Inorganics

13 pages, 4048 KiB

Open AccessArticle

Portable Electrochemical Immunosensor Based on a Gold Microblobs-Optimized Screen-Printed Electrode for SARS-CoV-2 Diagnosis

by Melissa M. Giacomet, Paulo H. M. Buzzetti, Oscar O. S. Junior, Alessandro F. Martins, Elton G. Bonafe and Johny P. Monteiro

Inorganics 2024, 12(9), 252; https://doi.org/10.3390/inorganics12090252 - 18 Sep 2024

Abstract

The development of biosensors for determining the most diverse biomolecules is a constant focus of many research groups. There is a latent need to propose sensors that combine portability, simple measurements, and good analytical performance. Here, we propose an electrochemical immunosensor that is [...] Read more.

The development of biosensors for determining the most diverse biomolecules is a constant focus of many research groups. There is a latent need to propose sensors that combine portability, simple measurements, and good analytical performance. Here, we propose an electrochemical immunosensor that is fully portable and energy-independent for diagnosing antibodies against SARS-CoV-2 (the virus that causes COVID-19). Initially, disposable screen-printed carbon electrodes (SPEs) were covered by gold microblobs (AuMBs), which were synthesized amperometrically from Au³⁺ ions. Then, the SPE-AuMBs were coated with cysteamine, which allowed the N-hydroxysuccinimide-activated SARS-CoV-2 antigen (spike protein) to be immobilized. The antigen-activated electrode was used to detect COVID-19 antibodies from current measurements obtained by differential pulse voltammetry. The AuMBs synthesis time was optimized, and the presence of gold structures improved the electrochemical responses of the SPE. It was possible to quantitatively determine antibodies in the concentration range of 0.25 to 10 µg mL⁻¹. This range includes concentrations found in biological fluids from patients at any stage of the disease. An analysis took approximately the same time as traditional rapid nasal tests (20 min) and costed less, considering all the steps necessary to prepare a disposable antigen-functionalized SPE. Full article

(This article belongs to the Special Issue Functional Inorganic Biomaterials for Molecular Sensing and Biomedical Applications)

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18 pages, 3144 KiB

Open AccessArticle

Theoretical Study of the Effects of Different Coordination Atoms (O/S/N) on Crystal Structure, Stability, and Protein/DNA Binding of Ni(II) Complexes with Pyridoxal-Semi, Thiosemi, and Isothiosemicarbazone Ligand Systems

by Violeta Jevtovic, Aleksandra Rakić, Odeh A. O. Alshammari, Munirah Sulaiman Alhar, Tahani Alenezi, Violeta Rakic and Dušan Dimić

Inorganics 2024, 12(9), 251; https://doi.org/10.3390/inorganics12090251 - 17 Sep 2024

Abstract

Nickel transition metal complexes have shown various biological activities that depend on the ligands and geometry. In this contribution, six Ni(II) nitrate complexes with pyridoxal-semi, thiosemi, and isothiosemicarbazone ligands were examined using theoretical chemistry methods. The structures of three previously reported complexes ([Ni(PLSC)(H [...] Read more.

Nickel transition metal complexes have shown various biological activities that depend on the ligands and geometry. In this contribution, six Ni(II) nitrate complexes with pyridoxal-semi, thiosemi, and isothiosemicarbazone ligands were examined using theoretical chemistry methods. The structures of three previously reported complexes ([Ni(PLSC)(H₂O)₃]∙2NO₃⁻, [Ni(PLTSC)₂] ∙2NO₃⁻∙H₂O, and [Ni(PLITSC)(H₂O)₃]∙2NO₃⁻) were investigated based on Hirshfeld surface analysis, and the most important stabilization interactions in the crystal structures were outlined. These structures were optimized at the B3LYP/6-311++G(d,p)(H,C,N,O,(S))/LanL2DZ(Ni) level of theory, and the applicability was checked by comparing theoretical and experimental bond lengths and angles. The same level of theory was applied for the optimization of three additional structures, ([Ni(PLSC)₂]²⁺, [Ni(PLTSC)(H₂O)₃]²⁺, and [Ni(PLITSC)₂]²⁺). The interactions between selected ligands and Ni(II) were examined using the Natural Bond Orbital (NBO) and Quantum Theory of Atoms in Molecules (QTAIM) approaches. Particular emphasis was placed on interactions between oxygen, sulfur, and nitrogen donor atoms and Ni(II). Human Serum Albumin (HSA) and the DNA-binding properties of these complex cations were assessed using molecular docking simulations. The presence of water molecules and various substituents in the thermodynamics of the processes was demonstrated. The results showed significant effects of structural parameters on the stability and reactivity towards important biomolecules. Full article

(This article belongs to the Special Issue Metal Complexes Diversity: Synthesis, Conformations, and Bioactivity)

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12 pages, 2658 KiB

Open AccessArticle

Research on Modification of Oxygen-Producing Adsorbents for High-Altitude and Low-Pressure Environments

by Ye Li, Huiqing Yue, Quanli Zhang, Dumin Yan, Ziyi Li, Zhiwei Liu, Yingshu Liu, Yongyan Wang, Shifeng Wang and Xiong Yang

Inorganics 2024, 12(9), 250; https://doi.org/10.3390/inorganics12090250 - 14 Sep 2024

Abstract

In oxygen production on plateaus, pressure swing adsorption (PSA) oxygen production is currently the most commonly used oxygen production method. In plateau regions, low pressure leads to a decrease in adsorbent nitrogen–oxygen separation performance, which affects the performance of PSA oxygen production, so [...] Read more.

In oxygen production on plateaus, pressure swing adsorption (PSA) oxygen production is currently the most commonly used oxygen production method. In plateau regions, low pressure leads to a decrease in adsorbent nitrogen–oxygen separation performance, which affects the performance of PSA oxygen production, so it is particularly important to enhance adsorbent nitrogen–oxygen separation performance. In this paper, Li-LSX (lithium low-silicon aluminum X zeolite molecular sieve) adsorbents were modified using the liquid phase ion exchange method, and five kinds of modified adsorbents were obtained, namely AgLi-LSX, CaLi-LSX, ZnLi-LSX, CuLi-LSX, and FeLi-LSX, respectively. The influences of different metal ions and modification time lengths on the adsorbent nitrogen adsorption and nitrogen–oxygen separation coefficients were analyzed. Through theoretical calculations, the nitrogen and oxygen adsorption and separation performances of the modified adsorbents at different altitudes and low adsorption pressures were investigated. It is shown that the nitrogen adsorption capacity of the AgLi-LSX-1 adsorbent obtained from the modification experiment reaches 27.92 mL/g, which is 3.24 mL/g higher than that of Li-LSX; the nitrogen–oxygen separation coefficients of S1 and S2 are 19.24 and 7.54 higher, respectively; and the nitrogen–oxygen separation coefficients of S4 are 20.85 and 7.54 higher than those of Li-LSX, respectively. With the increase in altitude from 50 m to 5000 m, the nitrogen–oxygen separation coefficient of the AgLi-LSX-1 adsorbent increased rapidly from 20.85 to 57, and its nitrogen–oxygen separation coefficient S4 exceeded that of the Li-LSX adsorbent to reach 47.61 at an altitude of 4000 m. Therefore, the modified adsorbent AgLi-LSX-1 in this paper can enhance the performance of the PSA oxygen process for oxygen production in plateau applications. Full article

(This article belongs to the Special Issue Inorganic Composites for Gas Separation)

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2 pages, 153 KiB

Open AccessEditorial

Recent Advances in Biological and Catalytic Applications of Metal Complexes

by Jose Manuel Mendez-Arriaga

Inorganics 2024, 12(9), 249; https://doi.org/10.3390/inorganics12090249 - 13 Sep 2024

Abstract

The use of metals in biological [...] Full article

(This article belongs to the Special Issue Recent Advances in Biological and Catalytic Applications of Metal Complexes)

14 pages, 3237 KiB

Open AccessArticle

NMR-Based Structural Insights on Folic Acid and Its Interactions with Copper(II) Ions

by Arian Kola and Daniela Valensin

Inorganics 2024, 12(9), 248; https://doi.org/10.3390/inorganics12090248 - 12 Sep 2024

Abstract

Folic acid (FA) is an essential vitamin involved in crucial metabolic processes, while copper(II) ions play significant roles in various biological functions. This study aims to investigate the interaction between FA and Cu²⁺ using ¹H and ¹³C NMR spectroscopy [...] Read more.

Folic acid (FA) is an essential vitamin involved in crucial metabolic processes, while copper(II) ions play significant roles in various biological functions. This study aims to investigate the interaction between FA and Cu²⁺ using ¹H and ¹³C NMR spectroscopy under different pH levels and concentrations. The research employed detailed NMR analysis to explore how Cu²⁺ binds to FA, focusing on changes in chemical shifts, diffusion coefficients, and copper-induced paramagnetic effects. The key findings reveal that Cu²⁺ predominantly coordinates with the pteridine ring (PTE) of FA, with minimal involvement from the glutamic acid (Glu) moiety. The interaction is strongly concentration-dependent: at lower FA concentrations, Cu²⁺ binds effectively to the PTE ring, while at higher concentrations, intermolecular interactions among FA molecules hinder copper binding. The study also observed pronounced paramagnetic effects on the PTE and p-aminobenzoic acid protons, with negligible effects on Glu signals. These results provide new insights into the structural characteristics of FA-Cu²⁺ complexes, contributing to a better understanding of their biochemical interactions and implications for folate metabolism. Full article

(This article belongs to the Special Issue Women’s Special Issue Series: Inorganics)

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16 pages, 1471 KiB

Open AccessReview

Synthesis and Study of Correlated Phase Transitions of CrN Nanoparticles

by Khan Alam

Inorganics 2024, 12(9), 247; https://doi.org/10.3390/inorganics12090247 - 11 Sep 2024

Abstract

Chromium nitride is an important transition metal nitride for studying fundamental properties and for advanced technological applications. It is considered a model system for exploring structural, electronic, and magnetic transitions. These transitions occur at 275 ± 10 K and appear to be coupled; [...] Read more.

Chromium nitride is an important transition metal nitride for studying fundamental properties and for advanced technological applications. It is considered a model system for exploring structural, electronic, and magnetic transitions. These transitions occur at 275 ± 10 K and appear to be coupled; however, many discrepant studies on these transitions can be found in the published literature. The underlying reasons for these controversies are suspected to be the CrN nanoparticles preparation methods, strains, impurities, stoichiometry, nanoparticle size, characterization methods, and ambient conditions for characterizing them. This article is focused on the review of the nanoparticle synthesis methods and the use of these nanoparticles for studying structural, electronic, and magnetic transitions. The focus is mainly on the experimental methods, while theoretical simulations are briefly reviewed at the end of the article. Full article

(This article belongs to the Special Issue Advanced Inorganic Semiconductor Materials, 2nd Edition)

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12 pages, 2675 KiB

Open AccessArticle

Thermal Shock Resistance of Commercial Oxide-Bonded Silicon Carbide Reticulated Foams under Concentrated Solar Radiation at PSA: A Feasibility Study

by Fernando de Almeida Costa Oliveira, José Galindo, José Rodríguez, Inmaculada Cañadas and Jorge Cruz Fernandes

Inorganics 2024, 12(9), 246; https://doi.org/10.3390/inorganics12090246 - 11 Sep 2024

Abstract

Volumetric ceramic receivers can be regarded as a promising technology to heat air above 1000 °C for solar thermal electricity production. In this study, the thermal shock behavior of commercial 10 ppi (A) and 20 ppi (B) oxide-bonded silicon carbide (ob-SiC) reticulated porous [...] Read more.

Volumetric ceramic receivers can be regarded as a promising technology to heat air above 1000 °C for solar thermal electricity production. In this study, the thermal shock behavior of commercial 10 ppi (A) and 20 ppi (B) oxide-bonded silicon carbide (ob-SiC) reticulated porous ceramic (RPC) foams was evaluated using the SF60 solar furnace at Plataforma Solar de Almería. The foams were subjected to well-controlled temperature cycles ranging from 800 to 1000, 1200, 1300 or 1400 °C, for 25, 100, and 150 cycles. The extent of the damage after thermal shock was determined by crushing tests. The damage was found to be critically dependent on both the bulk density and cell size. Decreasing both the bulk density and cell size resulted in better thermal shock resistance. The B foam exhibited approximately half the stress degradation compared to the A foam when exposed to a temperature difference of 600 K (in the range of 800 to 1400 °C) and subjected to 150 cycles. Full article

(This article belongs to the Special Issue Feature Papers in Inorganic Materials 2024)

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10 pages, 1261 KiB

Open AccessCommunication

The Structural Aspects of Mutually Trans-X-Cu(I)-X (X = OL, NL, CL, PL, SL, SeL, Cl or Br) Complexes

by Milan Melník, Veronika Mikušová and Peter Mikuš

Inorganics 2024, 12(9), 245; https://doi.org/10.3390/inorganics12090245 - 6 Sep 2024

Abstract

The structural parameters for sixty mutually trans-(X-Cu(I)-X) (X = OL, NL, CL, PL, SL, SeL, Cl or Br, where OL, NL, CL, PL, SL, and SeL are ligands L with respective donor atoms O, N, C, P, S and Se) complexes were analyzed [...] Read more.

The structural parameters for sixty mutually trans-(X-Cu(I)-X) (X = OL, NL, CL, PL, SL, SeL, Cl or Br, where OL, NL, CL, PL, SL, and SeL are ligands L with respective donor atoms O, N, C, P, S and Se) complexes were analyzed and classified. Within the studied group, there are two types of complexes; the by far most common one is based on coordination, and another one is organometalics based on only C-donor atoms. Linear and bent geometric possibilities exist for coordination number two. The former is dominant in the structures of mutually trans -X–Cu(I)-X. In general, there are three preparative procedures; the most common is the direct reaction of a copper(I) salt with the ligands in a non-aqueous solution (mostly acetonitrile). Copper(I) complex cations can be isolated from salts with larger anions. Unidentate ligands occupy two coordination sites, which results in the linear arrangement. The X–Cu(I)–X angles are between 172.3° and 180°. Overall, it is observed that the mean Cu–X distance increases the covalent radius of the ligating atom in the sequence 1.849 Å (O, 0.73 Å) < 1.886 Å (N, 0.75 Å) < 1.900 Å (C, 0.77 Å) < 2.104 Å (Cl, 0.99 Å) < 2.137 Å (S, 1.02 Å) < 2.236 Å (P, 1.06 Å) < 2.244 Å (Br, 1.14 Å) < 2.260 Å (Se, 1.17 Å). Full article

(This article belongs to the Section Coordination Chemistry)

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12 pages, 5596 KiB

Open AccessArticle

ZnO and ZnO/Ce Powders as Tribocatalysts for Removal of Tetracycline Antibiotic

by Dobrina Ivanova, Hristo Kolev, Bozhidar I. Stefanov and Nina Kaneva

Inorganics 2024, 12(9), 244; https://doi.org/10.3390/inorganics12090244 - 5 Sep 2024

Abstract

Research on tribocatalysis, which involves the triboelectric effect, is based on the concept that friction between dissimilar materials can generate charges capable of initiating catalytic reactions. This phenomenon holds significant potential for the degradation of wastewater contaminants in the environment. In this study, [...] Read more.

Research on tribocatalysis, which involves the triboelectric effect, is based on the concept that friction between dissimilar materials can generate charges capable of initiating catalytic reactions. This phenomenon holds significant potential for the degradation of wastewater contaminants in the environment. In this study, pure and Ce-modified (2 mol%) ZnO powders were investigated as tribocatalysts for the degradation of doxycycline (DC), a tetracycline antibiotic, in the absence of light. The research demonstrates that friction between the catalyst, the beaker, and the polytetrafluoroethylene (PTFE) magnetic rod induces charge transfer at their interfaces, leading to the breakdown of pollutants. Additionally, doxycycline degradation was observed at three different stirring speeds (100, 300, and 500 rpm). The results confirmed the tribocatalytic effect, showing that DC degradation increases with higher stirring speeds. Using ZnO and ZnO/Ce powders, maximum degradations of 80% and 55%, respectively, were achieved in 24 h at a stirring speed of 500 rpm. The findings of this study suggest that these samples can effectively degrade contaminants in water through the application of mechanical energy. Full article

(This article belongs to the Special Issue Metal Catalyst Discovery, Design and Synthesis)

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15 pages, 5450 KiB

Open AccessArticle

Synthesis of Sulfonic Acid-Functionalized g-C₃N₄/BiOI Bifunctional Heterojunction for Enhanced Photocatalytic Removal of Tartrazine and PEC Oxygen Evolution Reaction

by Sridharan Balu, Harikrishnan Venkatesvaran, Chien-Chih Wang, Joon Ching Juan and Thomas Chung-Kuang Yang

Inorganics 2024, 12(9), 243; https://doi.org/10.3390/inorganics12090243 - 5 Sep 2024

Abstract

A Z-scheme heterojunction photo(electro)catalyst was fabricated by coupling sulfonic acid-modified graphitic carbon nitride (SA-g-CN) with bismuth oxyiodide (BiOI). The SA-g-CN component was prepared via wet-impregnation, while BiOI was synthesized through a hydrothermal method. Comprehensive characterization elucidated the structural and morphological properties of the [...] Read more.

A Z-scheme heterojunction photo(electro)catalyst was fabricated by coupling sulfonic acid-modified graphitic carbon nitride (SA-g-CN) with bismuth oxyiodide (BiOI). The SA-g-CN component was prepared via wet-impregnation, while BiOI was synthesized through a hydrothermal method. Comprehensive characterization elucidated the structural and morphological properties of the resulting composite. The SA-g-CN/BiOI exhibited exceptional performance in both photocatalytic degradation of tartrazine (TTZ) and photoelectrochemical oxygen evolution reaction (OER). Notably, 98.26% TTZ removal was achieved within 60 min of irradiation, while an OER onset potential of 0.94 V (vs. Ag/AgCl) and a high photocurrent density of 6.04 mA were recorded under AM 1.5G illumination. Band energy calculations based on Mott–Schottky measurements confirmed the formation of a Z-scheme heterojunction, which facilitated efficient charge separation and transfer, thereby enhancing catalytic activity. These findings establish the SA-g-CN/BiOI composite as a promising candidate for sustainable energy generation and environmental remediation applications. Full article

(This article belongs to the Special Issue Advanced Inorganic Nanomaterials for Energy Conversion and Catalysis Applications)

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20 pages, 1823 KiB

Open AccessArticle

Synthesis, Copper(II) Binding, and Antifungal Activity of Tertiary N-Alkylamine Azole Derivatives

by Teresa Pissarro, Cláudia Malta-Luís, Luana Ferreira, Catarina Pimentel and Luís M. P. Lima

Inorganics 2024, 12(9), 242; https://doi.org/10.3390/inorganics12090242 - 5 Sep 2024

Abstract

The rise in antifungal resistance among medically important fungi causing severe infectious diseases has underscored the urgent need for developing more effective antifungal agents. Growing evidence suggests that compounds combining functional antifungal groups with metals are promising candidates and may well be the [...] Read more.

The rise in antifungal resistance among medically important fungi causing severe infectious diseases has underscored the urgent need for developing more effective antifungal agents. Growing evidence suggests that compounds combining functional antifungal groups with metals are promising candidates and may well be the key to addressing this global challenge. In this work, a range of new azole-containing tertiary amine compounds were prepared from three N-alkylamine azole skeletons appended with a 2,4-dihalogenobenzene function and one of the five different metal-binding motifs pyridine, quinoline, 8-hydroxyquinoline, 2-methoxyphenol, and 4-bromophenol. The copper(II) binding of these azole compounds was studied by spectrophotometric titrations in buffered aqueous medium to determine the metal binding equilibria and to comparatively characterize the copper(II)-binding ability of the compounds. The activity of all compounds against the opportunistic fungal pathogen Candida glabrata was also evaluated, allowing us to draw important conclusions about structure–activity relationships that will guide the future design of more effective metal-binding antifungal compounds. Full article

(This article belongs to the Special Issue Metal-Based Compounds: Relevance for the Biomedical Field)

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11 pages, 8759 KiB

Open AccessArticle

An Investigation of the Interface between Transition Metal Oxides (MnO_x, FeO_x, CoO_x and NiO_x)/MoO₃ Composite Electrocatalysts for Oxygen Evolution Reactions

by Karmegam Dhanabalan, Mrunal Bhosale, Ganesan Sriram, Thangarasu Sadhasivam and Tae Hwan Oh

Inorganics 2024, 12(9), 241; https://doi.org/10.3390/inorganics12090241 - 2 Sep 2024

Abstract

This study presents the synthesis of a multicomponent metal oxide electrocatalyst that increases the activity of the oxygen evolution reaction (OER). We synthesized transition metal oxides (MnO_x, FeO_x, CoO_x, and NiO_x) with MoO₃ heterostructures [...] Read more.

This study presents the synthesis of a multicomponent metal oxide electrocatalyst that increases the activity of the oxygen evolution reaction (OER). We synthesized transition metal oxides (MnO_x, FeO_x, CoO_x, and NiO_x) with MoO₃ heterostructures through a solid-state reaction approach at low cost. In comparison to the other compositions, CoO_x garnered higher attention and demonstrated superior performance on account of its large surface area and varied crystal facets. The MnO_x-MoO₃, FeO_x-MoO₃, CoO_x-MoO₃, and NiO_x-MoO₃ compositions attained an overpotential of 390 mV, 350 mV, 310 mV, and 340 mV, respectively, at a current density of 10 mA cm⁻² in alkaline solution. The performance of OER was enhanced in CoO_x-MoO₃ at 10 mA cm⁻², while FeO_x-MoO₃ exhibited a lower current density at 100 mA cm⁻² than other metal oxides. The CoO_x-MoO₃ material exhibited a favorable crystal interface transition due to the presence of MoO₃ oxide. For the first time, we report on the MoO₃-to-(MnO_x, FeO_x, CoO_x, and NiO_x) interface crystal transition and the active surface area for OER catalytic activity in water-splitting processes. This investigation intends to develop an electrocatalyst that is capable of producing hydrogen with the use of heterostructure metal oxides. Full article

(This article belongs to the Special Issue Mixed Metal Oxides II)

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12 pages, 19537 KiB

Open AccessArticle

Growth, Spectroscopic Characterization and Continuous-Wave Laser Operation of Er,Yb:GdMgB₅O₁₀Crystal

by Konstantin N. Gorbachenya, Elena A. Volkova, Victor V. Maltsev, Victor E. Kisel, Diana D. Mitina, Elizaveta V. Koporulina, Nikolai N. Kuzmin, Ekaterina I. Marchenko and Vladimir L. Kosorukov

Inorganics 2024, 12(9), 240; https://doi.org/10.3390/inorganics12090240 - 31 Aug 2024

Abstract

A transparent Er³⁺,Yb³⁺:GdMgB₅O₁₀ single crystal with dimensions up to 24 × 15 × 12 mm was grown successfully by the high-temperature solution growth on dipped seeds technique from K₂Mo₃O₁₀-based solvent. [...] Read more.

A transparent Er³⁺,Yb³⁺:GdMgB₅O₁₀ single crystal with dimensions up to 24 × 15 × 12 mm was grown successfully by the high-temperature solution growth on dipped seeds technique from K₂Mo₃O₁₀-based solvent. The grown crystal was characterized using PXRD, DSC and ATR techniques. Differential scanning calorimetry measurements and SEM analysis of the heat-treated solids revealed Er,Yb:GdMgB₅O₁₀ to be an incongruent melting compound with an onset point of 1087 °C. The absorption edge of the Er,Yb:GMBO sample is located in the region of 245 nm, which approximates a value of 4.8 eV. Absorption and emission spectra, and luminescence kinetics, were studied. The energy transfer efficiency from ytterbium to erbium ions was determined. The laser operation in continuous-wave mode was realized and output characteristics were measured. The maximal output power of 0.15 W with a slope efficiency of 11% was obtained at 1568 nm. Full article

(This article belongs to the Special Issue Synthesis and Application of Luminescent Materials)

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28 pages, 6795 KiB

Open AccessReview

Ruthenium-Based Sensors

by Bruno Therrien

Inorganics 2024, 12(9), 239; https://doi.org/10.3390/inorganics12090239 - 29 Aug 2024

Abstract

In the periodic table of the elements, ruthenium occupies an excellent position, just below iron. And like iron, it possesses several oxidation states, with +2 and +3 being the most common. Accordingly, ruthenium chemistry is extremely rich and well developed, and ruthenium complexes [...] Read more.

In the periodic table of the elements, ruthenium occupies an excellent position, just below iron. And like iron, it possesses several oxidation states, with +2 and +3 being the most common. Accordingly, ruthenium chemistry is extremely rich and well developed, and ruthenium complexes show excellent catalytic aptitude, tremendous redox capacity, and intriguing biological activity. However, in the design of sensors, the use of ruthenium complexes can be better exploited, as they possess valuable electro- and photochemical properties. Therefore, there is an opportunity here, and ruthenium-based complexes might become, one day, key players in sensing technology. Starting a new research project with ruthenium-based sensors ourselves, writing this review was essential to see the current state of research in the field, to better identify opportunities and to have an overview of state-of-the-art examples. Full article

(This article belongs to the Section Coordination Chemistry)

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21 pages, 11601 KiB

Open AccessArticle

The Influence of Carbon Nanotube Functionalization on Water Contaminated by Diesel and Benzoic Acid: A Comparison of Two Case Studies

by Pierantonio De Luca, Anastasia Macario, Luigi Madeo and Jànos B.Nagy

Inorganics 2024, 12(9), 238; https://doi.org/10.3390/inorganics12090238 - 29 Aug 2024

Abstract

This article simply aims to compare two case studies concerning the purification, using carbon nanotubes, of water contaminated by the following two different common pollutants: benzoic acid and diesel. In particular, the aim is to highlight how the different natures of both of [...] Read more.

This article simply aims to compare two case studies concerning the purification, using carbon nanotubes, of water contaminated by the following two different common pollutants: benzoic acid and diesel. In particular, the aim is to highlight how the different natures of both of the polluting molecules and the carbon nanotubes play a fundamental role in water treatment. These two pollutants were taken into consideration because of their different chemical natures: benzoic acid is a polar pollutant, while the molecules present in diesel are substantially nonpolar. The carbon nanotubes used were both functionalized and nonfunctionalized. Functionalization is a process that allows for the introduction of functional groups onto the surface of carbon nanotubes. In this research, carboxylic functionalization was performed, which allowed for the insertion of carboxylic groups through attacks with sulfuric and nitric acids. Thanks to the results obtained, it was possible to quantify the optimization of the purification process depending on the types of carbon nanotubes and polluting molecules considered. The functionalized nanotubes exhibited greater performances in the treatment of water contaminated by benzoic acid compared to the nonfunctionalized ones. Instead, in the treatment of water contaminated by diesel, a greater purification capacity was shown by the nonfunctionalized carbon nanotubes compared to the functionalized ones. Full article

(This article belongs to the Special Issue Carbon Nanomaterials for Advanced Technology)

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12 pages, 5416 KiB

Open AccessArticle

Tunable Electronic and Magnetic Properties of 3d Transition Metal Atom-Intercalated Transition Metal Dichalcogenides: A Density Functional Theory Study

by Yujie Liu, Guang Yang, Zhiwen He, Yanbiao Wang, Xianghong Niu, Sake Wang, Yongjun Liu and Xiuyun Zhang

Inorganics 2024, 12(9), 237; https://doi.org/10.3390/inorganics12090237 - 29 Aug 2024

Abstract

Currently, intercalation has become an effective way to modify the fundamental properties of two-dimensional (2D) van der Waals (vdW) materials. Using density functional theory, we systematically investigated the structures and electronic and magnetic properties of bilayer transition metal dichalcogenides (TMDs) intercalated with 3 [...] Read more.

Currently, intercalation has become an effective way to modify the fundamental properties of two-dimensional (2D) van der Waals (vdW) materials. Using density functional theory, we systematically investigated the structures and electronic and magnetic properties of bilayer transition metal dichalcogenides (TMDs) intercalated with 3d TM atoms (TM = Sc–Ni), TM@BL_MS₂ (M = Mo, V). Our results demonstrate that all the studied TM@BL_MS₂s are of high stability, with large binding energies and high diffusion barriers of TM atoms. Interestingly, most TM@BL_MoS₂s and TM@BL_VS₂s are found to be stable ferromagnets. Among them, TM@BL_MoS₂s (TM = Sc, Ti, Fe, Co) are ferromagnetic metals, TM@BL_MoS₂ (TM = V, Cr) and TM@BL_VS₂ (TM = Sc, V) are ferromagnetic half-metals, and the remaining systems are found to be ferromagnetic semiconductors. Exceptions are found for Ni@BL_MoS₂ and Cr@BL_VS₂, which are nonmagnetic semiconductors and ferrimagnetic half-metals, respectively. Further investigations reveal that the electromagnetic properties of TM@BL_MoS₂ are significantly influenced by the concentration of intercalated TM atoms. Our study demonstrates that TM atom intercalation is an effective approach for manipulating the electromagnetic properties of two-dimensional materials, facilitating their potential applications in spintronic devices. Full article

(This article belongs to the Special Issue Advanced Inorganic Semiconductor Materials, 2nd Edition)

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13 pages, 9835 KiB

Open AccessArticle

The Influence of Annealing Temperature on the Microstructure and Electrical Properties of Sputtered ZnO Thin Films

by Adil Alshoaibi

Inorganics 2024, 12(9), 236; https://doi.org/10.3390/inorganics12090236 - 29 Aug 2024

Abstract

Thin films are the backbone of the electronics industry, and their widespread application in heat sensors, solar cells, and thin-film transistors has attracted the attention of researchers. The current study involves the deposition of a hetero-structured (ZnO/Zn/ZnO) thin film on a well-cleaned glass [...] Read more.

Thin films are the backbone of the electronics industry, and their widespread application in heat sensors, solar cells, and thin-film transistors has attracted the attention of researchers. The current study involves the deposition of a hetero-structured (ZnO/Zn/ZnO) thin film on a well-cleaned glass substrate using the DC magnetron sputtering technique. The samples were then annealed at 100, 200, 300, 400, and 500 °C. The structural, morphological, and electrical characteristics of the annealed samples as well as one as-deposited sample were then examined using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and a Hall effect measuring apparatus. XRD analysis showed a hexagonal ZnO crystal structure for the samples annealed at 300 and 400 °C, whereas the samples annealed at 100 and 200 °C showed metallic zinc and hexagonal ZnO, and the crystallinity decreased for the sample annealed at 500 °C with pure hexagonal crystal symmetry. According to the AFM study, as the annealing temperature increases, the average roughness (R_a) decreases. Temperature has an inverse relationship with particle size. The optimal annealing temperature was determined to be 400 °C. Over this temperature range, the average roughness and particle size increased. Similarly, when R_a decreased, the conductivity increased and the resistance decreased. A fundamental difficulty is that the heating of the heterostructure to 400 °C melts the Zn-based intermediate layer, which alters the Zn phase and disrupts the sample homogeneity. Full article

(This article belongs to the Special Issue New Advances into Nanostructured Oxides, 2nd Edition)

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19 pages, 1885 KiB

Open AccessArticle

The Legacy of AAZTA—Synthesis and Coordination Chemistry of Two AAZTA Structural Analogs

by Federico Forgione, Madalina Ranga, Fabio Travagin, Mariangela Boccalon, Zsolt Baranyai, Giovanni B. Giovenzana and Luciano Lattuada

Inorganics 2024, 12(9), 235; https://doi.org/10.3390/inorganics12090235 - 29 Aug 2024

Abstract

AAZTA (6-amino-6-methylperhydro-1,4-diazepinetetraacetic acid) is a mesocyclic chelating agent forming stable complexes with several metal ions. Over the past 20 years since its inception, AAZTA and its bifunctional derivatives have gained a growing role in several applications ranging from MRI contrast agents to diagnostics [...] Read more.

AAZTA (6-amino-6-methylperhydro-1,4-diazepinetetraacetic acid) is a mesocyclic chelating agent forming stable complexes with several metal ions. Over the past 20 years since its inception, AAZTA and its bifunctional derivatives have gained a growing role in several applications ranging from MRI contrast agents to diagnostics and nuclear medicine. The recent market restrictions applied to nitroethane preclude the easy preparation of AAZTA, prompting the search for a suitable alternative. In this work, we report the synthesis of two structural analogs (AAZTA-Bn and AAZTA-Et) from commercially available chemicals and the thermodynamic and kinetic study of their complexing ability towards selected metal ions. A comparison of the complexing properties of AAZTA-Bn and AAZTA-Et with the former AAZTA allows us to identify the possible heir of this efficient chelating agent. Full article

(This article belongs to the Special Issue Supramolecular Coordination Complexes: Synthesis and Applications)

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16 pages, 2220 KiB

Open AccessArticle

A New Azide-Bridged Polymeric Manganese (III) Schiff Base Complex with an Allylamine-Derived Ligand: Structural Characterization and Activity Spectra

by Aynaz Talebi, Mehdi Salehi, A. J. Lopes Jesus, Maciej Kubicki, Rui Fausto and Reza Golbedaghi

Inorganics 2024, 12(9), 234; https://doi.org/10.3390/inorganics12090234 - 28 Aug 2024

Abstract

This paper reports the synthesis and structural characterization of a novel azide-bridged polymeric manganese (III) Schiff base complex, using 2-((allylimino)methyl)-6-ethoxyphenol as a ligand. The crystal structure of the synthesized compound, elucidated by single-crystal X-ray diffraction analysis, indicates that it crystallizes in the monoclinic [...] Read more.

This paper reports the synthesis and structural characterization of a novel azide-bridged polymeric manganese (III) Schiff base complex, using 2-((allylimino)methyl)-6-ethoxyphenol as a ligand. The crystal structure of the synthesized compound, elucidated by single-crystal X-ray diffraction analysis, indicates that it crystallizes in the monoclinic space group P2₁/c. The complex is found to display an octahedral geometry in which the central manganese Mn(III) coordinates with two bidentate donor Schiff base ligands via oxygen and nitrogen atoms. In addition, the metallic centers are linked together to form a one-dimensional chain bridged by end-to-end azide ligands. To offer a more thorough characterization of the synthesized compound, the study incorporates experimental data from FT-IR, UV-Vis, and cyclic voltammetry, alongside computational results from Hirshfeld surface analysis and DFT calculations conducted for both the ligand and complex. The computational analyses provided valuable insights into the intrachain and interchain interactions within the crystal structure, clarified the conformational characteristics of the isolated ligand molecule, and aided in the interpretation of the experimental IR spectra. Furthermore, an assessment of the compound’s drug-like properties was conducted using activity spectra for substances (PASS) predictions, revealing potential pharmacological activities. Full article

(This article belongs to the Special Issue Metal Complexes Diversity: Synthesis, Conformations, and Bioactivity)

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