Nanostructured Architectures Research Articles

Molecular-level insights into a tripolyphosphate and pyrophosphate templated membrane assembly.

Templated assembly of small molecules into nano-structural architectures has been used extensively by nature throughout its evolution. These systems have also been studied in artificial systems to design a phosphate templated assembly. However, it is yet to be investigated how the molecules interact among themselves at the molecular level and whether the phosphate templated assembly has any role in the formation of prebiotic protocellular membranes. Here, we report the prebiotic synthesis of choline-based cationic amphiphiles (-N+Me3) and the templated assembly of these amphiphiles with tripolyphosphate (TPP) and pyrophosphate (PPi). SEM, TEM, FLIM, DLS, fluorescence, and encapsulation studies suggest that the number of phosphate units in the phosphate backbone controls the formation and size of the protocell vesicles. Isothermal titration calorimetry, turbidimetric studies, and NMR experiments suggest that the cationic amphiphile forms a 3 : 1 catanionic complex with TPP and a 2 : 1 catanionic complex with PPi. The templated catanionic complex further self-assembles into vesicles, and the structure of the complex guides the size of the assembly. The size-controlling ability of the phosphate backbone might have been utilized in the prebiotic era to support the dynamics and tunability of protocellular membrane compartments.

Metal-organic framework-assisted Co3O4/CuO@CoMnP with core-shell nanostructured architecture on Cu fibers for fabrication of flexible wire-typed enzyme-free micro-sensors

Flexible fiber-based sensors have recently received increasing interest for real-time monitoring personal health, owing to their small size, high flexibility, lightweight, and application potentials in next-generation wearable electronics. Herein, we report a flexible wire-typed micro-sensor based on CoMnP@Co3O4/CuO core–shell nanohybrid array on 1D Cu wire substrate for sensitive detection of glucose. The synthesis process involves in-situ growth of ZIF-67 rhombic dodecahedron on the surface of CuO nanotubes, followed by thermal annealing and electrodeposition of CoMnP nanoparticles to form core–shell nanostructured architectures. Benefiting from desirable hybrid nanostructures, the as-made binder-free fiber microelectrode exposes more electroactive sites for transport of ions and electrons during the catalytic process and provides strong adhesion between electroactive species and metal fiber substrate. As a glucose sensor, the CoMnP@Co3O4/CuO fiber microelectrode displays favorable analytical properties, including two linear dynamic ranges of 0.001 mM – 0.55 mM and 0.55 mM – 3.03 mM with the sensitivities of 2445 μA mM−1cm−2 and 1774 μA mM−1cm−2, respectively, fast response time (1.62 s), excellent selectivity toward glucose at the presence interfering substances, and a low detection limit of 11.42 μM (S/N = 3). Moreover, the proposed wire-typed micro-sensor was successfully applied for measurement of glucose in human blood serum and saliva samples. Taking advantage of the versatility of 1D metal fiber current collector, MOF-assisted strategy and transition metal phosphides, the presented protocol here can be extended to the construction of other wearable and implantable sensing micro-devices.

Bubbles Templated Interconnected Porous Metallic Materials: Synthesis, Surface Modification, and their Electrocatalytic Applications for Water Splitting and Alcohols Oxidation

AbstractPorous metallic foams play a vital role in a diverse range of applications including electrocatalysis, electrochemical sensing, energy conversion and storage systems. Recently, template‐free electrochemical deposition or dynamic bubbles templating techniques have been very useful to precisely control the nanostructured metallic architecture without using any additional organic or inorganic template. Dynamic hydrogen/oxygen bubbles template electrodeposited metallic foams give micro/nano porosity with controlled pores size, pores channels and surface decorated nanoparticles. In this review, we describe the uniqueness of bubble‐templating electrochemical deposition techniques, their detailed implementation towards the synthesis of novel nanostructured metallic foam, and the progress made in the field of hydrogen bubbles, oxygen bubbles, and their derived templating approaches for the development of advanced nanometallic foam and their future prospective. Some modifications of porous metallic foams by galvanic replacement, chemical/electrochemical dealloying process, annealing and decoration of metallic and non‐metallic composites on the porous metallic foam are also summarized. Moreover, the role of porous metallic foam in electrochemical water splitting and alcohol oxidation reaction by offering a short diffusion pathway and concluding remarks about the recent development and future perspective of porous foam in the frontiers of surface structure are also critically reviewed.

Morphological evolution in nanostructured secondary phases in entropy stabilized oxides

High entropy oxides (HEO), containing equimolar ratios of five or more oxide components, have emerged recently as an important class of materials with a variety of interesting properties. Some, but not all, HEO systems can be classified as entropy stabilized oxide (ESO) materials, which means they have a phase state that is stabilized by entropy. In these materials, the competition between the metastable entropy stabilized and equilibrium enthalpy stabilized phase states leads to a reversible entropic phase transformation and the formation of secondary phases after heat treatment. The morphologies of the secondary phases (i.e., Cu-rich tenorite and Co-rich spinel) in bulk (Co,Cu,Mg,Ni,Zn)O were visualized in three dimensions for the first time by using focused ion beam (FIB) tomography. The Cu-rich tenorite secondary phase is observed to manifest as several highly complex particle morphologies with features in the nanometric regime. These morphologies are influenced by heat treatment conditions and the interaction with the Co-rich spinel secondary phase. Additionally, the morphology is dependent on the size of the secondary phase particles themselves, with the morphology evolving from spheres, to needles, to plates as the particles get larger. These results indicate that several strategies can be implemented to manipulate the morphologies of the secondary phases, making it possible to engineer bulk ESO materials with specific microstructural features. The ability to form complex nanostructured architectures will provide a powerful strategy for controlling behavior and expanding the possible applications of ESO materials. • Cu-rich tenorite and Co-rich spinel phases segregate in ESOs during heat treatment. • FIB tomography was used to examine the secondary phase particles in 3D. • Particles have complex geometries with sphere, needle, and plate morphologies. • Most particles have a nanostructured dimension, regardless of overall size. • Cu-rich tenorite phase particles have a size dependent morphological evolution.

Colloidal delivery of vitamin E into solid lipid nanoparticles as a potential complement for the adverse effects of anemia treatment

Vitamin E (VitE) is one of the most important antioxidants and plays a key role in decreasing the inflammatory effects of oxidative stress caused by recurrent doses of iron administration in anemia treatment. However, VitE is poorly soluble in aqueous environments. Here, VitE encapsulation into solid lipid nanoparticles (SLN) composed of myristil myristate to improve its bioavailability was proposed. A 99.9 ± 0.1% encapsulation efficiency with a drug/lipid ratio of 500 µg/mg and 478 higher VitE solubility was obtained. The antioxidant properties of VitE after encapsulation were maintained. SLN-VitE showed a 228.2 nm mean diameter with low polidispersitivity (0.335), and negative Z potential (ζ ≈ −9.0 mV). The SLN were well-dispersed, displayed spherical and homogeneous morphology by TEM. A controlled release of VitE from SLN was found. The XRD and FTIR analyses revealed the presence of a nanostructured architecture of SLN after VitE incorporation. We probed the safety of SLN-VitE after contact with three in vitro cell models: erythrocytes, lymphocytes and HepG2 cells. The cell viability in presence of SLN, SLN-VitE, and their combinations with iron was not affected. The comet assay demonstrated that the DNA damage caused by iron administration was decrease in presence of SLN-VitE.

Electrochemical Sensing of Cortisol in Human Saliva and Serum Using DNA-Steroid Conjugation with a Versatile DNA Nanostructure Sensor

Having a generalizable point of care (POC) method for clinically relevant biomolecules would greatly enhance healthcare management and disease diagnosis. Recently our group developed a novel DNA nanostructure architecture for versatile detection of analytes which is generalizable for assaying several small molecules and their larger protein binding partners (e.g. antibodies) in human serum. The DNA nanostructure is built through on-electrode enzymatic ligation of three oligos for electrode attachment, anchor binding, and electrochemical signaling. In this study, we developed an economical synthetic approach for making oligonucleotide-steroid conjugates, and we explored the capability of these DNA nanostructure sensors for small molecule/steroid detection.Cortisol is a steroid hormone secreted by the hypothalamic-pituitary-adrenal system in response to the body’s stress level. As the main stress hormone, it controls processes such as immune, adrenal, circulatory, and metabolic. Moreover, anomalies of cortisol levels can result in serious conditions such as Addison’s disease, Cushing’s syndrome, and adrenal insufficiencies. Every year, 120,000 deaths are attributed, in part, to elevated levels of stress. To minimize these issues, a simplified method for cortisol sensing is vital. In this study, we conjugated cortisol to amine-tagged DNA and used the conjugates in our sensors. Anti-cortisol antibodies induced a 67% signal drop, validating conjugation. A calibration curve for cortisol showed a limit of detection of 800 pM and a dynamic range of 1 – 100 nM. The sensor was validated in saliva and human serum samples using the gold standard method, ELISA. Changing cortisol levels in two human patients' saliva samples were successfully detected after several collection times throughout a single day. As a potential point-of-care (POC) detection device, our novel cortisol biosensor could detect the hormone in human serum and saliva samples within 6 minutes.

Nanoscale shape-dependent histone modifications.

Recent observations suggest a role for complex nanoscale particulate shape in the regulation of specific immune-related cellular and in vivo processes. We suspect that cellular recognition of nanostructure architecture could involve nonmolecular inputs, including cellular transduction of nanoscale spatially resolved stresses induced by complex shape. Here, we report nanoscale shape-dependent control of the cellular epigenome. Interpretation of ChIP-Seq sequencing suggests that differential marking of H3K27me3 may be linked to sensory and synapse-recognition of nanoscale forces induced by complex shape. The observations raise significant questions on the role of particle-shape-induced immune regulation and memory, with potential consequences in both causes and treatment of immune-related disease.

(Digital Presentation) Activated Carbon Supported Ni-Co Layered Double Hydroxides Nanowires: An Effective and Low-Cost Electrocatalyst Towards Ethanol Oxidation Reaction in Alkaline Media

Developing nanostructured architectures using non-noble, low-cost transition metals with good electrocatalytic activity and durability to replace noble electrocatalysts such as Pt and Pd have gained considerable attention in the field of sustainable and clean energy production technology. To address this, we adopted a facile synthesis route to synthesize Ni-Co layered double hydroxides (NiCo-LDH) nanowires supported on Activated Carbon (AC) via a one-pot hydrothermal synthesis method. The resulting NiCo-LDH nanowires, possessing a crystallite size of ~16.15 nm and a Surface area of 100.81 m2/g, have been utilized as a bifunctional electrocatalyst for ethanol oxidation reaction (EOR) in an alkaline medium. The electrochemical performance of the synthesized catalyst was investigated by Cyclic Voltammetry (CV), Chronoamperometry (CA), and Electrochemical Impedance Spectroscopy (EIS) techniques at room temperature. Impressively, NiCo-LDH/AC exhibited good electrocatalytic activity of 9.79 mA.cm-2 at 1.51 V vs. Saturated Calomel Electrode (SCE) and retained remarkable stability even after 200 cycles in 0.1 M NaOH with 1 M EtOH. The better electrocatalytic activity of NiCo/AC catalyst can be attributed to the presence of active sites and porous structures as well as the good electron transfer conductivity of AC. The attractive performance and facile synthesis of NiCo-LDH supported on AC highlights its potential application as an anodic material in direct ethanol fuel cells (DEFCs).

Poly(safranine T)-deep eutectic solvent/copper oxide nanoparticle-carbon nanotube nanocomposite modified electrode and its application to the simultaneous determination of hydroquinone and catechol

This work presents the combined use of safranine (SF) as a redox polymer and multiwalled carbon nanotubes (MWCNT)-copper oxide nanoparticles (CuO) in the development of a novel sensor for the simultaneous analysis of hydroquinone (HQ) and catechol (CAT). Electropolymerisation of SF was carried out in acid-doped ethaline deep eutectic solvent to prepare poly(safranine) (PSFEthaline) film electrodes with three different nanostructured architectures on pencil graphite electrodes (PGE) as electrode substrate. The polymerisation was done after nanomaterial surface modification to obtain PSFEthaline-HCl/MWCNT/PGE, PSFEthaline-HCl/CuO/PGE, and PSFEthaline-HCl/MWCNT-CuO/PGE. The synthesis, preparation, and characterisation of PSF film-coated electrodes were studied using cyclic voltammetry and electrochemical impedance spectroscopy to investigate the contribution of each nanomaterial on sensor performance. The best result for polymer film growth was obtained with PSF electrodeposited on MWCNT-CuO/PGE in HCl doped-ethaline. The analytical performance of the modified electrode was evaluated for electrochemical sensing of HQ and CAT by differential pulse voltammetry in aqueous Britton-Robinson buffer solution. Due to the combined effect of MWCNT-CuO nanocomposite film and PSF, the modified electrode sensor provided sensitive and selective detection of HQ and CAT with good peak separation. The simultaneousdetermination of HQ and CAT in both tap water and milk samples was successfully carried out to demonstrate the analytical applicability of the sensor. The sensor could be a promising analytical approach for monitoring the amount of HQ and CAT in real samples.

Prolonged repellent activity of Ruta graveolens essential oil adsorbed on different mineral matrices against Sitophilus zeamais (L.) (Coleoptera: Curculionidae)

Plant-derived essential oils (EOs) have been considered as promising alternatives to conventional insecticides. But because of their high biodegradability and rapid volatilization, EOs are not persistent. To overcome this drawback of short protection time, EOs can be adsorbed onto protective mineral matrices to enhance efficiency by slowing down volatilization. This work was aimed at assessing the potential effectiveness of Ruta graveolens L. (Rutaceae) essential oil (RGEO)-adsorbed zeolite (ZEO) and cloisite 20A (C20A) mineral bio-composites in prolonging the odor-driven repellent efficacy of RGEO towards Sitophilus zeamais (L.) (Coleoptera: Curculionidae). Chemical profile of RGEO was identified using GC and GC-MS. Produced bio-composites were physiochemically characterized by FTIR, SEM-EDS, and TGA. The compounds, 2-undecanone (44.7%) and 2-nonanone (30.3%) were the major constituents of RGEO. Repellent action of bio-composites accounting for 50–100% was persisted for 90 d towards S. zeamais adults, whereas the RGEO used without the adsorbents recorded 0% and 44% of repellent potency within 24 h at the lowest and highest concentrations respectively. Given the volatility of RGEO, IR analyses demonstrated successful adsorption and 90-d long persistence of RGEO on both mineral matrices. Micro-/nanostructural architecture of bio-composites ranged from hierarchically porous for ZEO to intercalated platelets for C20A. EDS imaging confirmed the homogenous dispersion of constituent elements of RGEO on both mineral matrices. Bio-composites indicated improved thermal stability in the presence of air flow relative to the neat mineral matrices. Repellent potency of the bio-composites was arranged in the sequence, RGEO-ZEO < RGEO-C20A throughout the 90 d of experimental period. Findings further suggested that formulations based on EOs adsorbed on solid minerals represent a promising strategy in overcoming EOs’ limitations through retaining enough volatility while maintaining their slow release, thereby prolonging the repulsive effect of EOs for use in stored-product protection.

Alloyed nanostructures integrated metal-phenolic nanoplatform for synergistic wound disinfection and revascularization

New materials for combating bacteria-caused infection and promoting the formation of microvascular networks during wound healing are of vital importance. Although antibiotics can be used to prevent infection, treatments that can disinfect and accelerate wound healing are scarce. Herein, we engineer a coating that is both highly compatible with current wound dressing substrates and capable of simultaneously disinfecting and revascularizing wounds using a metal-phenolic nanoplatform containing an alloyed nanostructured architecture (Ag@Cu-MPNNC). The alloyed nanostructure is formed by the spontaneous co-reduction and catalytic disproportionation reaction of multiple metal ions on a foundation metal-phenolic supramolecular layer. This synergistic presence of metals greatly improves the antibacterial activity against both Gram-negative and Gram-positive pathogenic bacteria, while demonstrating negligible cytotoxicity to normal tissue. In infected rat models, the Ag@Cu-MPNNC could kill bacteria efficiently, promoting revascularization and accelerate wound closure with no adverse side effects in infected in vivo models. In other words, this material acts as a combination therapy by inhibiting bacterial invasion and modulating bio-nano interactions in the wound.

Polytypic Phase Transition of Nb1-xVxSe2 via Colloidal Synthesis and Their Catalytic Activity toward Hydrogen Evolution Reaction.

Polytypes of two-dimensional transition metal dichalcogenide can extend the architecture and application of nanostructures. Herein, Nb1-xVxSe2 alloy nanosheets in the full composition range (x) were synthesized by a colloidal reaction. At x = 0.1-0.3, a phase transition occurred from various hexagonal (three 2H and one 4H types) phase NbSe2 to an atomically homogeneous 1T phase VSe2. Density functional theory calculations also revealed a polytypic phase transition at x = 0.3, which was shifted close to 0 in the presence of Se vacancies. Furthermore, the calculations validate favorable formation of Se vacancies at the phase transition. The sample at x = 0.3 exhibited enhanced electrocatalytic activity toward the hydrogen evolution reaction (HER) in 0.5 M H2SO4. The Gibbs free energy indicates that the catalytic HER performance is correlated with the active Se vacancy sites of polytypic structures.

Electrochemical Sensing of the Peptide Drug Exendin-4 Using a Versatile Nucleic Acid Nanostructure.

Although endogenous peptides and peptide-based therapeutics are both highly relevant to human health, there are few approaches for sensitive biosensing of this class of molecules with minimized workflow. In this work, we have further expanded on the generalizability of our recently developed DNA nanostructure architecture by applying it to electrochemical (EC) peptide quantification. While DNA-small molecule conjugates were used in a prior work to make sensors for small molecule and protein analytes, here DNA-peptide conjugates were incorporated into the nanostructure at the electrode surfaces, and antibody displacement permitted rapid peptide sensing. Interestingly, multivalent DNA-peptide conjugates were found to be detrimental to the assay readout, yet these effects could be minimized by solution-phase bioconjugation. The final biosensor was validated for quantifying exendin-4 (4.2 kDa)─a human glucagon-like peptide-1 receptor agonist important in diabetes therapy─for the first time using EC methods with minimal workflow. The sensor was functional in 98% human serum, and the low nanomolar assay range lies between the injected dose concentration and the therapeutic range, boding well for future applications in therapeutic drug monitoring.

Design of InAs nanosheet arrays with ultrawide polarization-independent high absorption for infrared photodetection

InAs nanowires have been considered as good candidates for infrared photodetection. However, one-dimensional geometry of a nanowire makes it unsuitable for broadband light absorption. In this work, we propose and design InAs nanosheet arrays to achieve polarization-independent, angle-insensitive, and ultrawide infrared absorption. Simulations demonstrate that two-dimensional InAs nanosheets can support multiple resonance modes, thus leading to a strong and broadband absorption from visible light to mid-wave infrared. Moreover, we can tune polarization-dependent property in InAs nanosheets to be polarization-insensitive by forming a nanosheet based clover-like and snowflake-like nanostructures. We further optimized the design of InAs nanosheet arrays based on such structures and achieved high absorption (up to 99.6%) covering a broad wavelength range from 500 to 3200 nm. These absorption properties are much superior to their nanowire and planar film counterparts, making it attractive for infrared photodetection applications. The architecture of such nanostructures can provide a promising route for the development of high-performance room-temperature broadband infrared photodetectors.

Revealing the mechanisms of hydrogel formation by laccase crosslinking and regeneration of feruloylated arabinoxylan from wheat bran

Feruloylated arabinoxylan (FAX) from cereal brans has large potential to generate multifunctional materials with customized macromolecular and nanostructural architectures and techno-functional properties. Here we investigate the chemical and structural mechanisms of hydrogel formation of wheat bran FAX following enzymatic crosslinking by laccase and a subsequent regeneration procedure involving freeze-drying and resuspension of the crosslinked FAX in different pH buffers, using a battery of biochemical, rheological and physical techniques. The laccase crosslinking induced the conversion of ferulic acid units into a wide diversity of dimeric forms, leading to an increased molecular weight and a closer-packing of the FAX chains. The regeneration step resulted in a remarkable increase in the viscosity and viscoelasticity for all tested pH values. The amount of crystallinity of FAX increased by enzymatic crosslinking, it was however decreased by the regeneration step. The structural characterization revealed that enzymatic crosslinking, in addition to the formation of covalent crosslinks, influences the physical intermolecular interactions between adjacent FAX domains, and the regeneration forms larger clusters with higher dynamic moduli. Our results reveal that both chemical and physical mechanisms influence the network formation and multiscale assembly of wheat bran FAX hydrogels, thus modulating their rheological properties fundamental for their use in food and biomedical applications.

Research priorities for seasonal energy storage using electrolyzers and fuel cells

Paul A. Kempler is a research assistant professor at the University of Oregon and the Associate Director for the Oregon Center for Electrochemistry (OCE). At the OCE, he has developed three graduate laboratory courses in electrochemistry and electrochemical engineering and serves as the liaison to industry partners. His current research interests include interfacial ion transfer in energy conversion and the technoeconomic analysis of decarbonized energy systems. Paul received his PhD in chemical engineering from the California Institute of Technology for research on catalyst integration and gas evolution in photoelectrochemical cells for water splitting. John James Slack is a senior scientist at Nikola Corporation. John specializes in developing novel materials, studying their interactions, and designing nanostructured architectures within fuel cell cores. In the first two years of his career, he authored two successful proposals worth $2.7 million and has co-authored several patents related to advancing the field of fuel cell membrane electrode assemblies. He is active in the fuel cell community, regularly presenting to the Department of Energy and to the Million Mile Fuel Cell Truck Consortium. John's background is in chemical engineering, and he obtained his PhD at Vanderbilt University in 2019. Andrew M. Baker is a senior scientist at Nikola Corporation. His current research is focused on improving the performance and durability of membrane-electrode-assembly materials and accelerated stress test development for heavy-duty PEM fuel cell applications. Prior to working at Nikola, he was a scientist at Los Alamos National Laboratory. He received his PhD in mechanical engineering from the University of Delaware in 2017.

Trioctylphosphine Oxide (TOPO)-Assisted Facile Fabrication of Phosphorus-Incorporated Nanostructured Carbon Nitride Toward Photoelectrochemical Water Splitting with Enhanced Activity.

Designing nanostructured arrays of two-dimensional surfaces and interfaces is a versatile approach to increasing their photoelectrochemical activity. Here, phosphorus (P)-incorporated nanostructured carbon nitride (h-PCN) with an enlarged surface area is fabricated by employing trioctylphosphine oxide (TOPO) as a dopant precursor for visible-light-driven photoelectrochemical water splitting to produce hydrogen. The structural, morphological, and electronic properties of the photocatalyst have been characterized through various physicochemical techniques. We show that the incorporation of P into the g-C3N4 framework enhances light absorption over broad regimes, charge separation, and migration, as well as the specific surface area, showing excellent photocurrent enhancement (5.4 folds) in the cathodic direction as compared to bulk g-C3N4. Moreover, the photocathode shows 3.3-fold enhancement in current at zero biased potential. Without using any cocatalyst, the photoelectrodes produced 27 μmol h-1 of H2 and 13 μmol h-1of O2 with 95% faradic efficiency. The excellent photoelectrochemical behavior toward water-splitting reactions by the photoelectrode is attributed to the synergistic effect of P incorporation and active sites emerging from the nanostructured architecture of the material. This work demonstrates the facile fabrication of nanostructured P-incorporated g-C3N4 toward water-splitting reactions to produce hydrogen without using a cocatalyst in a simple and cost-effective way.

Synthesis of block copolymers containing 3-chloro-2-hydroxypropyl methacrylate by NMP – a versatile platform for functionalization

This study highlights the potential of 3-chloro-2-hydroxypropyl methacrylate (ClHPMA) as a functional building block in nanostructured block copolymer architectures.

Bismuth/bismuth trioxide with a dual-carbon support for high and long life lithium storage

Bismuth (Bi) is regarded as a prospective candidate for new lithium-ion battery anodes, but its capacity and cycle life need to be improved. Even with design and preparation of various Bi/carbon (Bi/C) nanocomposites, the performance improvement of the Bi for lithium-ion battery anode is still not unfavorable. Herein, the peculiar dual-carbon supporting nanostructured architecture has been fabricated for the first time and demonstrated to be highly effective in improving the lithium storage of the Bi anode. This as-fabricated characteristic Bi/C nanocomposite is composed of Bi nanoparticles (containing small amounts of bismuth trioxide (Bi2O3)) with sizes ranging from 10 to 50 nm encapsulated within capsule-like porous carbon matrixes, which are further interlinked with amorphous porous carbon (PC) coated carbon nanotubes (CNT). This composite is therefore denoted as CNT@Bi/Bi2O3@PC. The results demonstrate that the well-designed architecture endows the as-fabricated composite with superior structural stability and improved electrochemical kinetics. As a result, the CNT@Bi/Bi2O3@PC displays unprecedented lithium storage performance, delivering high capacity of 513 mAh g−1 at 200 mA g−1 after 600 cycles and 232 mAh g−1 at 1000 mA g−1 after even 2500 cycles. Moreover, thus unprecedented performance of the CNT@Bi/Bi2O3@PC in association with its architecture advantages can offer inspiration for rational design of other nanostructured alloying-based anodes toward advanced lithium storage.

Engineering the shape of one-dimensional metallic nanostructures via nanopore electrochemistry

The architecture of nanostructures is pivotal to determine material properties at the nanoscale, indicating the importance of harnessing sophisticated nanochemistry to elicit desirable material morphology with uniformity. The simplicity of template-assisted electrodeposition makes it a promising strategy for the fabrication of anisotropic nanomaterials. However, a challenge it faces is the complexity of the materials. This study presents a facile strategy and fabrication mechanism to synthesize nanotubes or nanocoils by selecting additives such as vanadyl ions and L-ascorbic acid. Vanadyl ions stick to the protonated anodized aluminum oxide surface, paving the way for electronic conduction. When a higher electrical field is applied, linear sweep voltammetry implies surface conduction mode is dominant in the spatially confined template. As L-ascorbic acid is included in the electrolyte, the nanostructure can be regulated from nanotubes to nanocoils. The nanocoils consist of numerous nanocrystalline primary particle considered as building blocks, and their relationship affects the final structures. The reaction product, vanadyl ascorbate, acts as a hurdle by partially hindering surface conduction and a helical modifier, inducing the formation of primary particle and their nanocoil assembly. Finally, a state diagram is provided to illustrate the diverse nanostructures at optimized applied current and additive ratio conditions.