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19 pages, 10547 KiB

Open AccessArticle

Bimetallic Ni–Mn Electrocatalysts for Stable Oxygen Evolution Reaction in Simulated/Alkaline Seawater and Overall Performance in the Splitting of Alkaline Seawater

by Sukomol Barua, Aldona Balčiūnaitė, Daina Upskuvienė, Jūrate Vaičiūnienė, Loreta Tamašauskaitė-Tamašiūnaitė and Eugenijus Norkus

Coatings 2024, 14(8), 1074; https://doi.org/10.3390/coatings14081074 - 22 Aug 2024

Viewed by 767

Abstract

The perfect strategy for the generation of green and renewable hydrogen (H₂) fuels is the direct electrocatalytic splitting of plentiful seawater rather than scarce freshwater. One of the half-reactions taking place during the electrocatalytic splitting of seawater is oxygen evolution (OER). [...] Read more.

The perfect strategy for the generation of green and renewable hydrogen (H₂) fuels is the direct electrocatalytic splitting of plentiful seawater rather than scarce freshwater. One of the half-reactions taking place during the electrocatalytic splitting of seawater is oxygen evolution (OER). However, the OER is affected by slow four-electron transfer kinetics as well as competitive chlorine evolution reactions (CERs) in seawater. To overcome the kinematic and competitive barriers of seawater splitting and achieve an excellent overall performance of seawater splitting, we herein report a facile, low-cost, one-step fabrication procedure of 3D structured nickel–manganese (NiMn) coatings using a dynamic hydrogen bubble template (DHBT) technique. The electrocatalytic activities of the thus synthesized catalytic materials for OER in simulated seawater (0.5 M NaCl + 1 M KOH, denoted as SSW) and alkaline natural seawater (natural seawater + 1 M KOH, denoted as ASW) were investigated using linear sweep voltammetry (LSV) at varying temperatures from 25 to 75 °C. Scanning electron microscopy (SEM) and inductively coupled plasma–optical emission spectroscopy (ICP–OES) were used to examine the surface morphology and composition of the prepared catalysts. It was found that the prepared NiMn/Ti-1 catalyst in a plating bath containing a molar ratio of 1:1 Ni²⁺:Mn²⁺ and having the lowest Mn loading of 13.43 µg cm⁻² exhibited quite reasonable activity for OER in Cl⁻ ion rich SSW and ASW. To achieve the benchmark current density of 10 mA cm⁻² in SSW and ASW, the NiMn/Ti-1 electrocatalyst requires overpotentials of 386 and 388 mV, respectively. In addition, this optimal bimetallic electrocatalyst also demonstrated superior long-run stability at 1.81 V (vs. RHE) and 10 mA cm⁻² for 24 h in both working electrolytes. Impressively, the two-electrode electrolyzer—NiMn/Ti-5₍₋₎||NiMn/Ti-1₍₊₎—needs only 1.619 V to deliver 10 mA cm⁻² current density for overall alkaline seawater electrolysis, which is even 0.075 V lower than the noble metal-based electrolyzer (Pt₍₋₎||NiMn/Ti-1₍₊₎). Full article

(This article belongs to the Special Issue New Advance in Nanoparticles, Fiber, and Coatings)

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19 pages, 3299 KiB

Open AccessEditor’s ChoiceArticle

Bimetallic 3D Nickel-Manganese/Titanium Bifunctional Electrocatalysts for Efficient Hydrogen and Oxygen Evolution Reaction in Alkaline and Acidic Media

by Sukomol Barua, Aldona Balčiūnaitė, Jūrate Vaičiūnienė, Loreta Tamašauskaitė-Tamašiūnaitė and Eugenijus Norkus

Coatings 2023, 13(6), 1102; https://doi.org/10.3390/coatings13061102 - 15 Jun 2023

Cited by 4 | Viewed by 1860

Abstract

In this work, 3D nickel-manganese (NiMn) bimetallic coatings have been studied as electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline (1.0 M KOH) media and the HER in acidic (0.5 M H₂SO₄) media. [...] Read more.

In this work, 3D nickel-manganese (NiMn) bimetallic coatings have been studied as electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline (1.0 M KOH) media and the HER in acidic (0.5 M H₂SO₄) media. The catalysts have been deposited on a titanium substrate (1 × 1 cm²) using low-cost and facile electrochemical deposition method through a dynamic hydrogen bubble template technique. The electrocatalytic performance of these fabricated catalysts was investigated by using Linear Sweep Voltammetry (LSV) for HER and OER at different temperatures ranging from 25 up to 75 °C and also was characterized by scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES). It was found that fabricated NiMn/Ti-5 electrocatalyst with Ni²⁺/Mn²⁺ molar ratio of 1:5 exhibits excellent HER activity in alkaline media with overpotential of 127.1 mV to reach current density of 10 mA cm⁻². On the contrary, NiMn/Ti-1 electrocatalyst that fabricated with Ni²⁺/Mn²⁺ molar proportion of 1:1 and lowest Mn-loading of 13.43 µgcm⁻² demonstrates exceptional OER activity with minimum overpotential of 356.3 mV to reach current density of 10 mA cm⁻². The current densities increase ca. 1.8–2.2 times with an increase in temperature from 25 °C to 75 °C for both HER and OER investigation. Both catalysts also have exhibited excellent long-term stability for 10 h at constant potentials as well as constant current density of 10 mA cm⁻² that assure their robustness and higher durability regarding alkaline water splitting. Full article

(This article belongs to the Special Issue New Advance in Nanoparticles, Fiber, and Coatings)

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13 pages, 3371 KiB

Open AccessEditor’s ChoiceArticle

Bacterial Detection and Differentiation of Staphylococcus aureus and Escherichia coli Utilizing Long-Period Fiber Gratings Functionalized with Nanoporous Coated Structures

by Shuyue He, Jue Wang, Fan Yang, Tzu-Lan Chang, Ziyu Tang, Kai Liu, Shuli Liu, Fei Tian, Jun-Feng Liang, Henry Du and Yi Liu

Coatings 2023, 13(4), 778; https://doi.org/10.3390/coatings13040778 - 17 Apr 2023

Cited by 5 | Viewed by 1721

Abstract

A biosensor utilizing long-period fiber gratings (LPFG) functionalized with nanoporous coated structures was developed for the rapid detection of Staphylococcus aureus (S. aureus) bacteria. The nanoporous structure coatings on the LPFG surface facilitated specific adhesion and interaction with S. aureus, [...] Read more.

A biosensor utilizing long-period fiber gratings (LPFG) functionalized with nanoporous coated structures was developed for the rapid detection of Staphylococcus aureus (S. aureus) bacteria. The nanoporous structure coatings on the LPFG surface facilitated specific adhesion and interaction with S. aureus, resulting in an instantaneous shift in the resonance wavelength (RW) in the transmission spectrum of the LPFG. The LPFG with nanoporous polyelectrolyte coatings exhibited an approximately seven-fold RW shift compared to the bare LPFG under the optimal experiment conditions. By tracking the RW shifts, we were able to monitor the real-time S. aureus adhesion to study the interaction process in detail. The bacterial differentiation and S. aureus specificity of the method was confirmed through a series of studies using Escherichia coli (E. coli). This nanoporous structure-enabled LPFG-based biosensor scheme holds significant promise for rapid, reliable, and low-cost detection of S. aureus for biomedical applications. Full article

(This article belongs to the Special Issue New Advance in Nanoparticles, Fiber, and Coatings)

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13 pages, 4435 KiB

Open AccessArticle

Shear and Tensile Behaviors of Fiber-Reinforced Resin Matrix Composites Printed by the FDM Technology

by Yuexi Zhuang, Bin Zou, Shouling Ding and Peng Wang

Coatings 2022, 12(7), 1000; https://doi.org/10.3390/coatings12071000 - 15 Jul 2022

Cited by 10 | Viewed by 2140

Abstract

Resin/fiber composites were prepared by the FDM printing technology. The effects of arrangements, types (carbon, glass, and Kevlar), and volume fraction of fibers on the shear and tensile properties of resin 3D-printed composites are investigated in this paper. The experimental results show that [...] Read more.

Resin/fiber composites were prepared by the FDM printing technology. The effects of arrangements, types (carbon, glass, and Kevlar), and volume fraction of fibers on the shear and tensile properties of resin 3D-printed composites are investigated in this paper. The experimental results show that the addition of continuous fibers increases the shear strength and tensile strength of FDM-3D-printed composites, but the strength will not keep increasing with an increase in the fiber content. As the fiber content increases, the print quality decreases, and the porosity between the fibers increases. The enhancement degree of the shear stress of specimens by different fiber types can be classified as follows: glass fiber > carbon fiber > Kevlar fiber. Notch sensitivity is reduced when the 90° arrangement of fibers is added, while the addition of 0° arranged fibers will improve the notch sensitivity of the sample. The research results of this paper have an important guiding significance for selecting fiber types and arrangement mode of notched components in engineering applications. Full article

(This article belongs to the Special Issue New Advance in Nanoparticles, Fiber, and Coatings)

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24 pages, 9344 KiB

Open AccessFeature PaperArticle

Fabrication of Efficient Gold−Nickel-Supported Titania Nanotube Electrocatalysts for Sodium Borohydride−Hydrogen Peroxide Fuel Cells

by Aldona Balčiūnaitė, Aušrinė Zabielaitė, Zita Sukackienė, Virginija Kepenienė, Dijana Šimkūnaitė, Algirdas Selskis, Loreta Tamašauskaitė-Tamašiūnaitė and Eugenijus Norkus

Coatings 2022, 12(6), 850; https://doi.org/10.3390/coatings12060850 - 17 Jun 2022

Viewed by 2008

Abstract

Here we report the optimization of the fabrication conditions for AuNi bimetallic catalysts supported on self-ordered titania nanotube arrays (AuNi-TiO₂ntb). A series of efficient AuNi-TiO₂ntb catalysts with small amounts of Au in the range of 1.74 to 15.7 μg [...] Read more.

Here we report the optimization of the fabrication conditions for AuNi bimetallic catalysts supported on self-ordered titania nanotube arrays (AuNi-TiO₂ntb). A series of efficient AuNi-TiO₂ntb catalysts with small amounts of Au in the range of 1.74 to 15.7 μg_Au·cm⁻² have been fabricated by anodization, electroless Ni plating, and galvanic displacement techniques. The electrocatalytic activity of the catalysts has been evaluated for BH₄⁻ ion oxidation in an alkaline medium using cyclic voltammetry and chronoamperometry. The performance of a NaBH₄-H₂O₂ fuel cell with Ni-TiO₂ntb and AuNi-TiO₂ntb anode catalysts has been investigated at different temperatures. It was found that the electrocatalytic activity of AuNi-TiO₂ntbs catalysts was improved remarkably when the Ni layer of 100 and 400 nm was used for the deposition of Au crystallites. The Ni-TiO₂ntb catalyst generates the maximum power density values of ca. 85–121 mW·cm⁻² at a temperature of 25–55 °C, whereas the AuNi-TiO₂ntb catalysts that have the Au loading of 3.07 and 15.7 μg_Au·cm⁻² achieve the power density values of ca. 104–147 and 119–170 mW·cm⁻², respectively, at a temperature of 25–55 °C. Full article

(This article belongs to the Special Issue New Advance in Nanoparticles, Fiber, and Coatings)

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0 pages, 55074 KiB

Open AccessArticle

Curcuma longa Mediated Synthesis of Copper Oxide, Nickel Oxide and Cu-Ni Bimetallic Hybrid Nanoparticles: Characterization and Evaluation for Antimicrobial, Anti-Parasitic and Cytotoxic Potentials

by Shah Faisal, Najlaa S. Al-Radadi, Hasnain Jan, Abdullah, Sajjad Ali Shah, Sumaira Shah, Muhammad Rizwan, Zobia Afsheen, Zahid Hussain, Muhammad Nazir Uddin, Muhammad Idrees and Nadia Bibi

Coatings 2021, 11(7), 849; https://doi.org/10.3390/coatings11070849 - 14 Jul 2021

Cited by 57 | Viewed by 5843 | Correction

Abstract

Nanoparticles have long been known and their biomedical potent activities have proven that these can provide an alternative to other drugs. In the current study, copper oxide, nickel oxide and copper/nickel hybrid NPs were biosynthesized by using Curcuma longa root extracts as a [...] Read more.

Nanoparticles have long been known and their biomedical potent activities have proven that these can provide an alternative to other drugs. In the current study, copper oxide, nickel oxide and copper/nickel hybrid NPs were biosynthesized by using Curcuma longa root extracts as a reducing and capping agent, followed by characterization via UV-spectroscopy, Fourier transformed infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo galvanometric analysis (TGA), and band gap. FTIR spectroscopy shows the availability of various functional groups and biomolecules such as carbohydrate, protein, polysaccharides, etc. The EDX peak confirmed that the elemental nickel and copper were present in large quantity in the analyzed sample. Scanning electron micrographs showed that the synthesized CuO-NPs and NiO-NPs were polyhedral uniform and homogeneous in morphology, while the copper/nickel hybrid NPs were well dispersed, spherical in shape, and uniform in size. TEM micrographs of CuO-NPs had 27.72 nm, NiO had 23.13 nm and, for their hybrid, the size was 17.38 nm, which was confirmed respectively. The CuO and NiO NPs possessed spherical- to multi-headed shapes, while their hybrid showed a complete spherical shape, small size, and polydispersed NPs. The XRD spectra revealed that the average particle size for CuO, NiO, and hybrid were 29.7 nm, 28 nm and 27 nm, respectively. Maximum anti-diabetic inhibition of (52.35 ± 0.76: CuO-NPs, 68.1 ± 0.93: NiO-NPs and 74.23 ± 0.42: Cu + Ni hybrids) for α-amylase and (39.25 ± 0.18 CuO-NPs, 52.35 ± 1.32: NiO-NPs and 62.32 ± 0.48: Cu + Ni hybrids) for α-glucosidase were calculated, respectively, at 400 µg/mL. The maximum antioxidants capacity was observed as 65.1 ± 0.83 μgAAE/mg for Cu-Ni hybrids, 58.39 ± 0.62 μgAAE/mg for NiO-NPs, and 52.2 ± 0.31 μgAAE/mg for CuO-NPs, respectively, at 400 μg/mL. The highest antibacterial activity of biosynthesized NPs was observed against P. aeuroginosa (28 ± 1.22) and P. vulgaris (25 ± 1.73) for Cu + Ni hybrids, respectively. Furthermore, the antibiotics were coated with NPs, and activity was noted. Significant anti-leishmanial activity of 60.5 ± 0.53 and 68.4 ± 0.59 for Cu + Ni hybrids; 53.2 ± 0.48 and 61.2 ± 0.44 for NiO-NPs; 49.1 ± 0.39 and 56.2 ± 0.45 for CuO-NPs at 400 μg/mL were recorded for promastigote and amastigotes, respectively. The biosynthesized NPs also showed significant anti-cancerous potential against HepG2 cell lines. It was concluded from the study that NPs are potential agents to be used as an alternative to antimicrobial agents. Full article

(This article belongs to the Special Issue New Advance in Nanoparticles, Fiber, and Coatings)

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Review

Jump to: Research, Other

16 pages, 10100 KiB

Open AccessReview

Medicinal Plants and Biogenic Metal Oxide Nanoparticles: A Paradigm Shift to Treat Alzheimer’s Disease

by Roby Gul, Hasnain Jan, Gul Lalay, Anisa Andleeb, Hazrat Usman, Rimsha Zainab, Zeeshan Qamar, Christophe Hano and Bilal Haider Abbasi

Coatings 2021, 11(6), 717; https://doi.org/10.3390/coatings11060717 - 15 Jun 2021

Cited by 16 | Viewed by 3794

Abstract

Alzheimer’s disease (AD) is the most prevalent form of dementia. Improving the amount of acetylcholine in the brain is an efficient way to treat the illness. The global incidence of dementia is estimated to be as high as 50 million, and it is [...] Read more.

Alzheimer’s disease (AD) is the most prevalent form of dementia. Improving the amount of acetylcholine in the brain is an efficient way to treat the illness. The global incidence of dementia is estimated to be as high as 50 million, and it is expected to increase every 20 years until 2040, resulting in a costly burden of disease. Early-life risk factors for pathology include genes, chromosomal abnormalities, head injury, insulin resistance, and inflammation. Potentially modifiable risk factors including obesity, diabetes, hypertension, and smoking are associated with Alzheimer’s disease (AD) and represent promising targets for intervention. The drugs currently being used to manage AD have various drawbacks. The chemical inhibition of cholinesterase enzymes is an effective technique for treating signal related neuropathology, and possible sources of compounds with these properties are natural products and biogenic metal oxide nanoparticles. There is a potential source of AChE and BChE inhibitors in the abundance of plants in nature, and natural goods appear to offer useful medications and templates for the development of other compounds. This dissertation represents a review of the literature on species of medicinal plants and nanomaterial related plants tested for their inhibitory action of AChE and BChE. Plant species and the plant-mediated metal oxide nanoparticles referred to are possible cholinesterase inhibitors and can assist researchers in their study of natural products that may be beneficial in the treatment of AD. Full article

(This article belongs to the Special Issue New Advance in Nanoparticles, Fiber, and Coatings)

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Jump to: Research, Review

2 pages, 682 KiB

Open AccessCorrection

Correction: Faisal et al. Curcuma longa Mediated Synthesis of Copper Oxide, Nickel Oxide and Cu-Ni Bimetallic Hybrid Nanoparticles: Characterization and Evaluation for Antimicrobial, Anti-Parasitic and Cytotoxic Potentials. Coatings 2021, 11, 849

by Shah Faisal, Najlaa S. Al-Radadi, Hasnain Jan, Abdullah, Sajjad Ali Shah, Sumaira Shah, Muhammad Rizwan, Zobia Afsheen, Zahid Hussain, Muhammad Nazir Uddin, Muhammad Idrees and Nadia Bibi

Coatings 2024, 14(1), 43; https://doi.org/10.3390/coatings14010043 - 28 Dec 2023

Viewed by 688

Abstract

In the original publication [...] Full article

(This article belongs to the Special Issue New Advance in Nanoparticles, Fiber, and Coatings)

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