Laser Ablation In Liquid Research Articles

Control of the size distribution of AuNPs for colorimetric sensing by pulsed laser ablation in liquids

Gold nanoparticles (AuNPs) are extensively employed in colorimetric sensing, taking advantage of their optical properties to detect variables via observable color changes. These properties are primarily driven by localized surface plasmon resonance (LSPR), particularly pronounced in AuNPs within the visible spectrum. In this study, AuNPs were synthesized via pulsed laser ablation in liquids (PLAL) with a laser pulse energy (Ep) ranging from 25 mJ to 75 mJ. Size distributions, hydrodynamic diameters, polydispersity indices (PDI), absorbance intensity, and LSPR were characterized. Spherical AuNPs with FCC structure were synthesized, exhibiting a maximum absorption peak centered at approximately 529 nm wavelength and a size range between 50 nm and 178 nm, easily adjustable depending on the laser pulse energy used in the synthesis process. An anomalous behavior was noted at Ep=50 mJ, exhibiting three peaks in size distribution, high PDI, low absorbance intensity, and indistinct LSPR. By extending the ablation time from 10 min to 30 min, particle size decreased alongside lower PDI. Size distributions transitioned from three to two peaks, absorbance increased, and LSPR became readily identifiable. These findings underscore the size control over AuNP characteristics achievable through PLAL synthesis parameters, promising significant implications for the optimization of colorimetric sensor design and development.

Colloidal Titanium Nitride Nanoparticles by Laser Ablation in Solvents for Plasmonic Applications.

Titanium nitride (TiN) is a candidate material for several plasmonic applications, and pulsed laser ablation in liquids (PLAL) represents a rapid, scalable, and environmentally friendly approach for the large-scale production of nanomaterials with customized properties. In this work, the nanosecond PLAL process is developed, and we provide a concise understanding of the process parameters, such as the solvent and the laser fluence and pulse wavelength, to the size and structure of the produced TiN nanoparticles (NPs). TiN films of a 0.6 μm thickness developed by direct-current (DC) magnetron sputtering were used as the ablation targets. All laser process parameters lead to the fabrication of spherical NPs, while the laser pulse fluence was used to control the NPs' size. High laser pulse fluence values result in larger TiN NPs (diameter around 42 nm for 5 mJ and 25 nm for 1 mJ), as measured from scanning electron microscopy (SEM). On the other hand, the wavelength of the laser pulse does not affect the mean size of the TiN NPs (24, 26, and 25 nm for 355, 532, and 1064 nm wavelengths, respectively). However, the wavelength plays a vital role in the quality of the produced TiN NPs. Shorter wavelengths result in NPs with fewer defects, as indicated by Raman spectra and XPS analysis. The solvent type also significantly affects the size of the NPs. In aqueous solutions, strong oxidation of the NPs is evident, while organic solvents such as acetone, carbides, and oxides cover the TiN NPs.

Generation of nano-to-microplastics from polypropylene surfaces via femtosecond laser ablation in liquids with different viscosities

Preparation of polypropylene (PP) nano and microparticles, crucial for investigating the effects of plastics on both human health and the environment, presents a significant and immediate challenge. Utilizing an fs laser system in different liquid mediums such as water, dodecane, and hexadecane, we have successfully generated PP particles with sizes ranging from 1.8 to 4911 nm. This outcome is partly attributed to the constraint on plasma expansion caused by the viscosity of the liquid media. We investigated the areas of material removal and observed a transition from ordered to disordered removal patterns during this process. The formation of filaments and pillars within the material removal cavity, along with the deposition layer at the cavity edge, primarily occurred due to insufficient plasma formation at low laser energy levels. Furthermore, we observed neck-shaped filaments and nano cracks on the deposition surface, which were attributed to the heat effect during laser interaction with the PP substrate. Moreover, we collected distinct nano-Fourier transform infrared spectroscopy (FTIR) signals from both the nanoparticle area and the deposition layer, revealing a 2 cm−1 wavenumber difference between the two regions. This discrepancy proved to be a valuable method for distinguishing between the nanoparticle area and the deposition layer.

LASIS-Assisted Copper Nanoparticle Synthesis and Characterization, along with UV-Visible Spectroscopy

This study investigates the creation of copper nanoparticles (CuNPs) using chemical reduction and laser ablation in liquid (LASIS). UV-visible spectroscopy is used to examine the optical characteristics of the nanoparticles created by these techniques. The purpose of the study is to compare the stability, efficacy, and particle size of CuNPs produced using different techniques. When comparing the LASIS method to the chemical reduction process, Transmission Electron Microscopy (TEM) examination revealed that the former produced smaller and more uniform nanoparticles. This work demonstrates the effectiveness of both synthesis techniques, with LASIS clearly outperforming the other in the production of superior CuNPs with more control over particle size and dispersion. A thorough explanation of the chemical reduction method and LASIS used in the synthesis of copper nanoparticles is provided, and UV-visible spectroscopy is used to characterize the resulting particles.

Cu-based nanocatalyst by pulsed laser ablation in liquid for water splitting: Effect of the solvent

Hydrogen (HER) and Oxygen (OER) evolution reactions play a fundamental role in the field of green and environmental sustainability, because they are key reactions for water electrolysis. In this work copper (Cu) nanoparticles (NPs) are produced by pulsed laser ablation in liquid from a copper target in the framework of developing a low-cost, earth abundant and non-pollutant electrocatalyst. Various solvent and energy fluence are explored. Electrodes have been realized by drop-casting Cu NPs onto Nickel foam (NF) substrate, with a catalyst loading in the order of some μg/cm2. Electrochemical measurements have performed at room temperature in alkaline ambient and a three-electrode setup. The catalytic activity of the NPs is relevant already at 10mA/cm2 and the improvement with respect to the bare substrate become more evident at higher current densities. The ultra-low amount of the catalyst material makes these electrodes competitive in terms of mass activity compared to the state of the art.

Femtosecond laser synthesis of YAG:Ce3+ nanoparticles in liquid

YAG:Ce3+ nanocrystals are promising bio-labeling materials due to their low toxicity and high photostability. It is in demand to efficiently synthesize YAG:Ce3+ nanocrystals of a small size. Pulse laser ablation is an approach to produce nanoparticles directly from bulk materials with the advantages of smaller particle sizes and lower production costs. Here, we present the synthesis of YAG:Ce3+ nanocrystals from bulk crystal using the femtosecond laser ablation method in liquid. Comparing the liquid environment, we demonstrated that the lauryl dimethylaminoacetic acid betain (LDA) aqueous solution is preferred for the formation of smaller-sized YAG:Ce3+ nanoparticles than deionized water due to the attractiveness between the LDA molecules and the YAG:Ce3+ nanoparticles. We also verified that the high laser repetition rate had no effect on the average size of YAG:Ce3+ nanocrystals, where the fragmentation process is saturated under a high laser repetition rate. This study provides a simple and effective method to synthesize small size YAG:Ce3+ nanoparticles by femtosecond laser ablation in liquid.

Laser-based synthesis of silver nanoparticles embedded in cellulose paper for catalytic reduction of azo dyes and SERS sensing of pesticides

In this study, highly reactive bare silver nanoparticles (Ag NPs) are synthesized using the Pulsed Laser Ablation in Liquid (PLAL) technique. Ag NPs are then coated on the filter paper using the dip coating method. This process converts filter paper into a versatile substrate for catalysis and surface-enhanced Raman Spectroscopy (SERS) based sensing. The successful synthesis of spherical Ag NPs and their effective embedding into the filter paper was confirmed using UV–visible absorption spectroscopy, scanning electron microscopy (SEM), and Energy Dispersive x-ray analysis (EDX). SEM images revealed that the Ag NPs were embedded in the filter paper and attached to the cellulose fibers. The use of Ag NPs embedded filter paper as a catalyst substrate for the reduction of both cationic and anionic dyes demonstrated that higher concentrations of Ag NPs on the filter paper resulted in a faster reduction. In particular, filter paper impregnated with 52 μg of Ag NPs demonstrated a complete reduction of methylene blue and methyl orange in less than a minute and 4 min, respectively. To demonstrate the practical sensing capability of the Ag NPs embedded filter paper, it was utilized as a SERS substrate. This enabled the detection of trace levels of Rhodamine 6G (R6G) and the pesticide molecule chlorpyrifos, demonstrating its potential real-world applications.

Synthesis of Ultrawide Band Gap TeO2 Nanoparticles by Pulsed Laser Ablation in Liquids: Top Ablation versus Bottom Ablation.

Ultrawide band gap (UWBG) semiconductors are the future components of electronic devices due to their large energy band gap (>3.2 eV). In this article, spherical TeO2 nanoparticles, with sizes around ∼39 ± 12 and ∼29 ± 6 nm, were successfully synthesized by irradiating a pure tellurium target, totally submerged in ethanol, using a "Top-ablation" or "Bottom-ablation" synthesis protocol, respectively. Mostly, α-TeO2 nanoparticles were created (>95%) with only a small amount of γ-TeO2 nanoparticles being produced (<5%). Both colloids exhibited a ζ-potential larger than |30 mV|, indicating a stable colloidal solution. The energy band gaps of the TeO2 nanoparticles synthesized by the Top-ablation and Bottom-ablation synthesis protocols were determined to be around 5.3 and 5.8 eV, respectively. Finally, TeO2 UWBG nanoparticles were successfully synthesized using either a Top-ablation or Bottom-ablation synthesis protocol. The main advantage of the Bottom-ablation synthesis protocol is its ability to obtain smaller nanoparticles compared to that of the Top-ablation synthesis protocol.

CdS Nanoparticles Synthesized by Laser Ablation in Liquid

CdS Nanoparticles Synthesized by Laser Ablation in Liquid

Elucidating the Role of Electron Transfer in the Photoluminescence of MoS2 Quantum Dots Synthesized by fs-Pulse Ablation.

Herein, MoS2 quantum dots (QDs) with controlled optical, structural, and electronic properties are synthesized using the femtosecond pulsed laser ablation in liquid (fs-PLAL) technique by varying the pulse width, ablation power, and ablation time to harness the potential for next-generation optoelectronics and quantum technology. Furthermore, this work elucidates key aspects of the mechanisms underlying the near-UV and blue emissions the accompanying large Stokes shift, and the consequent change in sample color with laser exposure parameters pertaining to MoS2 QDs. Through spectroscopic analysis, including UV-visible absorption, photoluminescence, and Raman spectroscopy, we successfully unraveled the mechanisms for the change in optoelectronic properties of MoS2 QDs with laser parameters. We realize that the occurrence of a secondary phase, specifically MoO3-x, is responsible for the significant Stokes shift and blue emission observed in this QD system. The primary factor influencing these activities is the electron transfer observed between these two phases, as validated by excitation-dependent photoluminescence and XPS and Raman spectroscopies.

Investigation of ablation efficiency and properties of silicon carbide nanoparticles synthesised using pulsed laser ablation in liquid

This study optimised the synthesis and ablation efficiency of 3C silicon carbide (SiC) nanoparticles (NPs) using nanosecond pulsed laser ablation in liquid for electronic and biomedical applications. Various process parameters, including laser fluence, scanning speed, and ablation time, were systematically varied to assess their impact on ablation efficiency and NP properties. Statistical analysis identified optimal conditions: a 15 min ablation time, 0.5 m/s scanning speed, and 7.5 J/cm² laser fluence with the maximum mass productivity of 1.196 mg.h−1W−1. Characterisation techniques, including UV-Vis, Dynamic Light Scattering (DLS), FESEM with EDX, FTSEM, and XRD, confirmed that higher laser fluence, scanning speed, and ablation time increased colloid concentrations without altering NP shape or size. XRD analysis verified the phase composition as 3C SiC, with DLS showing smaller NP sizes than image analysis. The results also suggested that increasing the NP size decreased the optical band gap. A direct correlation was found between ablated mass and colloid concentration.

High-performance Ag-TiO2 nanoparticle composite catalyst synthesized by pulsed laser ablation in liquid: properties, mechanism and preparation studies

Precious metal doping can effectively improves the catalytic performance of TiO2. In this study, pulsed laser ablation in liquid (PLAL) is employed to integrate preparation with doping and control composite nanoparticle products by adjusting the laser action time to synthesise Ag-TiO2 composite nanoparticles with high catalytic performance. The generation and evolution of Ag-TiO2 nanoparticles are investigated by analysing particle size, microscopic morphology, crystalline phase, and other characteristics. The generation and doped-morphology evolution of composite nanoparticles are simulated based on thermodynamics, and the optimisation of Ag-doped structure on the composite nanomaterials is investigated based on density functional theory. The effect of Ag-TiO2 structural properties on its performance is examined under different catalytic conditions to determine optimal degradation conditions. In this study, the effect of laser ablation time on the doped structure during PLAL is analysed, which is of further research significance in exploring the structural evolution law of laser and composite nanoparticles, multi-variate catalytic performance testing, reduction of photogenerated carrier complexation rate, and expansion of its spectral absorption range, thereby providing the basis for practical production.

Preparation of Gallium Selenide Nanoparticles by Laser Ablation in Liquid

Preparation of Gallium Selenide Nanoparticles by Laser Ablation in Liquid

Optimization of carbon-based thin film microextraction supports for simultaneous detection of heavy metals using LIBS

One of the most versatile and effective methods to improve LIBS analysis of liquids is Thin Film Microextraction (TFME).This approach generally uses carbon-based adsorbent films to extract analytes from a liquid sample and bind them into a solid matrix, which is ideal for LIBS. In a previous work, we demonstrated the feasibility of TFME supports based on graphene prepared by Pulsed Laser Ablation in Liquid (PLAL) for LIBS analysis.In this paper, we optimized the preparation of such supports for the analysis of heavy metals in aqueous samples (i.e. chromium, lead and nickel), by analyzing both standard solutions and real samples. The feasibility of coupling TFME with NELIBS approach was also exploited. The procedure was applied to the analysis of both mineral water and well water samples.We obtained a standardized procedure for the extraction of three analytes (Pb, Cr and Ni) and estimated LOD values in spiked mineral water of the order of 0.6 mg/L for LIBS and 0.2 mg/L for NELIBS.

Synergistic influence of external electric field on laser ablation in liquid: correlating nanoparticle synthesis and cavitation bubble dynamics

The present study aims to investigate the changes in the properties of nanoparticles (NPs) and cavitation bubble dynamics by applying an external electric field during laser ablation in liquid (LAL). Investigating electric field assisted laser ablation in liquid (EFLAL) is crucial since phenomena such as plasma charging effect and electrostatic pressure have important role in determining the size, shape, and crystallinity. of the NPs. With this motivation, the present study has been conducted with different electric fields of 0, 100, 500 and 1000 V cm−1 to probe the effect of an external electric field on the dynamics of EFLAL. The charging effect observed on NPs during cavitation bubble dynamics was also investigated at these field intensities. The size of NPs witnesses a reduction from ∼30 nm without electric field to ∼19 nm in presence of electric field. Also, a significant narrowing of the size distribution by over 4 times was observed in the presence of electric field. This clearly demonstrates that EFLAL can be used to obtain NPs with uniform size distribution. Moreover, NPs of different shapes have also been observed by varying the electric field intensities (100 and 1000 V cm−1). The effect of the external electric field on the dynamics of the cavitation bubble produced during EFLAL has been probed using shadowgraphy technique. It has been observed that the bubble size increases with the presence of an electric field. The estimation of the bubble pressure in the presence of an electric field has revealed that the implosion bubble pressure is significantly lower than pressure in the absence of the field. The results obtained for NPs have been correlated to the changes in bubble parameters in this work.

Polyvinylalcohol Composite Filled with Carbon Dots Produced by Laser Ablation in Liquids.

Carbon dots (CDs), owing to their excellent photoluminescent features, have been extensively studied for physics preparation methods and for biomedical and optoelectronic device applications. The assessment of the applicability of CDs in the production of luminescent polymeric composites used in LEDs, displays, sensors, and wearable devices is being pursued. The present study reports on an original, environmentally friendly, and low-cost route for the production of carbon dots with an average size of 4 nm by laser ablation in liquid. Jointly, to prove the significance of the study for a wide range of applications, a free-standing flexible polyvinyl alcohol (PVA) composite containing photoluminescent carbon dots was manufactured. CDs were prepared using targets of porose charcoal with a density of 0.271 g/cm3 placed in phosphate-buffered saline (PBS) liquid solution and irradiated for 30 min by pulsed IR diode laser. The optical properties of the obtained suspension containing carbon dots were studied with UV-ViS and FTIR spectroscopies. The photoluminescence of the produced carbon dots was confirmed by the emission peak at 480 nm in the luminescence spectrum. A narrow luminescence band with a full width at half-maximum (FWHM) of less than 40 nm could be an asset in spectral emission analysis in different applications. Atomic force microscopy confirms the feasibility of manufacturing CDs in clean and biocompatible environments, paving the way for an easier and faster production route, crucial for their wider applicability.

Production of sub-micron-sized high-entropy alloy particles and nanoparticles via pulsed laser ablation of CrMnFeCoNi targets in water

High-entropy alloys (HEAs) are a class of materials known for their unique properties, including high strength, excellent wear resistance, and good corrosion resistance. Sub-micron- and nanosized HEA particles were fabricated via pulsed laser ablation in liquid using a Cantor alloy target. The Cr20Mn20Fe20Co20Ni20 target was immersed in pure water and ablated using a focused nanosecond-pulsed Nd: YAG laser. A dark solution containing HEA particles was obtained which was stable for about one week before agglomeration and precipitation was observed. The diameters of the obtained particles ranged from several tens of nanometers to several hundred nanometers. Increasing the laser power resulted in higher particle concentration and an increase in the intensity of UV-vis absorption spectra. Electron diffraction was used to confirm that the composition of the particles was close to that of the Cantor alloy, although the concentrations of Cr and Mn were slightly deficient. There was also a weak dependence of the composition on laser power, and all the particles also contained oxygen. Selected area electron diffraction revealed that the composition varied spatially within some particles and that they are mainly polycrystalline. This work shows that HEA particles can be quickly, safely, and effectively manufactured using liquid-based laser ablation, opening the pathway for mass manufacture and disruptive applications in, e.g., catalysis or tribology.

Nano-gold via laser ablation in liquid at different laser energies on porous silicon for photodetector application

Nano-gold via laser ablation in liquid at different laser energies on porous silicon for photodetector application

Synthesis of low dimensional nanomaterials by pulsed laser ablation in liquid

With the increasing application of functional nanomaterials in numerous fields, considerable effort has been devoted to exploring simple and efficient methods for their synthesis. Pulsed laser ablation in liquid (PLAL) is one such novel technique for producing colloidal nanomaterials. It is simple to setup, easy to operate, and can be carried out at room temperature and under atmosphere. This method employs a pulsed laser beam to ablate bulk targets or powders within different liquids, thereby creating colloidal nanomaterials. As a result, it holds significant promise for scalable processing. However, most prior research on PLAL has focused on the synthesis of larger spherical nanoparticles, even though low-dimensional nanomaterials, including zero-dimensional quantum dots, one-dimensional nanowires and nanotubes, and two-dimensional nanosheets and nanobelts, find more usage in various applications, such as optoelectronic devices, catalysis, and biomedicine. In the PLAL process, the high-intensity laser pulses not only fragment the illuminated solids to produce nanomaterials but also interact with liquid molecules, generating multiple reactive ions for chemical reactions. Consequently, various low-dimensional nanomaterials can also be generated. This study provides a comprehensive review of low-dimensional nanomaterials synthesized via PLAL, including their formation mechanisms and applications.

Polyvinyl pyrrolidone/ carboxymethyl cellulose (PVP/CMC) polymer composites containing CuO nanoparticles synthesized via laser ablation in liquids

Polyvinyl pyrrolidone/carboxymethyl cellulose (PVP/CMC) polymer composites containing CuO nanoparticles synthesized via laser ablation in liquids were prepared. Fourier transform infrared (FTIR) spectroscopy, UV/Vis spectroscopy, and scanning electron microscopy (SEM) were used to characterize the structural, optical, and morphological properties of the polymer composites. The addition of CuO nanoparticles resulted in changes in the FTIR spectra, indicating interaction between the polymer matrix and nanoparticles. UV/Vis spectroscopy showed a red shift in absorption and a decrease in optical bandgap with increasing CuO nanoparticle content. SEM micrographs revealed increases in surface roughness with higher CuO nanoparticle loading. Antibacterial activity of the composites against Gram-positive and Gram-negative bacteria increased with greater CuO nanoparticle concentration. The results suggest these biofilms have potential for use as coating materials in biomedical applications.