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The production of graphene–boron nitride nanosheet heterostructures via liquid phase exfoliation assisted by a milling process
摘要： Graphene–boron nitride (BN) nanosheet heterostructures have become one of the highly interesting matters in recent times owing to their advantages. In this study, the liquid phase exfoliation method was preferred for production of graphene–BN nanosheet heterostructures. However, a pre-milling process was applied to starting materials, instead of the classical liquid phase exfoliation method previously used in the literature. Hexagonal graphite (h-G) and h-BN mixtures were milled for 50 h and the milled powders were subjected to the liquid phase exfoliation process. As a result of the examinations, it was observed that graphene–BN nanosheet heterostructures were successfully synthesized. The widths of the synthesized nanosheets were 300–500 nm and nanosheets were multi-layers. It was seen that a large part of the powder mixture were occurred at high amorphization during the ball milling process. According to X-ray diffraction (XRD) peaks, the amorphization ratio was almost 90%. But, almost all of amorphous structures were removed during acid mixing and the thermal process. But, amorphous structures still existed in samples. In addition, the ball milling process damaged the sheets and defects formed. Despite all these disadvantages, the milling process carried out in this study provided formation of thinner and larger sheets compared with previous similar studies.
关键词： ball milling,BN nanosheets,exfoliation,heterostructures,Graphene
更新于2025-09-23 15:23:52
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Investigating the Role of Glass and Quartz Substrates on the Formation of Interfacial Droplets
摘要： Nanostructuring has been proved effective towards improving many energy storage and conversion devices, and is feasible for a wide range of materials. In particular, secondary nanoarchitectured materials exhibit collective advantages compared with nano-sized primary building blocks. Despite the manifold efforts in designed nanoarchitectures and synthetic routes, the underlying ion diffusion kinetics and phase transformation behaviors within nanoarchitectures still remain less explored. Herein, we probed enhanced lithium-ion transport behaviors using 2D holey zinc ferrite (ZFO) nanosheets as a model material, to demonstrate how self-assembled 2D holey nanoarchitectured electrodes can feature efficient ion diffusion channels, robust yet continuous electron transfer framework, and enlarged surface area, contributing to the superior performance over the ZFO nanoparticles without secondary structures. By revealing kinetic parameters through combined spectroscopic measurements and electrochemical techniques, our study manifests increased lithium-ion diffusion coefficients, higher capacitive charge storage contribution and reduced charge transfer impedance in holey nanosheets compared to randomly aggregated nanoparticles. Our results promote deeper understanding of significantly enhanced electrochemical energy storage properties of these 2D holey nanoarchitectured electrodes resulted from more uniform and complete phase transformation and better active material utilization.
关键词： nanostructuring,2D holey nanosheets,energy storage,transport kinetics,Li-ion battery
更新于2025-09-23 15:23:52
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Ultra-small two dimensional MXene nanosheets for selective and sensitive fluorescence detection of Ag+ and Mn2+ ions
摘要： The present work offers a new exploration for the selective sensing of metal ions (Ag+ and Mn2+) via fluorescence quenching of Ti3C2 MXene nanosheets (NSs). Monolayer MXene Ti3C2 NSs exhibited excellent ability to sense Ag+ and Mn2+ ions because of their good hydrophilicity and distinctive surface functionality. The as-synthesised Ti3C2 NSs exhibited highest emission fluorescence peak at 461 nm upon the excitation wavelength of 384 nm. The fluorescence emission peak of Ti3C2 NSs was remarkably quenched only upon the addition of Ag+ and Mn2+ ions, exhibiting good linear response between I0/I and concentration in the range of 0.1–40 μM and 0.5–60 μM for Ag+ and Mn2+ ions. The proposed sensor shows lower detection limits of 9.7 and 102 nM for Ag+ and Mn2+ ions with good selectivity. Additionally, the method is effectively applied to detect Ag+ and Mn2+ ions in food and real water samples with excellent recoveries.
关键词： FT-IR,MXene nanosheets,Florescence and UV–vis spectroscopic techniques,Ag+ and Mn2+ ions
更新于2025-09-23 15:23:52
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ZnIn2S4 nanosheets decorating WO3 nanorods core-shell hybrids for boosting visible-light photocatalysis hydrogen generation
摘要： We here report the fabrication of a core-shell WO3@ZnIn2S4 heterostructure by an interfacial seeding growth strategy, which is implemented by direct growth of ZnIn2S4 nanosheets on the surface of WO3 nanorods with forming a strong electronic interaction between two semiconductors that are beneficial for promoting the interfacial charge transfer. Systematic studies demonstrate that the WO3@ZnIn2S4 nanohybrids hold superior performance for photocatalytic hydrogen generation under visible light irradiation with a production rate of 3900 mmol g-1 h-1. This work provides an effective approach to construct the direct Z-scheme photocatalytic systems for efficient photocatalytic hydrogen evolution, which would be significant for the design of more direct Z-scheme system for various photocatalytic applications.
关键词： ZnIn2S4 nanosheets,WO3 nanorods,Photocatalytic H2 generation,Visible light,Z-scheme
更新于2025-09-23 15:23:52
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Synthesis and annealing process of ultra-large SnS nanosheets for FTO/SnS/CdS/Pt photocathode
摘要： SnS has been widely used in photoelectric devices due to its special band gap of 1.2–1.5 eV. Here, we reported on the fabrication of SnS nanosheets and the effect of synthesis condition together with heat treatment on its physical properties. The obtained band gap of the SnS nanosheets is in the rage of 1.37–1.41 eV. It was found that the photo-current density of a thin film comprised of SnS nanosheets could be enhanced significantly by annealing treatment. The maximum photo-current density of the stack structure of FTO/SnS/CdS/Pt was high as 389.5 μA cm-2, rendering its potential application in high efficiency solar hydrogen production.
关键词： SnS nanosheets,Water splitting,Photoelectrochemical properties
更新于2025-09-23 15:23:52
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Black phosphorus nanosheets based sensitive protease detection and inhibitor screening
摘要： Proteases, as one of the most significant kind of digestive enzymes, are closely related to a variety of physiological processes and diseases. Herein, a black phosphorus nanosheets (BPs) based sensitive fluorometric method for protease detection and inhibitor screening is proposed. The aqueous solution of perylene probe (probe 1) displays a strong fluorescence. BPs, as novel discovered two-dimensional (2D) materials, can adsorb probe 1 through electrostatic interactions, which causes fluorescence quenching of probe 1. Histone can control the interactions between the perylene probe and BPs, which can be further regulated by the introduction of a protease. Thus, the protease activity can be monitored by detecting the fluorescence intensity changes of probe 1. The method is label free, sensitive and selective. As low as 1 ng/mL trypsin can be easily detected.
关键词： trypsin,inhibitor,protease,black phosphorus nanosheets,fluorescence,perylene probe
更新于2025-09-23 15:23:52
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Ultrathin GeSe Nanosheets: from Systematic Synthesis, to Studies of Carrier Dynamics and Applications for High Performance UV-Vis Photo-Detector
摘要： Owing to the attractive energy band properties, black phosphorus (BP)-analogue semiconductor, germanium selenide (GeSe), shows a promising potential applied for optoelectronic devices. Herein, ultrathin GeSe nanosheets were systematically prepared via a facile liquid phase exfoliation (LPE) approach, with controllable nano-scale thickness. Different from BP, ultrathin GeSe nanosheets exhibits a good stability under both liquid and ambient conditions. Besides, its ultrafast carrier dynamics was probed by transient absorption spectroscopy. We showed that the GeSe nanosheets-based photo-detector exhibits excellent photoresponse behaviors ranging from ultraviolet (UV) to the visible regime, with high responsivity and low dark current. Furthermore, the detective ability of such a device can be effectively modulated by varying the applied bias potential, light intensity and concentration of electrolyte. Generally, our present contribution could not only supply fundamental knowledge of GeSe nanosheets-based photoelectrochemical (PEC)-type device, but also offer a guidance to extend other possible semiconductor materials in the application of PEC-type photo-detector.
关键词： photoelectrochemical,photo-detector,liquid phase exfoliation,carrier dynamics,GeSe nanosheets
更新于2025-09-23 15:23:52
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2D/2D/2D heterojunction of Ti3C2 MXene/MoS2 nanosheets/TiO2 nanosheets with exposed (001) facets toward enhanced photocatalytic hydrogen production activity
摘要： Exposing the highly active facets and hybridizing the photocatalyst with appropriate cocatalysts with right placement have been regarded as a powerful approach to high performance photocatalysts. Herein, TiO2 nanosheets (NSs) are in situ grown on highly conductive Ti3C2 MXene and then MoS2 NSs are deposited on the (101) facets of TiO2 NSs with mainly exposed high-active (001) facets through a two-step hydrothermal method. And a unique 2D-2D-2D structure of Ti3C2@TiO2@MoS2 composite is achieved. With an optimized MoS2 loading amounts (15 wt%), the Ti3C2@TiO2@MoS2 composite shows a remarkable enhancement in the photocatalytic H2 evolution reaction compared with Ti3C2@TiO2 composite and TiO2 NS. It also shows good stability under the reaction condition. This arises from: (i) the in situ growth of TiO2 NSs construct strong interfacial contact with excellent electronic conductivity of Ti3C2, which facilitates the separation of carriers; (ii) the coexposed (101) and (001) facets can form a surface heterojunction within single TiO2 NS, which is beneficial for the transfer and separation of charge carriers; and (iii) the MoS2 NSs are deposited on the electrons-rich (101) facets of TiO2 NSs, which not only effectively reduces the charge carriers recombination rate by capturing photoelectrons, but also makes TiO2 NSs expose more highly active (001) facets to afford high-efficiency photogeneration of electron-hole pairs.
关键词： Exposed active facet,Ti3C2 MXene,TiO2 nanosheets,Photocatalytic H2 production,MoS2 nanosheets
更新于2025-09-23 15:22:29
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Electronic structure and magnetic behaviors of exfoliated MoS<sub>2</sub> nanosheets
摘要： The correlation of electronic structure and magnetic behaviors of layered molybdenum disulfide (MoS2) nanosheets, mechanically exfoliated from pristine hexagonal crystal (2H-MoS2) have been studied. Raman spectra show the energy difference (ΔE) between two Raman peaks A1g and E12g was about 20.2 cm-1, indicating the formation of mono-/bi-layered MoS2 nanosheets as obtained after mechanical exfoliation from pristine 2H-MoS2. The absence of the reflection peak (002) in X-ray diffraction patterns confirms the formation of few-layered and mono-/bi-layered MoS2 nanosheets. Mo LII-edge and S K-edge X-ray absorption near edge structure spectra of mono-/bi-layered MoS2 nanosheets show the splitting of different peaks that cause a noticeable change in their band structure. Magnetic M-H hysteresis loops measurement clearly demonstrates the increase of room temperature ferromagnetism from pristine to mono-/bi-layer MoS2, due to the existence of defects (“S”- vacancies or defects at the grain boundaries region) and the increase of DOS. UPS (He-I) measurements show the valence band maximum position increased from 1.11 eV (pristine MoS2) to 1.57 eV (mono-/bi-layered MoS2 nanosheets), whereas the surface work function (Ф) reduced from 4.85 eV (pristine MoS2) to 4.47 eV (mono-/bi-layered MoS2 nanosheets). UPS (He-II) valence band density of states (DOS) of S 3p - derived states near Fermi level (Ef). Mo 3d and S 2p XPS core level peaks shifted to higher energy with the reduction of the number of layers in exfoliated MoS2. As the number of layers decreased, valence band spectra, as well as VB-PES spectra of mono-/bi-layered MoS2 nanosheets, exhibits an enhanced DOS with reduced thickness.
关键词： UPS,VB-PES,XANES,Exfoliated MoS2-nanosheets,XPS,RT-FM
更新于2025-09-23 15:22:29
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Vis-NIR light-responsive photocatalytic activity of C3N4-Ag-Ag2O heterojunction-decorated carbon-fiber cloth as efficient filter-membrane-shaped photocatalyst
摘要： C3N4-decorated carbon-fiber (CF) cloth has been demonstrated to be a filter-membrane-shaped photocatalyst for degrading flowing wastewater, but it can be excited only by visible light (λ < 450 nm). To extend the photoresponse range to NIR region, herein we have designed and prepared C3N4-Ag-Ag2O heterojunctions on CF cloth. The growth of C3N4 nanosheets (thickness: 20-30 nm) on CF cloth is realized by a thermal condensation method, and then Ag/Ag2O nanoparticles (10-20 nm) are deposited on CF/C3N4 cloth by a chemical precipitation method. CF/C3N4/Ag/Ag2O cloth exhibits excellent flexibility and strong photoabsorption in a broad Vis-NIR region (400-1400 nm), wider than CF/C3N4 (absorption edge: 450 nm). Under the irradiation of 808 nm or 980 nm laser, CF/C3N4/Ag/Ag2O cloth can remove 83%/41% AO7 and 72%/38% 4-CP in 140 min respectively, significantly higher than those (33%/13% AO7 and 31%/10% 4-CP) by CF/Ag/Ag2O cloth and those (3%/1% AO7 and 0%/1% 4-CP) by CF/C3N4 cloth. Interestingly, when CF/C3N4/Ag/Ag2O cloth is used as the filter-membrane to photo-degrade the flowing wastewater (AO7, 20 mg L-1, rate: 1.5 L h-1), the removal efficiency of AO7 reaches up 97% after 8 grade reactors. Therefore, CF/C3N4/Ag/Ag2O cloth can be used as an efficient filter-membrane-shaped photocatalyst with NIR photoresponse.
关键词： CF/C3N4/Ag/Ag2O cloth,nanosheets,photocatalysis,nanoparticles,Vis-NIR
更新于2025-09-23 15:22:29