UC Davis UC Davis Previously Published Works Title Template-based syntheses for shape controlled nanostructures. Permalink https://escholarship.org/uc/item/0m23w188 Journal Advances in colloid and interface science, 234 ISSN 0001-8686 Authors Pérez-Page, María Yu, Erick Li, Jun et al. Publication Date 2016-08-01 DOI 10.1016/j.cis.2016.04.001 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Advances in Colloid and Interface Science 234 (2016) 51–79 Contents lists available at ScienceDirect Advances in Colloid and Interface Science journal homepage: www.elsevier.com/locate/cis Template-based syntheses for shape controlled nanostructures☆ María Pérez-Page a,ErickYua,b,JunLia, Masoud Rahman a,DanielM.Drydena,b, Ruxandra Vidu a,b, Pieter Stroeve a,⁎ a Department of Chemical Engineering, University of California Davis, Davis, CA, 95616, United States b Department of Materials Science and Engineering, University of California Davis, Davis, CA, 95616, United States article info abstract Available online 20 April 2016 A variety of nanostructured materials are produced through template-based synthesis methods, including zero- dimensional, one-dimensional, and two-dimensional structures. These span different forms such as nanoparti- Keywords: cles, nanowires, nanotubes, nanoflakes, and nanosheets. Many physical characteristics of these materials such Template-based synthesis as the shape and size can be finely controlled through template selection and as a result, their properties as Nanostructured materials well. Reviewed here are several examples of these nanomaterials, with emphasis specifically on the templates Template-filling methods and synthesis routes used to produce the final nanostructures. In the first section, the templates have been Nanoporous membrane templates discussed while in the second section, their corresponding synthesis methods have been briefly reviewed, and lastly in the third section, applications of the materials themselves are highlighted. Some examples of the tem- plates frequently encountered are organic structure directing agents, surfactants, polymers, carbon frameworks, colloidal sol–gels, inorganic frameworks, and nanoporous membranes. Synthesis methods that adopt these tem- plates include emulsion-based routes and template-filling approaches, such as self-assembly, electrodeposition, electroless deposition, vapor deposition, and other methods including layer-by-layer and lithography. Template- based synthesized nanomaterials are frequently encountered in select fields such as solar energy, thermoelectric materials, catalysis, biomedical applications, and magnetowetting of surfaces. © 2016 Elsevier B.V. All rights reserved. Contents 1. Introduction............................................................... 52 2. Nanostructuresandtheirtemplates.................................................... 53 2.1. Zero-dimensionalstructures.................................................... 53 2.1.1. Smallorganicstructuredirectingagents(OSDAS)...................................... 53 2.1.2. Ionicsurfactantsandliquids................................................ 53 2.1.3. Non-ionicandamphiphilicsurfactants........................................... 54 2.1.4. Secondarytemplates................................................... 55 2.1.5. Carbonframeworks.................................................... 55 2.1.6. Biologicaltemplates.................................................... 56 2.2. One-dimensionalstructures.................................................... 56 2.2.1. Nanowires........................................................ 56 2.2.2. Nanocables........................................................ 57 2.2.3. Nanotubes........................................................ 58 2.2.4. Nanomushrooms..................................................... 59 2.3. Two-dimensionalstructures.................................................... 60 2.3.1. Nanodisks, nanoflakes,andnanosheets........................................... 60 3. Synthesismethods............................................................ 60 3.1. Hardandsofttemplatingsyntheses................................................. 60 3.1.1. Inorganicnanoparticles.................................................. 61 3.1.2. Polymericnanoparticles.................................................. 61 3.1.3. Semiconductingnanoparticles............................................... 62 ☆ Dedicated to Professor Eli Ruckenstein on the occasion of his 90th birthday. ⁎ Corresponding author. E-mail address: [email protected] (P. Stroeve). http://dx.doi.org/10.1016/j.cis.2016.04.001 0001-8686/© 2016 Elsevier B.V. All rights reserved. 52 M. Pérez-Page et al. / Advances in Colloid and Interface Science 234 (2016) 51–79 3.2. Template fillingsyntheses.....................................................62 3.2.1. Electrodeposition.....................................................62 3.2.2. Electrophoreticdeposition.................................................63 3.2.3. Sol–geldeposition.....................................................63 3.2.4. Vapordeposition.....................................................64 3.2.5. Melt and solution filling..................................................64 3.3. Othermethods..........................................................65 3.3.1. Layer-by-layerdeposition.................................................65 3.3.2. Lithographyandstamping.................................................65 4. Applications...............................................................66 4.1. Solarcells.............................................................66 4.2. Thermoelectrics..........................................................66 4.3. Catalysis.............................................................68 4.3.1. Cracking.........................................................68 4.3.2. Finechemicalsynthesis..................................................69 4.3.3. Reduction/oxidationreactions................................................69 4.4. Biomedicalapplications.......................................................69 4.4.1. Drugdelivery.......................................................69 4.4.2. Imaginganddetection...................................................70 4.4.3. Scaffoldsandmembranes..................................................70 4.5. WettingofSurfaces........................................................70 5. Trendsandconclusions..........................................................70 Acknowledgements..............................................................71 References..................................................................71 1. Introduction requires two constituents, a silica source and a templating agent. The former provides the silica, which forms the framework around the Nanostructured materials have attracted considerable attention in pore-determining template. While the silica sources are typically recent years. Control over size, shape, and morphology of nanostruc- tetraorthosilicates such as tetraethyl orthosilicate (TEOS), other sources tures is the most important advantage of template-based synthesis including silica fume [3], ash [4], and electronic waste [5] have been and can produce chemical and physical properties that differ markedly used successfully. The templating agent and its impact on the MSN from those of the bulk materials. Many different template materials structure are discussed in greater depth in Section 3.1. are available, and depending on their type and structure, a wide range Zeolites are nanostructured, crystalline aluminosilicates containing of nanomaterials can be synthesized. The general mechanism for tem- pores and cavities of molecular dimensions. Many occur as natural min- plate synthesis includes three principal stages, the template prepara- erals, but it is the synthetic varieties, which are among the most widely tion, directed synthesis of the target material using the template, and used sorbents, catalysts, and ion-exchange materials in the world. Zeo- template removal [1]. lite crystals are porous on a molecular scale with their structures reveal- Covered in this review are a variety of template-based methodologies ing regular arrays of channels and cavities (3–15 Å), thus creating a that govern the synthesis of some notable nanostructured materials, in- nanoscale labyrinth, which can be filled with water or other guest mol- cluding zeolites, mesoporous silica, semiconducting nanoparticles, nano- ecules. Zeolites are aluminosilicates with tetrahedrally connected wires, nanotubes, and thin films. Although template-based syntheses framework structures based on corner-sharing aluminate (AlO4) and encompass a tremendously broad range of methodologies, they share silicate (SiO4)tetrahedrons[6,7]. These tetrahedrons can arrange them- striking similarities in regard to their underlying principle and mecha- selves in many unique ways, giving rise to the many different types of nism. The types of templates, ranging from organic molecules to zeolites. The aluminum exists in Al+3 oxidation state bonded to four ox- membranes, are discussed, along with their corresponding common syn- ygen atoms, resulting in a net negative charge for each aluminum atom thesis methods and applications. to the framework. Silicon exists in Si+4 oxidation state bonded to four Two classic examples of heavily template-controlled nanomaterials oxygen anions, each shared between two silicon atoms,