Nano Template Research Articles

Efficient peroxymonosulfate activation and As(III) removal derived from Mn-FeOOH@nitrogen-deficient porous nanosheets: Key role of the N/O double vacancy

Nitrogen deficient porous nanosheets(NDCN) are a promising nano template that can combine defect engineering with Mn-FeOOH to suppress photo generated carrier complexation and optimize electron distribution. In this study, a unique structure with N/O double vacancies in Mn-FeOOH@NDCN was prepared using a magnesium thermal denitrification co-precipitation method. Furthermore, a series of Mn-FeOOH/NDCN/PMS reaction systems were constructed by adjusting the dosage of peroxymonosulfate(PMS). The experimental results indicate that the synergistic activation of N/O double vacancies on PMS enables the Mn-FeOOH/NDCN/PMS system to oxidize almost 10 mg/L of As(III) within 90 min. At the same time, the oxidized As(V) was completely adsorbed, thereby completely removing the total arsenic in the water. The reasonable construction of carbon networks is a prerequisite for the stability of Mn-FeOOH/NDCN composite catalysts, enabling them to have good cyclic stability. The experimental results confirm that oxygen vacancies directly participate in the activation of PMS, while nitrogen vacancies effectively adsorb As(III), thereby promoting the contact between As(III) and PMS, improving the mass transfer rate, and accelerating the catalytic degradation process. This study will provide a new way to completely remove arsenic pollution from water bodies.

A Simple Trick to Increase the Areal Specific Capacity of Polypyrrole Membrane: The Superposition Effect of Methyl Orange and Acid Treatment.

Polypyrrole (PPy) is one of the attractive conducting polymers that have been investigated as energy storage materials in devices like supercapacitors. Previously, we have reported a free-standing soft PPy membrane synthesized through interfacial polymerization in which methyl orange (MO) and ferric chloride were used as nano template and oxidant. In this work, we report that the presence of MO and the treatment of the PPy-MO membrane with sulfuric acid can dramatically increase the specific capacitance of the membrane. The properties of the membranes were evaluated using scanning electron microscope (SEM) for morphology, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) for chemistry, thermogravimetric analysis (TGA) for thermal stability, and cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) for electrochemical activity. It was found that the areal specific capacitance of the PPy membrane increased from 2226 mF/cm2 to 6417 mF/cm2 and the charge transfer resistivity decreased from about 17 Ω to 3 Ω between 10,000 and 0.1 Hz due to the presence of MO and the acid treatment. It is likely that the superposition effect of MO and acid treatment helped the charge transfer process and consequently enhanced the charge storage performance and specific capacitance of the PPy membrane.

Chitosan/benzyloxy-benzaldehyde modified ZnO nano template having optimized and distinct antiviral potency to human cytomegalovirus

Utilization of biomolecules encapsulated nano particles is currently originating ample attention to generate unconventional nanomedicines in antiviral research. Zinc oxide nanoparticle has been extensively studied for antimicrobial, antifungal and antifouling properties due to high surface to volume ratios and distinctive chemical as well as physical properties. Nevertheless, still minute information is available on their response on viruses. Here, in situ nanostructured and polysaccharide encapsulated ZnO NPs are fabricated with having antiviral potency and low cytotoxicity (%viability ~ 90%) by simply controlling the formation within interspatial 3D networks of hydrogels through perfect locking mechanism. The two composites ChH@ZnO and ChB@ZnO shows exceedingly effective antiviral activity toward Human cytomegalovirus (HCMV) having cell viability 93.6% and 92.4% up to 400 μg mL−1 concentration. This study brings significant insights regarding the role of ZnO NPs surface coatings on their nanotoxicity and antiviral action and could potentially guide to the development of better antiviral drug.

Optically sensitive isolated silver nano-dots development by broad ion implantation on nitrogen ion-induced pre-patterned silicon nano-templates

We report broad ion beam-induced isolated silver nano-dot formation on the pre-patterned silicon nitride nano template. The nano templates are developed and optimized on Si (100) surfaces using N2+ ion bombardment at different incidence angles and fluences. Atomic Force Microscopy shows that the well-defined pyramidal structures can be formed by 14 keV, N2 ion bombardment at incidence angle 70° with ion fluence 2 × 1018 ions/cm2. Optical sensitive, implanted Ag nano-dots are placed at selective sites of the patterns by exploiting the geometrical structure of the pattern and local ion implantation angle. Surface chemical analysis by X-ray photoelectron spectroscopy and cross-sectional investigation by transmission electron microscopy (TEM) confirms the presence of isolated Ag dots arrays at the specific sites of the nano-pyramidal template structures. The presence of isolated Ag dots on the silicon/silicon nitride surface shows a significant enhancement of the Raman signal, which further rises by the increase of Ag ion fluence. A change of light reflectance from the substrate surface is also observed due to the presence of Ag dots. The growth mechanism of the pyramidal structure by grazing incidence ion bombardment and the approach of isolated Ag dot formation by the self-masking process as well as optical responses are described.

Zinc oxide nanocolumns grown on self-assembled silica nanosphere monolayer templates

This paper presents a concept of a two-step growth process that first lays down a nano template by self-assembly to define the spatial distribution of the nanostructures, followed by a highly directional physical vapor deposition method to selectively grow material in a columnar configuration. Langmuir–Blodgett technique was used to construct self-assembled monolayers of silica nanospheres (SNSs) with five different radii, 1.9 μm, 590 nm, 425 nm, 250 nm, and 125 nm. Z-axis oriented ZnO crystalline nanostructures grown on top of the spheres by the Glancing Angle PLD formed columnar arrays that were observed to form a hcp structure. Columnar aspect ratios as well as the density per unit area were found to be dependent on underlying sphere size. In addition to the experimental demonstration of the technique, a nucleation model is presented to understand the mechanism of growth in this novel approach.

Organic molecule confinement reaction for preparation of the Sn nanoparticles@graphene anode materials in Lithium-ion battery

Sn@Graphene composites as anode materials in Lithium-ion batteries have attracted intensive interest due to the inherent high capacity. On the other side, the high atomic ratio (Li4.4Sn) induces the pulverization of the electrode with cycling. Thus, suppressing pulverization by designing the structure of the materials is an essential key for improving cyclability. Applying the nanotechnologies such as electrospinning, soft/hard nano template strategy, surface modification, multi-step chemical vapor deposition (CVD), and so on has demonstrated the huge advantage on this aspect. These strategies are generally used for homogeneous dispersing Sn nanomaterials in graphene matrix or constructing the voids in the inner of the materials to obtain the mechanical buffer effect. Unfortunately, these processes induce huge energy consumption and complicated operation.To solve the issue, new nanotechnology for the composites by the bottom-up strategy (Organic Molecule Confinement Reaction (OMCR)) was shown in this report. A 3D organic nanoframes was synthesized as a graphene precursor by low energy nano emulsification and photopolymerization. SnO2 nanoparticles@3D organic nanoframes as the composites precursor were in-situ formed in the hydrothermal reaction. After the redox process by the calcination, the Sn nanoparticles with nanovoids (~100 nm, uniform size) were homogeneously dispersed in a Two-Dimensional Laminar Matrix of graphene nanosheets (2DLMG) by the in-situ patterning and confinement effect from the 3D organic nanoframes. The pulverization and crack of the composites were effectively suppressed, which was proved by the electrochemical testing. The Sn nanoparticles@2DLMG not delivered just the high cyclability during 200 cycles, but also firstly achieved a high specific capacity (539 mAh g−1) at the low loading Sn (19.58 wt%).

Face-centred cubic CuO nanocrystals for enhanced pool-boiling critical heat flux and higher thermal conductivities

In this study, we established a face-centered cubic CuO nanocrystals (fcc.CuO), and their nano liquids (NLs), and apply them to pool boiling critical heat flux (pbCHF) and thermal conductivity (TC) applications. Additionally, we compared them to commercial CuO nonmaterials. The fcc.CuO was fabricated by a solution chemical method using a specific hydrophilic surfactant, such as polyvinyl pyrrolidone, as the capping agent for controlling the shape, and size. We investigated two kinds of nanoliquids which are fcc. CuO-NL and CuO-NL with 0.06 wt%, 0.03 wt%, 0.006 wt%, and 0.003 wt% for application of pbCHF, and TCs. The pbCHF of fcc.CuO-NL(0.06 wt%) was shown 121% compared to CuO-NL, and 132% higher compared with de-ionized (DI) water, respectively. The thermal conductivity of fcc.CuO-NL is 7.2% compared with DI water, owing to the effect of deposition of fcc.CuO with regular shape, and size. The contact angles (CAs) measurements shown higher hydrophilic nature due to the formation of the nano template layer on a Nichrome wire surface. Besides that, we evaluated the bubble site density, bubble growth, and departure studies during critical heat flux experiments using a speed camera. In conclusion, the developed fcc.CuO-NLs exhibited higher pbCHFs and Thermal conductivities with lower concentrations, respectively.

The Preparation of CNTs/PE Nanocomposites Particles with Coral Shape and Core-Shell Structure In Situ Produced via Nanotemplate Catalyst Based on MWCNTs

A kind of nano template catalyst was prepared through loading the active compound (m-CH3PhO)TiCl3 on carbon nanotubes (CNTs). This catalyst can catalyze (co)polymerization of ethylene to form CNTs/polyethylene (PE) nanocomposites particles. The nano template catalyst showed high catalytic activity up to 5.8 kg/(gTi.h.p) for the copolymerization of ethylene with 1-hexene. The results revealed that the nascent CNTs/PE nanocomposites particles looked like coral shape and featured with the core-shell structure which CNTs as the core and polyethylene as the shell.

Properties and microstructure of the Ru-coated carbon nano tube counter electrode for dye-sensitized solar cells.

In this study, we investigated the performance of dye-sensitized solar cells (DSSCs) with the ruthenium (Ru) coated multi-walled carbon nanotube (MWCNT) on the counter electrode (CE). High purity MWCNT (0.01~0.06 g) was sprayed on glass/fluorine-doped tin oxide (FTO). Then 30 nm-thick Ru thin films were coated on a MWCNT template at low temperature by atomic layer deposition (ALD) using RuDi and O2 as precursor to prepare Ru-CNT CE and the 0.45 cm2 DSSC device of glass/FTO/TiO2/Dye (N719)/electrolyte (C6DMII, GSCN)/Ru-CNT CE was fabricated. The surface morphology of CEs and the energy conversion efficiency of the DSSC device were characterized by scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), and photocurrent-voltage (I-V) measurement. We confirmed that effective surface of the CE increased linearly as the amount of MWCNT spray increased and the crystallized Ru was deposited very conformally around the MWCNT nano template. Moreover, the efficiency of the DSSC increased up to 3.3% as the amount of MWCNT increased.

에칭용액의 인산 첨가량에 따른 양극산화 알루미늄 템플레이트의 제작 및 특성

Anodic aluminum oxides (AAO) fabricated by the two-step anodizing process have attracted much attention for the fabrication of nano template because of pore structure with high aspect ratio, low cost process and ease of fabrication. AAOs are characterized by a homogeneous morphology of parallel pores that grow perpendicular to the template surface with a narrow distribution of diameter, length and inter-pores spacing, all of which can be easily controlled by suitably choosing of the anodizing parameters such as pH of the electrolyte, anodizing voltage and duration of anodizing. In this study, AAO templates were characterized by X-ray diffraction and field-emission scanning electron microscope (FE-SEM). The dependence of the pore size change according to the amount of addition of phosphoric acid, which was used to remove the initial alumina oxide layer, was not observed.

Growth control of carbon nanotubes using by anodic aluminum oxide nano templates.

Anodic Aluminum Oxide (AAO) template prepared in acid electrolyte possess regular and highly anisotropic porous structure with pore diameter range from five to several hundred nanometers, and with a density of pores ranging from 10(9) to 10(11) cm(-2). AAO can be used as microfilters and templates for the growth of CNTs and metal or semiconductor nanowires. Varying anodizing conditions such as temperature, electrolyte, applied voltage, anodizing and widening time, one can control the diameter, the length, and the density of pores. In this work, we deposited Al thin film by radio frequency magnetron sputtering method to fabricate AAO nano template and synthesized multi-well carbon nanotubes on a glass substrate by microwave plasma-enhanced chemical vapor deposition (MPECVD). AAO nano-porous templates with various pore sizes and depths were introduced to control the dimension and density of CNT arrays. The AAO nano template was synthesize on glass by two-step anodization technique. The average diameter and interpore distance of AAO nano template are about 65 nm and 82 nm. The pore density and AAO nano template thickness are about 2.1 x 10(10) pores/cm2 and 1 microm, respectively. Aligned CNTs on the AAO nano template were synthesized by MPECVD at 650 degrees C with the Ni catalyst layer. The length and diameter of CNTs were grown 2 microm and 50 nm, respectively.

Neuronal networks on the nano alumina templates (1127.4)

The hippocampus neuron cells were cultured on the nano‐alumina substrates. Several adhesion protein molecules e.g. Poly D Lysine (PDL), collagen (ECL) and leminin were applied as an interface in between the Al2O3 nano‐templates and the neuronal network before culturing the cells on top of them. The neuronal tissues were mechanically dissociated and cultured on the alumina nano template surfaces and incubated in an incubator. The cells grew on the top of the templates for 24 days. The well‐defined neuronal networks observed on the surface of the Al2O3‐nano templates. For control study, we also cultured neurons on the glass‐slip surfaces. This study revealed that the neurons can grow on any nano‐scale surfaces as well as on the standard cover slip if the proper growing environment will be provided.

Synthesis of Copper Nanowires in Highly Ordered Nanoporous Anodic Alumina Template

In this paper, the fabrication of nanoporous anodic alumina template from aluminum foil has been demonstrated using hard anodization process. Copper nanowires arrays were fabricated using continuous and pulse electrodeposition technique into the porous alumina template. Copper nanowires are grown su ccessfully in anodic alumina nano template. The pulse deposition technique using 50 ms off -time showed better quality samples than those madewith continuous deposition technique due to cooling of barrier layer during the off -time.

The Preparation of Nanosized Polyethylene Particles via Carbon Sphere Nanotemplates

A novel type of nano template was prepared by loading a Ziegler–Natta catalyst on nanosized carbon spheres for ethylene polymerization to form nanosized polyethylene (PE) particles; triethylaluminu...

NEURONAL NETWORKS ON THE NANO ALUMINA TEMPLATES

The hippocampus neuron cells were cultured on the nano‐alumina substrates. Several adhesion protein molecules e.g. Poly D Lysine (PDL), collagen (ECL) and leminin were applied as an interface in between the Al2O3 nano‐templates and the neuronal network before culturing the cells on top of them. The neuronal tissues were mechanically dissociated and cultured on the alumina nano template surfaces and incubated in an incubator. The cells grew on the top of the templates for 24 days. The well‐defined neuronal networks observed on the surface of the Al2O3‐nano templates. For control study, we also cultured neurons on the glass‐slip surfaces. This study revealed that the neurons can grow on any nano‐scale surfaces as well as on the standard cover slip if the proper growing environment will be provided.

The experimental study of reverse micellar phase in AOT/ Heptane/ (Water or aqueous) as nano template

In this paper electrical conductivity measurements and optical investigations takes place in AOT/ heptane/ (water or aqueous) systems. The water in oil system prepared with adding water in 50% by weight of AOT/ heptane solution. In other systems instead of water, aqueous solutions of 1) zinc acetate and water 2) Potassium Hydroxide and water were used. In each phase, the trend of the electrical conductivity values changes at a proper water or aqueous solution concentration. The optical properties investigated through two crossed Polaroid. The different phases can be distinguished from each other; the phases characterized are as isotropic, anisotropic or mixed phase.

Growth of copper-indium nanorods on Si substrate using porous anodic alumina as template

Copper-indium nanorod arrays have been synthesized by electrodeposition using porous anodic alumina nano template supported on a silicon substrate. Porous anodic alumina template was fabricated by evaporating aluminium film onto silicon substrate and then anodizing the aluminium film in diluted phosphoric acid. The approach employs a plasma etching to penetrate the alumina pore barrier layer before electrodeposition, which enables direct electrical and chemical contact with the silicon substrate electrode. The resulting template and copper-indium nonorods obtained were characterized using scanning electron microscopy (SEM) and energy-dispersived X-ray spectroscopic analyzer (EDS), the pores of alumina are found to have dimensions of 150–250 nm pore diameters and 330–510 nm pore spacings, partial filling of the pores of the alumina template by Cu-In is achieved. The results of this work reveal that the alumina nano template is particularly well suited to the etching mask and template-assisted growth of nanostructures to be integrated into rigid substrate.

Fabrication of metal nano dot dry etching mask using block copolymer thin film

Dense and periodic arrays of Au, Cr, Ni and Al nano dots were fabricated on silicon substrate. To obtain nano size patterns, self-assembling resists were used to produce a layer of uniformly distributed parallel cylinders of PMMA in a PS matrix. The PMMA cylinders were degraded and removed by acetic acid rinsing, forming a PS mask to transfer the pattern. The patterned holes of PS template were approximately 20 nm wide, 40 nm deep, and 50 nm apart. About 100 Å-thick Au, 30 Å-thick Cr, Ni, and Al thin film was deposited by using e-beam evaporator. PS template was removed by lift-off process using N -formyldimethylamine (DMF). Arrays of metal nano dots were dry etched by using fluorine-based reactive ion etching (RIE). As a result, the nano template of PS was analyzed with field-emission scanning electron microscope (FESEM) and the sizes of Cr, Ni, Au and Al nano dots left on Si surface were measured by atomic force microscope (AFM). The sizes of metal nano dots were in the range of 17–22 nm.

The photovoltaic effect of the p–n heterojunction organic photovoltaic device using a nano template method

Characteristics of ITO/polypyrrole (PPy) nano fibers/poly(3-hexylthiophene)/Al photovoltaic devices prepared by nano template method were studied. PPy nano fibers on ITO glass were formed through nano pores of polymer membrane template using home made special sample holder by electrochemical polymerization in an electrolyte solution of pyrrole and lithium perchlorate as a dopant in acetonitrile. Ordered structure with enhanced interfacial area formed by nano template method enable to fabricate polymeric photovoltaic device with improved photo-conversion efficiency. This nano fiber structures film possesses increased interfacial area, large charge separation area (photoactive zone) and secured charge transportation route. The effect of altering energy levels of PPy by changing doped state was also studied. Device made with nano fiber structure showed enhanced photovoltaic effect than that of overlayed film device.