Liquid Phase Pulsed Laser Ablation Research Articles

A Non-Disposable Electrochemical Sensor Based on Laser-Synthesized Pd/LIG Nanocomposite-Modified Screen-Printed Electrodes for the Detection of H2O2.

There have been many studies on the significant correlation between the hydrogen peroxide content of different tissues or cells in the human body and the risk of disease, so the preparation of biosensors for detecting hydrogen peroxide concentration has been a hot topic for researchers. In this paper, palladium nanoparticles (PdNPs) and laser-induced graphene (LIG) were prepared by liquid-phase pulsed laser ablation and laser-induced technology, respectively. The complexes were prepared by stirring and used for the modification of screen-printed electrodes to develop a non-enzymatic hydrogen peroxide biosensor that is low cost and mass preparable. The PdNPs prepared with anhydrous ethanol as a solvent have a uniform particle size distribution. The LIG prepared by laser direct writing has good electrical conductivity, and its loose porous structure provides more adsorption sites. The electrochemical properties of the modified electrode were characterized by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Compared with bare screen-printed electrodes, the modified electrodes are more sensitive for the detection of hydrogen peroxide. The sensor has a linear response range of 5 µM-0.9 mM and 0.9 mM-5 mM. The limit of detection is 0.37 µM. The above conclusions indicate that the hydrogen peroxide electrochemical biosensor prepared in this paper has great advantages and potential in electrochemical catalysis.

Fabrication and structural modification of graphene oxide-tetraethyl orthosilicate solution via liquid-phase pulsed laser ablation

Liquid-phase pulsed laser ablation (LP-PLA) is a physical deposition technique to fabricate micro- and nanoscale particles of polymer, glass, and ceramic materials. In this work, graphene oxide (GO) that was immersed in tetraethyl orthosilicate (TEOS) and ethanol was used to fabricate the graphene-silicone polymer using the LP-PLA technique. The GO-TEOS solution was ablated with different fluences of the laser. The ablated GO-TEOS solution was characterized by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive x-ray, and ultraviolet-visible (UV-Vis) spectroscopy to study the graphene-silicone polymer properties. The FTIR result shows that the laser ablation has provided sufficient laser energy to create or break the chemical species of GO and TEOS compounds as observed on Si–O and C–O bonds. The Raman result shows the changes in the intensity in the D band, which suggests that the carbon atom of the GO has been functionalized with other compounds. Several large flakes were observed in the SEM images, representing the silicon polymer with the GO aggregation. The particle size in the range of 3–8 and 66–110 μm was formed due to the presence of uniformly sized nanoparticles of the GO-TEOS mixture and aggregation of the GO-TEOS nanoparticles into clusters. The zeta potential results indicated that the stability of the GO-TEOS mixture decreases after laser ablation. The UV-Vis result shows a broad absorption band with center at 492 and 532 nm with increasing absorbance at low fluence then saturated and decreased at maximum laser fluence. From the results above, several chemical interactions between GO and TEOS were observed, and the data suggested the laser fluence as the major source to cause both photothermal and photochemical reactions on the samples. In short, laser ablations provide sufficient energy to induce chemical bonding, which further allows structural modification of materials.

The effect of laser energy on Cu2O nanoparticles formation by liquid-phase pulsed laser ablation

The effect of laser energy on Cu2O nanoparticles formation by liquid-phase pulsed laser ablation

Visible light sensitive Au–TiO2 nanocomposites formed by effective attachment of Au with TiO2 nanoparticles using liquid-phase pulsed-laser ablation

Liquid-phase pulsed-laser ablation was utilized to grow visible-light-sensitive Au–TiO2 nanocomposites. We performed the nanosecond pulsed-laser ablation of a Ti target in aqueous solution of HAuCl4 of different concentrations varying from 0 mM to 0.24 mM. Structural characterization studies using transmission electron microscopy (TEM) and X ray diffraction (XRD) analyses confirmed formation of the nanoparticles of TiO2 and Au–TiO2 in respective solutions. In Au–TiO2 samples, nanocomposites formation by efficient attachment between Au and TiO2 nanoparticles was confirmed by absorption and X-ray photoelectron spectroscopy (XPS) analyses. Optical absorption analysis revealed that with the attachment of Au, there is a red shift in the onset of the absorption band of TiO2 from the ultraviolet to visible range. This red shift is found to increase from 3.5 to 2.7 eV with respect to the increase in the amount of Au present in Au–TiO2 nanocomposites. While detailed XPS analysis suggested that when the amount of Au attached with TiO2 increased, the number density of oxygen vacancy or Ti3+ states increased. Therefore the attachment of Au nanoparticles and oxygen vacancy or Ti3+ states generations in TiO2 were found to be responsible for the large red shift in the onset of the TiO2 absorption band. Consequently our study showed that single step liquid phase laser ablation method and its subsequent nonequilibrium growth conditions are useful in synthesizing Au and TiO2 nanoparticles simultaneously and also in providing efficient attachment between Au and TiO2 which is responsible for visible range sensitization of Au-TiO2 nanocomposites .

Target phase-induced compositional control in liquid-phase pulsed laser ablation produced titanium ferrite nanomaterials

Target phase-induced compositional control in liquid-phase pulsed laser ablation produced titanium ferrite nanomaterials

Development of Er3+, Yb3+ Co-Doped Y2O3 NPs According to Yb3+ Concentration by LP-PLA Method: Potential Further Biosensor.

As diagnostic biosensors for analyzing fluids from the human body, the development of inorganic NPs is of increasing concern. For one, nanoceramic phosphors have been studied to meet the increasing requirements for biological, imaging, and diagnostic applications. In this study, Y2O3 NPs co-doped with trivalent rare earths (erbium and ytterbium) were obtained using a liquid phase–pulsed laser ablation (LP–PLA) method after getting high density Er, Yb:Y2O3 ceramic targets by Spark plasma sintering (SPS). Most NPs are under 50 nm in diameter and show high crystallinity of cubic Y2O3 structure, containing (222), (440), and (332) planes via HR–TEM. Excitation under a 980 nm laser to a nanoparticle solution showed 525 and 565 nm green, and 660 nm red emissions. The green emission intensity increased and decreased with increasing Yb3+ additive concentration, when the red spectrum continuously strengthened. Utilizing this study’s outcome, we suggest developing technology to mark invisible biomolecules dissolved in a solvent using UC luminescence of Er3+, Yb3+ co-doped Y2O3 NPs by LP–PLA. The LP–PLA method has a potential ability for the fabrication of UC NPs for biosensors with uniform size distribution by laser parameters.

Anomalously enhanced thermal conductivity of graphite-oxide nanofluids synthesized via liquid-phase pulsed laser ablation

Graphite-oxide (GO) nanofluids with enhanced thermal conductivity are successfully prepared using pulsed laser ablation in liquid (PLAL) of a graphite target in deionized water. The effects of laser frequencies are investigated on the variations of GO nanoparticles. The morphology, structure and composition of the nanoparticles are characterized using various spectroscopic techniques. During the PLAL process, graphite is oxidized to GO which is inherently hydrophilic, no surfactant is required in the preparation of nanofluid. The laser frequency significantly affects the size and morphology of the GO nanoparticles during laser ablation, leading to a profound variation in the thermophysical properties of the GO nanofluids. At the laser frequency of 10 Hz, the maximum thermal conductivity enhancement of 82% is achieved at a temperature of 50 °C while the maximum viscosity increment is recorded at a temperature of 30 °C. This study shows the great potential of the PLAL method in synthesizing GO nanofluid with anomalously enhanced thermal conductivity.

ZnO:Au nanocomposites with high photocatalytic activity prepared by liquid-phase pulsed laser ablation

This paper presents a simple and feasible method for liquid-phase fabrication of Au-decorated ZnO (ZnO:Au) nanocomposites by two-step liquid-phase pulsed laser ablation. Pristine ZnO were first prepared by pulsed laser ablation of zinc powers in water, and ZnO:Au nanocomposites were then synthesized by decorating the pristine ZnO with Au nanoparticles also via liquid-phase pulsed laser ablation. The prepared ZnO:Au NCs were characterized in liquid and solid phases for morphology, structure and optical properties, and used as photocatalysts for the evaluation of photocatalytic activity. The ZnO:Au nanocomposites are composed of Au nanoparticles surrounded by polycrystalline wurtzite ZnO, present high light absorption in the ultraviolet and visible region and have a plasmonic absorption band around 530 nm. Unlike pristine ZnO which has photocatalytic activity only in the ultraviolet region, the incorporation of Au nanoparticles with ZnO results in high photocatalytic activity in the ultraviolet as well as in the visible region by significantly enhancing the photogeneration of charge carriers and promoting the separation of the photogenerated charge carriers. Using Rhodamine B as a representative organic pollutant, the ZnO:Au nanocomposites were demonstrated to exhibit excellent photocatalytic performance as visible photocatalysts for the degradation of organic pollutants. Compared with pristine ZnO, the rate constant for the photodegradation of Rhodamine B with the ZnO:Au nanocomposites is nearly doubled under visible illumination.

Clean synthesis of Er, Yb doped fluorapatite upconversion luminescent nanoparticles through liquid phase pulsed laser ablation

The Er, Yb co-doped upconversion luminescent fluorapatite nanoparticle dispersed in water has been synthesized through liquid phase pulsed laser ablation (LPPLA). Fluorapatite is a highly biocompatible material and LPPLA is a clean procedure for the synthesis of nanoparticle colloidal solution. The synthesized material and synthesis method described here is striking in the case of biological applications. A transparent colloidal solution of nanoparticles of size 2–4 nm was obtained using this method. Synthesized colloidal solution showed a visible emission on IR excitation. Excitation power dependence on emission intensity was studied and found that absorption of two photons is involved in the emission of each photon. The synthesized biocompatible nanoparticles dispersed in water can be used for cell imaging applications.

Morphology-selective preparation and formation mechanism of few-layer graphene on Cu substrate by liquid-phase pulsed laser ablation

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.

The effect of laser pulse energy on ZnO nanoparticles formation by liquid phase pulsed laser ablation

Zinc Oxide nanoparticles were prepared using pulsed laser ablation process from a pure zinc metal placed inside a liquid environment. The latter is composed of acetyltrimethylammonium bromide (CTAB) of 10−3 molarity and distilled water. A Ti:Sapphire laser of 800 nm wavelength, 1 kHz pulse repetition rate, 130 fs pulse duration is used at three values of pulse energies of 0.05 mJ, 1.11 mJ and 1.15 mJ. The evaluation of the optical properties for the obtained suspension was applied through ultraviolet–visible absorption spectroscopy test (UV/VIS). The result showed peak wavelengths at 210 nm, 211 nm and 213 nm for the three used pulse energies 0.05 mJ, 1.11 mJ and 1.15 mJ respectively. This indicates a blue shift, which means smaller sizes of prepared nanoparticles, correlated with the decrease in laser energy. The blue shift in the absorption edge refers to the quantum confinement property for the produced nanoparticles. In addition, Fourier Transform Infrared Spectroscopy (FTIR) analysis was utilized to confirm zinc oxide nanoparticles formation represented by the absorption values at 435–445 cm−1. The shape and morphology of ZnO nanoparticles were characterized with scanning electron microscope (SEM).

Liquid Phase Pulsed Laser Ablation on Pyrite

Pulsed laser ablation in liquid (PLAL) using pyrite as a target was investigated. Hematite nanoparticles were obtained as the main product by PLAL in aqueous solution, ethanol, toluene, and acetone...

Laser-Fabricated Fluorescent, Ligand-Free Silicon Nanoparticles: Scale-up, Biosafety, and 3D Live Imaging of Zebrafish under Development

This work rationalizes the scalable synthesis of ultrasmall, ligand-free silicon nanomaterials via liquid-phase pulsed laser ablation process using picosecond pulses at ultraviolet wavelengths. Results showed that the irradiation time drives hydrodynamic NP size. Isolated, monodisperse Si-NPs are obtained at high yield (72%) using post-treatment process. The obtained Si-NPs have an average size of ∼10 nm (not aggregated) and display photoemission in the green spectral range. We directly characterized the ligand-free Si-NPs in a vertebrate animal (zebrafish) and assessed their toxicity during the development. In vivo assay revealed that Si-NPs are found inside in all the early life stages of embryos and larvae growth, showing that the biosafety of Si-NPs and malformation types are independent of the Si-NP dose. Si-NPs were directlyimaged inside developing embryos by spinning disk-imaging technique with optical sectioning capability. We showed that Si-NPs can passively enter inside embryos by the pore canals of chorion, can diffuse in the circulatory system, i.e., blood vessel, and accumulate inside larvae midgut and yolk sac, and in the eye lens, indicating the crossing of the blood barrier.

Drastic Improvement of 1D-CdS Solar-Driven Photocatalytic Hydrogen Evolution Rate by Integrating with NiFe Layered Double Hydroxide Nanosheets Synthesized by Liquid-Phase Pulsed-Laser Ablation

Solar-driven semiconductor-based molecular hydrogen production is an ideal protocol for converting abundant solar energy to green fuel. However, this process suffers from costly semiconductor nanostructures, low efficiency, and poor stability. Here, we design a noble-metal-free photocatalyst, CdS-NiFe layered double hydroxide (LDH) nanocomposite, which is synthesized using the liquid-phase pulsed-laser ablation and hydrothermal method. The nanocomposite has a unique morphology of 2D-NiFe LDH nanosheets on 1D-CdS nanorods. The interfacial contact of heterostructures allows the efficient carrier transport and migration due to the appropriate potentials, which greatly reduce the recombination of carriers. It also provides a significant number of catalytically active sites for the hydrogen evolution reaction due to its thin and flexible nature and high specific surface area. The CdS/NiFe nanocomposite exhibits a hydrogen evolution rate of 72 mmol g–1 h–1, which is higher than reported nanocomposites of CdS-ba...

Tin sulfide: Reduced graphene oxide nanocomposites for photovoltaic and electrochemical applications

Nanocomposite thin films of tin sulfide (SnS) with graphene oxide (GO) and reduced graphene oxide (rGO) were prepared by spray deposition of tin sulfide nanocolloids mixed with graphene oxide. SnS nanocolloidal suspensions were synthesized by liquid phase pulsed laser ablation of a SnS target in isopropyl alcohol and dimethyl formamide. Spherical morphology and orthorhombic crystalline structure of the nanoparticles were determined by transmission electron microscopy. Graphene oxide was synthesized through a chemical pathway (Marcano's method) and was mixed with SnS nanocolloid. Thin films were deposited by spraying SnS nanocolloid as well as the GO mixed SnS on heated substrates. The thin films were post-annealed under vacuum to form reduced graphene oxide. Structure, morphology and optoelectronic properties of thin films formed at various conditions were determined by different techniques. Scanning electron micrographs showed porous film surface with GO/rGO net-like structures embedded in SnS nanoparticles. Photocurrent measurements at different illumination wavelengths and cyclic voltammetry using SnS:rGO as working electrodes showed improvement in the properties of graphene oxide incorporated SnS. A solar cell was fabricated using SnS:rGO thin film and the results obtained are promising.

High-quality liquid phase-pulsed laser ablation graphene synthesis by flexible graphite exfoliation

This work reports a one-pot procedure of laser ablation on a graphite target in a liquid medium, based on the variation of different parameters such as target type, laser wavelength, and ablation medium, to obtain high-quality graphene nanosheets. The morphology of derived products was characterized by the field emission scanning electron microscopy (FE-SEM). Then, the morphology and structure of the optimized sample were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet-visible-near infrared (UV–vis-NIR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). By controlling the laser ablation parameters, we were able to prepare micrometer-sized few-layer graphene nanosheets with mainly less than ten layers. Such synthesized graphene nanosheets were grown at the surface of a flexible graphite target, indicating many potential applications in fundamental research, electrochemical and as hydrophobic surfaces.

In situ functionalization of gadolinium oxide nanoparticles with polyethylene glycol (PEG) by pulsed laser ablation in a liquid medium (PLAL)

Abstract Gadolinium oxide (Gd2O3) nanoparticles with paramagnetic properties and biocompatible surfaces are promising materials for bioimaging applications. We synthesized in situ pegylated Gd2O3 (Gd2O3@PEG) nanoparticles by liquid phase pulsed laser ablation (PLAL) of a gadolinium target in a polyethylene glycol (PEG) liquid medium. We characterized their shape and morphology using transmission electron microscopy (TEM), and confirmed their crystalline structure with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) in combination with energy-dispersive X-ray spectroscopy (EDX) elemental mapping. The magnetic properties of the nanoparticles were characterized by vibrating sample magnetometry (VSM). We have found that the crystalline nanoparticles generated have a spherical shape and a narrow distribution with average diameters of 15.0, 11.6, and 6.0 nm, for PEG concentrations of 0.01, 0.05, and 0.10 mM, respectively. We verified that partially oxidized molecules of PEG are attached to the nanoparticle surface as carboxyl groups. An analysis of the magnetization of Gd2O3@PEG nanoparticles revealed highly paramagnetic properties. Consequently, PLAL forms a green synthesis of Gd2O3@PEG, opening up new opportunities for bioimaging applications.

Clean synthesis of YOF:Er3+, Yb3+ upconversion colloidal nanoparticles in water through liquid phase pulsed laser ablation for imaging applications

Upconversion luminescent nanomaterials have great outlook towards imaging applications. These materials have high chemical and thermal stability, low auto fluorescence, high photo stability and IR excitation does not cause photo damage to living cells and penetrate deeply into tissue. Most of the reported nanoparticles are synthesized through chemical methods in which surface modification is needed for dispersing nanoparticles in water. In this paper we report clean and simple synthesis of upconversion luminescent yttrium oxyfluoride (YOF) nanoparticles through laser ablation in deionized water. YOF:Er3+, Yb3+ pellets were used for ablation. Er3+ is the emission centre Yb3+ is the sensitizer. Obtained colloidal solution is transparent to day light and showing red emission on exciting with 980 nm IR laser. By controlling ablation parameters particles of size less than 10 nm dispersed uniformly in water can be obtained through this surfactant free method. The synthesized nanoparticles can be used for cell imaging.

Laser Ablation of Silver in Liquid Organic Monomer: Influence of Experimental Parameters on the Synthesized Silver Nanoparticles/Graphite Colloids.

During the past decade, synthesizing silver nanoparticles (Ag NPs) by liquid phase-pulsed laser ablation (LP-PLA) has attracted a lot of attention. Basically, this technique allows producing various metallic nanoparticles with controlled size, shape, composition, or surroundings in several liquids (i.e., water, ethanol, acetone, toluene, and so forth). Recently, such processes have been studied in liquid organic monomer such as methyl methacrylate (MMA). However, the influence of the laser parameters on the materials synthesized in such reactive liquid and their features were not fully investigated so far. Here we investigate the LP-PLA of silver in two different but rather similar acrylate monomers: dodecyl acrylate (DOCA) and 1H,1H,2H,2H perfluorodecyl acrylate (PFDA). The influence of the fluence and the number of pulses on the production, size, and morphology of the materials has been examined. First, factorial design experiments have been achieved in order to determine the weight of the laser parameters in each precursor. This study shows two highly different behaviors in function of the monomer where the process took place. This has been explained by the plasma plume confinement and/or the "interpulses" self-absorption of the particles by the laser beam. The formation of graphite around the synthesized AgNPs has been highlighted by Raman spectroscopy at low number of pulses. Nevertheless, increasing the number of pulses could lead to three phenomenon depending on the fluence and the used monomer: degradation of the matrix, conservation of the matrix with changes in AgNPs size and distribution, or sustainment of the matrix with any changes in the particles properties. So the surrounding, the size, and stability could be triggered by adjusting these parameters. This paper does highlight that LP-PLA is a powerful technique to provide AgNPs in acrylate monomer with a good control of their features.

A facile synthesis of broad plasmon wavelength tunable silver nanoparticles in citrate aqueous solutions by laser ablation and light irradiation

A complete light based synthesis of silver nanoparticles of different shapes exhibiting strong and broad band plasmon resonances is demonstrated in aqueous solutions of single reagent tri-sodium citrate (TSC). This method involves synthesis of almost spherical nanoparticles using liquid phase pulsed laser ablation (LPPLA) followed by their photo-mediated shape transformation into triangular nanoplates by visible light irradiation. UV–vis spectroscopy and Mie theory based analytical calculations show that this method can produce high concentrations of nanoparticles at optimum TSC concentration. LPPLA method is shown to be potential for producing relatively smaller size, isolated spherical silver nanoparticles at optimum TSC concentration without aid of strong reducing agents like borohydrides. This method has also resulted interconnected nanoparticle networks in pure water or at very low TSC concentrations. These isolated spherical nanoparticles were further shown to act as seed particles for high yield synthesis of nanoplates. The concentration of TSC played a vital role in producing both highly stable spherical nanoparticles and their photo-mediated shape transformation into triangular nanoplates. At the optimum TSC concentration of about 10mM, pH about 7.5 and visible light irradiation of about 24h, the produced triangular nanoplates have shown strong plasmon absorption in visible to near NIR region, useful for solar light harvesting applications. Further during the light irradiation, presence of additional silver ions in the nanoparticle solution initially increased the growth of spherical nanoparticles which finally resulted in high yield formation of triangular nanoplates.