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19 pages, 2272 KiB

Open AccessFeature PaperArticle

Nonlinear Analysis of the Multi-Layered Nanoplates

by Mostafa Sadeghian, Arvydas Palevicius, Paulius Griskevicius and Giedrius Janusas

Mathematics 2024, 12(22), 3545; https://doi.org/10.3390/math12223545 - 13 Nov 2024

Viewed by 695

This text investigates the bending/buckling behavior of multi-layer asymmetric/symmetric annular and circular graphene plates through the application of the nonlocal strain gradient model. Additionally, the static analysis of multi-sector nanoplates is addressed. By considering the van der Waals interactions among the layers, the higher-order shear deformation theory (HSDT), and the nonlocal strain gradient theory, the equilibrium equations are formulated in terms of generalized displacements and rotations. The mathematical nonlinear equations are solved utilizing either the semi-analytical polynomial method (SAPM) and the differential quadrature method (DQM). Also, the available references are used to validate the results. Investigations are conducted to examine the effect of small-scale factors, the van der Waals interaction value among the layers, boundary conditions, and geometric factors. Full article

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19 pages, 5029 KiB

Open AccessEditor’s ChoiceArticle

Bromine Ion-Intercalated Layered Bi₂WO₆ as an Efficient Catalyst for Advanced Oxidation Processes in Tetracycline Pollutant Degradation Reaction

by Rama Krishna Chava and Misook Kang

Nanomaterials 2023, 13(18), 2614; https://doi.org/10.3390/nano13182614 - 21 Sep 2023

Cited by 6 | Viewed by 1846

Abstract

The visible-light-driven photocatalytic degradation of pharmaceutical pollutants in aquatic environments is a promising strategy for addressing water pollution problems. This work highlights the use of bromine-ion-doped layered Aurivillius oxide, Bi₂WO₆, to synergistically optimize the morphology and increase the formation of active sites on the photocatalyst’s surface. The layered Bi₂WO₆ nanoplates were synthesized by a facile hydrothermal reaction in which bromine (Br⁻) ions were introduced by adding cetyltrimethylammonium bromide (CTAB)/tetrabutylammonium bromide (TBAB)/potassium bromide (KBr). The as-synthesized Bi₂WO₆ nanoplates displayed higher photocatalytic tetracycline degradation activity (~83.5%) than the Bi₂WO₆ microspheres (~48.2%), which were obtained without the addition of Br precursors in the reaction medium. The presence of Br⁻ was verified experimentally, and the newly formed Bi₂WO₆ developed as nanoplates where the adsorbed Br⁻ ions restricted the multilayer stacking. Considering the significant morphology change, increased specific surface area, and enhanced photocatalytic performance, using a synthesis approach mediated by Br⁻ ions to design layered photocatalysts is expected to be a promising system for advancing water remediation. Full article

(This article belongs to the Special Issue Nanomaterials for Photocatalytic Degradation of Pollutant and Hydrogen Evolution)

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11 pages, 8646 KiB

Open AccessArticle

Preparation and Adsorption Properties of Nanostructured Composites Derived from Al/Fe Nanoparticles with Respect to Arsenic

by Sergey O. Kazantsev, Aleksandr S. Lozhkomoev and Nikolay G. Rodkevich

Nanomaterials 2022, 12(18), 3177; https://doi.org/10.3390/nano12183177 - 13 Sep 2022

Cited by 6 | Viewed by 2137

Abstract

Composite nanostructures containing iron in different forms exhibit a high adsorption capacity with respect to arsenic. The aim of our study was to investigate the adsorption activity of an adsorbent composite prepared by the oxidation of bimetallic Al/Fe nanoparticles under different conditions. Depending on the oxidation conditions, nanostructures with different morphologies in the form of nanosheets, nanoplates and nanorods with different compositions and textural characteristics could be obtained. The nanostructures obtained had a positive zeta potential and were characterized by a high specific surface area: 330 m²/g for the AlOOH/FeAl₂ nanosheets; 75 m²/g for the AlOOH/Fe₂O₃/FeAl₂ nanoplates; and 43 m²/g for the Al(OH)₃/FeAl₂ nanorods. The distribution of an FeAl₂ intermetallide over the surface of the AlOOH nanostructures led to an increase in arsenic adsorption of 25% for the AlOOH/FeAl₂ nanosheets and of 34% for the AlOOH/Fe₂O₃/FeAl₂ nanoplates and Al(OH)₃/FeAl₂ nanorods. The adsorption isotherms matched most preciously to the Freundlich model. This fact indicated the energy heterogeneity of the adsorbent surface and multilayer adsorption. The nanostructures studied can be used to purify water contaminated with arsenic. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Environmental Remediation)

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19 pages, 54589 KiB

Open AccessArticle

One-Step Multi-Doping Process for Producing Effective Zinc Oxide Nanofibers to Remove Industrial Pollutants Using Sunlight

by Osama Saber, Nagih M. Shaalan, Faheem Ahmed, Shalendra Kumar and Adil Alshoaibi

Crystals 2021, 11(10), 1268; https://doi.org/10.3390/cryst11101268 - 19 Oct 2021

Cited by 9 | Viewed by 2283

Abstract

Doping processes for optical materials are one of the driving forces for developing efficient and clean technologies for decontamination of aquatic effluents through lowering their band gap energy to become effective in sunlight. The current study has used a non-conventional technique for doping zinc oxide by multi metals, non-metals and organic dyes through a one-step process. In this trend, Zn-Al nanolayered structures have been used as hosts for building host–guest interactions. Organic dyes that have inorganic species of iron, nitrogen and sulfur have been used as guests in the intercalation reactions of Zn-Al layered double hydroxides. By intercalating green dyes, organic–inorganic nanohybrids were formed as nanolayered structures with expanding interlayered spacing to 2.1 nm. By changing the concentration of green dyes and thermal treatment, series of nanofibers and nanoplates of zinc oxides were formed and doped by aluminum, iron and sulfur in addition to colored species. The optical properties of the multi-doped zinc oxide indicated that it became suitable for solar applications because its band gap energy decreased from 3.30 eV to 2.80 eV. The experimental and kinetic results of the multi-doped zinc oxide concluded that the colored pollutants were effectively removed during 50 min of sunlight irradiation. Full article

(This article belongs to the Special Issue New Trends in Crystals at Saudi Arabia)

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9 pages, 4998 KiB

Open AccessArticle

α-MoO₃ Crystals with a Multilayer Stack Structure Obtained by Annealing from a Lamellar MoS₂/g-C₃N₄ Nanohybrid

by Pablo Martín-Ramos, Ignacio A. Fernández-Coppel, Manuel Avella and Jesús Martín-Gil

Nanomaterials 2018, 8(7), 559; https://doi.org/10.3390/nano8070559 - 22 Jul 2018

Cited by 20 | Viewed by 6832

Abstract

Transition metal oxides and chalcogenides have recently attracted great attention as the next generation of 2-D materials due to their unique electronic and optical properties. In this study, a new procedure for the obtaining of highly crystalline α-MoO₃ is proposed as an alternative to vapor-phase synthesis. In this approach, a first reaction between molybdate, citrate and thiourea allowed to obtain MoS₂, which—upon calcination at a temperature of 650 °C in the presence of g-C₃N₄—resulted in MoO₃ with a definite plate-like shape. The colorless (or greenish) α-MoO₃ nanoplates obtained with this procedure featured a multilayer stack structure, with a side-length of 1–2 μm and a thickness of several nanometers viewed along the [010] direction. The nucleation-growth of the crystal can be explained by a two-dimensional layer-by-layer mechanism favored by g-C₃N₄ lamellar template. Full article

(This article belongs to the Special Issue Preparation and Properties of 2D Materials)

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