Multidimensional Nanostructures Research Articles

Hierarchical Self-Assembly of Multidimensional Functional Materials from Sequence-Defined Peptoids.

Hierarchical self-assembly represents a powerful strategy for the fabrication of functional materials across various length scales. However, achieving precise formation of functional hierarchical assemblies remains a significant challenge and requires a profound understanding of molecular assembly interactions. In this study, we present a molecular-level understanding of the hierarchical assembly of sequence-defined peptoids into multidimensional functional materials, including twisted nanotube bundles serving as a highly efficient artificial light harvesting system. By employing synchrotron-based powder X-ray diffraction and analyzing single crystal structures of model compounds, we elucidated the molecular packing and mechanisms underlying the assembly of peptoids into multidimensional nanostructures. Our findings demonstrate that incorporating aromatic functional groups, such as tetraphenyl ethylene (TPE), at the termini of assembling peptoid sequences promotes the formation of twisted bundles of nanotubes and nanosheets, thus enabling the creation of a highly efficient artificial light harvesting system. This research exemplifies the potential of leveraging sequence-defined synthetic polymers to translate microscopic molecular structures into macroscopic assemblies. It holds promise for the development of functional materials with precisely controlled hierarchical structures and designed functions.

Hierarchical Self‐Assembly of Multidimensional Functional Materials from Sequence‐Defined Peptoids

AbstractHierarchical self‐assembly represents a powerful strategy for the fabrication of functional materials across various length scales. However, achieving precise formation of functional hierarchical assemblies remains a significant challenge and requires a profound understanding of molecular assembly interactions. In this study, we present a molecular‐level understanding of the hierarchical assembly of sequence‐defined peptoids into multidimensional functional materials, including twisted nanotube bundles serving as a highly efficient artificial light harvesting system. By employing synchrotron‐based powder X‐ray diffraction and analyzing single crystal structures of model compounds, we elucidated the molecular packing and mechanisms underlying the assembly of peptoids into multidimensional nanostructures. Our findings demonstrate that incorporating aromatic functional groups, such as tetraphenyl ethylene (TPE), at the termini of assembling peptoid sequences promotes the formation of twisted bundles of nanotubes and nanosheets, thus enabling the creation of a highly efficient artificial light harvesting system. This research exemplifies the potential of leveraging sequence‐defined synthetic polymers to translate microscopic molecular structures into macroscopic assemblies. It holds promise for the development of functional materials with precisely controlled hierarchical structures and designed functions.

Nanostructure Engineering of Cathode Layers in Proton Exchange Membrane Fuel Cells: From Catalysts to Membrane Electrode Assembly.

The membrane electrode assembly (MEA) is the core component of proton exchange membrane fuel cells (PEMFCs), which is the place where the reaction occurrence, the multiphase material transfer and the energy conversion, and the development of MEA with high activity and long stability are crucial for the practical application of PEMFCs. Currently, efforts are devoted to developing the regulation of MEA nanostructure engineering, which is believed to have advantages in improving catalyst utilization, maximizing three-phase boundaries, enhancing mass transport, and improving operational stability. This work reviews recent research progress on platinum group metal (PGM) and PGM-free catalysts with multidimensional nanostructures, catalyst layers (CLs), and nano-MEAs for PEMFCs, emphasizing the importance of structure-function relationships, aiming to guide the further development of the performance for PEMFCs. Then the design strategy of the MEA interface is summarized systematically. In addition, the application of in situ and operational characterization techniques to adequately identify current density distributions, hot spots, and water management visualization of MEAs is also discussed. Finally, the limitations of nanostructured MEA research are discussed and future promising research directions are proposed. This paper aims to provide valuable insights into the fundamental science and technical engineering of efficient MEA interfaces for PEMFCs.

Multi-dimensional engineering of transition metal dichalcogenides for enhanced performance in fuel cell technologies

Fuel cells are considered a highly competitive strategy in the pursuit of sustainable energy, which is crucial for achieving both environmental goals and long-term economic stability. However, challenges such as electrochemical corrosion and fuel penetration still persist in the catalytic layer and electrolyte diaphragm. Tailored nanostructures of two-dimensional (2D) transition metal dichalcogenides (TMDs) hold great potential in addressing these issues due to their wide-ranging modulated properties. Several prominent works are reviewed in this article summarizing the 1D, 2D, and 3D tailored-TMD nanostructures and their assembly techniques. Additionally, the breakthroughs achieved by multi-dimensional nanostructures in addressing limitations such as stacking issues, low conductivity, and loss of active sites in TMDs are discussed. In particular, the effects of manipulating catalysts and electrolyte diaphragms in fuel cells by introducing multi-dimensional nanostructures are highlighted and compared. Finally, the article concludes the challenges that are generally faced in making TMD-based nanostructures a reliable material for the future energy sector.

Polyoxometalate Induced Assembly Into Surface Functionalized Multidimensional Heterostructures with Enhanced Catalytic Activity.

The self-assembly of inorganic nanocrystals offers an efficient way for the fabrication of functional materials. However, it is still challenging for the construction of multidimensional nanostructures with controllable shapes, compositions and functions. Here, a series of heterostructures in different dimensions by surface modification of polyoxometalate (POM) clusters is developed. Three kinds of POM clusters(phosphomolybdic acid (PMA), phosphotungstic acid (PTA) and silicotungstic acid (STA) and five kinds of metal oxides (TiO2, VOx, La2O3, In2O3 and Gd2O3) can be used as building blocks, and a class of 1D, 2D and 3D heterostructures can be achieved by the control of surface ligand coverage. Compared with individual building blocks and other cluster-based superstructures, TiO2-PMA superstructures exhibit enhanced catalytic activity toward thioether oxidations, which is attributed to the electron transfer between TiO2 and POM clusters.

Engineering 2D MXene and LDH into 3D Hollow Framework for Boosting Photothermal Energy Storage and Microwave Absorption.

2D MXene is highly preferred for photothermal energy conversion and microwave absorption. However, the aggregation issue, insufficient dielectric loss capacity, and lack of magnetic loss capacity for MXene severely hinder its practical applications. Herein, the authors propose multi-dimensional nanostructure engineering to electrostatically assemble 2D MXene and layered double hydroxides (LDH) derived from ZIF-67 polyhedron into a 3D hollow framework (LDH@MXene), and subsequently calcined to construct a Co nanoparticle-modified 3D hollow C-LDH@MXene framework to encapsulate a paraffin wax (PW) phase change material (PCM). The 3D hollow C-LDH@MXene framework not only prevents 2D MXene from aggregation but also contributes a high thermal energy storage density (131.04 Jg-1 ). Benefiting from a 3D conductive network facilitating the rapid transport of photons and phonons from the interface to the interior and the synergistic localized surface plasmon resonance (LSPR) effect of MXene and Co magnetic nanoparticles, the C-LDH@MXene-PW composite PCM yielded a high photothermal storage efficiency of 96.52%. Besides, C-LDH@MXene-PW composite PCMs also exhibited efficient microwave absorption with a minimum reflection loss of -20.87dB at 13.30GHz with a matching thickness of only 2mm. This distinctive design provides constructive references for the development of integrated composite materials for energy storage and microwave absorption.

Metal-organic framework-derived ultrafine CoSe nanocrystal@honeycomb porous carbon nanofiber as multidimensional advanced anode for sodium-ion batteries

Ultrafine CoSe nanocrystals are embedded in honeycomb porous carbon nanofibers via spinning ZIF-67 nanocubes into polyacrylonitrile fibers, followed by etching of tannic acid, carbonization and selenization. Abundant cubic pores are densely distributed in carbon nanofibers. CoSe nanocrystals with an ultrafine size of 10–20 nm are distributed around cubic pores, and even move to other internal locations of the carbon nanofibers, achieving intimately coupling. CoSe nanocrystal@honeycomb porous carbon nanofiber is used as anode of sodium-ion batteries, exhibiting excellent electrochemical performance. The average discharge capacity at 0.1 A g−1 reaches 433 mAh g−1. It can deliver discharge capacity of 319 mAh g−1 at 1 A g−1 after 550 cycles, 254 mAh g−1 at 5 A g−1 after 500 cycles, 192 mAh g−1 at 10 A g−1 after 1000 cycles. The various kinetics analyses indicate the favorable Na+ diffusion (10−10.9 to 10−12.0 cm2 s−1), low internal resistance, fast interface reaction, and dominant capacitive effect in electrochemical reaction. The structure stability is demonstrated by ex-situ observation of the cycled electrodes. The outstanding sodium storage performance is attributed to 0D ultrafine CoSe nanocrystals, 3D honeycomb cubic pores and 1D short carbon nanofibers. The multidimensional nanostructures significantly improve kinetics and cycling stability of CoSe from different aspects.

Shape-controlled multi-dimensional In2O3/Mn2O3 p-n heterojunction for triethylamine detection

Due to the excellent properties, multi-dimensional p-n heterojunction materials are widely used in the field of gas sensing. In this work, In2O3-modified Mn2O3 nanorod was prepared by a hydrothermal method. The composites had excellent detection performance for triethylamine (TEA). The composites had rich 0D-1D multi-dimensional nanostructures. The sensing properties of composites with different In/Mn ratios were investigated by adjusting the proportion of Mn. The test results showed composite material had high response, excellent selectivity, ultra-high resistance stability and repeatability during repeated testing. High specific surface area, abundant active sites by the formation of multi-dimensional heterojunction, and Mn3+/Mn4+ fast redox cycling of compound material made the excellent sensing performance. This work provided a reference for designing multi-dimensional heterostructures and high performance gas sensors.

Deciphering the Relevance of Quantum Confinement in the Optoelectronics of CsPbBr3 Perovskite Nanostructures.

Perovskites (PVKs) have emerged as an exciting class of semiconducting materials owing to their magnificent photophysical properties and been used in solar cells, light-emitting diodes, photodetectors, etc. The growth of multidimensional nanostructures has revealed many exciting alterations in their optoelectronic properties compared to those of their bulk counterparts. In this work, we have spotlighted the influence of quantum confinement in CsPbBr3 PVKs like the quantum dot (PQD), nanoplatelet (PNPL), and nanorod (PNR) on their charge transfer (CT) dynamics with 1,4-naphthoquinone (NPQ). The energy band alignment facilitates the transfer of both electrons and holes in the PNPL to NPQ, enhancing its CT rate, while only electron transfer in the PQD and PNR diminishes CT. The tunneling current across a metal-nanostructure-metal junction for the PNPL is observed to be higher than others. The higher exciton binding energy in the PNPL results in efficient charge transport by enhancing the mobility of the excited-state carrier and its lifetime compared to those of the PNR and PQD.

YbSiOC ceramics with a multidimensional nanostructure for high-efficiency electromagnetic wave absorption

The controllable microstructure of a material plays a vital role in its electromagnetic (EM) wave absorption performance. Herein, a multidimensional nanostructure including a matchstick-like SiCnws network structure with a carbon nanocluster was grown in-situ in a porous Yb2Si2O7 ceramic by precursor infiltration and pyrolysis (PIP) to prepare YbSiOC ceramics. As the number of PIPs increased, the absorber (SiCnws and carbon) content increased to construct a multidimensional nanostructure, which also promoted conductivity loss, interfacial polarization loss and dipole polarization loss. The results showed that the YbSiOC ceramics (with an absorber content of 28.2 wt%) achieved a minimum reflection loss (RLmin) of − 50.0 dB at 9.39 GHz with 2.7 mm, and the effective absorption bandwidth (EAB) reached 4.2 GHz (in the X band) as the thickness increased from 2.1 to 3.5 mm. To conclude, the matchstick-like SiCnws and carbon nanoclusters build a multidimensional network structure that is capable of multiple reflections and scattering of EM waves in YbSiOC ceramics. This work proposes a feasible method to design rare earth silicates with EM absorbing performance, and it is expected to have durable applications in water-vapor environments.

Quantum element method for multi-dimensional nanostructures enabled by a projection-based learning algorithm

A projection-based learning method developed previously based on proper orthogonal decomposition (POD), together with the quantum element method (QEM), is investigated for a 2D multi-element quantum nanostructure, where an element denotes a generic subdomain of a group of nanostructures. Unlike many other projection-based models, the basis functions for the POD approach are trained via solution data of the electron wave functions in the selected quantum state (QS) derived from direct numerical simulation of the Schrödinger equation for the nanostructure. This learning process minimizes the least square error with a small set of basis functions to reduce computational effort. Based on the QEM, the nanostructures are first partitioned into smaller generic elements (i.e., building blocks), and each of the elements is projected onto the POD space and stored in a database. For a large nanostructure, several generic elements can then be selected and glued together to perform simulation of the selected large nanostructure with the interface continuity imposed by the discontinuous Galerkin method. It has been shown that the QEM offers a reduction in numerical degrees of freedom (DoF) by 3 to 4 orders of magnitude for the trained quantum states with a high accuracy compared to direct numerical simulation. For some untrained quantum states above the trained states, a reasonably accurate prediction can be achieved with a few more DoF.

Assembling zinc cobalt hydroxide/ternary sulfides heterostructure and iron oxide nanorods on three-dimensional hollow porous carbon nanofiber as high energy density hybrid supercapacitor

The critical challenge of supercapacitors lies in sluggish kinetics of electrodes and undesirable specific capacitance during charge discharge process including large volume change and inferior cyclic stability. In this work an elaborately designed three dimensional hierarchical heterostructure comprising ternary metal sulfides completely covered by nickel cobalt layered double hydroxide (NiCo-LDH@ZNCS) core shell arrays on electrospun three-dimensional hollow porous carbon nanofiber and used as free-standing electrode material for supercapacitors. The original built-in interfacial potential between NiCo-LDH and ZNCS on conducting three dimensional hollow PCF can acquire multidimensional channels for ion/electron transfer and validate to be a highly capacitive cathode material with a high specific capacity of 407.11 mA h g−1 at the current density of 1 mA cm−2 maintaining outstanding rate performance. The iron oxide nanorods (Fe2O3-PCF) anode (216.15 mA h g−1 at the current density of 1 mA cm−2) match well to the cathode. Benefiting from the powerful synergistic effect, the assembled quasi solid state asymmetric supercapacitor can deliver ultrahigh energy density of 111.72 W h kg−1 at a power density of 243 W kg−1 and extra ordinary life cycle stability (95.2 % capacity retention after 20,000 charge discharge cycles). Such superior electrochemical performances are attributed to the multidimensional nanostructures, porous carbon networks, improved conductivity, and synergistic interaction between the active components of NiCo-LDH/ZNCS arrays. This approach provides a new perspective for rational design of high energy density hybrid supercapacitors, holding unbounded possibilities in this energy dependent world.

Three-Dimensional Nanolithography with Visible Continuous Wave Laser through Triplet Up-Conversion.

Direct laser writing (DLW) technology usually fabricates micronanostructures based on the principle of two-photon polymerization. However, two-photon polymerization requires high laser intensity which can be achieved by expensive femtosecond lasers. To address the issue, a direct laser writing method has been proposed in this work; it is based on triplet up-conversion which is characterized by its low cost, high precision, multidimensional property, and rapid processing. The feasibility of this method is jointly verified by applying both dynamic modeling and experiments. Based on the obtained results, the low laser intensity fabrication of multidimensional nanostructures is achieved. The minimum line width (∼50 nm) of micronanostructures is reached when the laser intensity is set at 2.5 × 105 W/cm2 along with a processing speed of 150 μm/s. As a result, the direct laser writing method, based on triplet up-conversion, offers a new route to achieve low-intensity and high-precision micronanostructure fabrication.

Molecular dynamics simulation of the tool geometry effect on nanowire formation behavior during nanoskiving

Au nanowires have been promoted in flexible electronics, micro-nano bioelectrodes, and micro-electrochemical detection benefit from their inherent size effect, unique chemical stability, and biocompatibility. Nanoskiving methodology has been confirmed as a feasible approach to preparing multidimensional nanostructures simply and efficiently utilizing ultramicrotome. However, the morphology, dimension, and microstructure of the nanowires will be altered by the tool geometry under extrusion and shearing during the nanoskiving process. Herein, a molecular dynamics simulation and experiments of cutting polycrystalline Au utilizing nanoskiving were performed, and the nanowire formation behavior caused by the variation of the tool geometry was analyzed. Smaller rake angle and larger tool cutting edge radius favor thicker chip thickness, larger high-stress areas, increased machining forces, as well as a shift in cutting formation mechanism from shear to extrusion shear. The reduction in the clearance angle only increases the high-stress areas and machining forces. The stress state and dislocation density within the chip and plastic deformation zone were closely related to the tool topography. The conclusions provide a thorough technical analysis of the mechanism of polycrystalline Au nanowire formation as well as theoretical guidance for the design and selection of tools for nanoskiving processes.

Multi-dimensional Ni(OH)2/(Ni(OH)2(NiOOH).167).857@Ni3S2 hierarchical structure for high-performance asymmetric supercapacitor

Multi-phase composite with multi-dimensional nano-structure is proved to have a more optimized electronic structure and abundant reactive active sites, which can effectively enhance the electrochemical behavior of the material. Herein, a three-phase hierarchical nanostructure electrode, Ni(OH)2/(Ni(OH)2(NiOOH).167).857@Ni3S2 (Ni(O)OH@Ni3S2), composed of 3-dimension (3D) Ni3S2 particles coated on the surface of the interlaced 1-dimension (1D) nanowires and 2-dimension (2D) nanosheets Ni(O)OH array, is successfully designed and constructed by a facile one-pot hydrothermal strategy. The formation mechanism is discussed by exploring the effect of S element content and hydrothermal time on the products. Benefiting from the synergistic effect between multi-dimensional nanomaterials, the Ni(O)OH@Ni3S2-1.0 composite electrode can deliver a high areal capacitance (11.74F cm−2 at 2 mA cm−2), displaying remarkable electrochemical behavior. In addition, the assembled Ni(O)OH@Ni3S2//AC asymmetric supercapacitor exhibits an areal energy density of 0.632 mWh cm−2 and an excellent cycling stability performance of 86.4 % after 6000 cycles at 100 mA cm−2. This work proposes the possibility and effectiveness of a one-step method to fabricate multi-dimensional and multi-phase composites for high-performance energy storage devices.

4D nanoprinted sensor for facile organo-arsenic detection: A two-photon lithography-based approach

Engineered 3Dnanostructures have played a crucial role in the development of modern electronic devices. However, the demand for higher dimensional nanostructures have become a necessity for the development of superior next generation miniaturized devices. Traditional two-photon femtosecond laser-based fabrication techniques have enabled fabrication of 3D nanostructures. Carbon quantum dots have recently emerged as a new alternative for achieving subwavelength 3D optical lithography. Here, we report sensing of organo-arsenic(V) species at ppb levels using multimodal carbon quantum dots based 4D miniaturized ultrasensitive nanosensor and development of a device thereof using two-photon lithography. Manganese, nitrogen, and sulphur-doped carbon quantum dots have been used for development of this two-component, two-photon active functional resin for 3D printing of optically active 4D nanostructures. These have sub-wavelength resolved features, and are selectively sensitive to organo-arsenic species. The doped-carbon quantum dots initiate two-photon polymerization in the functional resin and induce emissive attributes to the polymerized nanostructures that impart selectivity towards dimethylarsinate ions (DAI) even at the ppb concentration levels. The miniaturized sensor strip shows a change in fluorescence of the nanostructures when subjected to the analyte. The emission intensities increases with increase in the concentration of DAI. The sensor can detect concentrations of the analyte as low as 1 ppb. This work opens new avenues to meet the demand for multi-dimensional nanostructures for development of superior next-generation of multifunctional miniaturized devices.

Ultrastrong Hybrid Fibers with Tunable Macromolecular Interfaces of Graphene Oxide and Carbon Nanotube for Multifunctional Applications.

Individual carbon nanotubes (CNT) and graphene have unique mechanical and electrical properties; however, the properties of their macroscopic assemblies have not met expectations because of limited physical dimensions, the limited degree of dispersion of the components, and various structural defects. Here, a state‐of‐the‐art assembly for a novel type of hybrid fiber possessing the properties required for a wide variety of multifunctional applications is presented. A simple and effective multidimensional nanostructure of CNT and graphene oxide (GO) assembled by solution processing improves the interfacial utilization of the components. Flexible GOs are effectively intercalated between nanotubes along the shape of CNTs, which reduces voids, enhances orientation, and maximizes the contact between elements. The microstructure is finely controlled by the elements content ratio and dimensions, and an optimal balance improves the mechanical properties. The hybrid fibers simultaneously exhibit exceptional strength (6.05 GPa), modulus (422 GPa), toughness (76.8 J g–1), electrical conductivity (8.43 MS m–1), and knot strength efficiency (92%). Furthermore, surface and electrochemical properties are significantly improved by tuning the GO content, further expanding the scope of applications. These hybrid fibers are expected to offer a strategy for overcoming the limitations of existing fibers in meeting the requirements for applications in the fiber industry.

Three-dimensional electron ptychography of organic–inorganic hybrid nanostructures

Three dimensional scaffolded DNA origami with inorganic nanoparticles has been used to create tailored multidimensional nanostructures. However, the image contrast of DNA is poorer than those of the heavy nanoparticles in conventional transmission electron microscopy at high defocus so that the biological and non-biological components in 3D scaffolds cannot be simultaneously resolved using tomography of samples in a native state. We demonstrate the use of electron ptychography to recover high contrast phase information from all components in a DNA origami scaffold without staining. We further quantitatively evaluate the enhancement of contrast in comparison with conventional transmission electron microscopy. In addition, We show that for ptychography post-reconstruction focusing simplifies the workflow and reduces electron dose and beam damage.

Structural evolution of palygorskite-rich clay as the nanocarriers of silver nanoparticles for efficient improving antibacterial activity

Clay minerals with rod-like or layered structures have been widely used as the carrier to fabricate metal nanoparticles-based antibacterial composites. Palygorskite-rich clay (PALC) contains not only one-dimensional nanorods (palygorskite) but also two-dimensional nanolamella (mainly illite), where its structure can be regulated by oxalic acid (OA) gradient leaching to obtain multi-dimensional nanoparticles (MDP). To further understand the activity of different rod-lamellar nanostructures of PALC and MDP induced by the OA leaching process, and also to prepare high-performance antibacterial materials, a series of nanocomposites based on silver nanoparticles (AgNPs) were prepared in this study, using PALC and MDP as the nanocarrier. TEM, FTIR, XRD, Zeta potential and other characterizations together proved that OA leaching of PALC in the range of 8–48 h (MDP-8 h, MDP-24 h, MDP-48 h) was the most beneficial for in-situ synthesis of monodispersed AgNPs. The antibacterial evaluation results showed that the growth of 99.30 %, 84.94 %, 60.72 %, 79.48 %, 87.78 % of E. coli, S.aureus, ESBL-E. coli, P. aeruginosa and MRSA (1.5 × 105 CFU/mL) were inhibited after treatment with 0.5 µg/mL of MDP-24 h/AgNPs, confirming its excellent and broad-spectrum antibacterial performance, which is mainly due to the most ideal natural multi-dimensional nanostructure of MDP after 24 h of OA leaching. In brief, a simple and efficient method was used in this study to realize the high-value application of natural multi-dimensional nanoclay and to prepare antibacterial composites with promising applications.

Structural and morphological effect of multidimensional TiO2 nanostructures on the dye-sensitized solar cells performance

Structural and morphological effect of multidimensional TiO2 nanostructures on the dye-sensitized solar cells performance