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Supra-Materials Nanoarchitectonics || Functional Layered Compounds for?Nanoarchitectonics
摘要： Inorganic layered materials are composed of stacked nanometer-thick inorganic crystalline sheets, which are weakly bound by electrostatic, van der Waals, or hydrogen bonding interactions. These materials are obtained from natural soil or are synthesized by hydrothermal heating or calcination at high temperature from mixture of raw chemicals. Depending on the chemical composition, layered materials possess functionalities such as conductivity, semiconductivity, magnetic property, luminescence property, and photocatalytic activity. In this section, recent development of nanoarchitectonics with layered materials as achieved by intercalation and exfoliation technique are reviewed as summarized in Fig. 7.1.
关键词： Functional Layered Compounds,Nanoarchitectonics,Nanosheets,Intercalation Compounds,Photofunctions
更新于2025-09-10 09:29:36
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Synthesis and characterization of ZnSe and ZnSe:Mn nanosheets and microflowers with high photoactive properties by microwave-assisted method
摘要： Zinc selenide (ZnSe) and manganese-doped zinc selenide (ZnSe:Mn) nanosheet and microflower morphologies were successfully fabricated in only 15-25 minutes in solvothermal reactions under microwave irradiation. In order to compare the effect of microwave heating on the properties of obtained ZnSe nanocrystals, the synthesis under conventional heating was conducted additionally in similar conditions. The obtained nanocrystals were systematically characterized in terms of structural and optical properties using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV-Vis spectroscopy (DR UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS), Atomic Absorption spectroscopy (AAS) and Brunauer-Emmett-Teller (BET) surface area analysis. ZnSe and ZnSe:Mn nanosheets were synthesized with the length of 300-600 nm, width of 150-400 nm, and thickness about 10-30 nm. The photocatalytic activity of ZnSe and ZnSe:Mn nanocrystals with different morphologies was evaluated by the degradation of methyl orange (MO). The results show that all samples had high coefficient of degradation of MO under ultraviolet irradiation (UV). Manganese-doped ZnSe nanocrystals exhibited superior photocatalytic activity and can offer many wide opportunities and perspectives in the field of photocatalysis and solar energy conversion.
关键词： photoactivity,microflowers,nanosheets,methyl orange,microwave,ZnSe:Mn,ZnSe
更新于2025-09-10 09:29:36
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A universal method for large-yield and high-concentration exfoliation of two-dimensional hexagonal boron nitride nanosheets
摘要： Hexagonal boron nitride (hBN) is an ultra-wide bandgap insulating material, which possesses a graphite-like layered structure, and the two-dimensional (2D) hexagonal boron nitride nanosheets (hBNNS), exfoliated from the bulk hBN, have promising applications in electronic packaging and high-power devices, due to the high thermal conductivity, excellent thermal/chemical stability as well as the ultra-wide band gap. However, the exfoliation of hBNNS is still a challenge with respect to high cost, time consuming, and low yield. Herein, a facile hydrothermal exfoliation method was proposed for the first time to exfoliate the hBNNS in a large yield and high concentration. In the optimized hydrothermal conditions, the lithium ion (Li+) intercalation, isopropanol (IPA) solvent, and the strong stirring could give rise to a large exfoliation yield up to (cid:1)55% and a high concentration (cid:1)4.13 mg/mL. In addition, the exfoliated hBNNS could enhance the methyl orange (MO) photodegradation efficiency of TiO2 from 91% to 96.4 %. Most importantly, this hydrothermal exfoliation method could be a universal approach for the exfoliation of 2D materials.
关键词： Hydrothermal exfoliation,Nanosheets,2D materials,Hexagonal boron nitride,Solubility parameters theory,Universal approach
更新于2025-09-10 09:29:36
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Biological interactions of biocompatible and water-dispersed MoS2 nanosheets with bacteria and human cells
摘要： Two dimensional materials beyond graphene such as MoS2 and WS2 are novel and interesting class of materials whose unique physico-chemical properties can be exploited in applications ranging from leading edge nanoelectronics to the frontiers between biomedicine and biotechnology. To unravel the potential of TMD crystals in biomedicine, control over their production through green and scalable routes in biocompatible solvents is critically important. Furthermore, considering multiple applications of eco-friendly 2D dispersions and their potential impact onto live matter, their toxicity and antimicrobial activity still remain an open issue. Herein, we focus on the current demands of 2D TMDs and produce high-quality, few-layered and defect-free MoS2 nanosheets, exfoliated and dispersed in pure water, stabilized up to three weeks. Hence, we studied the impact of this material on human cells by investigating its interactions with three cell lines: two tumoral, MCF7 (breast cancer) and U937 (leukemia), and one normal, HaCaT (epithelium). We observed novel and intriguing results, exhibiting evident cytotoxic effect induced in the tumor cell lines, absent in the normal cells in the tested conditions. The antibacterial action of MoS2 nanosheets is then investigated against a very dangerous gram negative bacterium, such as two types of Salmonellas: ATCC 14028 and wild-type Salmonella typhimurium. Additionally, concentration and layer-dependent modulation of cytotoxic effect is found both on human cells and Salmonellas.
关键词： antibacterial activity,biocompatibility,MoS2 nanosheets,two-dimensional materials,cytotoxicity
更新于2025-09-10 09:29:36
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Fabrication of novel 1D/2D V2O5/g-C3N4 composites as Z-scheme photocatalysts for CR degradation and Cr (VI) reduction under sunlight irradiation
摘要： Photocatalytic materials for environmental remediation of organic pollutants and heavy metals require not only a strong visible light response and high photocatalytic performance, but also the regeneration and reuse of catalysts. In this work, 1D/2D V2O5 nanorods/g-C3N4 nanosheets (VONRs/CNNs) composites were prepared by a facile impregnation method and employed in the degradation of a Congo red (CR) and reduction of Cr (VI) under sunlight irradiation. The as-prepared samples were studied by several characterization techniques including XRD, SEM, TEM, EDS, XPS, FTIR, UV-vis DRS and PL. Results revealed that the interface interaction between VONRs and CNNs was recognized via V2O5 nanorods loading on the surface of g-C3N4 nanosheets, improving the separation and transfer of photogenerated electron-hole pairs and restraining the recombination rate of charge carriers. As a result, the photocatalytic activity of the composites was enhanced in comparison with pure CNNs and VONRs. The photocatalytic efficiency of optimal composite (4-VONRs/CNNs) for the removal of CR (Cr (VI)) was about 9.33 (4.22) and 73.52 (19.2) times higher than that of pure CNNs and VONRs, respectively. Meanwhile, the 4-VONRs/CNNs exhibited good photocatalytic stability in recycling experiments. Such enormous enhancement in photocatalytic performance was predominantly ascribed to the efficient separation and transfer of photogenerated electron-hole pairs at the VONRs/CNNs interface imparted through the direct Z-scheme charge carrier migration mechanism. Moreover, the energy band structure and the quenching effects of different scavengers demonstrated that the electrons of CNNs and holes of VONRs with higher oxidizability and reducibility are the real participants in photocatalytic reactions.
关键词： g-C3N4 nanosheets,Z-scheme mechanism,Composites,Photocatalytic activity,V2O5 nanorods,1D/2D heterojunction
更新于2025-09-10 09:29:36
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TiO2 nanoparticles modified with 2D MoSe2 for enhanced photocatalytic activity on hydrogen evolution
摘要： As an emerging two-dimensional (2D) nanomaterial, 2D MoSe2 nanosheets has the advantages of wide light response and rapid charge migration ability. In this work, 2D MoSe2/TiO2 nanocomposites were successfully synthesized through a simple hydrothermal method. The microstructure and photocatalytic activity of the nanocomposites were systematically investigated and determined. The corresponding Raman peaks and crystal planes of MoSe2 were analysed by Raman spectroscopy and transmission electron microscopy respectively, demonstrating the successful combination of the MoSe2 nanosheets and TiO2 nanoparticles. UV-vis diffused re?ectance spectra demonstrated that the introduction of MoSe2 did increase the light absorption ability of the nanocomposites. A lower recombination of electrons and holes was demonstrated for the MoSe2/TiO2 heterojunction from photoluminescence results. The photocatalytic hydrogen evolution test showed that the hydrogen production rate was 4.9 mmol h?1 for the sample with 0.1 wt.% MoSe2, 2 times higher than that of bare TiO2. This work provides a novel strategy for improving the photocatalytic properties of semiconductor photocatalyst.
关键词： Water splitting,MoSe2 nanosheets,Two dimensional,Photocatalysis,TiO2
更新于2025-09-10 09:29:36
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Dimensional Impact of Metal-Organic Frameworks in Catalyzing Photo-Induced Hydrogen Evolution and Cyanosilylation Reactions
摘要： Metal-organic frameworks (MOFs) have been widely studied as heterogeneous catalysts. Compared to the MOFs with three dimensional (3D) topologies, two dimensional (2D) MOF nanosheets can allow facile access to the active sites on their external surface, thus having huge potentials in catalysis. Herein, we fabricate 2D MOF nanosheets, UiO-67-NS, as photocatalyst for H2 evolution reaction, and study their photocatalytic performance in relation to their 3D bulk counterparts (UiO-67). The UiO-67-NS exhibit an 84-fold increase in photocatalytic efficiency compared to UiO-67. Postsynthetic cation grafting of the UiO-67-NS with titanium leads to further enhancement in photocatalytic efficiency, giving a hydrogen evolution rate of up to 393 μmol g-1 h-1, which is 13-times higher than that of the non-grafting nanosheets under the same condition. Our results indicate that the 3D-to-2D dimensionality reduction can be a viable strategy for the development of MOFs as efficient photocatalysts. In addition, we have demonstrated that the improvement of catalytic performance based on the strategy of 3D-to-2D framework dimensionality reduction can be easily extended to heterogeneous cyanosilylation reaction.
关键词： Post-Synthetic Grafting,Metal-Organic Frameworks,Dimensional Impact,Photo-Induced Hydrogen Evolution,Metal-Organic Nanosheets
更新于2025-09-10 09:29:36
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Construction of acetaldehyde-modified g-C3N4 ultrathin nanosheets via ethylene glycol-assisted liquid exfoliation for selective fluorescence sensing of Ag+
摘要： We successfully prepared acetaldehyde-modified g-C3N4 ultrathin nanosheets (ACNNSs) by a simple ethylene glycol-assisted liquid exfoliation method. The introduction of acetaldehyde regulated the surface energy of g-C3N4 to better match with that of water, which improved the exfoliation efficiency. Moreover, the acetaldehyde introduces defects into the g-C3N4 structure, which can act as excitation energy traps and cause considerable variation in the fluorescence emission. Benefiting from the stable photoluminescence (PL) emission, good water solubility and biocompatibility, the obtained ACNNSs showed a selective fluorescent response to Ag+ both in aqueous solution and living cells. The strong absorption and intimate contact with Ag+, and its appropriate redox potential of ACNNSs contributed to this excellent fluorescent response. A simple and environmental friendly approach was proposed to simultaneously achieve modification and exfoliation of g-C3N4 in aqueous solution. These findings might lead to wider applications of carbon-based nanomaterials as active materials for fluorescence detection in the environment.
关键词： Graphitic carbon nitride nanosheets,Living-cell imaging,Glycol-assisted exfoliation,Fluorescent sensor,Acetaldehyde-modified,Ag+
更新于2025-09-10 09:29:36
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Polyphenol-Assisted Exfoliation of Transition Metal Dichalcogenides into Nanosheets as Photothermal Nanocarriers for Enhanced Antibiofilm Activity
摘要： Transition metal dichalcogenides (TMDs) nanosheets have evoked enormous research enthusiasm and have shown increased potentials in biomedical field. However, a great challenge lies in high-throughput, large-scale and eco-friendly preparation of TMDs nanosheets dispersions with high quality. Herein, we report a universal polyphenol-assisted strategy to facilely exfoliate various TMDs into monolayer or few-layer nanosheets. By optimizing the exfoliation condition of molybdenum disulfide (MoS2), the yield and concentration of as-exfoliated nanosheets is up to 60.5% and 1.21 mg/mL, respectively. This is the most efficient aqueous exfoliation method at present and is versatile for the choices of polyphenols and TMDs nanomaterials. The as-exfoliated MoS2 nanosheets possess superior biomedical stability as nanocarriers to load antibiotic drug. They show high photothermal conversion effect and thus induce a synergetic effect of chemotherapy and photothermal therapy to harvest enhanced antibiofilm activity under near-infrared (NIR) light. All these results offer an appealing strategy toward the synthesis and application of ultrathin TMDs nanosheets, with great implications for their development.
关键词： monolayer nanosheets,aqueous exfoliation,photothermal nanocarrier,transition metal dichalcogenides (TMDs),antibiofilm activity
更新于2025-09-10 09:29:36
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Chemical Vapor Deposited Vanadium Pentoxide Nanosheets with Highly Stable and Low Switching Voltages for Effective Selector Devices
摘要： Recently, attempts to overcome the physical limits of memory devices have led to the development of promising materials and architectures for next-generation memory technology. The selector device is one of the essential ingredients of high-density stacked memory systems. However, complicated constituent deposition conditions and thermal degradation are problematic, even with effective selector device materials. Herein, we demonstrate the highly stable and low threshold voltages of vanadium pentoxide (V2O5) nanosheets synthesized by facile chemical vapor deposition, which have not been previously reported on the threshold switching properties. The electrons occupying trap sites in poly-crystalline V2O5 nanosheet contribute to the perfectly symmetric threshold switching feature at the bias polarity and low threshold voltages in V2O5, confirmed by high-resolution transmission electron microscopy measurements. Furthermore, we find an additional PdO interlayer in V2O5 nanodevices connected with a Pd/Au electrode after thermal annealing treatment. The PdO interlayer decreases the threshold voltages, and the Ion/Ioff ratio increases because of the increased trap density of V2O5. These studies provide insight into V2O5 switching characteristics, which can support low power consumption in non-volatile memory devices.
关键词： nanosheets,selector devices,vanadium pentoxide,threshold switching,thermal annealing treatment
更新于2025-09-10 09:29:36