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Nanomaterials
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Laser Synthesis of Nanomaterials
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Laser Synthesis of Nanomaterials

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Synthesis, Interfaces and Nanostructures".

Deadline for manuscript submissions: closed (30 April 2021) | Viewed by 44618

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Prof. Dr. Mohamed Boutinguiza

E-Mail Website
Guest Editor
Applied Physics, University of Vigo, 36310 Vigo, Spain
Interests: laser materials processing (ablation, cutting, texturing, etc.); laser processing of biomaterials; laser synthesis and deposition of nanomaterials
Special Issues, Collections and Topics in MDPI journals
Dr. Antonio Riveiro

E-Mail Website
Guest Editor
Department of Materials Engineering, Applied Mechanics and Construction, School of Engineering, University of Vigo, Lagoas Marcosende s/n, 36310 Vigo, Spain
Interests: laser processing; laser welding; laser cutting; laser cladding; laser texturing; laser surface treatments; laser microprocessing; laser drilling; laser-based additive manufacturing; biomaterials; nanomaterials
Special Issues, Collections and Topics in MDPI journals
Dr. Jesús del Val

E-Mail Website
Guest Editor
1. Applied Physics Department, University of Vigo, Vigo, Spain
2. LaserON Laser Applications Research Group, University of Vigo, Industrial Technological Research Centre - MTI, Rúa Maxwel, 36310 Vigo, Spain
Interests: laser materials processing; laser surface modification; laser micro-cladding; laser micro-texturization; bioactive glasses processing and characterization; nanoparticle production by laser ablation
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Nanomaterials are one of the main topics of research at present. These materials, with at least one of their dimensions in the nanoscale (i.e., in a length range from 1 nm to 100 nm) have remarkable or unconventional properties compared to bulk materials. These materials are currently used in many applications; however, new potential uses are being investigated. In this sense, there is a large interest in their use in medicine, electronic devices, production and storage of energy, composite materials, etc. The production of nanomaterials is addressed through physical and/or chemical methods; however, most of these methods exhibit low reproducibility or a low production rate or make use of toxic chemicals. In order to avoid most of these drawbacks, laser-based synthesis of nanomaterials has emerged as an alternative to overcome these limitations. This family of methods uses a laser beam to produce different nanomaterials (e.g., nanoparticles, nanowires or 2D materials) using diverse approaches. Techniques such as those based on laser ablation, laser vaporization, pulsed laser deposition (PLD), laser–chemical vapor deposition (LCVD), etc. are being explored, at present, to fabricate these nanoscale materials with a controlled size and shape. In this context, the present Special Issue will include research papers addressing the most recent developments in this field to summarize the current state-of-the-art in the synthesis of nanomaterials using laser techniques.

Suitable topics include but are not limited to:

  • Laser nanoprocessing;
  • Laser ablation techniques, liquid-phase laser ablation;
  • Laser-assisted chemical vapor deposition (LCVD);
  • Pulsed laser deposition;
  • Ultrafast laser synthesis of nanomaterials;
  • Laser-Induced Fragmentation.

Prof. Dr. Mohamed Boutinguiza
Dr. Antonio Riveiro
Dr. Jesús del Val
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Nanomaterials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Laser ablation
  • Laser synthesis
  • Nanoparticles
  • Nanofibers
  • 2D materials
  • Laser-induced fragmentation
  • LCVD

Published Papers (15 papers)

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Editorial

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4 pages, 228 KiB  
Editorial
Laser Synthesis of Nanomaterials
by Mohamed Boutinguiza Larosi, Jesús del Val García and Antonio Riveiro Rodríguez
Nanomaterials 2022, 12(17), 2903; https://doi.org/10.3390/nano12172903 - 24 Aug 2022
Cited by 2 | Viewed by 1444
Abstract
Nanomaterials, defined as materials with typical dimensions of less than 100 nm in at least one dimension, exhibit very special physicochemical properties that are highly dependent on their size and shape [...] Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)

Research

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12 pages, 3458 KiB  
Article
Two Approaches to the Laser-Induced Formation of Au/Ag Bimetallic Nanoparticles in Supercritical Carbon Dioxide
by Alexey Rybaltovsky, Evgeniy Epifanov, Dmitriy Khmelenin, Andrey Shubny, Yuriy Zavorotny, Vladimir Yusupov and Nikita Minaev
Nanomaterials 2021, 11(6), 1553; https://doi.org/10.3390/nano11061553 - 11 Jun 2021
Cited by 3 | Viewed by 1962
Abstract
Two approaches are proposed for the synthesis of bimetallic Au/Ag nanoparticles, using the pulsed laser ablation of a target consisting of gold and silver plates in a medium of supercritical carbon dioxide. The differences between the two approaches related to the field of [...] Read more.
Two approaches are proposed for the synthesis of bimetallic Au/Ag nanoparticles, using the pulsed laser ablation of a target consisting of gold and silver plates in a medium of supercritical carbon dioxide. The differences between the two approaches related to the field of “green chemistry” are in the use of different geometric configurations and different laser sources when carrying out the experiments. In the first configuration, the Ag and Au targets are placed side-by-side vertically on the side wall of a high-pressure reactor and the ablation of the target plates occurs alternately with a stationary “wide” horizontal beam with a laser pulse repetition rate of 50 Hz. In the second configuration, the targets are placed horizontally at the bottom of a reactor and the ablation of their parts is carried out by scanning from above with a vertical “narrow” laser beam with a pulse repetition rate of 60 kHz. The possibility of obtaining Ag/Au alloy nanoparticles is demonstrated using the first configuration, while the possibility of obtaining “core–shell” bimetallic Au/Ag nanoparticles with a gold core and a silver shell is demonstrated using the second configuration. A simple model is proposed to explain the obtained results. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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17 pages, 4560 KiB  
Article
Application of Pulsed Laser Deposition in the Preparation of a Promising MoSx/WSe2/C(В) Photocathode for Photo-Assisted Electrochemical Hydrogen Evolution
by Roman Romanov, Vyacheslav Fominski, Maxim Demin, Dmitry Fominski, Oxana Rubinkovskaya, Sergey Novikov, Valentin Volkov and Natalia Doroshina
Nanomaterials 2021, 11(6), 1461; https://doi.org/10.3390/nano11061461 - 31 May 2021
Cited by 10 | Viewed by 2903
Abstract
We studied the possibility of using pulsed laser deposition (PLD) for the formation of a MoSx/WSe2 heterostructure on a dielectric substrate. The heterostructure can be employed for effective solar water splitting to produce hydrogen. The sapphire substrate with the conducting C(B) [...] Read more.
We studied the possibility of using pulsed laser deposition (PLD) for the formation of a MoSx/WSe2 heterostructure on a dielectric substrate. The heterostructure can be employed for effective solar water splitting to produce hydrogen. The sapphire substrate with the conducting C(B) film (rear contact) helped increase the formation temperature of the WSe2 film to obtain the film consisting of 2H-WSe2 near-perfect nanocrystals. The WSe2 film was obtained by off-axis PLD in Ar gas. The laser plume from a WSe2 target was directed along the substrate surface. The preferential scattering of selenium on Ar molecules contributed to the effective saturation of the WSe2 film with chalcogen. Nano-structural WSe2 film were coated by reactive PLD with a nanofilm of catalytically active amorphous MoSx~4. It was established that the mutual arrangement of energy bands in the WSe2 and MoSx~4 films facilitated the separation of electrons and holes at the interface and electrons moved to the catalytically active MoSx~4. The current density during light-assisted hydrogen evolution was above ~3 mA/cm2 (at zero potential), whilst the onset potential reached 400 mV under irradiation with an intensity of 100 mW/cm2 in an acidic solution. Factors that may affect the HER performance of MoSx~4/WSe2/C(В) structure are discussed. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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11 pages, 9894 KiB  
Article
Synthesis of Air-Stable Cu Nanoparticles Using Laser Reduction in Liquid
by Ashish Nag, Laysa Mariela Frias Batista and Katharine Moore Tibbetts
Nanomaterials 2021, 11(3), 814; https://doi.org/10.3390/nano11030814 - 23 Mar 2021
Cited by 12 | Viewed by 3572
Abstract
We report the synthesis of air-stable Cu nanoparticles (NPs) using the bottom-up laser reduction in liquid method. Precursor solutions of copper acetlyacetonate in a mixture of methanol and isopropyl alcohol were irradiated with femtosecond laser pulses to produce Cu NPs. The Cu NPs [...] Read more.
We report the synthesis of air-stable Cu nanoparticles (NPs) using the bottom-up laser reduction in liquid method. Precursor solutions of copper acetlyacetonate in a mixture of methanol and isopropyl alcohol were irradiated with femtosecond laser pulses to produce Cu NPs. The Cu NPs were left at ambient conditions and analyzed at different ages up to seven days. TEM analysis indicates a broad size distribution of spherical NPs surrounded by a carbon matrix, with the majority of the NPs less than 10 nm and small numbers of large particles up to ∼100 nm in diameter. XRD collected over seven days confirmed the presence of fcc-Cu NPs, with some amorphous Cu2O, indicating the stability of the zero-valent Cu phase. Raman, FTIR, and XPS data for oxygen and carbon regions put together indicated the presence of a graphite oxide-like carbon matrix with oxygen functional groups that developed within the first 24 h after synthesis. The Cu NPs were highly active towards the model catalytic reaction of para-nitrophenol reduction in the presence of NaBH4. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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10 pages, 1682 KiB  
Article
Fabrication of Hollow Channels Surrounded by Gold Nanoparticles in Hydrogel by Femtosecond Laser Irradiation
by Izumi Takayama, Akito Katayama and Mitsuhiro Terakawa
Nanomaterials 2020, 10(12), 2529; https://doi.org/10.3390/nano10122529 - 16 Dec 2020
Cited by 2 | Viewed by 2056
Abstract
The fabrication of hollow channels surrounded by gold nanoparticles in poly(ethylene glycol) diacrylate (PEGDA) is demonstrated. The absorption spectra show that gold nanoparticles were formed at the periphery of the focus by reduction of gold ions. The microscope observation and Raman spectroscopy analyses [...] Read more.
The fabrication of hollow channels surrounded by gold nanoparticles in poly(ethylene glycol) diacrylate (PEGDA) is demonstrated. The absorption spectra show that gold nanoparticles were formed at the periphery of the focus by reduction of gold ions. The microscope observation and Raman spectroscopy analyses indicate that the center of the channels were void of PEGDA, which can be attributed to the femtosecond laser-induced degradation of the hydrogel. Since both the hydrogel and gold nanoparticles are biocompatible, this technique of fabricating hollow channels surrounded by gold nanoparticles is promising for tissue engineering, drug screening, and lab-on-a-chip devices. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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24 pages, 8196 KiB  
Article
Specific Features of Reactive Pulsed Laser Deposition of Solid Lubricating Nanocomposite Mo–S–C–H Thin-Film Coatings
by Vyacheslav Fominski, Dmitry Fominski, Roman Romanov, Mariya Gritskevich, Maxim Demin, Petr Shvets, Ksenia Maksimova and Alexander Goikhman
Nanomaterials 2020, 10(12), 2456; https://doi.org/10.3390/nano10122456 - 08 Dec 2020
Cited by 6 | Viewed by 2926
Abstract
This work investigates the structure and chemical states of thin-film coatings obtained by pulsed laser codeposition of Mo and C in a reactive gas (H2S). The coatings were analysed for their prospective use as solid lubricating coatings for friction units operating [...] Read more.
This work investigates the structure and chemical states of thin-film coatings obtained by pulsed laser codeposition of Mo and C in a reactive gas (H2S). The coatings were analysed for their prospective use as solid lubricating coatings for friction units operating in extreme conditions. Pulsed laser ablation of molybdenum and graphite targets was accompanied by the effective interaction of the deposited Mo and C layers with the reactive gas and the chemical states of Mo- and C-containing nanophases were interdependent. This had a negative effect on the tribological properties of Mo–S–C–H nanocomposite coatings obtained at H2S pressures of 9 and 18 Pa, which were optimal for obtaining MoS2 and MoS3 coatings, respectively. The best tribological properties were found for the Mo–S–C–H_5.5 coating formed at an H2S pressure of 5.5 Pa. At this pressure, the x = S/Mo ratio in the MoSx nanophase was slightly less than 2, and the a-C(S,H) nanophase contained ~8 at.% S and ~16 at.% H. The a-C(S,H) nanophase with this composition provided a low coefficient of friction (~0.03) at low ambient humidity and 22 °C. The nanophase composition in Mo–S–C–H_5.5 coating demonstrated fairly good antifriction properties and increased wear resistance even at −100 °C. For wet friction conditions, Mo–S–C–H nanocomposite coatings did not have significant advantages in reducing friction compared to the MoS2 and MoS3 coatings formed by reactive pulsed laser deposition. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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13 pages, 2821 KiB  
Article
Laser Printing of Plasmonic Nanosponges
by Sergey Syubaev, Stanislav Gurbatov, Evgeny Modin, Denver P. Linklater, Saulius Juodkazis, Evgeny L. Gurevich and Aleksandr Kuchmizhak
Nanomaterials 2020, 10(12), 2427; https://doi.org/10.3390/nano10122427 - 04 Dec 2020
Cited by 5 | Viewed by 2243
Abstract
Three-dimensional porous nanostructures made of noble metals represent novel class of nanomaterials promising for nonlinear nanooptics and sensors. Such nanostructures are typically fabricated using either reproducible yet time-consuming and costly multi-step lithography protocols or less reproducible chemical synthesis that involve liquid processing with [...] Read more.
Three-dimensional porous nanostructures made of noble metals represent novel class of nanomaterials promising for nonlinear nanooptics and sensors. Such nanostructures are typically fabricated using either reproducible yet time-consuming and costly multi-step lithography protocols or less reproducible chemical synthesis that involve liquid processing with toxic compounds. Here, we combined scalable nanosecond-laser ablation with advanced engineering of the chemical composition of thin substrate-supported Au films to produce nanobumps containing multiple nanopores inside. Most of the nanopores hidden beneath the nanobump surface can be further uncapped using gentle etching of the nanobumps by an Ar-ion beam to form functional 3D plasmonic nanosponges. The nanopores 10–150 nm in diameter were found to appear via laser-induced explosive evaporation/boiling and coalescence of the randomly arranged nucleation sites formed by nitrogen-rich areas of the Au films. Density of the nanopores can be controlled by the amount of the nitrogen in the Au films regulated in the process of their magnetron sputtering assisted with nitrogen-containing discharge gas. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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13 pages, 2446 KiB  
Article
Synthesis of Oxide Iron Nanoparticles Using Laser Ablation for Possible Hyperthermia Applications
by María J. Rivera-Chaverra, Elisabeth Restrepo-Parra, Carlos D. Acosta-Medina, Alexandre. Mello and Rogelio. Ospina
Nanomaterials 2020, 10(11), 2099; https://doi.org/10.3390/nano10112099 - 23 Oct 2020
Cited by 32 | Viewed by 2623
Abstract
In this work, iron oxide nanoparticles produced using the laser ablation technique were studied in order to determine the characteristics of these nanoparticles as a function of the laser energy for the possible application in magnetic hyperthermia. Nanoparticles were obtained by varying the [...] Read more.
In this work, iron oxide nanoparticles produced using the laser ablation technique were studied in order to determine the characteristics of these nanoparticles as a function of the laser energy for the possible application in magnetic hyperthermia. Nanoparticles were obtained by varying the power of the laser considering values of 90, 173, 279 and 370 mJ. The morphology of these nanoparticles was determined using the dynamic light scattering (DLS) and scattering transmission electron microscopy (STEM) techniques, confirming that the size of the particles was in the order of nanometers. A great influence of the laser power on the particle size was also observed, caused by the competition between the energy and the temperature. The composition was determined by X-ray diffraction and Raman spectroscopy, showing the presence of magnetite, maghemite and hematite. The hyperthermia measurements showed that the temperature rise of the iron oxide nanoparticles was not greatly influenced by the energy change, the heating capacity of magnetic NPs is quantified by the specific absorption rate (SAR), that tends to decrease with increasing energy, which indicates a dependence of these values on the nanoparticles concentration. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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12 pages, 2140 KiB  
Article
Photocatalytic Properties of Graphene/Gold and Graphene Oxide/Gold Nanocomposites Synthesized by Pulsed Laser Induced Photolysis
by Li-Hsiou Chen, Huan-Ting Shen, Wen-Hsin Chang, Ibrahim Khalil, Su-Yu Liao, Wageeh A. Yehye, Shih-Chuan Liu, Chih-Chien Chu and Vincent K. S. Hsiao
Nanomaterials 2020, 10(10), 1985; https://doi.org/10.3390/nano10101985 - 07 Oct 2020
Cited by 14 | Viewed by 2699
Abstract
Graphene (Gr)/gold (Au) and graphene-oxide (GO)/Au nanocomposites (NCPs) were synthesized by performing pulsed-laser-induced photolysis (PLIP) on hydrogen peroxide and chloroauric acid (HAuCl4) that coexisted with Gr or GO in an aqueous solution. A 3-month-long aqueous solution stability was observed in the [...] Read more.
Graphene (Gr)/gold (Au) and graphene-oxide (GO)/Au nanocomposites (NCPs) were synthesized by performing pulsed-laser-induced photolysis (PLIP) on hydrogen peroxide and chloroauric acid (HAuCl4) that coexisted with Gr or GO in an aqueous solution. A 3-month-long aqueous solution stability was observed in the NCPs synthesized without using surfactants and additional processing. The synthesized NCPs were characterized using absorption spectroscopy, transmission electron microscopy, Raman spectroscopy, energy dispersive spectroscopy, and X-ray diffraction to prove the existence of hybrid Gr/Au or GO/Au NCPs. The synthesized NCPs were further evaluated using the photocatalytic reaction of methylene blue (MB), a synthetic dye, under UV radiation, visible light (central wavelength of 470 nm), and full spectrum of solar light. Both Gr/Au and GO/Au NCPs exhibited photocatalytic degradation of MB under solar light illumination with removal efficiencies of 92.1% and 94.5%, respectively. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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12 pages, 3013 KiB  
Article
ZnO Nanoparticle/Graphene Hybrid Photodetectors via Laser Fragmentation in Liquid
by Kristin Charipar, Heungsoo Kim, Alberto Piqué and Nicholas Charipar
Nanomaterials 2020, 10(9), 1648; https://doi.org/10.3390/nano10091648 - 21 Aug 2020
Cited by 19 | Viewed by 2837
Abstract
By combining the enhanced photosensitive properties of zinc oxide nanoparticles and the excellent transport characteristics of graphene, UV-sensitive, solar-blind hybrid optoelectronic devices have been demonstrated. These hybrid devices offer high responsivity and gain, making them well suited for photodetector applications. Here, we report [...] Read more.
By combining the enhanced photosensitive properties of zinc oxide nanoparticles and the excellent transport characteristics of graphene, UV-sensitive, solar-blind hybrid optoelectronic devices have been demonstrated. These hybrid devices offer high responsivity and gain, making them well suited for photodetector applications. Here, we report a hybrid ZnO nanoparticle/graphene phototransistor that exhibits a responsivity up to 4 × 104 AW−1 and gain of up to 1.3 × 105 with high UV wavelength selectivity. ZnO nanoparticles were synthesized by pulsed laser fragmentation in liquid to attain a simple, efficient, ligand-free method for nanoparticle fabrication. By combining simple fabrication processes with a promising device architecture, highly sensitive ZnO nanoparticle/graphene UV photodetectors were successfully demonstrated. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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10 pages, 1669 KiB  
Communication
Hybrid Orthorhombic Carbon Flakes Intercalated with Bimetallic Au-Ag Nanoclusters: Influence of Synthesis Parameters on Optical Properties
by Muhammad Abdullah Butt, Daria Mamonova, Yuri Petrov, Alexandra Proklova, Ilya Kritchenkov, Alina Manshina, Peter Banzer and Gerd Leuchs
Nanomaterials 2020, 10(7), 1376; https://doi.org/10.3390/nano10071376 - 15 Jul 2020
Cited by 4 | Viewed by 2391
Abstract
Until recently, planar carbonaceous structures such as graphene did not show any birefringence under normal incidence. In contrast, a recently reported novel orthorhombic carbonaceous structure with metal nanoparticle inclusions does show intrinsic birefringence, outperforming other natural orthorhombic crystalline materials. These flake-like structures self-assemble [...] Read more.
Until recently, planar carbonaceous structures such as graphene did not show any birefringence under normal incidence. In contrast, a recently reported novel orthorhombic carbonaceous structure with metal nanoparticle inclusions does show intrinsic birefringence, outperforming other natural orthorhombic crystalline materials. These flake-like structures self-assemble during a laser-induced growth process. In this article, we explore the potential of this novel material and the design freedom during production. We study in particular the dependence of the optical and geometrical properties of these hybrid carbon-metal flakes on the fabrication parameters. The influence of the laser irradiation time, concentration of the supramolecular complex in the solution, and an external electric field applied during the growth process are investigated. In all cases, the self-assembled metamaterial exhibits a strong linear birefringence in the visible spectral range, while the wavelength-dependent attenuation was found to hinge on the concentration of the supramolecular complex in the solution. By varying the fabrication parameters one can steer the shape and size of the flakes. This study provides a route towards fabrication of novel hybrid carbon-metal flakes with tailored optical and geometrical properties. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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10 pages, 2634 KiB  
Article
Zn-Doped Calcium Copper Titanate Synthesized via Rapid Laser Sintering of Sol-Gel Derived Precursors
by Yanwei Huang, Yu Qiao, Yangyang Li, Jiayang He and Heping Zeng
Nanomaterials 2020, 10(6), 1163; https://doi.org/10.3390/nano10061163 - 13 Jun 2020
Cited by 8 | Viewed by 2576
Abstract
Zn-doped calcium copper titanate (CCTO) was successfully synthesized by rapid laser sintering of sol-gel derived precursors without the conventional long-time heat treatment. The structural, morphological, and crystalline properties were characterized, and the performances of dielectrics and impedance were measured and discussed. The X-ray [...] Read more.
Zn-doped calcium copper titanate (CCTO) was successfully synthesized by rapid laser sintering of sol-gel derived precursors without the conventional long-time heat treatment. The structural, morphological, and crystalline properties were characterized, and the performances of dielectrics and impedance were measured and discussed. The X-ray diffractometer results show that Zn-doped CCTO is polycrystalline in a cubic structure, according to the doping ratio of Ca(Cu2Zn)Ti4O12. Electron microscopy showed that Zn-doped CCTO has a denser microstructure with better uniformness with shrunken interplanar spacing of 2.598 nm for the plane (220). Comparing with undoped CCTO, the permittivity almost remains unchanged in the range of 102–106 Hz, demonstrating good stability on frequency. The electrical mechanism was investigated and is discussed through the impedance spectroscopy analysis. The resistance of grain and grain boundary decreases with rising temperature. Activation energies for the grain boundaries for Zn- doped CCTO were calculated from the slope for the relationship of ln σ versus 1/T and were found to be 0.605 eV, smaller than undoped CCTO. This synthesis route may be an efficient and convenient approach to limit excessive waste of resources. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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16 pages, 5610 KiB  
Article
Fabrication and Deposition of Copper and Copper Oxide Nanoparticles by Laser Ablation in Open Air
by Mónica Fernández-Arias, Mohamed Boutinguiza, Jesús del Val, Antonio Riveiro, Daniel Rodríguez, Felipe Arias-González, Javier Gil and Juan Pou
Nanomaterials 2020, 10(2), 300; https://doi.org/10.3390/nano10020300 - 10 Feb 2020
Cited by 36 | Viewed by 4343
Abstract
The proximity of the “post-antibiotic era”, where infections and minor injuries could be a cause of death, there are urges to seek an alternative for the cure of infectious diseases. Copper nanoparticles and their huge potential as a bactericidal agent could be a [...] Read more.
The proximity of the “post-antibiotic era”, where infections and minor injuries could be a cause of death, there are urges to seek an alternative for the cure of infectious diseases. Copper nanoparticles and their huge potential as a bactericidal agent could be a solution. In this work, Cu and Cu oxide nanoparticles were synthesized by laser ablation in open air and in argon atmosphere using 532 and 1064 nm radiation generated by nanosecond and picosecond Nd:YVO4 lasers, respectively, to be directly deposited onto Ti substrates. Size, morphology, composition and the crystalline structure of the produced nanoparticles have been studied by the means of field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), the energy dispersive spectroscopy of X-rays (EDS), selected area electron diffraction (SAED) and X-ray diffraction (XRD). The UV-VIS absorbance of the thin layer of nanoparticles was also measured, and the antibacterial capacity of the obtained deposits tested against Staphylococcus aureus. The obtained deposits consisted of porous coatings composed of copper and copper oxide nanoparticles interconnected to form chain-like aggregates. The use of the argon atmosphere contributed to reduce significantly the formation of Cu oxide species. The synthesized and deposited nanoparticles exhibited an inhibitory effect upon S. aureus. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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20 pages, 4468 KiB  
Article
Comparative Study of the Structure, Composition, and Electrocatalytic Performance of Hydrogen Evolution in MoSx~2+δ/Mo and MoSx~3+δ Films Obtained by Pulsed Laser Deposition
by V. Fominski, M. Demin, D. Fominski, R. Romanov, A. Goikhman and K. Maksimova
Nanomaterials 2020, 10(2), 201; https://doi.org/10.3390/nano10020201 - 24 Jan 2020
Cited by 18 | Viewed by 3670
Abstract
Systematic and in-depth studies of the structure, composition, and efficiency of hydrogen evolution reactions (HERs) in MoSx films, obtained by means of on- and off-axis pulsed laser deposition (PLD) from a MoS2 target, have been performed. The use of on-axis PLD [...] Read more.
Systematic and in-depth studies of the structure, composition, and efficiency of hydrogen evolution reactions (HERs) in MoSx films, obtained by means of on- and off-axis pulsed laser deposition (PLD) from a MoS2 target, have been performed. The use of on-axis PLD (a standard configuration of PLD) in a buffer of Ar gas, with an optimal pressure, has allowed for the formation of porous hybrid films that consist of Mo particles which support a thin MoSx~2+δ (δ of ~0.7) film. The HER performance of MoSx~2+δ/Mo films increases with increased loading and reaches the highest value at a loading of ~240 μg/cm2. For off-axis PLD, the substrate was located along the axis of expansion of the laser plume and the film was formed via the deposition of the atomic component of the plume, which was scattered in Ar molecules. This made it possible to obtain homogeneous MoSx~3+δ (δ~0.8–1.1) films. The HER performances of these films reached saturation at a loading value of ~163 μg/cm2. The MoSx~3+δ films possessed higher catalytic activities in terms of the turnover frequency of their HERs. However, to achieve the current density of 10 mA/cm2, the lowest over voltages were −162 mV and −150 mV for the films obtained by off- and on-axis PLD, respectively. Measurements of electrochemical characteristics indicated that the differences in the achievable HER performances of these films could be caused by their unique morphological properties. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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13 pages, 2644 KiB  
Article
Spectroscopic and Microscopic Analyses of Fe3O4/Au Nanoparticles Obtained by Laser Ablation in Water
by Maurizio Muniz-Miranda, Francesco Muniz-Miranda and Emilia Giorgetti
Nanomaterials 2020, 10(1), 132; https://doi.org/10.3390/nano10010132 - 10 Jan 2020
Cited by 21 | Viewed by 3332
Abstract
Magneto-plasmonic nanoparticles constituted of gold and iron oxide were obtained in an aqueous environment by laser ablation of iron and gold targets in two successive steps. Gold nanoparticles are embedded in a mucilaginous matrix of iron oxide, which was identified as magnetite by [...] Read more.
Magneto-plasmonic nanoparticles constituted of gold and iron oxide were obtained in an aqueous environment by laser ablation of iron and gold targets in two successive steps. Gold nanoparticles are embedded in a mucilaginous matrix of iron oxide, which was identified as magnetite by both microscopic and spectroscopic analyses. The plasmonic properties of the obtained colloids, as well as their adsorption capability, were tested by surface-enhanced Raman scattering (SERS) spectroscopy using 2,2′-bipyridine as a probe molecule. DFT calculations allowed for obtaining information on the adsorption of the ligand molecules that strongly interact with positively charged surface active sites of the gold nanoparticles, thus providing efficient SERS enhancement. The presence of iron oxide gives the bimetallic colloid new possibilities of adsorption in addition to those inherent to gold nanoparticles, especially regarding organic pollutants and heavy metals, allowing to remove them from the aqueous environment by applying a magnetic field. Moreover, these nanoparticles, thanks to their low toxicity, are potentially useful not only in the field of sensors, but also for biomedical applications. Full article
(This article belongs to the Special Issue Laser Synthesis of Nanomaterials)
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