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Synthesis and Characterization of Aluminum Nanoparticles Prepared in Vinegar Using a Pulsed Laser Ablation Technique
摘要： The second harmonic wavelength of a neodymium-doped yttrium-aluminum-garnet (Nd-YAG) laser (λ = 532 nm) was used in a pulsed laser ablation technique (PLAL) to synthesize aluminum nanoparticles suspended in white vinegar from an aluminum target. The nanoparticles were characterized by HRTEM and UV-Vis spectrophotometry. They were found to range in size between 2 and 50 nm in diameter, with an average diameter of 12 ± 9 nm. The nanoparticles had a maximum absorption peak at 237 nm and were found to exhibit a core-shell structure with an Al core coated by a thin layer of an amorphous material which could be attributed to amorphous carbon. HRTEM results revealed that the small nanoparticles (<20 nm) had an fcc phase of aluminum crystalline structure, where the larger particles represented alumina (γ-Al2O3) nanoparticles. Such observation suggests that the use of white vinegar as an ablation medium could facilitate the synthesis of aluminum nanoparticles with minimal evidence of the existence of aluminum oxide nanoparticles in the resultant suspension.
关键词： pulsed laser ablation in liquid (PLAL),UV-Vis spectrophotometry,white vinegar,HRTEM,Aluminum nanoparticles
更新于2025-09-19 17:13:59
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Numerical Investigation of Ultrashort Laser-Ablative Synthesis of Metal Nanoparticles in Liquids Using the Atomistic-Continuum Model
摘要： We present a framework based on the atomistic continuum model, combining the Molecular Dynamics (MD) and Two Temperature Model (TTM) approaches, to characterize the growth of metal nanoparticles (NPs) under ultrashort laser ablation from a solid target in water ambient. The model is capable of addressing the kinetics of fast non-equilibrium laser-induced phase transition processes at atomic resolution, while in continuum it accounts for the effect of free carriers, playing a determinant role during short laser pulse interaction processes with metals. The results of our simulations clarify possible mechanisms, which can be responsible for the observed experimental data, including the presence of two populations of NPs, having a small (5–15 nm) and larger (tens of nm) mean size. The formed NPs are of importance for a variety of applications in energy, catalysis and healthcare.
关键词： metal nanoparticles,femtosecond laser ablation,dual nanoparticle distribution,pulsed laser ablation in liquids
更新于2025-09-16 10:30:52
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Laser-Ablative Synthesis of Isotope-Enriched Samarium Oxide Nanoparticles for Nuclear Nanomedicine
摘要： Nuclear nanomedicine is an emerging field, which utilizes nanoformulations of nuclear agents to increase their local concentration at targeted sites for a more effective nuclear therapy at a considerably reduced radiation dosage. This field needs the development of methods for controlled fabrication of nuclear agents carrying nanoparticles with low polydispersity and with high colloidal stability in aqueous dispersions. In this paper, we apply methods of femtosecond (fs) laser ablation in deionized water to fabricate stable aqueous dispersion of 152Sm-enriched samarium oxide nanoparticles (NPs), which can capture neutrons to become 153Sm beta-emitters for nuclear therapy. We show that direct ablation of a 152Sm-enriched samarium oxide target leads to widely size- and shape-dispersed populations of NPs with low colloidal stability. However, by applying a second fs laser fragmentation step to the dispersion of initially formed colloids, we achieve full homogenization of NPs size characteristics, while keeping the same composition. We also demonstrate the possibility for wide-range tuning of the mean size of Sm-based NPs by varying laser energy during the ablation or fragmentation step. The final product presents dispersed solutions of samarium oxide NPs with relatively narrow size distribution, having spherical shape, a controlled mean size between 7 and 70 nm and high colloidal stability. The formed NPs can also be of importance for catalytic and biomedical applications.
关键词： nuclear nanomedicine,samarium (Sm) oxide nanoparticles,pulsed laser ablation in liquids,femtosecond laser ablation and fragmentation
更新于2025-09-16 10:30:52
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Synthesis of Porous ZnO Nanosheets and Carbon Nanotube Hybrids as Efficient Photocatalysts via Pulsed Laser Ablation
摘要： Zinc oxide (ZnO) has attractive photocatalytic properties. However, the high recombination rate of the photo-excited charge carriers on this material often restricts application. Here, we report that hybridization of one dimensional (1D) carbon nanotubes (CNT) on two dimensional (2D) porous ZnO nanosheets (NS) can be a promising strategy to overcome some of the challenges of ZnO. Specifically, a pulsed laser ablation technique was utilized to hybridize 1D CNT with 2D porous ZnO NS in environmentally friendly as well as super-economic (short time, less than 10 min) conditions. The synthesized ZnO NS-CNT hybrids show a significantly enhanced photocatalytic activity for water splitting relative to their counterpart ZnO NS.
关键词： pulsed laser ablation,water splitting,carbon nanotube,photocatalyst,zinc oxide,nanocomposites
更新于2025-09-16 10:30:52
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Simple preparation of graphene quantum dots with controllable surface states from graphite
摘要： Graphite is economic and earth-abundant carbon precursor for preparing graphene quantum dots (GQDs). Here, we report a facile and green approach to produce GQDs from graphite flakes via a pulsed laser ablation (PLA) method assisted by high-power sonication. A homogeneous dispersion of graphite flakes, caused by high-power sonication during PLA, leads to the formation of GQDs following a laser fragmentation in liquid (LFL) rather than laser ablation in liquid (LAL) mechanism. The final product of GQDs exhibits the distinct structural, chemical, and optical properties of pristine graphene itself. However, graphene oxide quantum dots (GOQDs) with abundant surface oxygen-rich functional groups are readily formed from graphite flakes when high-power sonication is not employed during the PLA process. GQDs and GOQDs show a significantly different luminescence nature. Hence, selective production of either functional GQDs or GOQDs can be achieved by simply turning the high-power sonication during the PLA process on and off. We believe that our modified PLA process proposed in this work will further open up facile and simple routes for designing functional carbon materials.
关键词： high-power sonication,graphene quantum dots,luminescence,pulsed laser ablation,graphite flakes
更新于2025-09-16 10:30:52
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Morphology-selective preparation and formation mechanism of few-layer graphene on Cu substrate by liquid-phase pulsed laser ablation
摘要： This paper presented a morphology-selective preparation and formation mechanism of few-layer graphene (FLG) on a Cu substrate by pulsed laser ablation in liquid. It is a simple and controllable route to grow FLG directly on the surface of a copper foil at ambient temperature and normal pressure, which does not need other precursor materials. FLG with 3–10 layers of thickness and continuous hundreds of micrometers in lateral size is obtained. The morphology and structure of FLG were investigated by using a Raman spectrometer, scanning electron microscope, high-resolution transmission electron microscope, and atomic force microscope. The formation mechanism of FLG and the role of the plasma-produced carbon species are put forward based on the interaction between the laser, material, and substrate. Our finding, the direct deposition of FLG on the Cu substrate by pulsed laser ablation in liquid, will open a door to apply this green route to the production of FLG with controlled morphology.
关键词： formation mechanism,Cu substrate,morphology-selective preparation,few-layer graphene,liquid-phase pulsed laser ablation
更新于2025-09-16 10:30:52
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Effect of substrate temperature, laser energy and post-deposition annealing on the structural, morphological and optical properties of laser-ablated perovskite BaSnO3 films
摘要： Perovskite BaSnO3 thin films suitable for excitonic solar cell applications were deposited on quartz substrate by pulsed-laser ablation method. The effect of various deposition parameters on the structural, morphological and optical properties is systematically studied by various characterization techniques. Phase-pure films with cubic crystalline nature were evolved at a substrate temperature of 600 °C with a laser energy of 60 mJ and post-deposition annealing further improved the structural purity and optical quality of the films. An exponential growth in film thickness was observed with increasing laser energy in which Stranski–Krastnov growth mechanism dominated. Chemical states of BaSnO3 were confirmed from XPS analysis. The deposited films present luminescence in the visible region at 452 nm, 480 nm and 580 nm wavelength.
关键词： Optical properties,BaSnO3,Thin films,Pulsed-laser ablation,Perovskite
更新于2025-09-16 10:30:52
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Laser-induced anchoring of WO3 nanoparticles on reduced graphene oxide sheets for photocatalytic water decontamination and energy storage
摘要： In this work, the synthesis of tungsten oxide/reduced graphene oxide (WO3-rGO) nanocomposite, using a simple method of pulsed laser ablation in liquids (PLAL) is reported. The pulsed laser beam of 355 nm wavelength carries out two simultaneous processes: the reduction of graphene oxide and at the same time the anchoring of nanostructured WO3 on reduced graphene oxide. In the photo-catalytic application, WO3-rGO shows much better visible light absorption and less photo-generated charge recombination than pure WO3, as indicated by optical absorption and photoluminescence spectra. These improved features in WO3-rGO significantly enhanced the photo-catalytic decontamination of methylene blue (MB) dye in the water, compared to the use of pure WO3 as a photocatalyst. A Poly 2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS) based electrolyte together with the high electrical conductance and porosity of rGO which were produced after anchoring WO3 on the graphene oxide, were harnessed for the energy storage application using this material for a supercapacitor. The specific capacitance for WO3-rGO based device is achieved to be 577 F g?1 measured by the galvanostatic charge-discharge (GCD) method. Also, at a power density of 1000 W kg?1, the as-synthesized WO3-rGO demonstrated a large energy density value of 76.3 Wh Kg?1 that is much larger than obtained, using WO3 alone. Besides these photocatalytic and energy storage performance evaluation of WO3-rGO, the optical, morphological and elemental characteristics of synthesized WO3-rGO were also investigated to study the improved performance of the nanocomposite in these two applications.
关键词： PAMPS,Supercapacitor,Pulsed laser ablation in liquid,Energy storage,Photo-catalytic decontamination
更新于2025-09-16 10:30:52
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Laser additive manufacturing of oxide dispersion strengthened steels using laser-generated nanoparticle-metal composite powders
摘要： A new route for the synthesis of powder composites suitable for processing with laser additive manufacturing is demonstrated. The powder composites, consisting of micrometer-sized stainless steel powder, homogenously decorated with nano-scaled Y2O3 powder particles, are manufactured by laser processing of colloids and electrostatic deposition. Consolidated by laser metal deposition and selective laser melting, the resulting specimens show superior mechanical properties at elevated temperatures, caused by the nano-sized, homogenously distributed dispersoids.
关键词： Laser additive manufacturing,Pulsed laser ablation in liquids,Selective Laser Melting,Oxide dispersion strengthened materials,ODS
更新于2025-09-12 10:27:22
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A new approach to coat PA12 powders with laser-generated nanoparticles for selective laser sintering
摘要： The modification of selective laser sintering (SLS) powder materials by nanoadditives offers the possibility to adapt the powder properties to the laser sintering process or the resulting part properties. To avoid agglomeration of the nanofiller, a new approach in which surfactant-free laser-generated colloidal nanoparticles are adsorbed onto the polymer surface directly in an aqueous solution is demonstrated. Based on this novel approach, polyamide 12 (PA12) powders are decorated with metal and oxide nanoparticles and processed via SLS. Electron microscopy and confocal laser scanning imaging are utilized to analyze the dispersion of the filler.
关键词： selective laser sintering,laser additive manufacturing,polymer powders,pulsed laser ablation in liquids,nanoparticles
更新于2025-09-12 10:27:22