One-dimensional Nanowires Research Articles

Preparation and Characterization of TiO₂ Nanowires Modified Organically with Coupling Agents.

Anatase-type one-dimensional TiO₂ nanowire was prepared by hydrothermal method. The nanowires were modified by three kinds of silane coupling agents, such as KH550, KH560 and KH570. Flocculation was caused when the amount of modifier reached a certain level. When KH570 was used at 3.0 percent, at 80 °C, 4 h, and pH value between 9 and 10, modified nanowires had the highest 56.5 percent lipophilization degree, the lowest 0.562 per/nm² surface hydroxyl number, and the maximal 121.2° static contact angle.

En route to the transformation of porphyrin molecules for PDT: Theoretical insights on the reactive oxygen generation of 1D nano-wires and 2D covalent organic frameworks

• The PSs used in hypoxic environment are investigated by using theoretical method. • The newly discovered photocatalytic activity ensures to get reactive oxygen OH . • The novel Type I PSs for photodynamic therapy are presented. The application of photosensitizers (PSs) is sometimes limited due to hypoxic environment. To overcome this drawback, one-dimensional infinite tetraphenylporphyrin nano-wires (1D-TPP-WIREs) and two-dimensional tetraphenylporphyrin covalent organic frameworks (2D-TPP-COFs) as Type I photosensitizers (PSs) for photodynamic therapy (PDT) are presented. Meanwhile, the mono-TPP, bis-TPP, and terta-TPP molecules are also studied to investigate the influence of conjugative and metallic effect on the properties of the TPP system. Compared with mono-TPPs, the intra-molecular charge transfer in bis-TPPs and tetra-TPPs is more obvious, the absorption spectra intensity of bis-TPPs and tetra-TPPs is strengthened. Moreover, the 1D-TPP-WIREs and 2D-TPP-COFs with more large conjugated TPP system exhibit photocatalytic activity, which can abstract hydrogen from water to get reactive oxygen OH for treatment of hypoxic tumours. Comprehensively consider the properties of charge density distribution, absorption spectra, band edge position of the CB and VB potentials, the 1D-TPP-WIRE-HCu and 2D-TPP-COF-HCu is more suitable for hypoxic Type I PDT.

Biomimetic Synthesis of Ultrafine Mixed-Valence Metal–Organic Framework Nanowires and Their Application in Electrochemiluminescence Sensing

Metal-organic frameworks (MOFs) prepared via typical procedures tend to exhibit issues like poor water stability and poor conductivity, which hinder their application in electrochemical sensing. Herein, we report a strategy for the preparation of mixed-valence ultrafine one-dimensional Ce-MOF nanowires based on a micelle-assisted biomimetic route and subsequent investigation into their growth mechanism. The prepared mixed-valence Ce-MOF nanowires exhibited a typical size of ∼50 nm and were found to present good water stability and high conductivity. On this basis, we examined the introduction of these nanowires into the luminol hydrogen peroxide luminescence system and proposed a novel dual-route self-circulating electrochemiluminescence (ECL) catalytic amplification mechanism. Finally, in combination with molecular imprinting, a MOF-based ECL sensor was developed for the detection of trace amounts of imidacloprid in plant-derived foods. This sensor exhibited a linearity of 2-120 nM and a detection limit of 0.34 nM. Thus, we proposed not only a novel route to MOF downsizing but also a facile and robust methodology for the design of a MOF-based molecular imprinting ECL sensor.

Mo and Zn-Dual doped CuxO nanocrystals confined High-Conductive Cu arrays as novel sensitive sensor for neurotransmitter detection

The development of sensitive and selective sensors using facile and low-cost methods for detecting neurotransmitter molecules is a critical factor in the health care system in regard to early diagnosis. In this research, an electrocatalyst derived from Mo,Zn dual-doped CuxO nanocrystals-based layer coating over one-dimensional copper nanowire arrays (Mo,Zn-CuxO/CuNWs) was successfully designed using a facile electrodeposition approach and used as an electrochemical sensor for non-enzymatic dopamine (DA) neurotransmitter detection. The synergistic effect caused by the dual-doping effect along with its excellent conductivity produced a large electroactive surface area and an improved hetero-charge transfer, thereby boosting DA sensing ability with a low limit detection of 0.32 µM, wide-range of detection (0.5 µM − 3.9 mM), long-term stability (5 weeks), and high selectivity in phosphate buffer solution (pH 7.4). Also, the sensor accurately determined DA in real blood serum-spiked solutions. The achieved results evidenced that the Mo,Zn-CuxO/CuNWs derived sensor is highly suitable for DA detection. Therefore, it also opens new windows for the development of low-cost, accurate, high-performance, and stable sensors for other neurotransmitter sensing for the purposes of better health care and early diagnosis.

Construction of 3D MXene/Silver nanowires aerogels reinforced polymer composites for extraordinary electromagnetic interference shielding and thermal conductivity

The novel multifunctional materials with anti-electromagnetic interference (EMI) and effective thermal management are ideal for modern electronic industry. Generally, the EMI shielding effectiveness (SE) and thermal conductivity (TC) of materials can be effectively enhanced by compounding with high electrically and thermally conductive fillers. However, it seems that the high-performance cannot be compensated without sacrificing the high fillers loading. Herein, from one-dimensional silver nanowires (AgNWs) and two-dimensional MXene, three-dimensional MXene/AgNWs aerogels were designed as electric and heat transferring skeletons for epoxy nanocomposites by directional-freezing and freeze-drying methods. The resultant MXene/AgNWs/Epoxy nanocomposites with a low MXene/AgNWs content of 8.2 wt% combine a high electrical conductivity of 1532 S/m, and an exceptional EMI SE value of 94.1 dB with 3 mm thickness at the X-band frequency, as well as an improved TC of 2.34 W/m·K. The fabricated MXene/AgNWs/Epoxy nanocomposites possess excellent comprehensive properties enable valuable applications in electronic devices for EMI shielding and thermal management.

Electron correlation effects in superconducting nanowires in and out of equilibrium

One-dimensional nanowires with strong spin–orbit coupling and proximity-induced superconductivity are predicted to exhibit topological superconductivity with condensed-matter analogues to Majorana fermions. Here, the nonequilibrium Green’s function approach with the generalized Kadanoff–Baym ansatz is employed to study the electron-correlation effects and their role in the topological superconducting phase in and out of equilibrium. Electron-correlation effects are found to affect the transient signatures regarding the zero-energy Majorana states, when the superconducting nanowire is subjected to external perturbations such as magnetic-field quenching, laser-pulse excitation, and coupling to biased normal-metal leads.

Ultrathin Ti3C2 nanowires derived from multi-layered bulks for high-performance hydrogen evolution reaction

One-dimensional ultrathin nanowires (NWs) offer a great deal of promising properties for electrochemical energy storage and conversion due to their nanoscale confinement effect and high surface-to-volume ratios. It is highly desirable to precisely design and synthesize ultrathin Ti3C2 NWs in the aspect of size, crystalline structure and composition. Here, we report a simple alkalization strategy to design the ultrathin Ti3C2 NWs for hydrogen evolution reaction (HER) by modulating the surface-active sites. The design principle can well improve the amount of the defect sites and ion accessibility to increase the interactions between Ti3C2 NWs and H*. The optimized Ti3C2 NWs achieve an overpotential of 476 mV at the current density of 10 mA/cm2 and a Tafel slope of 129 mV/dec for HER catalysis, which are superior to that of Ti3C2 nanosheets and m-Ti3C2. It paves an avenue for the rational transformation of MXene bulks to one-dimensional NWs catalysts for HER.

Organic ligand mediated evolution from aluminum-based superalkalis to superatomic molecules and one-dimensional nanowires

Organic ligand mediated evolution from aluminum-based superalkalis to superatomic molecules and one-dimensional nanowires

Synthesis of metal free organic dyes: Experimental and theoretical approach to sensitize one-dimensional cadmium sulphide nanowires for solar cell application

Synthesis of metal-free organic dyes PDR and PDP based on the phenothiazine core unit have been attempted through solution chemistry approach and anchored on to one dimensional cadmium sulphide nanowires (CdS NWs) to be used as light harvesters in dye sensitized solar cell (DSSC) device application. Simple and cost effective solution chemistry approach leads to enable CdS NWs interconnected nano network. Synthesized dyes have been investigated through optical and electrochemical studies in addition to theoretical calculations using density functional theory (DFT). Dye anchored CdS films cover wider light absorption than bare CdS in the visible part of solar spectrum. The complete device configuration has been assembled as FTO/CdS compact/CdS NWs/Organic dye/electrolyte/Platinum electrode. PDR and PDP sensitized CdS NWs yield 0.24 and 0.28% efficiency which are 2.36 and 2.77 times as compared to bare CdS NWs (0.10%) with sun light of standard conditions of illuminations. External quantum efficiency enhancement is well supported with the obtained results and correlated well with the absorption studies. The present work successfully demonstrates the use of novel synthesized organic dyes as light harvesters.

S-scheme carrier kinetic pathway constructed by covalent-anion channels in self-assembled cadmium/rhenium sulfide hybrids for efficient Cr(VI) reduction

Exploring photocatalysts to accelerate heavy metal Cr(VI) photoreduction is of great significance. Different from traditional strategies, this work proposes a simple and feasible strategy to construct cadmium/rhenium sulfide (CdS/ReS2) S-scheme heterojunctions for enhancing carrier separation through a covalent-anion-driven self-assembling approach. Herein, the construction of internal electric field induced by an atomic-hybridization at CdS/ReS2 interface drives the photoexcited electrons from one-dimensional CdS nanowires to two-dimensional ReS2 nanosheets upon light irradiation, resulting in the formation of an S-scheme carrier kinetic pathway, which enables the separation of electron-hole pairs to accelerate Cr(VI) photoreduction. As a result, the reduction reaction of CdS/ReS2 heterojunction is increased about 11.4 and 24.3 times compared to pristine CdS and ReS2. Our findings provide a new insight in regulating carrier transfer pathway and designing new-type photocatalysts.

YBCO superconductor added with one-dimensional TiO2 nanostructures: Frequency dependencies of AC susceptibility, FC-ZFC magnetization, and pseudo-gap studies

This article reports the role of adding one-dimensional titanium dioxide nanowires (TiO2-NWs, having 30 nm in diameter and some micrometers in length) on FC-ZFC magnetization, frequency-dependent AC susceptibility, and electrical measurements of the YBCO bulk system. The non-added (A0) and added TiO2-NWs samples (A1) were prepared by solid-state reaction route. TiO2-NWs did not affect the crystalline structure of YBCO. SEM examinations revealed that TiO2-NWs preferred to localize at the grain boundaries filling the pores existing between YBCO grains. FC-ZFC magnetization and frequency-dependent AC susceptibility analysis showed an enhancement of flux pinning properties with TiO2-NWs addition. TiO2-NWs addition affected also the electrical and pseudo-gap analysis of the samples.

Photoelectrochemical water oxidation kinetics and antibacterial studies of one-dimensional SiC nanowires synthesized from industrial waste

Photoelectrochemical water oxidation kinetics and antibacterial studies of one-dimensional SiC nanowires synthesized from industrial waste

Multifunctional Textiles Based on Three-Dimensional Hierarchically Structured TiO2 Nanowires.

The development of three-dimensional (3D) micro-/nanostructures with multiscale hierarchy offers new potential for the improvement of the pristine textile properties. In this work, a polyester fabric coated with 3D hierarchically structured rutile TiO2 nanowires (THNWP) was fabricated by a facile hydrothermal strategy. The THNWP samples exhibit markedly improved photocatalytic activities and antibacterial properties owing to their 3D hierarchical architecture constructed by one-dimensional nanowire structures, good crystallinity, excellent light-harvesting capability, and fast electron-transfer rate. Furthermore, the unique 3D hierarchical nanostructures also combine with the monofilament to produce ternary-scale hierarchy, which endows the fabric surface with outstanding superamphiphobicity after further facile fluorination treatment. The supportive air-pockets trapped within the unique ternary-scale architectures are proved to be the crucial factor in the achievement of high liquid repellency, and the highest performing superamphiphobic surface is capable of repelling liquids down to a minimal surface tension of 23.4 mN m-1. We envision that our findings may possess great potential in the bottom-up design of high-performance textiles.

Schottky junction devices by using bio-molecule DNA template-based one dimensional CdS-nanostructures

Creating a well-defined nanostructure through de-oxyribo nucleic acid (DNA)-nanotechnology, and specifically the development of metal/inorganic semiconductor junctions on DNA-assembled nanostructures, is an emerging research area. Herein, we investigate the electrical properties of biomolecule DNA-template based one-dimensional nanowires (NWs)-CdS/Au and without-template based nanoparticles (NPs)-CdS/Au devices grown on the Indium Tin Oxide (ITO) glass substrates. More importantly, the NWs-CdS/Au device displays a dramatic augmentation of current flow and also a striking change in threshold voltage (~55 mV) in comparison to NPs (~190 mV) and reported bulk-CdS/Au (~680 mV) devices. Albeit the manifestation of non-linear/asymmetric current-voltage (I–V) characteristic establishes the CdS/Au junction as Schottky device, but captivatingly, the large ideality factor of about 24 found in NWs-CdS/Au device could be due to the DNA-assembled based organic process CdS-semiconductor. Capacitance-voltage (C–V) measurements of the NWs-CdS/Au divulge a remarkable hump-like feature at lower frequency owing to the frequency dispersion effect. In contrast, the effect appears to be enfeebled with increasing frequency. We conjecture that the density of surface/interface traps materialises at the interface of nanostructures-CdS/metal-Au results in the changes in underlying electrical properties. The observation of significant differences in the electrical properties of DNA-assembled NWs-based Schottky junctions could possibly be helpful for the fabrication of more sophisticated and higher multispecificity biosensors for medical applications.

Wire spherical-shaped Co-MOF electrode materials for high-performance all-solid-state flexible asymmetric supercapacitor device

The exploration of an inexpensive, low-energy consumption and environmentally friendly preparation process to synthesize high capacitance performance MOF-based electrode materials is an important prerequisite for their commercialization. We propose a non-calcined strategy to synthesize nanowire microsphere shaped Co-BTC (CBNWM). Making MOF into one-dimensional nanowire structure can effectively increase its active sites and the ion transfer rate. After the MOF nanowires are entangle and reunite into microspheres, their mechanical property and chemical stability are improved. Therefore, compared with Co-BTC crystal (CBC), the electrochemical properties of CBNWM have been significantly improved. The specific capacity of CBNWM reaches 1020 F g−1 at 5 mV s−1 or 657 F g−1 at 0.5 A g−1 with the capacity remains 81.4% after 3000 cycles. Subsequently, a flexible asymmetric device of CBNWM//AC was fabricated, whose maximum energy density can achieve 34.4 W h kg−1 with the related power density of 375.3 W kg−1.

Resolving few-layer antimonene/graphene heterostructures

Two-dimensional (2D) antimony (Sb, “antimonene”) is of interest in electronics and batteries. Sb however exhibits a large allotropic structural diversity, which is also influenced by its support. Thus, Sb heterostructure formation is key in 2D Sb integration. Particularly, 2D Sb/graphene interfaces are important. We thus study here few-layered 2D Sb/graphene heterostructures with atomic resolution (scanning) transmission electron microscopy. We find two Sb morphologies to coexist: first, a 2D morphology of layered β-Sb with β-Sb(001)||graphene(001) texture. Second, one-dimensional Sb nanowires which can be matched to β-Sb[2-21]⊥graphene(001) and are closely related to cubic Sb(001)||graphene(001). Importantly, both Sb morphologies show rotational van-der-Waals epitaxy with graphene. Both are resilient against oxidation, although superficial Sb-oxide formation merits consideration, including epitaxial Sb2O3(111)/β-Sb(001) heterostructures. Exact Sb growth behavior depends on processing and substrate properties including, notably, the support underneath the graphene. Our work elucidates the rich phase and epitaxy landscape in 2D Sb and 2D Sb/graphene heterostructures.

Pd-Doping-Induced Oxygen Vacancies in One-Dimensional Tungsten Oxide Nanowires for Enhanced Acetone Gas Sensing.

Metal oxide semiconductors (MOS) with different nanostructures have been widely used as gas sensing materials due to the tunable interface structures and properties. However, further improvement of the sensing sensitivity and selectivity is still challenging in this area. Constructing appropriate heterogeneous interface structures and oxygen vacancies is one of the important strategies to tune the sensing properties of MOS. In the present study, interfacial heterostructures in PdxW18O49 nanowires (PdxW18O49 NWs) were fabricated and manipulated by doping different Pd contents through a simple hydrothermal process. Relevant characterization proved that the structure and composition of the one-dimensional (1D) nanomaterial can be effectively changed by Pd doping. It was found that the oxygen vacancy concentration increases first with the increase of Pd content, and when the Pd content increases to 7.18% (Pd7.18%W18O49 NWs), the oxygen vacancy content reaches the maximum (52.5%). If the Pd content continues to increase, the oxygen vacancy ratio decreases. The gas sensing investigations illustrated that the PdxW18O49 NWs exhibited enhanced sensing properties than pure W18O49 NWs toward acetone. Among the as-prepared catalysts, the Pd7.18%W18O49 NWs showed the best sensing response and the fastest response-recovery speeds (5 and 10 s, respectively) at a working temperature of 175 °C. In addition, this 1D nanostructure with fabricated heterostructures also delivers a good sensing selectivity and a wide detection range from 100 ppb to 300 ppm, with maintaining excellent performance in the presence of high concentrations of ethanol and carbon dioxide. The excellent gas sensing behavior could be attributed to the generated oxygen vacancies and the heterostructures upon Pd doping. This study offers a novel strategy for the design of high-performance gas sensors for ppb-level acetone sensing.

One-dimensional Sub-stoichiometric W3O8Nanowires Filled Carbon Nanotubes

One-dimensional Sub-stoichiometric W₃O₈Nanowires Filled Carbon Nanotubes

PdAu alloy nano wires for the elevated alcohol electro-oxidation reaction

In the search of a satisfactory electrocatalyst for fuel cells, herein, we are reporting Au rich PdAu nano wires with excellent electro-catalytic activity towards methanol and ethanol oxidation. Ultrathin one-dimensional PdAu nanowires were prepared rapidly through a simple one step process. Among the prepared catalysts, the 10% Pd incorporated PdAu nano wire catalyst imparted greater catalytic activity, which exhibited ten times enhancement higher activity towards methanol as well as six times higher activity towards ethanol than that of the pure Pd catalyst. Eventually, the amount of Pd metal reduced to 90% without compromising its catalytic efficiency. Distinctive properties of one-dimensional Au were attributed to the improved catalytic activity.

Elaboration and photocatalytic properties of CoFe2O4/TiO2 composite nanowires with the side-by-side structure

The one-dimensional composite nanowires of CoFe2O4/TiO2 (CFO/TO) were prepared by the dual needle electrostatic spinning followed by heat treatment. One-dimensional side-by-side nanowire structure is obtained under 500 ℃ and 700 ℃, which is assembled with numerous nanoparticles of CoFe2O4 and TiO2 along the axis of the nanowire. With the increase of annealing temperature, the side-by-side structure is broken. By contrast, the side-by-side nanowires show the better photocatalytic efficiency. In addition, all samples exhibit ferromagnetic properties which is helpful for recycling. As a result, this work supply a feasible way to fabricate new structure of nanocomposites with better photocatalytic properties.