloy nanocrystals with no elemental ordering, it is challenging to synthesize intermetallic nanocrystals with a tight control over their size and shape. Here, recent progress in the synthesis of intermetallic nanocrystals with controllable sizes and well-defined shapes is highlighted. A simple analysis and some insights key to the selection of experimental conditions for generating intermetallic nanocrystals are presented, followed by examples to highlight the viable use of intermetallic nanocrystals as electrocatalysts or catalysts for various reactions, with a focus on the enhanced performance relative to their alloy counterparts that lack elemental ordering. Within the conclusion, perspectives on future developments in the context of synthetic control, structure-property relationships, and applications are discussed.
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Affiliation(s)
- Yucong Yan
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China
| | - Jingshan S Du
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Deren Yang
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
- School of Chemistry and Biochemistry, School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Hui Zhang
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China
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23
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Abstract
This article highlights the mechanisms that guide the growth of nanocrystals to asymmetric shapes based on rationally designed wet-chemical syntheses.
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Affiliation(s)
- Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering
- Georgia Institute of Technology and Emory University
- Atlanta
- USA
| | - Hsin-Chieh Peng
- School of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
| | - Xuan Yang
- The Wallace H. Coulter Department of Biomedical Engineering
- Georgia Institute of Technology and Emory University
- Atlanta
- USA
| | - Aleksey Ruditskiy
- School of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering
- Georgia Institute of Technology and Emory University
- Atlanta
- USA
- School of Chemistry and Biochemistry
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24
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Zhu C, Xue J, Gilroy KD, Huo D, Shen S, Xia Y. Micropatterned Polymer Nanorod Forests and Their Use for Dual Drug Loading and Regulation of Cell Adhesion. ACS Appl Mater Interfaces 2016; 8:34194-34197. [PMID: 27930880 PMCID: PMC6625765 DOI: 10.1021/acsami.6b14468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This paper describes a simple method for the fabrication of micropatterned polymer nanorod forests by templating against the channels in an anodized aluminum oxide membrane partially masked by gelatin. The nanorod forests easily support bimodal drug loading, with one drug encapsulated in the nanorods and the other physisorbed on their surface. During cell culture, preosteoblasts are predominantly attracted to the nanorod forests and driven to climb up along the nanorods. This type of scaffold integrates both microscale and nanoscale features into a single substrate, holding great potential for applications in cell culture and tissue engineering.
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Affiliation(s)
- Chunlei Zhu
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Jiajia Xue
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Da Huo
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Song Shen
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
- School of Chemistry and Biochemistry, School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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25
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Affiliation(s)
- Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 USA
- School of Chemistry and Biochemistry School of Chemical and Biomolecular Engineering Georgia Institute of Technology Atlanta GA 30332 USA
| | - Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 USA
| | - Hsin‐Chieh Peng
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 USA
| | - Xiaohu Xia
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 USA
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26
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Abstract
Seed-mediated growth is a powerful and versatile approach for the synthesis of colloidal metal nanocrystals. The vast allure of this approach mainly stems from the staggering degree of control one can achieve over the size, shape, composition, and structure of nanocrystals. These parameters not only control the properties of nanocrystals but also determine their relevance to, and performance in, various applications. The ingenuity and artistry inherent to seed-mediated growth offer extensive promise, enhancing a number of existing applications and opening the door to new developments. This Review demonstrates how the diversity of metal nanocrystals can be expanded with endless opportunities by using seeds with well-defined and controllable internal structures in conjunction with a proper combination of capping agent and reduction kinetics. New capabilities and future directions are also highlighted.
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Affiliation(s)
- Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA.,School of Chemistry and Biochemistry, School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Hsin-Chieh Peng
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Xiaohu Xia
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
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27
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Zhou S, Li J, Gilroy KD, Tao J, Zhu C, Yang X, Sun X, Xia Y. Facile Synthesis of Silver Nanocubes with Sharp Corners and Edges in an Aqueous Solution. ACS Nano 2016; 10:9861-9870. [PMID: 27649269 DOI: 10.1021/acsnano.6b05776] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
It remains a challenge to synthesize Ag nanocubes in an aqueous system, although the polyol process was successfully adopted more than one decade ago. Here, we report an aqueous method for the synthesis of Ag nanocubes with an average edge length of 35-95 nm. It involves the formation of AgCl octahedra by mixing CF3COOAg with cetyltrimethylammonium chloride, followed by the nucleation and growth of Ag nanocrystals in the presence of ascorbic acid (AA) and FeCl3. The Fe3+/Fe2+ redox pair is responsible for the removal of multiply twinned seeds through oxidative etching. The Cl- ions play two critical roles in the nucleation and growth of Ag nanocubes with a single-crystal structure. First, the Cl- ions react with Ag+ ions to generate nanometer-sized AgCl octahedra in the initial stage of a synthesis. In the presence of room light and a proper reducing agent such as AA, the AgCl can be reduced to generate Agn nuclei followed by their evolution into single-crystal seeds and then Ag nanocrystals. Second, the Cl- ions can act as a specific capping agent toward the Ag(100) surface, enabling the formation of Ag nanocubes with sharp corners and edges. Based on the results from a set of time-lapse studies and control experiments, we formulate a plausible mechanism to account for the formation of Ag nanocubes that resembles the formation and development of latent image centers in silver halide grains in the photographic process.
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Affiliation(s)
| | - Jianhua Li
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
| | - Jing Tao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory , Upton, New York 11973, United States
| | - Chunlei Zhu
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
| | - Xuan Yang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
| | | | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
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28
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Liu M, Gilroy KD, Peng HC, Chi M, Guo L, Xia Y. The effect of surface capping on the diffusion of adatoms in the synthesis of Pd@Au core-shell nanocrystals. Chem Commun (Camb) 2016; 52:13159-13162. [PMID: 27763648 DOI: 10.1039/c6cc07456a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We offer new insights into the roles played by surface capping in controlling the pattern of growth involving Pd cubic seeds and a HAuCl4 precursor. The final products can take different surface structures (concave vs. flat side faces) depending on the presence or absence of surface capping.
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Affiliation(s)
- Maochang Liu
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA.
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29
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Neretina S, Hughes RA, Gilroy KD, Hajfathalian M. Noble Metal Nanostructure Synthesis at the Liquid-Substrate Interface: New Structures, New Insights, and New Possibilities. Acc Chem Res 2016; 49:2243-2250. [PMID: 27622782 DOI: 10.1021/acs.accounts.6b00393] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Modern technologically driven societies could not exist in their current form if it were not for a great many synthetic achievements reliant on solution-based chemistry and substrate-based processing techniques. It is, hence, not surprising that these same materials preparation techniques have given rise to an impressive list of functional nanomaterials including those derived from noble metals, a class of materials renowned for their extraordinary optical and catalytic properties. Acting as the foundation for substrate-based processing is a collection of techniques such as physical and chemical vapor deposition, epitaxy, self- and directed assembly, and a host of lithographic methods. These techniques allow for precise control over nanostructure placement, but where the fabrication of sophisticated architectures and sub-50 nm feature sizes are often unattainable or reliant on the use of technically demanding cost-prohibitive routes. In contrast, solution-based chemistry allows for the formation of complex nanostructures while maintaining synthetic ease, cost-effectiveness, and exacting control over monodispersity, size, shape, composition, and crystallinity. While many methods exist for the dispersal of colloids onto substrates, few are capable of achieving nanostructure ensembles where nanostructure placement allows for true long-range order as well as control over the crystallographic alignment of the nanostructures relative to each other and the underlying substrate. A more exhaustive comparison of these two approaches reveals that, more often than not, a weakness of substrate-based processing is a strength of colloidal synthesis and vice versa. In this Account, we describe a synthetic strategy devised and validated by the Neretina laboratory that integrates the competencies of substrate-based techniques with colloidal chemistry and, in doing so, brings this rich and exciting chemistry and its associated functionalities to the substrate surface. The strategy takes advantage of an impressive collection of seed-mediated solution-based protocols in which dispersed seeds direct noble metal nanostructure formation along orderly reaction pathways. It, however, replaces the seed colloid with substrate-immobilized templates formed in periodic arrays where the crystallographic orientation of the templates is defined by an epitaxial relationship with the substrate. Demonstrated are syntheses at the liquid-substrate interface in which organized surfaces of crystalline templates formed through templated dewetting are subjected to galvanic replacement, preferential etching, and/or heterogeneous deposition facilitated by redox reactions in both the presence and absence of capping agents. While the protocols utilized are adapted from some of the most well-studied colloidal syntheses, in no case do they yield reaction products that are identical since the substrate inflicts asymmetries onto the growth mode. We believe that the strategy described herein not only demonstrates a family of nanostructures unobtainable through other means but also establishes a synthetic foundation that offers unprecedented flexibility, expands the palette of accessible template materials, provides a new vantage point from which complex reactions occurring in liquid media can be examined, and has the potential to underpin photovoltaic, catalytic, and sensing applications reliant on substrate-based noble metal nanostructures.
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Affiliation(s)
- Svetlana Neretina
- College
of Engineering, University of Notre Dame, Fitzpatrick Hall, Notre Dame, Indiana 46556, United States
| | - Robert A. Hughes
- College
of Engineering, University of Notre Dame, Fitzpatrick Hall, Notre Dame, Indiana 46556, United States
| | - Kyle D. Gilroy
- College
of Engineering, Temple University, 1947 N. 12th St., Philadelphia, Pennsylvania 19122, United States
| | - Maryam Hajfathalian
- College
of Engineering, Temple University, 1947 N. 12th St., Philadelphia, Pennsylvania 19122, United States
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30
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Lee SR, Park J, Gilroy KD, Yang X, Figueroa‐Cosme L, Ding Y, Xia Y. Palladium@Platinum Concave Nanocubes with Enhanced Catalytic Activity toward Oxygen Reduction. ChemCatChem 2016. [DOI: 10.1002/cctc.201600600] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Sujin R. Lee
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta Georgia 30332 United States
| | - Jinho Park
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta Georgia 30332 United States
| | - Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical engineering Georgia Institute of Technology and Emory University Atlanta Georgia 30332 United States
| | - Xuan Yang
- The Wallace H. Coulter Department of Biomedical engineering Georgia Institute of Technology and Emory University Atlanta Georgia 30332 United States
| | - Legna Figueroa‐Cosme
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta Georgia 30332 United States
| | - Yong Ding
- School of Material Science and Engineering Georgia Institute of Technology Atlanta Georgia 30332 United States
| | - Younan Xia
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta Georgia 30332 United States
- The Wallace H. Coulter Department of Biomedical engineering Georgia Institute of Technology and Emory University Atlanta Georgia 30332 United States
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31
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Sun X, Kim J, Gilroy KD, Liu J, König TAF, Qin D. Gold-Based Cubic Nanoboxes with Well-Defined Openings at the Corners and Ultrathin Walls Less Than Two Nanometers Thick. ACS Nano 2016; 10:8019-25. [PMID: 27458731 DOI: 10.1021/acsnano.6b04084] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report a facile synthesis of Au-based cubic nanoboxes as small as 20 nm for the outer edge length, together with well-defined openings at the corners and walls fewer than 10 atomic layers (or <2 nm) in thickness. The success relies on the selective formation of Ag2O at the corners of Ag nanocubes, followed by the conformal deposition of Au on the side faces in a layer-by-layer fashion. When six atomic layers of Au are formed on the side faces to generate Ag@Au6L core-shell nanocubes, we can selectively remove the Ag2O patches at the corner sites using a weak acid, making it possible to further remove the Ag core by H2O2 etching without breaking the ultrathin Au shell. This synthetic approach works well for Ag nanocubes of 38 and 18 nm in edge length, and the wall thickness of the nanoboxes can be controlled down to 2 nm. The resultant Au nanoboxes exhibit strong plasmonic absorption in the near-infrared region, consistent with computational simulations.
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Affiliation(s)
- Xiaojun Sun
- School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Junki Kim
- School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Kyle D Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
| | - Jingyue Liu
- Department of Physics, Arizona State University , Tempe, Arizona 85287, United States
| | - Tobias A F König
- Leibniz-Institut für Polymerforschung Dresden e.V., Institute of Physical Chemistry and Polymer Physics , Hohe Straße 6, 01069 Dresden, Germany
| | - Dong Qin
- School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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32
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Gilroy KD, Xia Y. Dimerization of Colloidal Particles through Controlled Aggregation for Enhanced Properties and Applications. Chem Asian J 2016; 11:2341-51. [DOI: 10.1002/asia.201600979] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Indexed: 01/22/2023]
Affiliation(s)
- Kyle D. Gilroy
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 (USA)
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University Atlanta GA 30332 (USA)
- School of Chemistry&Biochemistry School of Chemical&Biomolecular Engineering Georgia Institute of Technology Atlanta GA 30332 USA
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Affiliation(s)
- Kyle D. Gilroy
- The
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | | | | | | | - Younan Xia
- The
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
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Hajfathalian M, Gilroy KD, Hughes RA, Neretina S. Citrate-Induced Nanocubes: A Re-Examination of the Role of Citrate as a Shape-Directing Capping Agent for Ag-Based Nanostructures. Small 2016; 12:3444-3452. [PMID: 27174815 DOI: 10.1002/smll.201600545] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/12/2016] [Indexed: 06/05/2023]
Abstract
Seed-mediated syntheses utilizing facet-selective surface passivation provide the necessary chemical controls to direct noble metal nanostructure formation to a predetermined geometry. The foremost protocol for the synthesis of (111)-faceted Ag octahedra involves the reduction of metal ions onto pre-existing seeds in the presence of citrate and ascorbic acid. It is generally accepted that the capping of (111) facets with citrate dictates the shape while ascorbic acid acts solely as the reducing agent. Herein, a citrate-based synthesis is demonstrated in which the presence or absence of ascorbic acid is the shape-determining factor. Reactions are carried out in which Ag(+) ions are reduced onto substrate-immobilized Ag, Au, Pd, and Pt seeds. Syntheses lacking ascorbic acid, in which citrate acts as both the capping and the reducing agent, result in a robust nanocube growth mode able to withstand wide variations in the concentration of reactants, reaction rates, seed material, seed orientation and faceting, pH, and substrate material. If, however, ascorbic acid is included in these syntheses, then the growth mode reverts to one that advances the octahedral geometry. The implication of these results is that citrate, or one of its oxidation products, selectively caps (100) facets, but where this capability is compromised by ascorbic acid.
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Affiliation(s)
- Maryam Hajfathalian
- College of Engineering, Temple University, Philadelphia, PA, 19122, United States
| | - Kyle D Gilroy
- College of Engineering, Temple University, Philadelphia, PA, 19122, United States
| | - Robert A Hughes
- College of Engineering, Temple University, Philadelphia, PA, 19122, United States
| | - Svetlana Neretina
- College of Engineering, Temple University, Philadelphia, PA, 19122, United States
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Hajfathalian M, Gilroy KD, Golze SD, Yaghoubzade A, Menumerov E, Hughes RA, Neretina S. A Wulff in a Cage: The Confinement of Substrate-Based Structures in Plasmonic Nanoshells, Nanocages, and Nanoframes Using Galvanic Replacement. ACS Nano 2016; 10:6354-6362. [PMID: 27172588 DOI: 10.1021/acsnano.6b02712] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Galvanic replacement reactions carried out on solid core-shell structures typically yield a noble metal nanorattle geometry in which a mobile core is contained within a hollowed shell. Here, we adapt this colloidal synthesis to substrate-based structures to obtain a fundamentally altered product in which an immobilized core is separated from the shell by a well-defined gap, an architecture unobtainable using colloidal techniques and that offers unique advantages in terms of generating plasmonic near-field effects within the confines of a single structure. In the devised route, Wulff-shaped templates of Au, Pt, or Pd, formed through the dewetting of ultrathin films, are first transformed into core-shell structures through the reduction of Ag(+) ions onto their surface and then further transformed through the galvanic replacement of Ag with Au. Through suitable adjustments to the shell geometry, the epitaxial relationship with the substrate, and the extent to which the shell is replaced, it is possible to generate an entire family of nanostructures in which a Wulff-shaped core is confined within a nanoshell, nanocage, or nanoframe, where, in all cases, bonds formed between the structure and the substrate preclude motion. With the potential to tune the gap width, the geometry of the confining structure, and the composition of the core, shell, and substrate, these structures could find application as catalytic nanoreactors able to drive both single-step and cascade reactions or as plasmon-based sensing elements for biological and chemical detection.
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Affiliation(s)
- Maryam Hajfathalian
- College of Engineering, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Kyle D Gilroy
- College of Engineering, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Spencer D Golze
- College of Engineering, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Ali Yaghoubzade
- College of Engineering, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Eredzhep Menumerov
- College of Engineering, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Robert A Hughes
- College of Engineering, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Svetlana Neretina
- College of Engineering, Temple University , Philadelphia, Pennsylvania 19122, United States
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36
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Menumerov E, Gilroy KD, Hajfathalian M, Murphy CJ, McKenzie ER, Hughes RA, Neretina S. Plastically deformed Cu-based alloys as high-performance catalysts for the reduction of 4-nitrophenol. Catal Sci Technol 2016. [DOI: 10.1039/c6cy00734a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Plastically deformed mesoscopic structures exposed to an etching procedure are demonstrated as highly catalytic in the reduction of 4-nitrophenol.
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37
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Gilroy KD, Sundar A, Hajfathalian M, Yaghoubzade A, Tan T, Sil D, Borguet E, Hughes RA, Neretina S. Transformation of truncated gold octahedrons into triangular nanoprisms through the heterogeneous nucleation of silver. Nanoscale 2015; 7:6827-6835. [PMID: 25807181 DOI: 10.1039/c5nr00151j] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Described is a straightforward procedure for forming organized substrate-immobilized nanoprisms which are single crystalline, surfactant-free and which form a heteroepitaxial relationship with the underlying substrate. The devised route utilizes truncated Au octahedrons formed through solid state dewetting techniques as high temperature heterogeneous nucleation sites for Ag adatoms which are arriving to the substrate surface in the vapour phase. Observed is a morphological and compositional transformation of the Au structures to triangular nanoprisms comprised of a homogeneous AuAg alloy. During this transformation, the localized surface plasmon resonance red-shifts, broadens and increases in strength. The shape transformation, which cannot be rationalized using thermodynamic arguments dependent on the surface energy minimization, is described in terms of a kinetically driven growth mode, previously predicted by molecular dynamic simulations. The so-formed structures, when coated with a thin layer of Pd, are demonstrated as plasmonic sensing elements for hydrogen detection.
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Affiliation(s)
- K D Gilroy
- College of Engineering, Temple University, Philadelphia, Pennsylvania 19122, USA.
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38
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Abstract
We report on the heterogeneous nucleation of Ag on Au seeds using a surfactant-free synthesis where nanoparticle aggregation is nullified through the immobilization of bare Au seeds on the surface of a substrate. Requiring only silver nitrate, ascorbic acid, and Au seeds, the synthesis is facile and, from a mechanistic standpoint, far less convoluted than conventional protocols. The results reveal that, even in the absence of surfactants, highly anisotropic growth modes are achieved which result in a lone Ag structure emanating from a single (100) Au facet. Consistent with surfactant-based protocols is the ability to vary the product of the reaction by varying the reaction rate. It allows for kinetic control which is able to direct the reaction toward either a bimetallic heterodimer or a core-shell configuration. The observed growth modes cannot be explained in terms of those proposed for surfactant-based growth modes where surfactants, surface diffusion, and/or collision patterns are used to rationalize the reaction product. We, instead, propose a growth mode reliant on the formation of a space charge region around each seed consisting of a double layer of ions, where the integrity of the layer is dependent upon the facets expressed by the seed, the rate at which the reduced ions are being deposited, and the pH of the solution. Our work reveals the rich nature of surfactant-free heteroepitaxial growth modes as well as the utility of the substrate-based platform in defining growth pathways.
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Affiliation(s)
- Kyle D Gilroy
- College of Engineering, Temple University , Philadelphia, Pennsylvania 19122, United States
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Şenel Ayaz HG, Perets A, Ayaz H, Gilroy KD, Govindaraj M, Brookstein D, Lelkes PI. Textile-templated electrospun anisotropic scaffolds for regenerative cardiac tissue engineering. Biomaterials 2014; 35:8540-52. [DOI: 10.1016/j.biomaterials.2014.06.029] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/16/2014] [Indexed: 01/06/2023]
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Sundar A, Farzinpour P, Gilroy KD, Tan T, Hughes RA, Neretina S. Eutectic combinations as a pathway to the formation of substrate-based Au-Ge heterodimers and hollowed au nanocrescents with tunable optical properties. Small 2014; 10:3379-3388. [PMID: 24729512 DOI: 10.1002/smll.201400383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 03/27/2014] [Indexed: 06/03/2023]
Abstract
Pairs of immiscible elements with deep eutectics are used to synthesize periodic arrays of heterodimers and hollowed metal nanocrescents. In the devised route, substrate-immobilized Au or Ag nanostructures act as heterogeneous nucleation sites for Ge adatoms. At elevated temperatures the adatoms collect in sufficient quantities to transform each site into a AuGe liquid alloy which, upon cooling, phase separates into elemental components sharing a common interface. The so-formed Au-Ge and Ag-Ge heterodimers exhibit a complex morphology characterized by a noble metal nanocrescent which partially encapsulates one end of the Ge domain. Through the use of a selective etch the Ge component is removed, leaving behind a periodic array of hollow noble metal nanocrescents on the surface of the substrate. Optical characterization of both the heterodimers and nanocrescents indicates that the presence of Ge gives rise to a relative blue-shift in the localized surface plasmon peak, a result that is in stark contrast to the red-shifts typically observed when plasmonic nanostructures are in contact with a dielectric medium. Simulations are used to both rationalize the observed shift and show the potential for deriving unexpected behaviors when semishell-like noble metal structures are in contact with high permittivity dielectric mediums.
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Affiliation(s)
- Aarthi Sundar
- College of Engineering, Temple University, Philadelphia, Pennsylvania, 19122, USA
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41
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Sil D, Gilroy KD, Niaux A, Boulesbaa A, Neretina S, Borguet E. Seeing is believing: hot electron based gold nanoplasmonic optical hydrogen sensor. ACS Nano 2014; 8:7755-7762. [PMID: 25072929 DOI: 10.1021/nn500765t] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report on the rapid optical detection of gaseous hydrogen using hot electrons generated from resonantly excited substrate-based gold nanohemispheres (Au NHs). We consider hot electron induced H2 dissociation and the subsequent formation of a metastable gold hydride (AuHx) to account for changes in optical transmission. The excitation wavelength was varied to demonstrate a maximum response at the localized surface plasmon resonance (LSPR) wavelength of the AuNHs. Numerical simulations, using the discrete dipole approximation, were employed to corroborate the optical changes associated with the formation of metastable AuHx. Finite time difference domain (FDTD) calculations were also performed to account for the enhanced photocatalytic activity arising due to the confinement of electric fields by the Au NHs. FDTD simulations show that the excitation of the Au NHs plasmon modes generates stronger electric fields at the interface in comparison to a spherical geometry of similar dimensions.
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Farzinpour P, Sundar A, Gilroy KD, Eskin ZE, Hughes RA, Neretina S. Dynamic templating: a large area processing route for the assembly of periodic arrays of sub-micrometer and nanoscale structures. Nanoscale 2013; 5:1929-1938. [PMID: 23354129 DOI: 10.1039/c3nr33992k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A substrate-based templated assembly route has been devised which offers large-area, high-throughput capabilities for the fabrication of periodic arrays of sub-micrometer and nanometer-scale structures. The approach overcomes a significant technological barrier to the widespread use of substrate-based templated assembly by eliminating the need for periodic templates having nanoscale features. Instead, it relies upon the use of a dynamic template with dimensions that evolve in time from easily fabricated micrometer dimensions to those on the nanoscale as the assembly process proceeds. The dynamic template consists of a pedestal of a sacrificial material, typically antimony, upon which an ultrathin layer of a second material is deposited. When heated, antimony sublimation results in a continuous reduction in template size where the motion of the sublimation fronts direct the diffusion of atoms of the second material to a predetermined location. The route has broad applicability, having already produced periodic arrays of gold, silver, copper, platinum, nickel, cobalt, germanium and Au-Ag alloys on substrates as diverse as silicon, sapphire, silicon-carbide, graphene and glass. Requiring only modest levels of instrumentation, the process provides an enabling route for any reasonably equipped researcher to fabricate periodic arrays that would otherwise require advanced fabrication facilities.
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Farzinpour P, Sundar A, Gilroy KD, Eskin ZE, Hughes RA, Neretina S. Altering the dewetting characteristics of ultrathin gold and silver films using a sacrificial antimony layer. Nanotechnology 2012; 23:495604. [PMID: 23154213 DOI: 10.1088/0957-4484/23/49/495604] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Solid state dewetting of ultrathin films is the most straightforward means of fabricating substrate-supported noble metal nanostructures. This assembly process is, however, quite inflexible, yielding either densely packed smaller structures or widely spaced larger structures. Here, we demonstrate the utility of introducing a sacrificial antimony layer between the substrate and noble metal overlayer. We observe an agglomeration process which is radically altered by the concurrent sublimation of antimony. In stark contrast with conventional dewetting, where the thickness of the deposited metal film determines the characteristic length scales of the assembly process, it is the thickness of the sacrificial antimony layer which dictates both the nanoparticle size and interparticle spacing. The result is a far more flexible self-assembly process where the nanoparticle size and areal density can be varied widely. Demonstrations show nanoparticle areal densities which are varied over four orders of magnitude assembled from the identical gold layer thickness, where the accompanying changes to nanostructure size see a systematic shift in the wavelength of the localized surface plasmon resonance. As a pliable self-assembly process, it offers the opportunity to tailor the properties of an ensemble of nanostructures to meet the needs of specific applications.
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Affiliation(s)
- P Farzinpour
- College of Engineering, Temple University, Philadelphia, PA 19122, USA
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