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Carbon nanotubes have shown great promise for high-performance, large-area, solution processable field-effect transistors due to their exceptional charge transport properties. In this study, we utilize the spin-coating method to form networks from selectively sorted semiconducting single-walled carbon nanotubes (s-SWNTs), aiming for scalable electronic device fabrication. The one-dimensional nature of s-SWNTs, however, introduces significant roughness and charge trap sites, hindering charge transport due to the van der Waals gap (∼0.32 nm) between nanotubes. Addressing this, we explored the effects of anion doping on the spin-coated s-SWNT random network, with a focus on the influence of the small size of halogen anions (0.13–0.22 nm) on these electronic properties. Raman and ultraviolet–visible–near-infrared optical spectroscopy results indicate that smaller anions significantly enhance doping effects through strong non-covalent anion–π interactions, improving charge transport and carrier injection efficiency in s-SWNTs, especially for n-type operation. This improvement is inversely proportional to the size of the halogen anions, with the smallest anion (fluorine) effectively transitioning the electrical characteristics of the s-SWNT network from ambipolar to n-type by reducing both junction and contact resistances through anion doping, based on anion–π interaction. [ABSTRACT FROM AUTHOR]

The photochemical generation of nicotinamide cofactor 1,4-NADH, facilitated by inorganic photosensitizers, emerges as a promising model system for investigating charge transfer phenomena at the interface of semiconductors and bacteria, with implications for enhancing photosynthetic biohybrid systems (PBSs). However, extant semiconductor nanocrystal model systems suffer from achieving optimal conversion efficiency under visible light. This study investigates quasi-one-dimensional CdS nanorods as superior light absorbers, surface modified with catalyst Cp*Rh(4,4'-COOH-bpy)Cl2 to produce enzymatically active NADH. This model subsystem facilitates easy product isolation and achieves a turnover frequency (TOF) of 175 h-1, one of the highest efficiencies reported for inorganic photosensitizer-based nicotinamide cofactor generation. Charge transfer kinetics, fundamental for catalytic solar energy conversion, range from 106 to 108 s-1 for this system highlighting the superior electron transfer capabilities of NRs. This model ensures efficient cofactor production and offers critical insights into advancing systems that mimic natural photosynthesis for sustainable solar-to-chemical synthesis.

Living cells regulate the dynamics of developmental events through interconnected signaling systems that activate and deactivate inert precursors. This suggests that similarly, synthetic biomaterials could be designed to develop over time by using chemical reaction networks to regulate the availability of assembling components. Here we demonstrate how the sequential activation or deactivation of distinct DNA building blocks can be modularly coordinated to form distinct populations of self-assembling polymers using a transcriptional signaling cascade of synthetic genes. Our building blocks are DNA tiles that polymerize into nanotubes, and whose assembly can be controlled by RNA molecules produced by synthetic genes that target the tile interaction domains. To achieve different RNA production rates, we use a strategy based on promoter nicking and strand displacement. By changing the way the genes are cascaded and the RNA levels, we demonstrate that we can obtain spatially and temporally different outcomes in nanotube assembly, including random DNA polymers, block polymers, and as well as distinct autonomous formation and dissolution of distinct polymer populations. Our work demonstrates a way to construct autonomous supramolecular materials whose properties depend on the timing of molecular instructions for self-assembly, and can be immediately extended to a variety of other nucleic acid circuits and assemblies.

Dimensions and molecular structures play pivotal roles in the principle of heat conduction. The dimensional characteristics of a solution within nanoscale systems depend on the degrees of confinement. However, the influence of such variations on heat transfer remains inadequately understood. Here, we perform quasi-one-dimensional non-equilibrium molecular dynamics simulations to calculate the thermal conductivity of water molecules confined in carbon nanotubes. The structure of water molecules is determined depending on the nanotube radius, forming a single-file, a single-layer, and a double-layer structure, corresponding to an increasing radius order. We reveal that the thermal conductivity of liquid water has a sublinear dependency on nanotube length exclusively when water molecules form a single file. A stronger confinement leads to behavioral and structural characteristics closely resembling a one-dimensional nature. Moreover, single-layer-structured water molecules exhibit enhanced thermal conductivity. We elucidate that this is due to the increase in the local water density and the absence of transitions to another layer, which typically occurs in systems with double-layer water structures within relatively large radius nanotubes. [ABSTRACT FROM AUTHOR]

In extreme and nanoconfinement conditions, the tetrahedral arrangement of water molecules is challenged, resulting in a rich and new phase behavior unseen in bulk phases. The unique phase behavior of water confined in hydrophobic nanoslits has been previously observed, such as the formation of a variety of two-dimensional (2D) ices below the freezing temperature. The primary identified 2D ice phase, termed square tube ice (STI), represents a unique arrangement of water molecules in 2D ice, which can be viewed as an array of 1D ice nanotubes stacked in the direction parallel to the confinement plane. In this study, we report the molecular dynamics (MD) simulations evidence of a novel 2D ice phase, namely, helical square tube ice (H-STI). H-STI is characterized by the stacking of helical ice nanotubes in the direction parallel to the confinement plane. Its structural specificity is evident in the presence of helical square ice nanotubes, a configuration unseen in both STI and single-walled ice nanotubes. A detailed analysis of the hydrogen bonding strength showed that H-STI is a 2D ice phase diverging from the Bernal–Fowler–Pauling ice rules by forming only two strong hydrogen bonds between adjacent molecules along its helical ice chain. This arrangement of strong hydrogen bonds along ice nanotube and weak bonds between the ice nanotube shows a similarity to quasi-one-dimensional van der Waals materials. Ab initio molecular dynamics simulations (over a 30 ps) were employed to further verify H-STI's stability at 1 GPa and temperature up to 200 K. [ABSTRACT FROM AUTHOR]

Layered or chain materials have received significant research attention owing to their interesting physical properties, which can dramatically change when the material is thinned from bulk (three-dimensional) to thin two-dimensional sheet or one-dimensional (1D) chain form. Materials with the stoichiometry AX2 with A = Si or Ge and X = S or Se form an especially intriguing semiconducting class. For example, bulk silicon dichalcogenides (SiX2) consist of 1D chains held together by van der Waals forces. Although this structural configuration has the potential to reveal interesting physical phenomena within the 1D limit, obtaining SiX2 single chains has been challenging. We here examine experimentally and theoretically SiX2 materials in the low chain number limit. Carbon nanotubes serve as growth templates and stabilize and protect the structures, and atomic-resolution scanning transmission electron microscopy directly identifies the atomic structure. Two distinct chain structures are observed for SiX2. SixGe1-xS2(1-y)Se2y quaternary alloy chains are also synthesized and characterized, demonstrating tunable semiconducting properties at the atomic-chain level. Density functional theory calculations reveal that the band gap of these alloy chains can be widely tuned through composition engineering. This work offers the possibilities for synthesizing and controlling semiconductor compositions at the single-chain limit to tailor material properties.

Many researchers observed enhanced water flow through carbon nanotubes (CNTs) and attributed the reason to large slips. Even after taking significant slip effects into account, there remain unaddressed observations of significant improvements in flow rates. As CNTS are deformable, we represent nanotubes with a deformable-wall using a linear pressure–area relationship. We assume lubrication assumption, and using the properties of nanoconfined water, we derive the model for deformable-nanotubes. We validated our derived model in its limiting cases with the previously reported results in the literature. We compare the predictions by our deformable-wall and rigid-wall model with the experimental results and the MD-simulation predictions by multiple literature studies. Many studies were well-predicted by the rigid-wall model with slips. However, we find that there are many studies with high porosity and thin wall tubes, where elasticity or deformability of the tube is essential in modeling, which is well-predicted by our deformable-wall model with slips. In our study, we focus on investigating the impact of two key factors: the deformability, and the slip length on the flow rate. We find that the flow rate inside the tube increases as the deformability increases or the thickness T and elastic modulus E of the tube-wall decrease). We also find that the flow rate in deformable tubes scales as m ˙ deformable ∼ 1 / α 0 for (Δ p / α A o ) ≪ 1 , m ˙ deformable ∼ 1 / α for (Δ p / α A o ) ∼ O (10 − 1) and m ˙ deformable ∼ α 2 for (Δ p / α A o ) ∼ O (1). Further, for a given deformability, the percentage change in flow rate in the smaller diameter of the tube is much larger than the larger diameter. As the tube diameter decreases for the given pressure, Δ m ˙ / m ˙ increases. We find that for rigid-tube, the flow rate varies m ˙ rigid ∼ Δ p , whereas for the deformable-tubes, the flow rate scales as m ˙ deformable ∼ Δ p 2 for (Δ p / α A o ) ∼ O (10 − 1) , and finally to m ˙ deformable ∼ Δ p 3 for (Δ p / α A o ) ∼ O (1). We further find that slip also significantly increases flow rate, but, deformability has more substantial effect. [ABSTRACT FROM AUTHOR]

In order to solve the problems of low energy utilization and poor structural stability of photothermal conversion materials, a graphene-based photothermal conversion material was prepared, which was structurally integrated with a light-absorbing upper layer and a heat insulating base. During the preparation process, a tightly arranged nanotube array upper layer was constructed on the basis of graphene films by microimprinting technology, and a porous aerogel base was molded by a fixed-point titration and multiple-foaming method. The results show that the light trap constructed from graphene hollow nanotubes can significantly increase the number of light reflections and reduce light reflectivity. Meanwhile, the length of the nanotubes is directly proportional to the light-absorbing capacity of the material, which can increase the light-absorbing rate to more than 98% under the embossing conditions of 85 kN and 8h. In addition, the porous aerogel insulation base can effectively improve the photothermal conversion effect, and a photothermal conversion efficiency of 87% and a water evaporation rate of 1.3 kg/(m2 h) can be achieved at a base thickness of 6 mm. [ABSTRACT FROM AUTHOR]

We demonstrate a high electron conductivity (>102 S/cm and up to 103 S/cm) of tungsten suboxide W18O52.4−52.9 (or equivalently WO2.91−2.94) nanotubes (2–3 nm in diameter, ∼μm long). The conductivity is measured in the temperature range of 120–300 K by a four-probe scanning tunneling microscope in ultrahigh vacuum. The nanotubes are synthesized by a low-temperature and low-cost solvothermal method. They self-assemble in bundles of hundreds of nanotubes forming nanowires (∼μm long, few tens nm wide). We observe a large anisotropy of the conductivity with a ratio (longitudinal conductivity/perpendicular conductivity) of ∼105. A large fraction of them (∼65%–95%) shows a metallic-like, thermal activation-less electron transport behavior. Few of them, with a lower conductivity from 10 to 102 S/cm, display a variable range hopping behavior. In this latter case, a hopping barrier energy of ∼0.24 eV is inferred in agreement with the calculated energy level of the oxygen vacancy below the conduction band. This result is in agreement with a relative average concentration of oxygen vacancies of ∼3%, for which a semiconductor-to-metal transition was theoretically predicted. These tungsten suboxide nanostructures are prone to a wide range of applications in nanoelectronics. [ABSTRACT FROM AUTHOR]

The electric polarizability and the spread of the total position tensors are used to characterize the metallic vs insulator nature of large (finite) systems. Finite clusters are usually treated within the open boundary condition formalism. This introduces border effects, which prevent a fast convergence to the thermodynamic limit and can be eliminated within the formalism of periodic boundary conditions. Recently, we introduced an original approach to periodic boundary conditions, named Clifford boundary conditions. It considers a finite fragment extracted from a periodic system and the modification of its topology into that of a Clifford torus. The quantity representing the position is modified in order to fulfill the system periodicity. In this work, we apply the formalism of Clifford boundary conditions to the case of carbon nanotubes, whose treatment results in a particularly simple zigzag geometry. Indeed, we demonstrate that at the Hückel level, these nanotubes, either finite or periodic, are formally equivalent to a collection of non-interacting dimerized linear chains, thus simplifying their treatment. This equivalence is used to describe some nanotube properties as the sum of the contributions of the independent chains and to identify the origin of peculiar behaviors (such as conductivity). Indeed, if the number of hexagons along the circumference is a multiple of three, a metallic behavior is found, namely a divergence of both the (per electron) polarizability and total position spread of at least one linear chain. These results are in agreement with those in the literature from tight-binding calculations. [ABSTRACT FROM AUTHOR]

From the perspective of a bond-order-length-strength correlation, we put forward an analytical solution to describe the size, shape, and wall thickness dependency of melting temperature, entropy, and enthalpy for metallic nanostructures. Theoretical reproduction of measurements clarified that (i) when the crystal size reduces, the atomic coordination number lowers, the atomic cohesive energy decreases, and the surface-to-volume ratio increases; (ii) at the same equivalent radius, with the decrease in the number of sides for polyhedral nanoparticles and polygonal nanowires or nanotubes, the melting temperature, entropy, and enthalpy depress; and (iii) the melting temperature, entropy, and enthalpy of nanotubes are always lower than those of nanowires with the same cross-sectional radius. The present formulation is accurate and convenient, which not only shows deeper insight into the physical origins of a melting thermodynamic property response to perturbations but also provides guidance for the design and optimization of electronic nanodevices. [ABSTRACT FROM AUTHOR]

Highlights The electromagnetic properties of epoxy‐based composites filled with carbon‐coated copper (Cu@C) nanoparticles and multi‐walled carbon nanotubes (MWCNTs), along with hybrid MWCNT/Cu@C/Epoxy systems containing varying concentrations of nanoinclusions, were systematically investigated across multiple frequency and temperature ranges. Measurements were conducted in the low‐frequency range (20 Hz–1 MHz) and over a temperature span of 40–500 K, as well as in the microwave frequency range (26–37 GHz) at room temperature. The percolation threshold was identified at approximately 2.5 vol% for composites containing only Cu@C nanoparticles and at 0.3 vol% for composites with MWCNTs. Notably, the hybrid MWCNT/Cu@C/Epoxy composites exhibited significantly enhanced electromagnetic properties compared to those of the single‐filled systems. At room temperature, an epoxy composite containing 5 vol% Cu@C and 1 vol% MWCNT exhibits a conductivity of approximately 4 × 10−2 S/m, which increases by nearly two orders of magnitude following a thermal cycle up to 500 K. The total electromagnetic interference (EMI) shielding effectiveness in the 26–37 GHz range was measured between 4 and 9 dB, indicating the material's promising potential for attenuating microwave noise. Dynamic mechanical analysis (DMA) results revealed that increasing the MWCNT content improved the storage modulus of the composites but led to a reduction in the glass transition temperature (Tg), which was observed to range between 40 and 50°C. The incorporation of MWCNTs and Cu@C nanoparticles into epoxy matrices offers a promising approach for the development of lightweight multifunctional composites with superior electrical, mechanical, and EMI shielding properties. The percolation threshold in MWCNT/Epoxy composites is 0.3%. The percolation threshold in Cu@C/Epoxy composites is 2%. The conductivity value of MWCNT/Cu@C/Epoxy composites is around 4 × 10−2 S/m. The total shielding effectiveness in the Ka‐band range between 4 and 9 dB. Glass transition temperature of MWCNT/Cu@C/Epoxy is between 40 and 50°C. [ABSTRACT FROM AUTHOR]

In order to better understand the confinement effect of CNTs on the properties of Ni based catalysts, Ni/CNTs catalysts with different Ni locations via the modification of CNTs pretreatment and impregnation process were prepared, characterized and tested in glycerol steam reforming. The Ni-in/CNTs catalyst showed excellent low temperature reaction activity, with initial Ni time yield of 0.064 mol C3H8O3 ·g Ni −1·h−1 and H 2 yield of 50.1% at 275 °C, 0.1Mpa. The confinement of Ni particles inside CNTs nanotubes led to more active sites with weak H 2 absorption strength, which were more related to the activity for glycerol steam reforming reaction. All the catalysts exhibited a noticeable deactivation during the reaction, however, their main deactivation mechanisms were not the same. The confinement effect of CNTs nanotubes could limit the sintering degree of Ni particles, and thus the deactivation of Ni-in/CNTs catalyst was slow in the initial stage; nevertheless, its deactivation became faster in the subsequent stage, which was due to the severe carbon deposition. For the two catalysts with Ni particles on the outer surface of supports, their main deactivation reason was the significant sintering of Ni species, and therefore, their deactivation was faster first and then slow down. [Display omitted] • Ni-in/CNTs showed excellent activity at the temperature as low as 275 °C. • The confinement effect of CNTs nanotubes limits the sintering of Ni particles. • Weak H 2 adsorbed active sites were more related to the activity for GSR reaction. • Deactivation on Ni-in/CNTs was mainly due to carbon deposition. • Deactivation on Ni-out/CNTs and Ni/CNF was mainly due to sintering of Ni particles. [ABSTRACT FROM AUTHOR]

The development of cost-effective and highly efficient electrocatalysts is critical to help electrochemical non-enzymatic sensors achieve high performance. Here, a new class of catalyst, Ru single atoms confined on Cu nanotubes as a single-atom alloy (Ru1Cu NTs), with a unique electronic structure and property, was developed to construct a novel electrochemical non-enzymatic glucose sensor for the first time. The Ru1Cu NTs with a diameter of about 24.0 nm showed a much lower oxidation potential (0.38 V) and 9.0-fold higher response (66.5 μA) current than Cu nanowires (Cu NWs, oxidation potential 0.47 V and current 7.4 μA) for glucose electrocatalysis. Moreover, as an electrochemical non-enzymatic glucose sensor, Ru1Cu NTs not only exhibited twofold higher sensitivity (54.9 μA mM−1 cm−2) and wider linear range (0.5–8 mM) than Cu NWs, but also showed a low detection limit (5.0 μM), excellent selectivity, and great stability. According to theoretical calculation results, the outstanding catalytic and sensing performance of Ru1Cu NTs could be ascribed to the upshift of the d-band center that helped promote glucose adsorption. This work presents a new avenue for developing highly active catalysts for electrochemical non-enzymatic sensors. [ABSTRACT FROM AUTHOR]

Here, integrated functional components into a hybrid heterostructure via highly stabilized network‐like interconnected electronic nanoarchitecture of 1D N‐doped holey‐carbon nanotube (NHCNT) with 2D nickel─metal–organic framework (Ni─MOF) nanosheets are developed as high‐performance electrocatalyst for overall water splitting. The NHCNT promoting electron transport pathways in electrocatalyst, and formation of holes in nanotubes further enables excellent diffusion of ions for promoting the overall reaction rate. An excellent combination of 1D/2D structure of NHCNT/Ni─MOF‐4 electrocatalyst exhibits excellent oxygen evolution reaction (η10 = 207.8 mV, and Tafel = 62.6 mV dec−1) and reasonable hydrogen evolution reaction (η10 = 159.8 mV, and Tafel = 107.69 mV dec−1) activity with consistent and stable performance in a 1 m KOH. The highly interconnected network structure contains Ni2+ and Ni3+ species in the NHCNT/Ni─MOF‐4 electrocatalyst, which possesses high specific surface area (SSA) (235.53 m2 g−1), electrochemically active surface area (ECSA) (796.2 cm2), mass activity (4.76 mA mg−1), and turnover frequency (3.99 × 10−2 s−1), which provide remarkable electrocatalytic performance via generating synergy between the NHCNT and Ni─MOF. For overall water splitting, NHCNT/Ni─MOF‐4 attains a low cell voltage (1.77 V@10 mA cm−2). [ABSTRACT FROM AUTHOR]

Mitochondrial loss and dysfunction drive T cell exhaustion, representing major barriers to successful T cell-based immunotherapies. Here, we describe an innovative platform to supply exogenous mitochondria to T cells, overcoming these limitations. We found that bone marrow stromal cells establish nanotubular connections with T cells and leverage these intercellular highways to transplant stromal cell mitochondria into CD8+ T cells. Optimal mitochondrial transfer required Talin 2 on both donor and recipient cells. CD8+ T cells with donated mitochondria displayed enhanced mitochondrial respiration and spare respiratory capacity. When transferred into tumor-bearing hosts, these supercharged T cells expanded more robustly, infiltrated the tumor more efficiently, and exhibited fewer signs of exhaustion compared with T cells that did not take up mitochondria. As a result, mitochondria-boosted CD8+ T cells mediated superior antitumor responses, prolonging animal survival. These findings establish intercellular mitochondrial transfer as a prototype of organelle medicine, opening avenues to next-generation cell therapies. [Display omitted] • BMSCs transfer mitochondria to CD8+ T cells via intercellular nanotube connections • Mitochondrial transfer between BMSCs and CD8+ T cells depends on Talin 2 • Mitochondrial transfer augments CD8+ T cell mitochondria mass and metabolic fitness • Mitochondria-boosted mouse and human CD8+ T cells exhibit superior antitumor efficacy Transfer of mitochondria via nanotubes from bone marrow stem cells to CD8+ T cells augments cellular metabolism, empowering engineered T cells and tumor-infiltrating lymphocytes to counteract exhaustion and fight tumors more effectively. [ABSTRACT FROM AUTHOR]

Yolk-shell SnO2 mesoporous double-layer nanotubes were synthesized in one-step by single nozzle electrospinning. Compared with the traditional electrospinning using polyvinylpyrrolidone (PVP) as the precursor polymer to obtain the single nanotube material, two PVPs (PVPK88-96 and PVPK23-27) with different molecular weights in solution coupled with Sn2+ easily form the core-shell structure nanofiber through phase separation. The yolk-shell double-layer SnO2 nanotubes were obtained after calcination at 600 °C for 2 h. The yolk-shell SnO2 mesoporous double-layer nanotube is a promising sensing material toward 3-hydroxy-2-butanone as it shows high sensitivity, cycling stability, and selectivity. Moreover, the response and recovery times of the yolk-shell SnO2 mesoporous double-layer nanotubes toward 1 ppm 3-hydroxy-2-butanone were 122 s and 117 s. [ABSTRACT FROM AUTHOR]

Achieving a high dispersity of deposited transition metal is crucial in the anodization preparation of noble‐metal‐free composites for photocatalytic hydrogen generation. Herein, for the first time, an in situ ion pumping anodization method is proposed to confine single‐atom Fe within the spatially ordered structure of anodized TiO2 nanotubes (TNT), assisted by ferric sodium salt of ethylenediaminetetraacetic acid (EDTA) as an "ion pump" to deliver Fe3+ toward anodes. Both experimental and theoretical calculations confirm that highly dispersed single‐atom Fe can interact with single‐electron‐trapped oxygen vacancies (SETOV), effectively reducing the oxygen vacancy concentration in TiO2 nanotubes. This reduction promotes efficient charge carrier separation through the Fe(III)/Fe(II) pathway and enhances hydrogen desorption, ultimately boosting the photocatalytic hydrogen evolution performance. [ABSTRACT FROM AUTHOR]

Semiconductor heterojunctions have garnered extensive interest in photocatalytic hydrogen generation, yet the limited light absorption and charge transfer efficiencies still restrict the photocatalytic performance. The topological insulator has unique surface states and high‐mobility electrons, demonstrating the significant potential for enhancing photocatalysis. Herein, a ternary photocatalyst based on a topological insulator, in which CdS and ZnS nanoparticles are grown on Bi2Se3 nanotube, is prepared for efficient photocatalysis driven by topological surface state for the first time. Under simulated solar light irradiation, the CdS/ZnS/Bi2Se3 nanotubes display a robust photocatalytic hydrogen production rate of 7.13 mmol h−1 g−1, which is 69.2 times of CdS and comparable to many CdS‐based photocatalysts. The unique hollow structure, topological surface state of Bi2Se3, and cooperative bandgap excitations of the three components endow the hybrids with wide light response to harvest solar energy. Meanwhile, the multichannel charge transfer facilitated by topological surface state and internal electric fields within the hybrids effectively suppresses the recombination of the photogenerated charge carriers. This mechanism maintains a high concentration of stable electrons on Bi2Se3, resulting in highly efficient hydrogen production. This work provides a new inspiration for designing heterojunction photocatalysts based on topological insulators for high‐efficiency solar‐driven energy conversion. [ABSTRACT FROM AUTHOR]

Broadening the scope of functionalities that can be covalently bound to single‐walled carbon nanotubes (SWCNTs) is crucial for enhancing the versatility of this promising nanomaterial class in applied settings. Here we report the covalent linkage of triphenylphosphine oxide [Ph3P(O)] to SWCNTs, a hitherto overlooked surface functionality. We detail the synthesis and structural characterization of a new family of phosphine oxide‐functionalized diaryliodonium salts that can facilitate direct Ph3P(O) transfer and afford novel SWCNTs with tunable Ph3P(O) content (SWCNT‐P). The molecularly‐distributed and robust nature of the covalent Ph3P(O) attachment in SWCNT‐P was supported by a combination of characterization methods including Raman, infrared, UV/Vis‐NIR and X‐ray photoelectron spectroscopies coupled with thermogravimetric analysis. Electron microscopy further revealed the effectiveness of the Ph3P(O) moiety for de‐bundling SWCNTs to yield SWCNT‐P with superior dispersibility and processability. Finally, electrochemical studies established that SWCNT‐P is sensitive to the presence of Li+, Na+ and K+ wherein the Gutmann‐Beckett Lewis acidity parameters of the ions were quantitatively transduced by Ph3P(O) to electrochemical responses. This work hence presents a synthetic, structural, spectroscopic and electrochemical foundation for a new phosphorus‐enriched responsive nanomaterial platform featuring the Ph3P(O) functionality. [ABSTRACT FROM AUTHOR]

We produced poly(lactic acid) (PLA) matrix carbon fiber and carbon nanotube‐reinforced hybrid composites with enhanced thermal conductivity (0.48–0.59 W/mK) and electrical conductivity (0.35–0.97 S/cm). The conductive fillers greatly decreased the toughness, which was compensated with oligomeric lactic acid (OLA). Since fillers and plasticizers greatly alter the flow and thermal properties of the material as well, it was necessary to optimize several parameters of the injection molding process that were predetermined based on theoretical considerations. Based on oscillatory shear rheometry, we explored the rheological behavior of the materials in a wide temperature and shear rate range for the optimum injection molding temperatures, injection volume rates. We showed that by adding 15 wt% OLA as a plasticizer to the composites, the optimal processing temperature decreased by 45–135°C. This remarkable change illustrates the need for rheological studies of PLA compounds. The injection molded hybrid composites containing 5% oligomeric lactic had a tensile strength, modulus of elasticity, and work of fracture higher by 41%, 10%, and 150%, respectively, compared to samples without OLA. [ABSTRACT FROM AUTHOR]

The structural rigidity of tetrakis(4‐pyridyl)porphyrin (TPyP) has been utilised to prepare a robust novel porous coordination polymer of composition Cd2(TPyP)(sez)2 (TPyP=5,10,15,20‐tetra(4‐pyridyl)porphyrin, sez=1,2,5‐benzoselenadiazole‐5‐carboxylate). The coordination polymer may be described as a hexagonal porphyrin nanotube (PNT) and has the potential to bind guest molecules through chalcogen bonding. Single crystal X‐ray diffraction (SCXRD) data indicate an internal pore diameter ~9 Å which represents ~35 % of the crystal volume. Immersion of the PNTs in solvents such as DMSO and CS2 result in the incorporation of these molecules within the nanotubes with chalcogen bonding between host and guest. The crystallographic guest‐inclusion investigations are complemented by solid‐state 77Se, 13C, 113Cd and 2H NMR studies which provide insights into dynamic behaviour. The porosity of the crystals was further explored using gas adsorption experiments, indicating the reversible uptake of CO2, CH4, H2 and N2. Structure‐function relationships are clearly established from complementary crystallographic, NMR and adsorption investigations. [ABSTRACT FROM AUTHOR]

To separate the oil/water mixtures, polyvinylidene fluoride (PVDF) nanofiber mats were produced using electrospinning. Additionally, PVDF films were made using the solvent evaporation method, and the effectiveness of their separation was evaluated against that of nanofiber mats. By choosing oxygen‐functionalized graphene (with HNO3) as a nano reinforcement, the hydrophobic properties of the PVDF materials made using both techniques were transformed into hydrophilic ones. It has been determined how the characteristics of the solution (viscosity, conductivity, molecular weight, surface tension, and contact angle) relate to the diameter of the nanofiber. Fourier transform infrared spectroscopy‐attenuated total reflection (FT‐IR/ATR), x‐rays diffraction (XRD), scanning electron microscope, thermogravimetric analyses (TGA)/DTG, and differential scanning calorimetric (DSC) have been used to study the chemical and crystal structures, morphology, and thermal behavior of PVDF materials. The addition of oxygen‐functionalized graphene was found to cause a peak in the PVDF composites' FT‐IR/ATR spectrum, roughly in the wavenumber 1400 cm−1, which was identified as the C‐OH bending vibration. Together with the shift in peak strengths, the lack of a discernible shift in the PVDF peak location in the XRD patterns indicates that the addition of oxygen‐functionalized graphene has caused a phase transition in the PVDF in the semi‐crystal structure. Surface hydrophobicity has also been measured using contact angle measurements. The addition of oxygen‐functionalized graphene has been seen to decrease the PVDF's contact angle, resulting in the development of a hydrophilic characteristic. These PVDF‐based materials' oil/water separation capabilities have also been evaluated. PVDF composite films were not as effective as PVDF nanofiber mats with oxygen‐functionalized graphene in the studies to separate the oil/water mixtures. The permeate flux value was determined to be 240 Lm−2 h−1, and the oil/water separation efficiency of nanofibers containing 10% (m/m) PVDF534000 combined with oxygen‐functional graphene was found to be 99%. [ABSTRACT FROM AUTHOR]

Nanostructured metamaterials can offer optical properties beyond what is achievable in conventional media, such as negative refraction or sub‐wavelength imaging. Due to their structural anisotropy, the class of high aspect ratio metamaterials is of interest for the possibility of achieving hyperbolic optical properties, i.e., both metallic and dielectric behavior based on the excitation direction. Although investigated numerically, the fabrication of tailor‐made metamaterials is complex or often beyond the reach of current technology. For wire metamaterials composed of aligned metallic nanowires in a dielectric matrix, since the free carrier concentration in metals is fixed, light‐matter interaction cannot be adjusted after fabrication. Here, metamaterials based on plasmonic ITO nanotubes with controllable hyperbolic response are introduced. The synthesis is achieved by a template‐based liquid‐phase technique. The tuning mechanism is based on controlling the carrier density in ITO via oxygen vacancy concentration. The process is reversible, the photonic features are activated by creating oxygen vacancies and can be switched off by filling them up again. Further, it is shown that the carrier concentration can also be controlled via a static electric field. Optical simulations support the experimental findings and highlight the parameters that determine the optical response of the metamaterial. [ABSTRACT FROM AUTHOR]

The study of the structure and conformational properties of ammonia–boron trifluoride in the cavity of 24 carbon and inorganic nanotubes using the PBE/3ζ DFT approximation showed that the conformational preference of the encapsulated molecule is determined by geometry and chemical composition of the host nanostructure. The combined effect of these factors leads to the predominance of eclipsed conformation of guest molecule for four endoclusters. In other cases, the main minimum on the potential energy surface corresponds to the staggered or pseudo‐staggered forms of BF3←NH3. The guest molecule carries the electric charge and has a shortened B←N bond. These conclusions are confirmed by the results of the virtual reaction of ammonia and boron trifluoride in the cavity of individual nanotubes. [ABSTRACT FROM AUTHOR]

The present study aims to improve the mechanical strength of hydrogels via a simplified method, involving the creation of a nanocomposite hydrogel using polyvinyl alcohol (PVA) incorporated with un‐modified multiwalled carbon nanotubes (um‐MWCNTs). Departing from conventional freezing–thawing cycles, our research employs a facile approach, in which high‐shear mixing along with solvent exchange with deionized water was utilized. Morphological analysis unveiled a compact and dense microstructure within the nanocomposite hydrogel in correlation with MWCNT concentration. Attenuated total reflection‐Fourier transform infrared spectroscopy (ATR‐FTIR) elucidated the chemical structure of PVA/um‐MWCNTs hydrogel nanocomposite. Rheological studies on the viscoelastic properties indicated the formation of more "solid‐like" structure in the developed hydrogel nanocomposite. Broadband dielectric spectroscopy revealed alterations in dielectric properties of the fabricated PVA/um‐MWCNTs hydrogel nanocomposite corresponding to MWCNTs content in the PVA matrix. This comprehensive investigation highlights the impact of minimal MWCNTs concentration on the rheology, mechanical, and dielectric properties of developed PVA/um‐MWCNTs hydrogel nanocomposite. [ABSTRACT FROM AUTHOR]

The influence of mixed ion‐electronic conductive fillers on the physical characteristics of protonated polyaniline (P‐PANI) nanocomposite films is investigated by incorporating titanium nanoparticles (TiNPs) and lithium trifluoromethanesulfonate (LiOTf) at various concentrations. The introduction of TiNPs into the P‐PANI matrix results in the appearance of additional X‐ray diffraction peaks ascribed to a titanium phase, confirming the presence of TiNPs. The incorporation of LiOTf leads to changes in intensities, linewidths, and diffraction angles, indicating interactions between Li+ ions and nitrogen atoms in the PANI matrix. The bandgap energy for the pristine P‐PANI film is 3.40 eV, being reduced to 3.29 eV upon incorporating TiNPs in the P‐PANI matrix. An increase in the concentration of LiOTf in the P‐PANI/TiNPs composite films with decreasing TiNPs concentration leads to a continuous increase in bandgap energy to 3.59 eV. The electrical conductivity of pristine P‐PANI is 0.49 mS/cm. The addition of TiNPs increases the conductivity to 2.16 mS/cm, while the addition of LiOTf increases it to 1.72 mS/cm. Notably, (P‐PANI)/TiNPs nanocomposite films with 7:3 and 5:5 wt.% ratios exhibit superior electrical conductivity compared with individual (P‐PANI)/TiNPs and (P‐PANI)/LiOTf films, attributed to effective ionic‐electronic coupling at phase‐separated region interfaces. This study reveals impact of TiNPs and LiOTf on the structural, optical, and electrical properties of P‐PANI nanocomposite films, thereby enhancing their potential for integration into advanced electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Single-walled carbon nanotubes (SWCNTs) are promising materials for use in multifunctional polymer composites. A special feature of SWCNTs is their tendency to aggregate into bundles with 2D close packing. The coherence of such packing leads to the appearance of diffraction maxima at small-angle X-ray scattering. Using the Debye equation for X-ray scattering, this work presents the results of a theoretical analysis of the influence exerted by various parameters of SWCNT bundles (length and diameter of SWCNTs, transverse dimensions of SWCNT bundles, distribution of diameters and the number of SWCNTs in bundles) on the position, width, and shape of these diffraction peaks. To this end, atomic models of both the individual tubes and their bundles were constructed taking into account the diameter distribution of nanotubes, which has a significant effect. The results obtained can be used to correctly interpret the experimental diffraction data. [ABSTRACT FROM AUTHOR]

This study presents a comparative analysis of anodization and hydrothermal techniques for synthesizing TiO2 nanotubes directly on titanium foil. It emphasizes its advantages as a substrate due to its superior conductivity and efficient charge transfer. Optimized synthesis conditions enable a thorough evaluation of the resulting nanotubes' morphology, structure, and optical properties, ultimately assessing their photoelectrochemical and photocatalytic performances. Scanning electron microscopy (SEM) reveals differences in tube diameter and organization. An X-ray diffraction (XRD) analysis shows a dominant anatase (101) crystal phase in both methods, with the hydrothermally synthesized nanotubes exhibiting a biphase structure after annealing at 500 °C. UV–Vis and photoluminescence analyses indicate slight variations in band gaps (around 0.02 eV) and recombination rates. The anodized TiO2 nanotubes, exhibiting superior hydrophilicity and order, demonstrate significantly enhanced photocatalytic degradation of a model pollutant, amido black (80 vs. 78%), and achieve a 0.1% higher photoconversion efficiency compared to the hydrothermally synthesized tubes. This study underscores the potential advantages of the anodization method for photocatalytic applications, particularly by demonstrating the efficacy of direct TiO2 nanotube growth on titanium foil for efficient photocatalysis. [ABSTRACT FROM AUTHOR]

1D nanomaterials feature distinct physical properties owing to their characteristic anisotropy and size‐induced quantization; yet, creating an ordered ensemble of the nanomaterials is nontrivial, marking it as a grand challenge in materials science. Herein, the spontaneous alignment of a model 1D nanomaterial, boron nitride nanotube (BNNT), into a highly ordered multidomain film is presented. A conventional, benchtop gravity filtration is employed, during which thickening of the BNNT dispersion leads to a formation of the liquid crystal (LC) phase that is readily isolatable. The spontaneity of the phase separation excludes notoriously persisting synthetic impurities to a degree >99%, from ≈50% of the initial material purity. The LC‐based thin film features an aligned multidomain with an exceptionally low angular deviation of <2.5° and a domain size of >50 μm. A piezoelectric nanogenerator based on the thin film records a 1000‐fold increase in the piezocurrent compared to its random analog. This work demonstrates the first example of the spontaneous alignment of an unconventional nanotube system and the realization of the macroscopic properties therefrom, which can be readily expanded to 1D materials in general. [ABSTRACT FROM AUTHOR]

LiFe5O8 is regarded as a promising material, which is used as anode for lithium‐ion batteries on account of its lower cost and higher theoretical capacity. However, its practical applications are hindered by the low electron transfer rate, poor cycling performance, and huge magnification of lattice volume. In this work, a LiFe5O8/carbon nanotubes (CNTs) composite anode is designed to realize the ideal anode for low‐cost lithium‐ion batteries, showing broad commercial application prospects. It is found that the three‐dimensional conductive network of CNTs is used to accelerate electron transfer rate within the LiFe5O8 particles, thereby significantly reducing the reversible reaction barrier (Fe/Fe3O4). In addition, it can also alleviate the volume change of electrode, which maintains a stable Li+ insertion/extraction behavior during long‐term cycles. As a consequence, there is still a high capacity (427.3 mAh g−1) of the LiFe5O8/CNTs 3% anode reserved after 50 cycles at 0.5 C whereas the bare LiFe5O8 anode only delivers a low capacity of 220.6 mAh g−1 along with a poor cycling stability. This work highlights the outstanding contribution of electronic conductivity toward the electrochemical performance of LiFe5O8 anode and provides a low‐cost and commercially applicable composite anode for developing lower cost lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

The purpose of the study was to compare the fluoride release in two conventional glass ionomer cements (Ionobond, Ketac Molar) and two resin-modified glass ionomer cements (Vitrebond, Fuji II LC) adapted with halloysite nanotubes preloaded with sodium fluoride at different concentrations. In total, 96 samples were prepared and distributed into four control groups and eight experimental groups (5 % and 10 %). Totals of 10 % and 5 % of the total weight of ionomer powder needed to prepare the samples were replaced with nanotubes, preloaded at 2,000 parts per million, respectively. The experimental groups were followed for 120 days at seven time intervals. All the samples were stored at 37 °C. All the experimental groups showed significant differences compared with the control groups; likewise, differences were observed between the concentrations of 5% and 10%. The experimental groups (conventional and resin-modified glass ionomer cements adapted with preloaded nanotubes) released a higher and more constant amount of fluoride compared to the control groups. [ABSTRACT FROM AUTHOR]

A highly sensitive non-enzymatic biosensor based on a deposition of silver nanoparticles with Cu2O on TiO2 nanotube arrays has been developed for the detection of glucose. The TiO2 nanotubes (TNTs) were fabricated by anodization on a thin plate Ti6Al4V titanium alloy. Subsequently, Cu2O was deposited on the TNTs using the wet chemical bath deposition method, followed by the electro-deposition of Ag nanomaterials. The crystal structure, phases, and morphology of the nanostructure (Ag-Cu2O@TiO2) were examined using energy-dispersive X-ray, transmission electron microscopy, and field emission scanning electron microscopy. The addition of Cu2O and Ag to TNTs enhances the electroactive surface area, which results in a faster rate of electron transfer. The electrochemical behavior of Ag-Cu2O@TiO2 was investigated using cyclic voltammetry, electrochemical impedance spectroscopy, and amperometry techniques. The Ag-Cu2O@TiO2 exhibited a high level of sensitivity (1010.20 μA mM−1 cm−2), low detection limit of 36 µM, and a rapid response time (2 s). Furthermore, the real-time analysis of glucose in human blood serum demonstrated a high level of accuracy. This work illustrates the deposition of Ag-Cu2O on TNTs for fabrication of excellent selectivity, reproducibility, and remarkable stability. [ABSTRACT FROM AUTHOR]

Nanotechnology, with its distinctive characteristics and versatile applications, demonstrates considerable potential in detecting, removing, and degrading pollutants such as heavy metals, organic compounds, and microplastics. The utilization of nanotechnology for environmental remediation presents a promising and innovative approach to tackle the growing environmental challenges. This review article offers a thorough examination of recent advancements in nanotechnology and its application in addressing various types of environmental pollutants and highlights the potential of nanomaterials, such as metal-based nanoparticles, carbon nanotubes, and nanofibrous membranes, in various remediation processes. The article investigates the underlying mechanisms of nanomaterials in pollutant adsorption and degradation, highlighting the significance of their high surface-to-volume ratio, enhanced reactivity, and customizable surface properties. Nanoadsorbents demonstrate high adsorption capacities and selectivity for the removal of pollutants from water and soil. Nanofiltration membranes offer precise separation capabilities for the removal of contaminants from water sources. Photocatalysis using nanomaterials shows promise for air pollution remediation. Additionally, the development of nanosensors enables real-time monitoring and detection of pollutants. Overall, nanotechnology offers innovative and efficient solutions for addressing environmental pollution. [ABSTRACT FROM AUTHOR]

Tubular self‐assembled architectures are highly appealing supramolecular objects that participate in diverse essential biological processes. Controlling with precision their dimensions, and in particular their pore diameter, is a key objective to develop the full applied potential of these structures. Here, using a strategy that relies on the controlled supramolecular polymerization of Watson–Crick H‐bonded macrocycles, we target the assembly of 3 sets of nanotubes in which pore diameter is finely controlled from 1.8, to 3.2 and to 4.3 nm. This is simply done by elongating the oligo(phenylene‐ethynylene) block placed in between guanine and cytosine nucleobases in the monomer. Moreover, this structural change leads to a gradual reduction in the chelate cooperativity of the cyclization process and, at the same time, to an enhancement in the tendency of the macrocycles to stack, which critically influences the coupling between these consecutive supramolecular processes. [ABSTRACT FROM AUTHOR]

This study delves into the exploration of hybrid nanofluids within the context of a stretching cylinder, a domain that has captivated numerous researchers owing to its pivotal applications in industrial manufacturing processes, particularly in metal forming and stretch dies. The authors, recognizing the significance of these applications, have introduced a novel heat transfer fluid termed hybrid nanofluid, comprising molybdenum disulfide and carbon nanotubes suspended in the base liquid, water. The investigation focuses on the flow of the hybrid nanofluid within a stretching cylinder, considering various influential factors such as Joule heating, thermal radiation, porous medium, and magnetic field effects. To model this complex problem, we employed modified Navier–Stokes equations. Employing similarity transformations, assumptions, and non-dimensional parameters, the problem was effectively simplified. The MATLAB bvp4c technique, a well-established numerical approach, was then employed to solve the resulting mathematical formulation. Graphical representations are presented to illustrate various aspects of the flow, facilitating a comprehensive understanding of the system. Comparisons are drawn among the flow characteristics of mono nanofluid, and the developed hybrid nanofluid. It is noted from the current analysis that the temperature strength increases with higher values of the magnetic field parameter, curvature parameter, radiation parameter, and Eckert number in both fluid cases. The Nusselt number increases with higher values of Prandtl number and thermal relaxation parameter. The identified patterns in velocity distribution, temperature strength, and fluid behavior provide a valuable foundation for optimizing thermal efficiency in diverse industrial applications. By leveraging the insights gained from this research, manufacturers can make informed decisions to enhance heat transfer processes, particularly in areas such as metal forming and stretch dies. [ABSTRACT FROM AUTHOR]

While the promise of clean and defect‐free MoS2$\left(\text{MoS}\right)_{2}$ nanotubes as quantum electronic devices is obvious, ranging from strong spin–orbit interaction to intrinsic superconductivity, device fabrication still poses considerable challenges. Deterministic transfer of transition metal dichalcogenide nanomaterials and transparent contacts to the nanomaterials are nowadays highly active topics of research, both with fundamental research and applications in mind. Contamination from transport agents as well as surface adsorbates and surface charges play a critical role for device performance. Many techniques have been proposed to address these topics for transition metal dichalcogenides in general. Herein, their usage for the transfer‐based fabrication of MoS2$\left(\text{MoS}\right)_{2}$ nanotube devices is analyzed. Further, different contact materials are compared in order to avoid the formation of a Schottky barrier. [ABSTRACT FROM AUTHOR]

Molybdenum‐based nanoparticles are often used as oil additives to enhance a material's tribological performance. Here, we present a highly efficient synthetic route for the bulk production of two types of MoS2 nanostructures: multi‐wall nanotubes and fullerene‐like nanostructures. The presented two‐step synthesis involves the transformation of ammonium heptamolybdate tetrahydrate and aniline into precursor nanowires, which are later transformed into MoS2 through heating in a H2S, H2, and argon atmosphere to approximately 800 °C. Depending on the heating rate, we successfully grew MoS2 layered compounds in various shapes and sizes. The resulting structures and compositions were characterised by X‐ray powder diffraction, Raman spectroscopy, energy‐dispersive X‐ray spectroscopy, and electron microscopy. To assess the application potential of these MoS2 compounds, they were dispersed in polyalphaolefin (PAO 6) oil. Improved tribological properties were observed compared to typically used transition metal dichalcogenides. [ABSTRACT FROM AUTHOR]

Biomass three‐dimensional composite aerogels have garnered significant attention in the realm of wearable electronic skin owing to their favorable properties, including excellent human compatibility, environmentally benign degradability, and continuous porous architecture. However, conventional biomass aerogels suffer from inadequate mechanical flexibility, susceptibility to irreversible deformation under high compressive stress, and limited reusability, thereby constraining their applicability in sensing technologies. To address these limitations, this study presents the development of porous CCS/KH560/PEI/CNT‐COOH (CKPC) composite aerogels through a freeze–drying process. Chemical crosslinking was achieved using silane coupling agent (KH560) with carboxymethyl chitosan (CCS) and polyethyleneimine (PEI), while carboxylated carbon nanotubes (CNT‐COOH) were incorporated as conductive fillers. This approach successfully overcame the issues of poor mechanical properties, low elasticity, and unbalanced sensitivity‐sensing range trade‐off in chitosan‐based aerogel sensors. The results revealed that the porous CKPC aerogels exhibited a remarkable mechanical compressive strain of 86.3% while maintaining structural integrity post‐unloading. The CKPC composite aerogel‐based sensor demonstrated a high sensitivity of 42.9 within a wide strain range of 60%–76.3%, accompanied by a stable and repeatable electrical signal response across varying strains. The porous structure of the CKPC conductive aerogel sensor holds promising applications in human motion monitoring and flexible electronics. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction of nitrogen oxides with NH3 at low temperatures remains a crucial goal for industrial applications. However, effective catalysts operating at 70–90 °C are rarely reported, limiting SCR scenarios to high‐temperature conditions. Herein, we report a unique MnO2 nanofilament catalyst grown on activated semi‐coke synthesized via a one‐step in situ hydrothermal approach, which exhibits a stable and marked 100 % conversion rate of NO to N2 with 100 % selectivity at 90 °C, superior to the other prepared structures (nanowires, nanorods, and nanotubes). Temperature‐programmed desorption shows a large number of acid sites on MnO2(NFs)/ASC, benefiting the formation of NH4+ ions. Meanwhile, diffuse reflectance infrared Fourier transform spectroscopy reveals the activation of NO with O2 to form bidentate nitrate/bridging nitrate NO2 intermediates via bidentate nitrate species, triggering the Fast SCR with NH3 at low temperatures. Such an effective, easy‐to‐prepare, and low‐cost catalyst paves a new pathway for low‐temperature SCR for a wide range of application scenarios. [ABSTRACT FROM AUTHOR]

In this research, we present a novel facile, scalable, and template-free technique of synthesizing graphitic carbon nitride (g-C 3 N 4) nanotubes for generating hydrogen through photocatalysis. The hybrid technique involves a two-fold mixing of the precursor materials melamine (M) and cyanuric acid (CA), involving ball milling followed by solution mixing. By varying the M:CA molar ratios, different compositions of g-C 3 N 4 nanotubes were fabricated. The study focused on examining the surface characteristics and the photocatalytic hydrogen evolution performance of these nanotubes. Nanotubes with high specific surface area of 206 m2 g−1 for M:CA molar ratio of 1:3 and 178 m2 g−1 for M:CA molar ratio of 1:5 were produced, with H 2 evolution rates of 543 μmol h−1 g−1 and 740 μmol h−1 g−1 respectively, which were an increase of 4 and 5-fold, respectively, in comparison to the pristine sample. The enhanced efficiency of hydrogen production through photocatalysis by nanotubes, when contrasted with pristine material, can be ascribed to their high crystallinity, superior specific surface areas, decreased recombination rates of electron-hole pairs generated during light exposure, and improved dynamics of charge carriers. This hybrid technique provides a new pathway for cost-effective fabrication of g-C 3 N 4 nanotubes with substantial surface areas and high yield photocatalysts on an industrial scale, without the use of templates and hydrothermal processes for efficient hydrogen generation. [Display omitted] • Graphitic carbon nitride (g-C 3 N 4) nanotubes were synthesized using a novel hybrid synthesis technique involving dual precursor mixing. • High specific surface area g-C 3 N 4 nanotubes of ∼206 m2 g−1 and 178 m2 g−1 were achieved. • A g-C 3 N 4 nanotube with a 1:3 melamine-cyanuric acid molar ratio achieved enhanced H 2 evolution performance (740 µmol h⁻¹ g⁻¹). • The stability of g-C 3 N 4 nanotubes was shown by the consistent H 2 evolution rate during extended irradiation. [ABSTRACT FROM AUTHOR]

As one of the most important synthetic fine chemicals and pharmaceuticals, benzaldehyde is widely used in pharmaceuticals, dyestuffs, fragrances and pesticides. It is still a difficult challenge to promote the conversion of benzyl alcohol to benzaldehyde by photocatalysis with high selectivity and high conversion. In this paper, the content of the reactive substance ·O2− is regulated by constructing suitable oxygen vacancies in TiO2 nanotubes, thus improving the photocatalytic conversion and selectivity. Herein, we have prepared TiO2-X 1D nanotubes enriched with different concentrations of oxygen vacancies by template method, hydrolysis of tetrabutyl titanate and vacuum annealing. By constructing suitable concentrations of oxygen vacancies in the TiO2 material, we can increase its ability to adsorb oxygen to produce more ·O2− on the one hand, and help to construct defective energy levels to prevent the compounding of photogenerated charge carriers to enhance photocatalytic activity on the other. As a result, the best photocatalytic activity of TiO2-X nanotubes obtained by vacuum annealing at 300 °C was 78% for benzyl alcohol conversion and 88% for benzaldehyde production selectivity, which is 2.6 and 1.8 folds higher than that of pristine TiO2 nanoparticles. Our work may provide insights for designing efficient photocatalysts for selective oxidation of benzyl alcohols. [ABSTRACT FROM AUTHOR]

[Display omitted] Solar-light driven oxidation of benzylic alcohols over photocatalysts endows significant prospects in value-added organics evolution owing to its facile, inexpensive and sustainable process. However, the unsatisfactory performance of actual photocatalysts due to the inefficient charge separation, low photoredox potential and sluggish surface reaction impedes the practical application of this process. Herein, we developed an innovative Z-Scheme Cs 3 BiBr 9 nanoparticles@porous C 3 N 4 tubes (CBB-NP@P-tube-CN) heterojunction photocatalyst for highly selective benzyl alcohol oxidation. Such composite combining increased photo-oxidation potential, Z-Scheme charge migration route as well as the structural advantages of porous tubular C 3 N 4 ensures the accelerated mass and ions diffusion kinetics, the fast photoinduced carriers dissociation and sufficient photoredox potentials. The CBB-NP@P-tube-CN photocatalyst demonstrates an exceptional performance for selective photo-oxidation of benzylic alcohol into benzaldehyde with 19, 14 and 3 times higher benzylic alcohols conversion rate than those of C 3 N 4 nanotubes, Cs 3 Bi 2 Br 9 and Cs 3 Bi 2 Br 9 @bulk C 3 N 4 photocatalysts, respectively. This work offers a sustainable photocatalytic system based on lead-free halide perovskite toward large scale solar-light driven value-added chemicals production. [ABSTRACT FROM AUTHOR]

Heterostructure photocatalytic materials with a high surface area have garnered significant attention in recent years. In this investigation, we successfully synthesized g-C 3 N 4 /TiO 2 tubes using an enhanced impregnation-calcination method. The photocatalytic efficiency of the composite tubes was evaluated by examining the degradation of tetracycline hydrochloride (TCH) solution, revealing a photocatalytic degradation rate 3.7 times and 8.0 times higher than that of pure TiO 2 and g-C 3 N 4 when subjected to simulated sunlight. The enhanced photocatalytic performance can be ascribed to the expanded specific surface area and enhanced separation rate of photo-generated charge carriers. Density functional theory (DFT) calculations and trapping experiments revealed a possible photogenerated electrons transfer pathway in the degradation process of TCH. The photocatalytic fuel cell (PFC) system composed of the g-C 3 N 4 /TiO 2 tubes demonstrated remarkable performance in the concurrent degradation of TCH and electricity generation when being exposed to light. It achieved a short circuit current density of 26.9 mA/g/cm2 and a power density of 5.51 mW/g/cm2. The present study offers a cost-effective approach for both organic waste treatment and electrical power generation. [ABSTRACT FROM AUTHOR]

Assembling doped metal oxide nanocrystals (NCs) into one-dimensional (1D) structures can enhance the optical and electrochemical properties of thin films. However, achieving this assembly without damaging the NCs' properties has been challenging. Here, we present facile method to assemble near-infrared (NIR) absorbing plasmonic indium tin oxide (ITO) NCs into 1D nanotubes (NTs) using track-etched polycarbonate (PC) membranes as templates. By infiltrating freestanding PC membranes with 3% doped ITO NCs, attaching them to an adhesive layer, and then annealing, we produce robust ITO NTs on substrates. Fabricated ITO NTs, featuring mesopores and macropores, exhibit rapid NIR modulation under electrochemical potential while maintaining static visible opacity, making them useful for privacy protection and thermal management. Incorporating NbOx into these ITO NT films demonstrates rapid switching and electrochemically stable visible and NIR dual-band electrochromic modulation, highlighting the significance of structuring NCs. [ABSTRACT FROM AUTHOR]

The creation of complex hollow nanostructures with precise control over size and shape represents a great challenge in supramolecular soft materials. Here, we have further developed a bioinspired methodology for the formation of aqueous nanotubes of well‐defined dimensions and pore coating through the self‐assembly of amphiphiles that are chemically programmed with complementary nucleobases. These nanotubes are endowed with a hydrophobic lumen, whose diameter can be expanded as a function of the monomer length, in which apolar dyes can be efficiently encapsulated. [ABSTRACT FROM AUTHOR]

Graphene (Gr) and carbon nanotubes (CNTs), the two intriguing carbon nanomaterials, have presented great potential in serving as high‐performance electrocatalysts in lithium−sulfur (Li−S) chemistry. The concurrent management of both materials would achieve a promoted synergistic effect. Nevertheless, there still remains a lack of an effective material synthesis route. Herein, a single‐step plasma‐enhanced chemical vapor deposition (PECVD) strategy is devised to prepare Gr@CNTs heterostructures with strong bonded connections. In the PECVD system, the damaged sidewalls generated in CNT tubes can serve as appropriate nucleation sites for further Gr growth. The formation mechanisms are thoroughly explored in aspects of both experimental characterizations and theoretical calculations. To confirm the validity of this approach, thus‐constructed Gr@CNTs architectures are employed as the sulfur host, enabling boosted redox kinetics of polysulfides. This project provides fundamental insight into the mechanism exploration for single‐step PECVD growth of Gr@CNTs heterostructure, hence promoting the practical application prospect of carbon nanomaterials toward Li−S systems. [ABSTRACT FROM AUTHOR]

In this study, we compare synergistic performance of two different nanofillers, namely halloysite nanotubes (HNT) clay and multiwalled carbon nanotubes (MWCNT), in conjunction with a fixed concentration (0.125 phr) of semi‐anthracite coal‐derived graphene oxide (AC‐GO) on mechanical properties improvement of EGFPs (E‐glass fiber‐based epoxy resin composites). The dispersion of AC‐GO with HNT clay (GO‐H) and AC‐GO with MWCNT (GO‐C) within epoxy matrix was achieved using sonication and homogenization. Further mixture was incorporated into mats of E‐glass fiber employing "vacuum‐assisted resin infusion molding" (VARIM). Significant enhancements (18.3% flexural strength, 14.6% tensile strength, and a slight increase of impact strength (1.8%)) were observed in EGFPs reinforced with GO‐H at 0.50 phr loading of HNT, with an AC‐GO concentration maintained at 0.125 phr. Correspondingly, optimal values for GO‐C reinforced EGFPs at 0.25 phr were 40.3%, 18.7%, and a 10.5% decrease in impact strength, respectively. Analytical techniques such as XRD, FESEM, EDX mapping, and FTIR reveal presence of relatively abundant functionalities and strong interfacial adhesion in GO‐H as well as GO‐C. The cost of HNT clay is approximately 15 times cheaper than industrial‐grade MWCNTs, therefore, these results underscore potential of GO‐H as a very economical nano‐reinforcement alternative to GO‐C for polymer nanocomposites. Highlights: 0.50 phr HAGRP improves 18.3% flexural, 14.6% tensile, 1.8% impact strengths.Beyond 0.50 phr HAGRP and 0.25 phr CAGRP, mechanical properties decreased.0.25 phr CAGRP improves 40.3% flexural, and18.7% tensile strengths.FESEM, FTIR reveal strong interfacial adhesion between nanofillers and epoxy.GO‐H has proven to be an inexpensive reinforcement for polymer nanocomposites. [ABSTRACT FROM AUTHOR]

In this work, Hui-Shia model is developed to reveal the efficiency of a deficient interphase on the tensile modulus of polymer halloysite nanotube (HNT) nanocomposites. "Lc" as essential HNT length providing full stress transferring is defined and effective HNT size, effective HNT concentration, and efficiency of stress transferring (Q) are expressed by "Lc". Furthermore, the influences of all terms on the "Q" and nanocomposite's modulus are clarified, and also the calculations of the model are linked to the tested data of some nanocomposites. Original Hui-Shia model overpredicts the moduli, but the innovative model's predictions appropriately fit the measured data. Lc = 200 nm maximizes the sample's modulus to 2.6 GPa, but the modulus reduces to 2.11 GPa at Lc = 700 nm. Therefore, there is a reverse relation between the sample's modulus and "Lc". Q = 0.5 produces the system's modulus of 2.1 GPa, while the modulus of 2.35 GPa is achieved at Q = 1 providing a direct relation between the nanocomposite's modulus and "Q". Generally, narrow and big HNTs, along with a low "Lc", enhance the "Q", because a lower "Lc", reveals a tougher interphase improving the stress transferring. [ABSTRACT FROM AUTHOR]