- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Solvent-exfoliation of transition-metal dichalcogenide MoS2 to provide more active sites for enhancing photocatalytic performance of BiOIO3/g-C3N4 photocatalyst
摘要： The ternary complex photocatalysts of BiOIO3/g-C3N4/MoS2 by solvent-exfoliation method was synthesized for the first time. In the typical procedure, the BiOIO3/g-C3N4 was obtained via hydrothermal synthesis technique, and then the BiOIO3/g-C3N4/MoS2 photocatalysts were prepared via ultrasonic solvent-exfoliation method from bulk commercial MoS2 in the alcohol solution. The samples of BiOIO3/g-C3N4/MoS2 were analyzed by PL, XRD and other characterization analysis methods. The photocatalytic activity of the as-prepared samples was investigated by removing gas phase mercury irradiation under visible light. The as-prepared BCM-0.3 exhibits excellent photocatalytic performance, being with the highest efficiency of 70.58%. Owing to the electronic channels of field-effect, an internal electric field was formed through the corresponding band-gap engineering, improving photocatalytic reaction. Besides, the excellent activity of the ternary photocatalysts BiOIO3/g-C3N4/MoS2 is attributed to heterostructure between BiOIO3/g-C3N4 and MoS2, which enlarges spectral response and improved separation efficiency of charge carriers, and MoS2-composing, which provides more active sites for catalytic oxidation. In addition, the as-prepared samples with excellent photocatalytic performance also offer a perspective insight into the hydrogen evolution, CO2 conversion and degradation of organic pollutants.
关键词： Photocatalytic,Solvent-exfoliation,Heterostructure,Oxidation,Field-effect
更新于2025-11-20 15:33:11
-
Two-dimensional beta-lead oxide quantum dots
摘要： In recent years, black-phosphorus-analogue (BPA) two-dimensional (2D) materials have been explored to demonstrate promising optoelectronic performances and distinguished ambient stabilities, holding great promise in practical applications. Here, one new kind of BPA material, orthorhombic β-PbO quantum dots (QDs), is successfully fabricated by a facile liquid phase exfoliation (LPE) technique. The as-prepared β-PbO QDs show a homogeneous distribution of the lateral size (3.2 ± 0.9 nm) and thickness (2.5 ± 0.5 nm), corresponding to 4 ± 1 layers. The carrier dynamics of β-PbO QDs was systematically investigated via a femtosecond resolution transient absorption approach in the visible wavelength regime and it was clarified that two decay components were resolved with a decay time of τ1 = 2.3 ± 0.3 ps and τ2 = 87.9 ± 6.0 ps, respectively, providing important insights into their potential applications in the field of ultrafast optics, nanomechanics and optoelectronics. As a proof-of-concept, β-PbO QDs were, for the first time to our knowledge, fabricated as a working electrode in a photoelectrochemical (PEC)-typed photodetector that exhibits significantly high photocurrent density and excellent stability under ambient conditions.
关键词： photoelectrochemical photodetector,β-PbO quantum dots,carrier dynamics,liquid phase exfoliation
更新于2025-11-19 16:56:42
-
Facile and Green Synthesis of Graphene-Based Conductive Adhesives via Liquid Exfoliation Process
摘要： In this study, we report a facile and green process to synthesize high-quality and few-layer graphene (FLG) derived from graphite via a liquid exfoliation process. The corresponding characterizations of FLG, such as scanning electron microscopy (SEM), transmission electron microscope (TEM), atomic force microscopy (AFM) and Raman spectroscopy, were carried out. The results of SEM show that the lateral size of as-synthesized FLG is 1–5 μm. The results of TEM and AFM indicate more than 80% of graphene layers is <10 layers. The most surprising thing is that D/G ratio of graphite and FLG are 0.15 and 0.19, respectively. The result of the similar D/G ratio demonstrates that little structural defects were created via the liquid exfoliation process. Electronic conductivity tests and resistance of composite ?lm, in terms of different contents of graphite/polyvinylidene di?uoride (PVDF) and FLG/PVDF, were carried out. Dramatically, the FLG/PVDF composite demonstrates superior performance compared to the graphite/PVDF composite at the same ratio. In addition, the post-sintering process plays an important role in improving electronic conductivity by 85%. The composition-optimized FLG/PVDF thin ?lm exhibits 81.9 S·cm?1. These results indicate that the developed FLG/PVDF composite adhesives could be a potential candidate for conductive adhesive applications.
关键词： conductive adhesives,liquid exfoliation,graphene,?exiable,polyvinylidene ?uoride
更新于2025-09-23 15:23:52
-
Linear and Nonlinear Optical Properties of Few-Layer Exfoliated SnSe Nanosheets
摘要： Monochalcogenides of group IV elements have been considered as phosphorene analogs due to their similar crystal and electronic structure. Here, few-layer SnSe nanosheets are synthesized by a sonication-assisted liquid phase exfoliation process and their linear and nonlinear optical properties are examined. The as-exfoliated few-layer (FL) SnSe demonstrates layer thickness from 2 to 10 nm and lateral size of 150 nm with high crystallinity. Optical measurement confirms the layer-number dependent bandgap, which is also corroborated by first-principle calculation. In addition, the FL SnSe shows a transition from saturable absorption to reverse saturable absorption with the increase of pumping power, and the nonlinear absorption is characterized by an ultrafast response time of picosecond scale. The nonlinear optical response in FL SnSe could be explained by defect-involved recombination of photogenerated carriers as well as the Auger scattering process, which is further enhanced by structural two-dimensionality.
关键词： nonlinear optics,phosphorene analogue,SnSe,liquid-phase exfoliation,2D semiconductors
更新于2025-09-23 15:23:52
-
Mechanism Behind the Easy Exfoliation of Ga <sub/>2</sub> O <sub/>3</sub> Ultra-Thin Film Along (100) Surface
摘要： The transparent wide band gap semiconductor β-Ga2O3 has gained wide attention due to its suitability to a wide range of applications. Despite not being a van der Waals material and having highly strong ionic bonding, the material can be mechanically cleaved and exfoliated easily along favorable surfaces to make ultra-thin layers and used in device fabrications. One of the interesting properties of this material is that thin layers preserve the pristine bulk-like electronic properties, which makes it even more promising for applications in power devices. However, very little is known about the mechanism why such ultra-thin film or even single bilayer exfoliation is favorable from the bulk. In this letter, we have explained the mechanism of such phenomenon by detailed analyses of different types of Ga–O bonding character. The protocol of methodology used and developed in this study can be utilized in general to understand bond breaking and forming of other complex materials as well. This understanding will give us a better control to fabricate thin film 2D devices.
关键词： density functional theory,bond energy,computational physics,2D Ga2O3,easy exfoliation,surface energy
更新于2025-09-23 15:23:52
-
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
-
Structure and photocatalytic oxidation desulfurization performance of CeO2/HTi2NbO7-NS nanocomposite
摘要： CeO2/HTi2NbO7-NS nanocomposite based on HTi2NbO7 nanosheet (HTi2NbO7-NS) and Cerium dioxide nanoparticles (CeO2-NPs) was fabricated through an exfoliation-restructuring method. The as-prepared samples were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), laser Raman Spectroscopy (LRS), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflection spectroscopy (UV-Vis DRS) and N2 adsorption-desorption measurements. The adsorption and photocatalytic properties of the as-prepared samples were evaluated using ethyl mercaptan (EM) in methane gas as the model pollutant. The results indicated that CeO2-NPs were uniformly distributed on the surface of HTi2NbO7-NS and the band gap energy of CeO2/HTi2NbO7-NS nanocomposite was reduced compared with its precursor. The type-Ⅱ heterojunction was formed due to suitable band structures of host and guest materials. The CeO2/HTi2NbO7-NS nanocomposite owns the best adsorption capacity and photocatalytic oxidation activity, which was mainly attributed to the lower band gap and efficient separation of electron-hole pairs of CeO2/HTi2NbO7-NS nanocomposite.
关键词： CeO2/HTi2NbO7-NS,ethyl mercaptan (EM),exfoliation-restructuring,photocatalytic oxidation,type-Ⅱ heterojunction
更新于2025-09-23 15:23:52
-
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
-
Achieving high yield of graphene nanoplatelets in poloxamer-assisted ultrasonication of graphite in water
摘要： The role of surfactant (Pluronic? F 127) concentration on the yield and morphological characteristics of graphene nanoplatelets (GNPs) produced from the sonication of aqueous graphene suspensions is investigated in this work. By employing a wide surfactant concentration range (0.1–15 wt%) and sonication power densities up to 420 W L?1 we identify two graphene exfoliation regimes: the first occurs at low sonication power densities (<340 W L?1) and produces GNPs with sizes 200–300 nm, aspect ratios between 70 and 100, and concentrations up 1 mg mL?1. In that regime, the surfactant concentration has no effect on the exfoliation results. In the second exfoliation regime (>340 W L?1), surfactant concentrations greater than 10 wt% produce dramatic increases in GNP yields, namely up to 3.0 mg mL?1, and overall larger GNPs (350–500 nm) with smaller aspect ratios (5–60). We attribute these changes to the onset of a more energy intensive mechanism, termed cleavage. Cleavage involves the separation of graphite clusters in sub-bulk multi-layered graphene entities, as opposed to exfoliation, which involves the separation of individual or few-layer GNPs. Choosing an exfoliation regime by tuning simple process parameters enables control over the yield, size and morphology of the produced GNPs.
关键词： Poloxamer,Graphite exfoliation,Surfactant-assisted exfoliation,Ultrasonication,Graphene nanoplatelets
更新于2025-09-23 15:22:29
-
The Size Effect of Exfoliated MoS <sub/>2</sub> Based Thin Film Humidity Sensor
摘要： Layered two-dimensional nanomaterials such as MoS2 show great potential for sensor application owing to their distinct nature that most atoms are surface atoms. The difficult in mass production of exfoliated MoS2 hinders its practical application. In this study, we investigate the ultrasound assisted liquid method to efficiently exfoliate MoS2 into nanosheets and nanoparticles. The dependence of ultrasonic dosing, e.g., ultrasonic time, on the morphology and yield of final products are studied. The exfoliated MoS2 nanomaterials are fabricated into thin film sensors and examined with humidity gas. The sensors exhibit excellent and quick response toward humidity gas. We find the sensor prepared with longer ultrasonic treatment presents higher response owing to that the longer ultrasonic irradiation exposes more active edge sites.
关键词： Exfoliation,Humidity Sensor,MoS2,Size Effect,Thin Film
更新于2025-09-23 15:22:29