Nano Materials Science最新文献

Nanoscale hierarchically porous metal-organic frameworks (NH-MOFs) synergistically combine the advantages of nanoscale MOFs and hierarchically porous MOFs, resulting in remarkable characteristics such as increased specific surface area, greater porosity, and enhanced exposure of active sites. Herein, nanoscale hierarchically porous UIO-66 (UIO-66_X) was synthesized using a defect-induced strategy that employed ethylene diamine tetraacetic acid (EDTA) as a modulator. The introduced EDTA occupies the coordination sites of organic ligands, promoting the formation and growth of UIO-66 crystal nuclei and inducing defects during synthesis. The as-synthesized UIO-66_X crystals exhibit a uniform distribution with an average size of approximately 100 ​nm. In addition, the total pore volume attains a remarkable value of 0.95 ​cm³ ​g⁻¹, with mesopores constituting 36.8 % of the structure. Furthermore, the porosities of UIO-66_X can be easily tuned by controlling the molar ratio of EDTA/Zr⁴⁺. In addition, the as-synthesized UIO-66_X exhibits excellent adsorption capacities for n-hexane (344 ​mg ​g⁻¹) and p-xylene (218 ​mg ​g⁻¹), which are 44.5 % and 27.5 % higher than those of conventional UIO-66, respectively. Finally, the adsorption behavior of n-hexane and p-xylene molecules in UIO-66_X was investigated using density functional theory simulations.

In response to thermal runaway (TR) of electric vehicles, recent attention has been focused on mitigation strategies such as efficient heat dredging in battery thermal management. Thermal management with particular focus on battery cooling has been becoming increasingly significant. TR usually happened when an electric vehicle is unpowered and charged. In this state, traditional active battery cooling schemes are disabled, which can easily lead to dangerous incidents due to loss of cooling ability, and advanced passive cooling strategies are therefore gaining importance. Herein, we developed an enhanced thermal radiation material, consisting of ∼1 ​μm thick multilayered nano-sheet graphene film coated upon the heat dissipation surface, thereby enhancing thermal radiation in the nanoscale. The surface was characterized on the nanoscale, and tested in a battery-cooling scenario. We found that the graphene-based coating's spectral emissivity is between 91 ​% and 95 ​% in the mid-infrared region, and thermal experiments consequently illustrated that graphene-based radiative cooling yielded up to 15.1 ​% temperature reduction when compared to the uncoated analogue. Using the novel graphene surface to augment a heat pipe, the temperature reduction can be further enlarged to 25.6 ​%. The new material may contribute to transportation safety, global warming mitigation and carbon neutralization.

With characteristics and advantages of functional composite materials, they are commendably adopted in numerous fields especially in oxygen electrocatalysis, which is due to the significant synergies between various components. Herein, a novel bifunctional oxygen electrocatalyst (Co-CNT@COF-Pyr) has been synthesized through in-situ growth of covalent organic frameworks (COFs) layers on the outer surface of highly conductive carbon nanotubes (CNTs) followed by coordination with Co(Ⅱ). For electrocatalytic OER, Co-CNT@COF-Pyr reveals a low overpotential (438 ​mV) in alkaline electrolyte (1.0 ​M aqueous solution of KOH) with a current density of 10 ​mA ​cm⁻², which is comparable to most discovered COF-based catalysts. For electrocatalytic ORR, Co-CNT@COF-Pyr exhibits a low H₂O₂ yield range (9.0 ​%–10.1 ​%) and a reaction pathway close to 4e⁻ (n ​= ​3.82–3.80) in alkaline electrolyte (0.1 ​M aqueous solution of KOH) within the test potential range of 0.1–0.6 ​V vs. RHE, which is superior to most reported COF-based catalysts. Hence, this research could not only offer an innovative insight into the construction of composites, but also facilitate the practical application of renewable fuel cells, closed water cycle, and rechargeable metal-air batteries.

This review explores glucose monitoring and management strategies, emphasizing the need for reliable and user-friendly wearable sensors that are the next generation of sensors for continuous glucose detection. In addition, examines key strategies for designing glucose sensors that are multi-functional, reliable, and cost-effective in a variety of contexts. The unique features of effective diabetes management technology are highlighted, with a focus on using nano/biosensor devices that can quickly and accurately detect glucose levels in the blood, improving patient treatment and control of potential diabetes-related infections. The potential of next-generation wearable and touch-sensitive nano biomedical sensor engineering designs for providing full control in assessing implantable, continuous glucose monitoring is also explored. The challenges of standardizing drug or insulin delivery doses, low-cost, real-time detection of increased blood sugar levels in diabetics, and early digital health awareness controls for the adverse effects of injectable medication are identified as unmet needs. Also, the market for biosensors is expected to expand significantly due to the rising need for portable diagnostic equipment and an ever-increasing diabetic population. The paper concludes by emphasizing the need for further research and development of glucose biosensors to meet the stringent requirements for sensitivity and specificity imposed by clinical diagnostics while being cost-effective, stable, and durable.

Aqueous Zn batteries are promising candidates for grid-scale renewable energy storage. Foil electrodes have been widely investigated and applied as anode materials for aqueous Zn batteries, however, they suffer from limited surface area and severe interfacial issues including metallic dendrites and corrosion side reactions, limiting the depth of discharge (DOD) of the foil electrode materials. Herein, a low-temperature replacement reaction is utilized to in-situ construct a three-dimensional (3D) corrosion-resistant interface for deeply rechargeable Zn foil electrodes. Specifically, the deliberate low-temperature environment controlled the replacement rate between polycrystalline Zn metal and oxalic acid, producing a Zn foil electrode with distinct 3D corrosion-resistant interface (3DCI-Zn), which differed from conventional two-dimensional (2D) protective structure and showed an order of magnitude higher surface area. Consequently, the 3DCI-Zn electrode exhibited dendrite-free and anti-corrosion properties, and achieved stable plating/stripping performance for 1000 ​h at 10 ​mA ​cm⁻² and 10 mAh cm⁻² with a remarkable DOD of 79 ​%. After pairing with a MnO₂ cathode with a high areal capacity of 4.2 mAh cm⁻², the pouch cells delivered 168 ​Wh L⁻¹ and a capacity retention of 89.7 % after 100 cycles with a low negative/positive (N/P) ratio of 3:1.

Temperature regulating fibers (TRF_s) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRF_s are not high, and the preparation methods are still at the laboratory scale. It remains a great challenge to use industrial spinning equipment to achieve continuous processing of TRF_s with excellent thermal and mechanical properties. Here, polyamide 6 (PA6) based TRF_s with a sheath-core structure were prepared by bicomponent melt-spinning. The sheath-core TRF (TRF_sc) are composed of PA6 as sheath and functional PA6 as core, which are filled with the shape stable phase change materials (ssPCM), dendritic silica@polyethylene glycol (SiO₂@PEG). With the aid of the sheath structure, the filling content of SiO₂@PEG can reach 30 ​%, so that the enthalpy of the TRF_s can be as high as 21.3 ​J/g. The ultra-high enthalpy guarantees the temperature regulation ability during the alternating process of cooling and heating. In hot environment, the temperature regulation time is 6.59 ​min, and the temperature difference is 12.93 ​°C. In addition, the mechanical strength of the prepared TRF_sc reaches 2.26 cN/dtex, which can fully meet its application in the field of thermal management textiles and devices to manage the temperature regulation of the human body or precision equipment, etc.

Single-atom catalysts (SACs) are gaining popularity in catalytic reactions due to their nearly 100 ​% atomic utilization and defined active sites, which provide great convenience for studying the catalytic mechanism of catalysts. However, SACs still present challenges such as complex formation processes, low loading and easy agglomeration of catalysts. Herein, we systematically discuss the synthesis methods for SACs, including co-precipitation, impregnation, atomic layer deposition, pyrolysis and Anti-Ostwald ripening etc. Various techniques for characterizing single-atom catalysts (SACs) are described in detail. The utilization of individual atoms in various photocatalytic reactions and their mechanisms of action in different reactions are explained. The purpose of this review is to introduce single-atom synthesis methods, characterization techniques, specific catalytic action and their applications in the direction of photocatalysis, and to provide a reference for the industrialization of photocatalytic single-atoms, which is currently impossible, in the hope of promoting further development of photocatalytic single-atoms.

Graphene-doped CuO (rGO-CuO) nanocomposites with flower shapes were prepared by an improved solvothermal method. The samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and UV–visible spectroscopy. The active species in the degradation reaction of rGO-CuO composites under ultrasonic irradiation were detected by electron paramagnetic resonance. On the basis of comparative experiments, the photodegradation mechanisms of two typical dyes, Rhodamine B (Rh B) and methyl orange (MO), were proposed. The results demonstrated that the doped CuO could improve the degradation efficiency. The catalytic degradation efficiency of rGO-CuO (2:1) to rhodamine B (RhB) and methyl orange (MO) reached 90 ​% and 87 ​% respectively, which were 2.1 times and 4.4 times of the reduced graphene oxide. Through the first-principles and other theories, we give the reasons for the enhanced catalytic performance of rGO-CuO: combined with internal and external factors, rGO-CuO under ultrasound could produce more hole and active sites that could interact with the OH· in pollutant molecules to achieve degradation. The rGO-CuO nanocomposite has a simple preparation process and low price, and has a high efficiency of degrading water pollution products and no secondary pollution products. It has a low-cost and high-efficiency application prospect in water pollution industrial production and life.

This research investigates the hydrothermal synthesis and annealing duration effects on nickel sulfide (NiS₂) quantum dots (QDs) for catalytic decolorization of methylene blue (MB) dye and antimicrobial efficacy. QD size increased with longer annealing, reducing catalytic activity. UV–vis, XRD, TEM, and FTIR analyses probed optical, structural, morphological, and vibrational features. XRD confirmed NiS2's anorthic structure, with crystallite size growing from 6.53 to 7.81 ​nm during extended annealing. UV–Vis exhibited a bathochromic shift, reflecting reduced band gap energy (Eg) in NiS₂. TEM revealed NiS₂ QD formation, with agglomerated QD average size increasing from 7.13 to 9.65 ​nm with prolonged annealing. Pure NiS₂ showed significant MB decolorization (89.85%) in acidic conditions. Annealed NiS2 QDs demonstrated notable antibacterial activity, yielding a 6.15 ​mm inhibition zone against Escherichia coli (E. coli) compared to Ciprofloxacin. First-principles computations supported a robust interaction between MB and NiS₂, evidenced by obtained adsorption energies. This study highlights the nuanced relationship between annealing duration, structural changes, and functional properties in NiS₂ QDs, emphasizing their potential applications in catalysis and antibacterial interventions.

Carbon nanotubes (CNTs) with high aspect ratio and excellent electrical conduction offer huge functional improvements for current carbon aerogels. However, there remains a major challenge for achieving the on-demand shaping of carbon aerogels with tailored micro-nano structural textures and geometric features. Herein, a facile extrusion 3D printing strategy has been proposed for fabricating CNT-assembled carbon (CNT/C) aerogel nanocomposites through the extrusion printing of pseudoplastic carbomer-based inks, in which the stable dispersion of CNT nanofibers has been achieved relying on the high viscosity of carbomer microgels. After extrusion printing, the chemical solidification through polymerizing RF sols enables 3D-printed aerogel nanocomposites to display high shape fidelity in macroscopic geometries. Benefiting from the micro-nano scale assembly of CNT nanofiber networks and carbon nanoparticle networks in composite phases, 3D-printed CNT/C aerogels exhibit enhanced mechanical strength (fracture strength, 0.79 ​MPa) and typical porous structure characteristics, including low density (0.220 ​g ​cm⁻³), high surface area (298.4 ​m² ​g⁻¹), and concentrated pore diameter distribution (∼32.8 ​nm). More importantly, CNT nanofibers provide an efficient electron transport pathway, imparting 3D-printed CNT/C aerogel composites with a high electrical conductivity of 1.49 ​S ​cm⁻¹. Our work would offer feasible guidelines for the design and fabrication of shape-dominated functional materials by additive manufacturing.