General Synthesis of Ordered Crystallized Metal Oxide Nanoarrays Replicated by Microwave‐Digested Mesoporous Silica

Abstract

sulated between any two points on the exposed area of two adjacent grids. Therefore, the transferred PPy lines are electrically separated and so might find application in plastic electronics. [19] In summary, we have demonstrated for the first time to our knowledge that electropolymerization on semiconductor substrates patterned with self-assembled films results in patternamplified conducting polymer microstructures. It is a facile and versatile way to directly form positively patterned threedimensional conducting polymer structures, which we believe will find applications in related high-technology fields, such as nano-/microscale electromechanical systems and biosensors. ExperimentalPatterning was realized making use of the well-established lCP method, using a PDMS stamp to transfer OTS onto freshly cleaned substrate [8]. The substrates used include three types of silicon wafers (n-type (111), 0.015 X cm; n-type (100), 4 X cm; p-type (111), 15 X cm); and ITO (4±7 X cm). Electrodeposition was preformed on a Chi660a (Shanghai Chenhua Apparatus Co. Ltd) electrochemical workstation. A three-electrode system was used, with the patterned substrate as the working electrode, Pt wire as the counter electrode, and Ag/Ag + (10 mM AgNO 3 in acetonitrile) as the reference electrode. The plating solution of acetonitrile contains 0.2 M pyrrole and 0.1 M 1-hexyl-3-methylimidazolium tetrafluoroborate (a gift from Dr. Wang and Dr. Ye of our laboratory) as the supporting electrolyte. To transfer the PPy microstructure, the PPy pattern on the substrate was coated with Sylgard 184 (Dow Corning) and cured at 100 C for 2 h. Then the silicone elastomer was peeled off from the substrate.Resistance measurements were performed making use of a two-probe method. The adhesion strength of the PPy to the silicone elastomer was determined by a peel-off test using a domestic adhesive tape. AFM measurements were taken using an SPM-9500 apparatus (Shimazu). Optical microscopic images were collected on a charge-coupled device (CCD) camera (USA) equipped to a microhardness tester (USA). A variety of synthetic pathways has been proposed for the development of nanostructures because of their numerous potential applications. Received[1] The use of soft templates [2±4] (chelating agents, surfactants, DNA, etc.) and hard templates [5±11] (anionic alumina, carbon nanotubes, and mesoporous materials) has sparked wonderful contributions. Though various metal and semiconductor nanostructures have successfully been exploited, [2±4] uniform mesostructured crystallized metal oxide patterns are rarely reported, [10n,o,12] probably a result of the difficulty of choosing the proper synthesis precursor and the auxiliary reagents. In this respect, a general synthetic strategy for mesostructured metal oxides guided by ªhost± guest chemistryº is much desired. For the preparation of ordered nanostructure arrays, a hard template has some advantages when compared with a soft template, especially in its specific topological stability, veracity, predictability, and...

Facile preparation of 3D ordered mesoporous CuOx–CeO2 with notably enhanced efficiency for the low temperature oxidation of heteroatom-containing volatile organic compounds

“…have uniform mesocavities, high surface areas, and large pore volumes, which makes them the perfect candidates to serve as ''hard templates''. 35,37,38 Among these, SBA-16 has three-dimensional (3D) channels and a cubic Im3m (bodycentered cubic arrangement of cages with 8 apertures to the nearest neighbors) structure, which could be more favorable for mass and thermal transfer than a unidirectional pore system. 39 In order to introduce the maximum quantity of metal precursors, as many silanol groups as possible must be retained during the preparation of the silica template.…”

“…In our previous work, we found that the mesochannels of SBA-15 and KIT-6 were far from completely filled by metal precursors due to a large loss of Si-OH groups during the organic template removal process that involved a thermal calcination, 40,41 and this phenomenon has also been reported by other groups. 35,42,43 Other approaches such as using solvents and supercritical fluid extraction require long periods of operation (.24 h) and it is difficult to remove the organic template completely. 44 Tian et al proposed microwave irradiation as an effective technique for making organic templates such as Pluronic P123 quickly and with total removal of the onedimensional (1D) SBA-15 material with the greatest preservation of the original mesoporous structure and surface hydroxyl groups.…”

“…[31][32][33] The use of soft templates (e.g., chelating agents and surfactants) and hard templates (e.g., mesoporous materials and carbon nanotubes) has led to some wonderful contributions. [34][35][36] Compared with soft templates, hard templates have some advantages for the preparation of ordered mesoporous arrays. Supramolecular mesoporous silica templates (MCM41S, SBA-15, KIT-6, SBA-16, etc.)…”

Effect of anions on the morphology of Co3O4 nanostructures grown by hydrothermal method and their pH sensing application

“…Co3O4 nanostructures are expected to show even more excellent and tunable properties due to their versatile morphologies and structures. So far, many interesting nanostructures of Co3O4, including nanowires/nanorods [16,17], nanotubes [18,19], nanocubes [20][21][22], nanospheres [23][24][25], nanoplates [26] and nanowalls [27], have been prepared by using different growth methods. He et al synthesized Co3O4nanocrystals by a solubility controlled method using surfactant [28].…”

General Synthesis of Ordered Nonsiliceous Mesoporous Materials

“…In contrast to calcination, MWD technique is facile and effective in removing the surfactant without sacrificing the silanols on pore walls and distinct framework shrinkage (90). It is reasonable that the microwave digested silicates with large pore volumes, high surface areas, and the most important of all, abundant silanols serve as the ideal hard templates for nanocasting replicas (90,91).…”