Electrodeposition of Metallic Nanowire Thin Films Using Mesoporous Silica Templates

Abstract

Nanostructured materials are one of the most active areas of materials science research. This interest is due to their unique properties (e.g., magnetic, optical, electronic, mechanical) and potential applications.[1] Metallic nanostructured materials, such as metal nanowires and nanoarrays, have potential applications in nanoscale devices, sensors, nonlinear optics, magnetic storage media, and anisotropic conductors. [1,2] Synthetic methods such as electron-beam lithography, step-edge decoration, and templated growth have been developed to prepare metallic nanostructured materials.[3] The templated growth method, which involves confined growth of metallic materials to a template (e.g., a pore) followed by removal of the template, provides a flexible and affordable synthetic route to a large variety of metal nanowires. Examples of such templates include hard templates [4] (e.g., porous alumina films, track-etched polycarbonate films, and mesoporous silica) and soft templates [1a,5] (e.g., liquid-crystalline phases and amphiphilic block copolymers). The hard templating approach is conceptually simple to implement; however, the use of porous alumina or polycarbonate membranes as templates usually results in polycrystalline nanowires or nanowires with large wire diameters (20±1000 nm), which may preclude quantum confinement effects. Surfactant-templated mesoporous silica possesses unique mesoscale pore channels and a controllable pore surface chemistry, which make it an ideal template for the synthesis of metal nanowires.[6±8] Electrodeposition is an efficient and ready technique for depositing metal coatings. In this Communication, we report the fabrication of metal thin films composed of ordered arrays of metal nanowires that are grown electrochemically within silica mesoporous channels. Although syntheses of metal nanowires by chemical reduction of metallic complexes and by chemical vapor infiltration of mesoporous silica pore channels have been reported previously, [8] as-synthesized metal nanowires usually lack macroscopic continuity. In this new method, nanowires are continually grown from the bottom conductive substrate upward until the mesoporous channels are filled. This provides a ready and efficient route to macroscopic, hierarchical metal nanowire thin films. The metal nanowire thin films before and after removal of silica were characterized using X-ray diffraction (XRD). Figure 1 shows the XRD patterns of a mesoporous silica thin film (A) and a silica/metal thin film before (B) and after (C) removal of the silica template. Trace A exhibits a typical one-dimensional hexagonal pattern with an intense (100) diffraction peak with a d-spacing of 67.4 and with a (200) peak of 35.6 . The mesostructured silica after metal deposition (trace B) shows a diffraction pattern similar to that for trace A, except for the expected decrease in the XRD peak intensity at low angles.[8b] The inset shows the XRD pattern of the silica/palladium thin film at higher 2h angles. The presence of the characteristic diffraction ...

The modification of MoO3 nanoparticles supported on mesoporous SBA-15: characterization using X-ray scattering, N2 physisorption, transmission electron microscopy, high-angle annular darkfield technique, Raman and XAFS spectroscopy

“…Such incorporated nanoparticles may have interesting optical, magnetic, and catalytic properties. In addition to the studies of the formation of metal nanoparticles and nanowires, such as Pt [3][4][5], Pd [6][7][8][9], Au [3-5, 10, 11], Ag [3], and Ti [12], the formation of binary nanomaterials such as PbS [13], CdS [14], TiN [15], and GaN [16] within the nanoscale channels of these mesoporous materials have been explored. More recently, highly ordered quantum wires of Zn 1-x Mn x S [17] and Cd 1-x Mn x S [18] have been successfully synthesized within the mesopores of SBA-15.…”

“…Recently, SBA-15-supported MoO 3 materials were used as an intermediate for the preparation of MoS 2 catalysts. Different synthesis strategies were applied like thermal treatment of SBA-15 impregnated with ammonium heptamolybdate (AHM) [30], thermal spreading of MoO 3 [31], or sonochemical decomposition of Mo(CO) 6 in organic solvents [32]. The main aim of these investigations was the preparation of active HDS catalysts.…”

Formation of Titanium Nitride Nanoparticles within Mesoporous Silica SBA-15

“…[8][9][10][11][12][13][14][15][16][17][18][19][20] More recently, a number of studies have been directed at the synthesis of metal nanowires and nanoparticles in mesoporous silica films. [21][22][23] In addition to studies on the growth of singleelement metal nanoparticles and nanowires in mesoporous silica materials, several studies have explored the formation of binary systems such as GaN, CdS, CdSe, ZnS, and ZnO. [5][6][7][23][24][25][26][27][28] These binary materials are all semiconductors that have potential applications in optoelectronics.…”

A simple electrochemical method for conversion of Pt wires to Pt concave icosahedra and nanocubes on carbon paper for electrocatalytic hydrogen evolution

“…In order to control the morphology of noble metal nanostructures using the electrochemical method, anodic aluminum oxide membranes or mesoporous silicon templates are normally used [29][30][31][32]. However, further process is required to remove these templates in order to purify noble metal nanomaterials used for various applications including electrocatalysis.…”