Rational Design of Mesoporous Metals and Related Nanomaterials by a Soft-Template Approach
ABSTRACT We review recent developments in the preparation of mesoporous metals and related metal-based nanomaterials. Among the many types of mesoporous materials, mesoporous metals hold promise for a wide range of potential applications, such as in electronic devices, magnetic recording media, and metal catalysts, owing to their metallic frameworks. Mesoporous metals with highly ordered networks and narrow pore-size distributions have traditionally been produced by using mesoporous silica as a hard template. This method involves the formation of an original template followed by deposition of metals within the mesopores and subsequent removal of the template. Another synthetic method is the direct-template approach from lyotropic liquid crystals (LLCs) made of nonionic surfactants at high concentrations. Direct-template synthesis creates a novel avenue for the production of mesoporous metals as well as related metal-based nanomaterials. Many mesoporous metals have been prepared by the chemical or electrochemical reduction of metal salts dissolved in aqueous LLC domains. As a soft template, LLCs are more versatile and therefore more advantageous than hard templates. It is possible to produce various nanostructures (e.g., lamellar, 2D hexagonal (p6mm), and 3D cubic (Ia\3d)), nanoparticles, and nanotubes simply by controlling the composition of the reaction bath.
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- "Thus, there is possibility for forming effective hydrogen bonding between individual or combined surfactant groups and hydrated metal ions/complexes. The excellent control of the composition of the framework is of considerable importance in terms of the functional design of mesoporous materials  . Once, the concentrations of Pluronic F127 are much higher than the critical micelle concentration, packed and relatively ordered micelles (e.g., highly hexagonal-packed micelles) can be obtained. "
ABSTRACT: Mesoporous binary nickel–cobalt (Ni–Co) oxy-hydroxides have been obtained through the microwave-assisted hydrothermal annealing (MAHA) method. The porosity control of the nanostructured Ni–Co oxy-hydroxide nanoparticles is achieved through adding the pluronic triblock copolymer F127 as the surfactant. The structural and electrochemical properties of porous Ni–Co oxy-hydroxide nanostructures are characterized by means of X-ray diffraction (XRD), Brumauer–Emmett–Teller (BET) analysis, transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and cyclic voltammetry (CV). The electrochemical measurement demonstrates that the Ni–Co oxy-hydroxides calcined at 200 °C are able to deliver a specific capacitance of 636 F g−1 in 1 M NaOH, suggesting their high potential as a novel electrode material of pseudocapacitors with good electrochemical reversibility. In the asymmetric supercapacitor test, the positive electrode is Ni–Co oxy-hydroxide and negative electrode is activated carbon. The specific energy and power, measured at 2 A g−1, for this asymmetric combination are equal to ca. 17 Wh kg−1 and 1.6 kW kg−1, respectively.Electrochimica Acta 09/2014; 94:104–112. DOI:10.1016/j.electacta.2013.01.125 · 4.50 Impact Factor
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- "High surface area nanostructured electrodes have received considerable attention in recent years                  . These materials are conductive, have surface areas that are typically 2–1000 times larger than a planar electrode of similar size, and consist of either oriented, well-defined or random pore morphology . "
ABSTRACT: Nanoporous gold prepared by dealloying Au:Ag alloys has recently become an attractive material in the field of analytical chemistry. This conductive material has an open, 3D porous framework consisting of nanosized pores and ligaments with surface areas that are 10s to 100s of times larger than planar gold of an equivalent geometric area. The high surface area coupled with an open pore network makes nanoporous gold an ideal support for the development of chemical sensors. Important attributes include conductivity, high surface area, ease of preparation and modification, tunable pore size, and a bicontinuous open pore network. In this paper, the fabrication, characterization, and applications of nanoporous gold in chemical sensing are reviewed specifically as they relate to the development of immunosensors, enzyme-based biosensors, DNA sensors, Raman sensors, and small molecule sensors.
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ABSTRACT: Giant metal cages: Mesoporous Pt particles, with mesocages connected closely in three dimensions (see picture), are prepared by an electrodeposition process through soft templating from lyotropic liquid crystals of diblock copolymers. The size of the mesocages is the largest (about 15 nm) reported in mesoporous metals. The method can be extended to other metals and mesostructures, and the mesopores can be controlled over a range of pore sizes. (Figure Presented)Angewandte Chemie International Edition 07/2008; 47(29):5371-3. DOI:10.1002/anie.200801381 · 11.26 Impact Factor