Construction Of Nanostructures Research Articles

Rational Synthesis of Spongy Fe3N@N-Doped Carbon Nanorods with Controlled Topography and Porosity for Enhanced Energy Storage Anodes in Lithium-Ion Batteries.

Iron nitrides with the merits of high theoretical capacities, cost-effectiveness, and good electronic/ionic conductivity have been recognized as attractive anode candidates for lithium-ion batteries (LIBs). Carbon compositing, pore engineering, and nanostructure construction have proved to be effective strategies to prepare high-performance metal nitride anodes for LIBs. Herein, we synthesized a series of Fe3N-embedded and N-doped carbon nanorods (Fe3N@NCNR) with a hierarchical porous system and controllable topography by metal-catalyzed graphitization-nitridization of the Fe(III)-triazole framework (Fe-MOF) and thermal evaporation of the triblock copolymer F127 template assembled in Fe-MOF via hydrogen bonding interaction, followed by the air oxidation and urea-assisted ammonolysis processes. The Fe3N@NCNR as anodes for LIBs display extraordinary lithium storage capabilities with a high reversible capacity of 830 mA h g-1 at 0.1 C, a good rate performance of 576 mAh g-1 at 5 C, and a long-term cycling stability of 742 mA h g-1 over 600 cycles at 1 C. Such outstanding performance benefits from the spongy carbon nanorods with rich macropores for rapid electronic/ionic transport and effective accommodation of electrode volume expansion, abundant N-doped meso-/microporous carbon for the additional storage of Li+ via capacitive effect, and the efficient utilization of Fe3N nanoparticles uniformly distributed through carbon nanorods. Importantly, this work introduces an effective strategy to construct superior performance nitride anodes from MOF surfactants based on hydrogen bonding-driven interface self-assembly and provides insight into the preparation of highly efficient nanoarchitectures for Li+ storage.

Organometallic Chemistry Tools for Building Biologically Relevant Nanoscale Systems.

The recent emergence of organometallic chemistry for modification of biomolecular nanostructures has begun to rewrite the long-standing assumption among practitioners that small-molecule organometallics are fundamentally incompatible with biological systems. This Perspective sets out to clarify some of the existing misconceptions by focusing on the growing organometallic toolbox for biomolecular modification. Specifically, we highlight key organometallic transformations in constructing complex biologically relevant systems on the nanomolecular scale, and the organometallic synthesis of hybrid nanomaterials composed of classical nanomaterial components combined with biologically relevant species. As research progresses, many of the challenges associated with applying organometallic chemistry in this context are rapidly being reassessed. Looking to the future, the growing utility of organometallic transformations will likely make them more ubiquitous in the construction and modification of biomolecular nanostructures.

Single activator doped fluoride nanoparticles for X-ray excited high-resolution and delayed flexible nonplanar imaging

Lanthanide doped fluoride nanoparticles (NPs) exhibit adjustable X-ray excited optical/persistent luminescence (XEOL/XEPL) and possessing extensive potential in XEPL-based delay imaging. However, the high-resolution and delayed XEPL-based delay imaging always requires strict introduction of sensitized or heterovalent ions and the construction of complex structures for excellent XEPL performance of lanthanide-doped fluoride NPs, which is attributed to a lack of effective and convenient strategies. Here we show that the intense XEPL strength was obtained by single Tb3+ activated ion doping and simple CsY2F7@NaYF4 core/shell structure for X-ray excited high-resolution and delayed flexible nonplanar imaging. The strict introduction and control of sensitized or heterovalent ions, and the construction of intricate multilayer nanostructure are avoided. In addition, we enable the NPs to achieve high and long-term XEPL performance by simply thermal processing strategy. We successfully mixed minimized amount of the NPs into flexible film to create a scintillation screen which consequently exhibit high surface smoothness, environmental stability, and transparency. Our results demonstrate high resolution delayed imaging of the NPs integrated flexible film for the interior of nonplanar objects. The spatial resolution of 14.3 lp mm−1 is substantially higher than the typical spatial resolutions required for medical CT scans (2 lp mm−1) and X-ray imaging (3.5 lp mm−1). These findings will promote the development of advanced delayed X-ray nonplanar imaging applications.

Thermally Stable Oxide-Capsulated Metal Nanoparticles Structure for Strong Metal-Support Interaction via Ultrafast Laser Plasmonic Nanowelding.

Strong metal-support interaction (SMSI) has drawn much attention in heterogeneous catalysts due to its stable and excellent catalytic efficiency. However, construction of high-performance oxide-capsulated metal nanostructures meets great challenge in materials thermodynamic compatibility. In this work, dynamically controlled formation of oxide-capsulated metal nanoparticles (NPs) structures is demonstrated by ultrafast laser plasmonic nanowelding. Under the strong localized electromagnetic field interaction, metal (Au) NPs are dragged by an optical force toward oxide NPs (TiO2). Intense energy is simultaneously injected into this heterojunction area, where TiO2 is precisely ablated. With the embedding of metal into oxide, optical force on Au gradually turned from attractive to repulsive due to the varied metal-dielectric environment. Meanwhile, local ablated oxides are redeposited on Au NP. Upon the whole coverage of metal NP, the implantation behavior of metal NP is stopped, resulting in a controlled metal-oxide eccentric structure with capsulated oxide layer thickness ≈0.72-1.30nm. These oxide-capsulated metal NPs structures can preserve their configurations even after thermal annealing in air at 600°C for 10min. This ultrafast laser plasmonic nanowelding can also extend to oxide-capsulated metal nanostructure fabrication with broad materials combinations (e.g., Au/ZnO, Au/MgO, etc.), which shows great potential in designing/constructing nanoscale high-performance catalysts.

Tailoring emission spectra by using core-shell nanostructures with a random forest algorithm

Abstract We propose a scheme to tailor emission spectra through the engineering of the local density of states by using core-shell nanostructures. A random forest algorithm is used to train a forward model for spectrum prediction and an inverse model for the construction of core-shell nanostructures. From the simulation results, it can be seen that we can predict the spectra very well and achieve good effects for tailoring the emission spectra with core-shell nanostructures based on the established models, eliminating the time-consuming and laborious design process with manual intervention.

Recent Progress in the Construction of Chiral Plasmonic Gold Nanostructures and Their Biochemical Sensing Applications

Recent Progress in the Construction of Chiral Plasmonic Gold Nanostructures and Their Biochemical Sensing Applications

Triggered Directed Electron Redistribution Endowed by Efficient Ohmic Contacts of NiMoN/Ni3S2 for Boosting Large Current‐Density Overall Seawater Splitting

AbstractThe rational construction of interfacial nanostructures of metal/semiconductor (MS) contacted electrocatalysts has a significant impact on improving their intrinsic activities. However, MS contacts are often plagued by a strong Fermi‐level pinning effect, resulting in the formation of the Schottky barrier that affects the adsorption of hydrogen/oxygen intermediates. Herein, an Ohmic contact between metallic Ni3S2 and semiconducting NiMoN is well‐designed, which effectively reduces the electron conduction barriers. The as‐obtained NiMoN/Ni3S2 has remarkable bifunctional water electrolysis performance. At 10 mA·cm−2, the overpotential of hydrogen evolution and oxygen evolution reaction is 70 and 154 mV, respectively. Impressively, the formation of hydroxide during surface reconstruction can avoid the chlorine evolution on the catalyst surface. At an industrial process temperature of 85 °C, it takes only 340 mV for the overall seawater splitting of 500 mA·cm−2. UPS and UV‐VIS diffuse spectra combined with theoretical calculation results confirm that the self‐driven directed electron transfer derived from the Ohmic contact can induce local electron enrichment at the interface region, thus promoting the formation of *O to *OOH. This study provides important insights into the coordinated modulation of built‐in electric fields and the preparation of efficient multifunctional catalysts with a high abundance of active sites.

Anisotropic growth of Ag nanonails induced by plasmon-mediated chemical reactions in cross-shaped nanocavity array

The Ag nanonail rooted in Au cross-channel nanocavity is fabricated by plasmon-mediated chemical reactions (PMCRs). The Au cross-channel nanocavity is prepared based on two-dimensional polystyrene (PS) nanosphere template through wet etching, and the shape of Au cross-channel nanocavity changes from trapezoidal to triangular, depending on the wet etching time. The growth of Ag nanostructures in Au channels by PMCRs indicates the morphology of Ag nanostructures has changed from Ag nanoparticles to nanonails, which is regulated by the shape of Au nanocavities and the exciting light polarization. The hotspots distributions results in the anisotropic growth of Ag nanostructures induced by PMCRs, which leading to the different Ag nanostructures depending on the shape of Au nanocavity and light polarization, as confirmed by FDTD simulations. In comparison with others reports, our nanocavity provide more parameters to control the shapes of Ag nanostructures, the nanocavity shape, the light polarization and the growth time. Our work provides a profound insight into the construction of periodic nanostructures and reconstruction of hotspots.

Construction of self-stacking nanostructure with MXene and CNT through dopamine polymerization

Construction of self-stacking nanostructure with MXene and CNT through dopamine polymerization

Construction of 3D hollow NiCo-layered double hydroxide nanostructures for high-performance industrial overall seawater electrolysis

Construction of 3D hollow NiCo-layered double hydroxide nanostructures for high-performance industrial overall seawater electrolysis

Crystal facet engineering of hollow cadmium sulfide for efficient photocatalytic hydrogen evolution

Metal sulfides have been considered as potential candidates for photocatalytic hydrogen production, but their practical applications are still limited by incident light utilization and charge separation despite the impressive advances in recent decades. To address these challenges, the construction of hollow nanostructure with exposing high active facets offers a desirable pathway for developing novel and high-efficiency photocatalysts. Here, by taking wurtzite CdS as an example, we first develop a general template-assisted cation exchange route for the preparation of hollow CdS nanostructures with diverse exposed facets. The obtained hollow CdS octahedrons with dominant {101} facets exhibit superior photocatalytic H2 evolution rate under visible-light irradiation compared with common CdS nanorods. According to the characterization results and density functional theory calculations, the excellent photocatalytic performance is attributed to the construction of hollow nano-octahedrons with exposed {101} active facets, which facilitates efficient light harvesting and photoinduced charge separation of CdS photocatalyst. The present approach gives a reference to design advanced semiconductors with remarkable photocatalytic activity for realizing efficient solar-to-chemical conversion.

Expanding DNA Origami Design Freedom with De Novo Synthesized Scaffolds.

The construction of DNA origami nanostructures is heavily dependent on the folding of the scaffold strand, which is typically a single-stranded DNA genome extracted from a bacteriophage (M13). Custom scaffolds can be prepared in a number of methods, but they are not widely accessible to a broad user base in the DNA nanotechnology community. Here, we explored new design and construction possibilities with custom scaffolds prepared in our cost- and time-efficient production pipeline. According to the pipeline, we de novo produced a variety of scaffolds of specified local and global sequence characteristics and consequent origami constructs of modular arrangement in morphologies and functionalities. Taking advantage of this strategy of template-free scaffold production, we also designed and produced three-letter-coded scaffolds that can fold into designated morphologies rapidly at room temperature. The expanded design and construction freedom immediately brings in many new research opportunities and invites many more on the horizon.

High-Performance Aluminum Fuels Induced by Monolayer Self-Assembly of Nano-Sized Energetic Fluoride Vesicles on the Surface.

Surface modification is frequently used to solve the problems of low combustion properties and agglomeration for aluminum-based fuels. However, due to the intrinsic incompatibility between the aluminum powder and the organic modifiers, the surface coating is usually uneven and disordered, which significantly deteriorates the uniformity and performances of the Al-based fuels. Herein, a new approach of monolayer nano-vesicular self-assembly is proposed to prepare high-performance Al fuels. Triblock copolymer G-F-G is produced by glycidyl azide polymer (GAP) and 2,2'-(2,2,3,3,4,5,5-Octafluorohexane-1,6-diyl) bis (oxirane) (fluoride) ring-open addition reaction. By utilizing G-F-G vesicular self-assembly in a special solvent, the nano-sized vesicles are firmly adhered to the surface of Al powder through the long-range attraction between the fluorine segments and Al. Meanwhile, the electrostatic repulsion between vesicles ensures an extremely thin coating thickness (≈15nm), maintaining the monolayer coating structure. Nice ignition, combustion, anti-agglomeration, and water-proof properties of Al@G-F-G(DMF) are achieved, which are superior among the existing Al-based fuels. The derived Al-based fuel has excellent comprehensive properties, which can not only inspire the development of new-generation energetic materials but also provide facile but exquisite strategies for exquisite surface nanostructure construction via ordered self-assembly for many other applications.

Folding molecular origami from ribosomal RNA

Approximately 80 percent of the total RNA in cells is ribosomal RNA (rRNA), making it an abundant and inexpensive natural source of long, single-stranded nucleic acid, which could be used as raw material for the fabrication of molecular origami. In this study, we demonstrate efficient and robust construction of 2D and 3D origami nanostructures utilizing cellular rRNA as a scaffold and DNA oligonucleotide staples. We present calibrated protocols for the robust folding of contiguous shapes from one or two rRNA subunits that are efficient to allow folding using crude extracts of total RNA. We also show that RNA maintains stability within the folded structure. Lastly, we present a novel and comprehensive analysis and insights into the stability of RNA:DNA origami nanostructures and demonstrate their enhanced stability when coated with polylysine-polyethylene glycol in different temperatures, low Mg2+ concentrations, human serum, and in the presence of nucleases (DNase I or RNase H). Thus, laying the foundation for their potential implementation in emerging biomedical applications, where folding rRNA into stable structures outside and inside cells would be desired.Graphical

Heteromultivalent DNA Enhances the Assembly Yield of Hybrid Nanoparticles and Facilitates Dynamic Disassembly for Bioanalysis Using ICP-MS.

To obtain enhanced physical and biological properties, various nanoparticles are typically assembled into hybrid nanoparticles through the binding of multiple homologous DNA strands to their complementary counterparts, commonly referred to as homomultivalent assembly. However, the poor binding affinity and limited controllability of homomultivalent disassembly restrict the assembly yield and dynamic functionality of the hybrid nanoparticles. To achieve a higher binding affinity and flexible assembly choice, we utilized the paired heteromultivalency DNA to construct hybrid nanoparticles and demonstrate their excellent assembly characteristics and dynamic applications. Specifically, through heteromultivalency, DNA-functionalized magnetic beads (MBs) and gold nanoparticles (AuNPs) were efficiently assembled. By utilizing ICP-MS, the assembly efficiency of AuNPs on MBs was directly monitored, enabling quantitative analysis and optimization of heteromultivalent binding events. As a result, the enhanced assembly yield is primarily attributed to the fact that heteromultivalency allows for the maximization of effective DNA probes on the surface of nanoparticles, eliminating steric hindrance interference. Subsequently, with external oligonucleotides as triggers, it was revealed that the disassembly mechanism of hybrid nanoparticles was initiated, which was based on an increased local concentration rather than toehold-mediated displacement of paired heteromultivalency DNA probes. Capitalizing on these features, an output platform was then established based on ICP-MS signals that several Boolean operations and analytical applications can be achieved by simply modifying the design sequences. The findings provide new insights into DNA biointerface interaction, with potential applications to complex logic operations and the construction of large DNA nanostructures.

In-situ construction of bioactive nanostructures on Ti alloy surfaces through ultra-low concentration alkali treatment and low-temperature annealing

Osseointegration is crucial for the long-term stability of orthopedic implants. Nanosurfacing can impart osteoinductivity to the implant. However, the application potential of most available nanotechnologies in surface modification of implants is limited, and there is an urgent need to develop new effective nanosurfacing techniques with greater practicality. In this study, we for the first time, utilized an ultra-low concentration NaOH solution (0.55 mM) combined with low-temperature annealing to achieve solid-state dewetting (SSD) on Ti alloy surfaces, resulting in well-defined TiO2 nanoisland-like crystals. In vitro cell experiments demonstrated that the constructed nanostructures significantly affected the adhesion, proliferation, and osteogenic differentiation capability of MC3T3-E1 cells. The nanostructures formed at 550 °C exhibited the most pronounced enhancement of cell osteogenic differentiation capability. This method is simple, easy to operate, and scalable, holding significant application potential in the surface modification of Ti alloys.

Separation of Halogen Atoms by Sodium from Dehalogenative Reactions on a Au(111) Surface.

On-surface dehalogenative reactions have been promising in the construction of nanostructures with diverse morphologies and intriguing electronic properties, while halogen (X), as the main byproduct, often impedes the formation of extended nanostructures and property characterization, and the reaction usually requires high C-X activation temperatures, especially on relatively inert Au(111). Enormous efforts in precursor design, halogen-to-halide conversion, and the introduction of extrinsic metal atoms have been devoted to either eliminating dissociated halogens or reducing reaction barriers. However, it is still challenging to separate halogens from molecular systems while facilitating C-X activation under mild conditions. Herein, a versatile halogen separation strategy has been developed based on the introduction of extrinsic sodium (Na) into dehalogenative reactions on Au(111) as model systems that both isolates the dissociated halogens and facilitates the C-Br activation under mild conditions. Moreover, the combination of scanning tunneling microscopy imaging and density functional theory calculations reveals the formation of sodium halides (NaX) from halogens in these separation processes as well as the reduction in reaction temperatures and barriers, demonstrating the versatility of extrinsic sodium as an effective "cleaner" and "dehalogenator" of surface halogens. Our study demonstrates a valuable strategy to facilitate the on-surface dehalogenative reactions, which will assist in the precise fabrication of low-dimensional carbon nanostructures.

Endowing polymeric carbon nitride photocatalyst with CO2 activation sites by anchoring atomic cobalt cluster

Photocatalytic CO2 reduction to high value-added fuels and chemicals is a promising strategy for alleviating both energy and environmental crises. However, the poor CO2 adsorption and activation ability seriously restrict the CO2 photoreduction activity of metal-free carbon nitride (C3N4), which is an emerging material for photocatalysis applications. In this paper, cobalt (Co) atomic clusters were modified on the surface of hierarchical urchin-like hollow C3N4 nanotubes by NaBH4 reduction, which endowed the as-designed Co atomic cluster-anchored and B-doped C3N4 (Co@B-HCN) catalyst with strong CO2 activation and CO2 photoreduction ability. Theoretical calculations and in situ characterization confirmed that the Co atomic clusters anchoring enabled the change in the bond length/angle of adsorbed CO2 molecules, as well as the change from a linear model to a bending model. This could enhance the CO2 adsorption and activation, which played a vital role in reducing the energy barrier of CO2-to-CO reaction. In addition, the construction of the hierarchical urchin-like nanostructure, the anchoring of Co atomic clusters, and the doping of B favored the surface adsorption and charge separation. Attributed to the above merits, the CO yield of Co@B-HCN photocatalyst reaches 157.51 μmol⋅g−1⋅h−1, which is approximately 22 times that of bulk C3N4. This work provides an insight for the surface engineering of C3N4 photocatalysts to realize high-performance photocatalytic CO2 reduction.

Review on Structural Adjustment Strategies of Titanium‐Based Metal Oxide Dimensionally Stable Anodes in Electrochemical Advanced Oxidation Technology

Emerging organic pollutants and refractory pollutants in water bodies have caused severe harm to the ecological environment and human health. Electrochemical advanced oxidation processes (EAOPs) are currently one of the most effective oxidation methods to deal with refractory organic pollutants. Electrode materials serve as the most critical component in influencing the EAOP performance. Dimensionally stable anodes (DSAs) have the advantages of dimensional stability, structural diversity, chemical stability, low oxygen evolution potential and long service life, etc. Herein, several types of Ti‐based metal oxide DSAs (Ti/MOx DSAs) commonly used in EAOPs in the past 5 years, including Ti/IrO2, Ti/RuO2, Ti/PbO2, Ti/Sb–SnO2, and Ti/TiO2, are introduced. The modification methods including metal doping, composition adjustment, nanostructure construction, introduction of intermediate layers, compositing with carbon materials, and formation of 3D structures as well as the applications of these modified Ti‐based DSAs in EAOP for the rapid degradation of various organic pollutants are summarized and their advantages and current shortcomings of electrodes are pointed out. Finally, the Ti‐based DSA's current limitations and future development prospects are concluded.

DNA polyhedrons cube, prism, and square pyramid protect the catalytic activity of catalase: A thermodynamics and kinetics study

DNA is widely used as building block material for the construction of polyhedral nanostructures. DNA polyhedrons (DNA prism, cube, and square pyramid) are small 3D wireframed nanostructures with tunable shapes and sizes. Despite substantial progress in synthesis, the study regarding cellular responses to DNA polyhedrons is limited. Herein, the molecular interaction between DNA polyhedrons and the antioxidant enzyme, catalase has been explored. The enzymatic activity of bovine liver catalase (BLC) remains unaltered in the presence of DNA polyhedrons after 1 h of incubation. However, the activity of BLC was protected after 24 h of incubation in the presence of DNA polyhedrons as compared to the natural unfolding. The kinetics study confirmed the protective role of DNA polyhedrons on BLC with lower KM and higher catalytic efficiency. Furthermore, no profound conformational changes of BLC occur in the presence of DNA polyhedrons as observed in spectroscopic studies. From fluorescence quenching data we confirmed the binding between DNA polyhedrons and BLC. The thermodynamic parameters indicate that non-covalent bonds played a major role during the interaction of BLC with DNA polyhedrons. Moreover, the hepatic catalase activity remains unaltered in the presence of DNA polyhedrons. The cytotoxicity assay revealed that DNA polyhedrons were biocompatible in the cellular environment. The protective role of DNA polyhedrons on enzyme activity and the unaltered conformational change of protein ensures the biocompatibility of DNA polyhedrons in the cellular environment.