Inorganics

17 pages, 4192 KiB

Open AccessArticle

Significant Enhancement of Strength and Ductility in Bioresorbable Zn–0.1Mg Alloy via ECAP Processing

by Iryna Cuperová, Martin Fujda, Róbert Kočiško, Patrik Petroušek, Zuzana Molčanová, Miloš Matvija, Róbert Džunda, Beáta Ballóková, Dávid Csík, Katarína Gáborová and Karel Saksl

Inorganics 2025, 13(6), 193; https://doi.org/10.3390/inorganics13060193 - 10 Jun 2025

Abstract

Zinc (Zn)-based alloys are considered promising bioresorbable materials for intracorporeal implants due to their good biocompatibility and suitable degradation rate in physiological environments. However, their broader application is hindered by insufficient mechanical properties, which are essential for fulfilling the therapeutic function of bioresorbable [...] Read more.

Zinc (Zn)-based alloys are considered promising bioresorbable materials for intracorporeal implants due to their good biocompatibility and suitable degradation rate in physiological environments. However, their broader application is hindered by insufficient mechanical properties, which are essential for fulfilling the therapeutic function of bioresorbable implants. This study investigates the effect of severe plastic deformation on the microstructure and mechanical properties of as-cast Zn–0.1Mg (wt.%) alloy. The as-cast alloy, characterised by a coarse-grained microstructure with intermetallic phases at grain boundaries and low strength and ductility, was subjected to two passes of Equal Channel Angular Pressing (ECAP). The intense plastic deformation transformed the coarse-grained structure into an ultrafine-grained solid solution matrix. This substantial microstructural refinement led to a significant enhancement in mechanical performance. The yield strength (YS) and ultimate tensile strength (UTS) more than doubled, reaching 198 MPa and 215 MPa, respectively. Remarkably, the elongation increased from 2.2% to 187% in tensile testing. These findings confirm the beneficial effect of grain refinement and dynamic recrystallisation on the mechanical behaviour of bioresorbable Zn–0.1Mg alloy and highlight the high potential of ECAP processing for optimising the mechanical properties of Zn-based biodegradable materials. Full article

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

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22 pages, 4227 KiB

Open AccessReview

Redox Mediators for Li₂CO₃ Decomposition

by Zixuan Liu, Haoshen Huang, Zhengfei Chen, Haiyong He, Deyu Wang and Zhoupeng Li

Inorganics 2025, 13(6), 192; https://doi.org/10.3390/inorganics13060192 - 8 Jun 2025

Abstract

Lithium–air batteries (LABs) possess the highest energy density among all energy storage systems, and have drawn widespread interest in academia and industry. However, many arduous challenges are still to be conquered, one of them is Li₂CO₃, which is a [...] Read more.

Lithium–air batteries (LABs) possess the highest energy density among all energy storage systems, and have drawn widespread interest in academia and industry. However, many arduous challenges are still to be conquered, one of them is Li₂CO₃, which is a ubiquitous product in LABs. It is inevitably produced but difficult to decompose; therefore, Li₂CO₃ is perceived as the “Achilles’ heel of LABs”. Among various approaches to addressing the Li₂CO₃ issue, developing Li₂CO₃-decomposing redox mediators (RMs) is one of the most convenient and versatile, because they can be electrochemically oxidized at the gas cathode surface, then they diffuse to the solid-state products and chemically oxidize them, recovering the RMs to a pristine state and avoiding solid-state catalysts’ contact instability with Li₂CO₃. Furthermore, because of their function mechanism, they can double as catalysts for Li₂O₂/LiOH decomposition, which are needed in LABs/LOBs anyway regardless of Li₂CO₃ incorporation due to the sluggish kinetics of oxygen reduction/evolution reactions. This review summarizes the progress in Li₂CO₃-decomposing RMs, including halides, metal–chelate complexes, and metal-free organic compounds. The insights into and discrepancies in the mechanisms of Li₂CO₃ decomposition and corresponding catalysis processes are also discussed. Full article

(This article belongs to the Special Issue Novel Research on Electrochemical Energy Storage Materials)

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11 pages, 11517 KiB

Open AccessArticle

Kinetics-Controlled Simple Method for the Preparation of Au@Ag Hierarchical Superstructures for SERS Analysis

by Mengqi Lyu, Ming Jiang, Hanting Yu, Kailiang Wu, Peitao Zhu, Yingke Zhu, Yan Xia and Juan Li

Inorganics 2025, 13(6), 191; https://doi.org/10.3390/inorganics13060191 - 7 Jun 2025

Abstract

Silver nanostructures exhibit exceptional surface-enhanced Raman scattering (SERS) performance due to their strong plasmonic resonance. However, their practical applications are often hindered by structural instability, leading to deformation and performance degradation. In this study, we developed a kinetics-controlled synthetic strategy to fabricate gold-encapsulated [...] Read more.

Silver nanostructures exhibit exceptional surface-enhanced Raman scattering (SERS) performance due to their strong plasmonic resonance. However, their practical applications are often hindered by structural instability, leading to deformation and performance degradation. In this study, we developed a kinetics-controlled synthetic strategy to fabricate gold-encapsulated silver (Au@Ag) hierarchical superstructures (HSs) with enhanced SERS activity and stability. By leveraging polyvinylpyrrolidone (PVP) as a surface modifier and precisely regulating the introduction rate of reaction precursors, we achieved meticulous control over the galvanic replacement kinetics, thereby preserving the structural integrity of pre-synthesized Ag HSs during the formation of Au@Ag HSs. The resulting well-defined Au@Ag HSs demonstrated superior SERS performance, achieving a detection limit of 10⁻⁹ M for crystal violet (CV) while exhibiting outstanding signal reproducibility (relative standard deviation, RSD = 11.60%). This work provides a robust and scalable approach to designing stable, high-efficiency SERS-active nanostructures with broad potential in analytical and sensing applications. Full article

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14 pages, 2999 KiB

Open AccessArticle

The Growth-Inhibitory Effect of Glass Ionomer Liners Reinforced with Fluoride-Modified Nanotubes

by Ricardo De Jesús-Pascual, Elias Nahum Salmerón-Valdés, Adriana Alejandra Morales-Valenzuela, Leticia Verónica Jiménez-Rojas, Rodrigo Correa-Prado, Edith Lara-Carrillo, Víctor Hugo Toral-Rizo, Osmar Alejandro Chanes-Cuevas, Ulises Velázquez-Enríquez, Raúl Alberto Morales-Luckie and Javier Jaramillo-García

Inorganics 2025, 13(6), 190; https://doi.org/10.3390/inorganics13060190 - 7 Jun 2025

Abstract

The aim of this research was to compare the growth-inhibitory effect of halloysite-based nanotubes preloaded with sodium fluoride incorporated into two commercial glass ionomers (Vitrebond 3M^TM and Ionobond VOCO) for indirect pulp capping. Methods: Sixty samples were prepared and were distributed into [...] Read more.

The aim of this research was to compare the growth-inhibitory effect of halloysite-based nanotubes preloaded with sodium fluoride incorporated into two commercial glass ionomers (Vitrebond 3M^TM and Ionobond VOCO) for indirect pulp capping. Methods: Sixty samples were prepared and were distributed into two control groups, two positive control groups and two experimental groups. A total of 10% of the total weight of ionomer powder required to prepare each sample was replaced with nanotubes that had been preloaded at 2000 parts per million (minimum inhibitory dose for Streptococcus mutans established in this study using the McFarland index). The growth-inhibitory effect was determined by placing the samples in Petri dishes inoculated with S. mutans for 24 h at 37 °C. Results: Regarding the control groups, only Vitrebond demonstrated a growth inhibition zone; both experimental groups showed an inhibitory effect, and statistical differences were observed when the experimental Ionobond group and control groups were compared. Conclusions: The ionomers reinforced with fluorine-modified nanotubes showed an adequate inhibitory effect on Streptococcus mutans. Full article

(This article belongs to the Special Issue Recent Research and Application of Amorphous Materials)

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16 pages, 1384 KiB

Open AccessArticle

Transition Metal (II) Coordination Chemistry Ligated by a New Coplanar Tridentate Ligand, 2,6-Bis(5-isopropyl-1H-pyrazol-3-yl)pyridine

by Kiyoshi Fujisawa, Yurika Minakawa and David James Young

Inorganics 2025, 13(6), 189; https://doi.org/10.3390/inorganics13060189 - 6 Jun 2025

Abstract

Transition metal (II) complexes stabilized by 2,6-di(pyrazol-3-yl)pyridine as a novel coplanar tridentate nitrogen-donor ligand have been reported for their unusual structures and photoluminescent properties. In this work, the ligand 2,6-bis(5-isopropyl-1H-pyrazole-3-yl)pyridine (denoted as L) and its transition metal (II) halogenido complexes [...] Read more.

Transition metal (II) complexes stabilized by 2,6-di(pyrazol-3-yl)pyridine as a novel coplanar tridentate nitrogen-donor ligand have been reported for their unusual structures and photoluminescent properties. In this work, the ligand 2,6-bis(5-isopropyl-1H-pyrazole-3-yl)pyridine (denoted as L) and its transition metal (II) halogenido complexes viz [ZnCl₂(L)] (1), [ZnBr₂(L)] (2), [CuCl₂(L)] (3), and [CuCl(L)(thf)](PF₆) (4) were synthesized and characterized by single crystal X-ray crystal analysis. Its structures contained N–H groups in its pyrazole rings and hydrogen bonds between these N–H donors and the coordinated halogenide ions and lattice solvent molecules. Tautomers between 3-pyridyl and 5-pyridyl substitutes were also observed. In L, the N–H group at the pyrazole nitrogen was located adjacent to the pyridine ring to form hydrogen bonds with adjacent pyrazoles. However, on complexation, the H atoms at the pyrazole nitrogens are shifted remotely to the pyridine. The zinc (II) complexes [ZnCl₂(L)] (1) and [ZnBr₂(L)] (2) possessed distorted trigonal pyramidal structures in the solid state. By comparison, the copper (II) complexes [CuCl₂(L)] (3) and [CuCl(L)(thf)](PF₆) (4) adopted square pyramidal geometry with a Jahn–Teller distortion resulting from their d⁹ electron configurations. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series in “Featuring Ligands and Their Applications in Coordination Chemistry”, 2nd Edition)

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15 pages, 5030 KiB

Open AccessArticle

Decorating Ti₃C₂ MXene Nanosheets with Fe-N_x-C Nanoparticles for Efficient Oxygen Reduction Reaction

by Han Zheng, Fagang Wang and Weimeng Si

Inorganics 2025, 13(6), 188; https://doi.org/10.3390/inorganics13060188 - 6 Jun 2025

Abstract

Finding alternatives to platinum that exhibit high activity, stability, and abundant reserves as oxygen reduction electrocatalysts is crucial for the advancement of fuel cells. In this study, we first mixed FeCl₂·4H₂O, 1,10-phenanthroline, and Vulcan XC-72, followed by pyrolysis in [...] Read more.

Finding alternatives to platinum that exhibit high activity, stability, and abundant reserves as oxygen reduction electrocatalysts is crucial for the advancement of fuel cells. In this study, we first mixed FeCl₂·4H₂O, 1,10-phenanthroline, and Vulcan XC-72, followed by pyrolysis in a nitrogen atmosphere, to obtain FeNC. Subsequently, we combined FeNC with MXene produce FeNC/MXene composites. The FeNC/MXene catalyst achieved a half-wave potential of 0.857 V in an alkaline medium, exhibiting better oxygen reduction reaction (ORR) activity and durability than commercial Pt/C catalysts. The layered structure of MXene endows the material with a high specific surface area and facilitates efficient electron transfer pathways, thereby promoting rapid charge transfer and material diffusion. The cleavage of Ti-C bonds in Ti₃C₂ at elevated temperatures results in the transformation of MXene into TiO₂, where the coexistence of anatase and rutile phases generates a synergistic effect that enhances both the mass transfer rate and the electrical conductivity of the catalytic layer. Additionally, the unique electronic structure of the FeN_x sites simultaneously optimizes electrocatalytic activity and stability. Leveraging these structural advantages, the FeNC/MXene composite catalysts demonstrate exceptional catalytic activity and long-term stability in oxygen reduction reactions. Full article

(This article belongs to the Special Issue Advanced Electrocatalysis Materials Design: Innovations and Applications)

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19 pages, 3801 KiB

Open AccessArticle

Effect of BaO Content on the Photoluminescence Properties of Mn²⁺ and Eu²⁺-Codoped Sr_3−xBa_xMgSi₂O₈ Phosphors

by Shu-Han Liao, Fang-Tzu Hsu, Cheng-Fu Yang and Kao-Wei Min

Inorganics 2025, 13(6), 187; https://doi.org/10.3390/inorganics13060187 - 6 Jun 2025

Abstract

In this study, Mn²⁺ and Eu²⁺-codoped Sr_3−xBa_xMgSi₂O₈ (x = 0–1.5) phosphors were synthesized at 1400 °C under a reducing atmosphere composed of 5% H₂ and 95% N₂ to produce [...] Read more.

In this study, Mn²⁺ and Eu²⁺-codoped Sr_3−xBa_xMgSi₂O₈ (x = 0–1.5) phosphors were synthesized at 1400 °C under a reducing atmosphere composed of 5% H₂ and 95% N₂ to produce materials with blue light emission. The resulting powders were characterized using several analytical techniques: X-ray diffraction (XRD) was employed to identify the crystalline phases, scanning electron microscopy (SEM) was used to observe the microstructure, and photoluminescence excitation (PLE) and emission (PL) spectra were measured using a fluorescence spectrophotometer. The results revealed several key findings. XRD analysis showed that the Sr₃MgSi₂O₈ (Sr_3−xBa_xMgSi₂O₈) phase coexisted with secondary phases of Sr₂SiO₄ and Sr₂MgSi₂O₇. SEM observations indicated that the synthesized powders exhibited a distinctive needle-like structure anchored on the surfaces of the particles. The PL and PLE intensities increased sharply as the BaO content increased from x = 0 to x = 0.6, followed by a more gradual increase, reaching a peak at x = 1.2. Additionally, as the value of x increased, the wavelengths corresponding to maximum PL and PLE intensities exhibited a blue shift, moving to shorter wavelengths. Further investigation focused on the excitation behavior by replotting the PLE spectra using energy (eV) as the x-axis. A Gaussian fitting function was applied to deconvolute the excitation bands, enabling an in-depth analysis of how compositional variations influenced the Stokes shift. Full article

(This article belongs to the Section Inorganic Solid-State Chemistry)

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14 pages, 3662 KiB

Open AccessArticle

Size-Activity Relationship of TiO₂-Supported Pt Nanoparticles in Hydrogenation Reactions

by Qi Zhang, Tianbo Li, Xiang-Ting Min, Shu-Xian Li, Xunzhu Jiang, Qian Zhang, Yangyang Li, Xinlong Yan, Rui Feng, Feifei Yang, Wei Zhou, Xiaoyan Hu, Botao Qiao and Zhonghai Ni

Inorganics 2025, 13(6), 186; https://doi.org/10.3390/inorganics13060186 - 6 Jun 2025

Abstract

Quantitative assessments of the geometric influence on catalytic activity are crucial for catalyst design and understanding reaction mechanisms. In this study, we synthesized a series of catalysts comprising TiO₂-supported Pt nanoparticles with varying particle sizes, which were systematically evaluated in representative [...] Read more.

Quantitative assessments of the geometric influence on catalytic activity are crucial for catalyst design and understanding reaction mechanisms. In this study, we synthesized a series of catalysts comprising TiO₂-supported Pt nanoparticles with varying particle sizes, which were systematically evaluated in representative hydrogenation reactions. A consistent size–activity relationship is established, wherein overall turnover frequency (TOF) values (TOF_overall: calculated as moles of reactant converted per mole of Pt per hour) are modeled as functions of the average diameter of the supported Pt particles, yielding slope values consistently near −1 across a variety of common substrates. This finding underscores that catalytic activity predominantly originates from surface sites on the Pt nanoparticles rather than from interfacial, edge, or corner active sites. Full article

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25 pages, 2617 KiB

Open AccessReview

Recent Advances in Zinc Complexes for Stereoselective Ring-Opening Polymerization and Copolymerization

by Xia Li, Yang Li, Gangqiang Zhang, Yat-Ming So and Yu Pan

Inorganics 2025, 13(6), 185; https://doi.org/10.3390/inorganics13060185 - 5 Jun 2025

Abstract

Recent advances in zinc complexes for stereoselective ring-opening polymerization (ROP) and copolymerization (ROCOP) highlight their pivotal role in synthesizing biodegradable aliphatic polyesters and polycarbonates. These materials address the urgent demand for sustainable alternatives to petroleum-based plastics, with stereochemical control directly impacting polymer crystallinity, [...] Read more.

Recent advances in zinc complexes for stereoselective ring-opening polymerization (ROP) and copolymerization (ROCOP) highlight their pivotal role in synthesizing biodegradable aliphatic polyesters and polycarbonates. These materials address the urgent demand for sustainable alternatives to petroleum-based plastics, with stereochemical control directly impacting polymer crystallinity, thermal stability, and degradability. Zinc catalysts, leveraging low toxicity and versatile coordination chemistry, enable precise stereoregulation, whose performance is modulated by ligand steric/electronic effects, coordination geometry, and reaction conditions. This review summarizes the recent developments in zinc complexes for stereoselective ROP and ROCOP, focusing on ligand design strategies to enhance catalytic performance. Full article

(This article belongs to the Special Issue Synthesis, Characterization and Application of Novel Coordination and Organometallic Complexes)

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15 pages, 5342 KiB

Open AccessArticle

Synthesis of Dimethyl Terephthalate from Terephthalic Acid Esterification over the Zeolite Catalysts

by Ningyu Jia, Haoyu Han, Tao Yang, Meng Zhang and Zhongyi Liu

Inorganics 2025, 13(6), 184; https://doi.org/10.3390/inorganics13060184 - 5 Jun 2025

Abstract

The esterification of terephthalic acid (PTA) with methanol to dimethyl terephthalate (DMT) was investigated using commercially available zeolite catalysts as the eco-friendly solid acids. Six typical zeolites (ZSM-5-25, ZSM-5-50, ZSM-5-100, ZSM-35, MOR, and β) were systematically evaluated. Among them, β zeolite showed excellent [...] Read more.

The esterification of terephthalic acid (PTA) with methanol to dimethyl terephthalate (DMT) was investigated using commercially available zeolite catalysts as the eco-friendly solid acids. Six typical zeolites (ZSM-5-25, ZSM-5-50, ZSM-5-100, ZSM-35, MOR, and β) were systematically evaluated. Among them, β zeolite showed excellent catalytic performance, achieving nearly 100% PTA conversion and 76.1% DMT selectivity under the conditions of 200 °C, of 0.5 MPa N₂ pressure, m(PTA):V(methanol) of 1:40 (g/mL), m(PTA):m(catalyst) of 10:1 over 4 h. The characterization results show that the catalytic efficiency was correlated with acid site strength, specific surface area, and mesoporous structure of the zeolite. After optimization, β zeolite achieved 100% PTA conversion and 94.1% DMT selectivity under the conditions of 200 °C, of 1 MPa N₂ pressure, m(PTA)/V(methanol) of 1:30 (g/mL), m(PTA)/m(catalyst) of 8:1 over 8 h. Moreover, β zeolite exhibited superior stability, maintaining over 92% of its initial activity after five cycles, highlighting its potential for sustainable DMT production. Full article

(This article belongs to the Special Issue Inorganics Emerging Investigators Themed Collection 2024/2025)

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30 pages, 3060 KiB

Open AccessReview

Solid–Solid Interface Design for Hydrogen Production by Direct Seawater Electrolysis: Progress and Challenges

by Bowei Zhou, Tong Wu, Yilin Dong, Yinbo Zhan, Fei Wei, Dongliang Zhang and Xia Long

Inorganics 2025, 13(6), 183; https://doi.org/10.3390/inorganics13060183 - 4 Jun 2025

Abstract

Using direct seawater electrolysis (DSE) for hydrogen production has garnered increasing scientific attention as a promising pathway toward sustainable energy solutions. Given the complex ionic environment of seawater, researchers have proposed a diverse range of strategies aimed at addressing the issue of enhancing [...] Read more.

Using direct seawater electrolysis (DSE) for hydrogen production has garnered increasing scientific attention as a promising pathway toward sustainable energy solutions. Given the complex ionic environment of seawater, researchers have proposed a diverse range of strategies aimed at addressing the issue of enhancing the corrosion resistance of anodes, yet no optimal solution has been found so far. Among the emerging approaches, a design using multilayer electrode architecture offers notable advantages by introducing abundant active sites, diverse chemical environments, and robust physical structures. Crucially, these configurations enable the synergistic integration of distinct material properties across different layers, thereby enhancing both electrochemical activity and structural stability in harsh seawater environments. Despite these benefits, a limited understanding of the role played by solid–solid interfaces has hindered the rational design and practical application of such electrodes. This review focuses on the design principles and functional roles of solid–solid interfaces in multilayer anodes for the oxygen evolution reaction (OER) under DSE conditions. In addition, we systematically summarize and discuss the representative fabrication methods for constructing solid–solid interfaces in hierarchically structured electrodes. By screening recent advances in these techniques, we further highlight how engineered interfaces influence interfacial bonding, electron transfer, and mass transport during DSE processes, enhancing the intrinsic catalytic activity, as well as protecting the metallic electrode from corrosion. Finally, current challenges and future research directions to deepen the mechanistic understanding of interface phenomena are discussed, with the aim of accelerating the development of robust and scalable electrodes for direct seawater electrolysis. Full article

(This article belongs to the Special Issue Novel Catalysts for Photoelectrochemical Energy Conversion)

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14 pages, 1214 KiB

Open AccessCommunication

Variable Unidentate Ligands in Cu(I)(XXY) and Cu(I)(XYZ) Complexes—Structural Aspects

by Milan Melník, Veronika Mikušová and Peter Mikuš

Inorganics 2025, 13(6), 182; https://doi.org/10.3390/inorganics13060182 - 1 Jun 2025

Abstract

This manuscript provides a structural analysis of over eighty copper(I) compounds mostly reported in the Cambridge Structural Database (CSD) version 5.45 in which unidentate ligands build up various inner coordinate spheres. These complexes crystallized in four crystal classes: trigonal (1 example), triclinic (10 [...] Read more.

This manuscript provides a structural analysis of over eighty copper(I) compounds mostly reported in the Cambridge Structural Database (CSD) version 5.45 in which unidentate ligands build up various inner coordinate spheres. These complexes crystallized in four crystal classes: trigonal (1 example), triclinic (10 examples), orthorhombic (13 examples), and monoclinic (58 examples). The analyzed complexes can be divided into two groups according to the type of coordinating ligands (L = X, Y, Z) incorporated into their structure: Cu(XXY) (more common) and Cu(XYZ). The structural data of L-Cu-L bond angles show that the angular distortion from the regular trigonal geometry grows with total mean values of deviation from 120.0°, in the order within the first group: 3.2°(Cu(IIP)) < 6.1°(Cu(ClClY)) < 6.5°(Cu(SSY)) < 8.2°(Cu(PPY)) < 8.9°(Cu(BrBrY)) < 16.9°(Cu(NNY)) < 19.8°(Cu(CCY)) < 25.5°(Cu(SeSeY)) and within the second group: 3.1°(Cu(SIP)) < 14.3°(Cu(SClP) < 15.5°(Cu(SBrP). The donor atoms are responsible for the distortion as follows: the soft donor atoms diminish the distortion while the borderline and the hard growing amplify the distortion. Given the importance of Cu(I) compounds in (bio)inorganic functional materials and catalysis, the correct interpretation of the geometry of Cu(I) complexes in terms of the coordination polyhedra is crucial for understanding the properties of the respective compounds. Full article

(This article belongs to the Special Issue Applications and Future Trends for Novel Copper Complexes)

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13 pages, 4213 KiB

Open AccessArticle

Carbon Nanotubes-Doped Metal Oxides and Metal Sulfides Heterostructure Achieves 3D Morphology Deposition of Li₂S and Stable Long-Cycle Lithium–Sulfur Batteries

by Yu-Lin Luo, Hai Huang, Cheng-Wei Zhu, Wen-Qi Lv, Ye Zeng, Gui-Fang Li, Xiao-Hong Fan, Ding-Rong Deng and Qi-Hui Wu

Inorganics 2025, 13(6), 181; https://doi.org/10.3390/inorganics13060181 - 1 Jun 2025

Abstract

The “shuttle effect” caused by the shuttling of soluble long-chain polysulfides between the anode and cathode electrodes has persistently hindered lithium–sulfur batteries (LSBs) from achieving stable and high-capacity performance. Numerous materials have been explored to mitigate the adverse effects of this phenomenon, among [...] Read more.

The “shuttle effect” caused by the shuttling of soluble long-chain polysulfides between the anode and cathode electrodes has persistently hindered lithium–sulfur batteries (LSBs) from achieving stable and high-capacity performance. Numerous materials have been explored to mitigate the adverse effects of this phenomenon, among which metal oxides and metal sulfides are regarded as promising solutions due to their strong adsorption capability toward lithium polysulfides (LiPSs). However, the poor electrical conductivity of the metal oxides and sulfides, coupled with their inherent morphological limitations, makes it challenging to sustainably suppress LiPS shuttling. In this study, we designed a heterostructured catalyst composed of a metal oxide–metal sulfide heterostructure integrated with carbon nanotubes (CNTs). This design addresses the low conductivity issue of metal oxides/sulfides while optimizing the material’s morphology, enabling persistent LiPSs adsorption. Furthermore, the composite successfully facilitates three-dimensional (3D) Li₂S deposition. The assembled battery exhibits stable and high-capacity performance, delivering an initial discharge capacity of 622.45 mAh g⁻¹ at 2C and retaining 569.5 mAh g⁻¹ after 350 cycles, demonstrating exceptional cycling stability. Full article

(This article belongs to the Special Issue New Semiconductor Materials for Energy Conversion)

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13 pages, 2415 KiB

Open AccessArticle

Synthesis, Characterization, and Biological Activities of Rare Earth Metal Complexes with Gallic Acid

by Nguyen Thi Hien Lan, Hoang Phu Hiep, Dinh Cong Trinh and Pham Van Khang

Inorganics 2025, 13(6), 180; https://doi.org/10.3390/inorganics13060180 - 28 May 2025

Abstract

This study reports the synthesis and characterization of four novel rare earth-gallic acid complexes, Sm(Gal)₃·4H₂O, Eu(Gal)₃·4H₂O, Tb(Gal)₃·4H₂O, and Dy(Gal)₃·4H₂O. These complexes were synthesized under optimized conditions (60 [...] Read more.

This study reports the synthesis and characterization of four novel rare earth-gallic acid complexes, Sm(Gal)₃·4H₂O, Eu(Gal)₃·4H₂O, Tb(Gal)₃·4H₂O, and Dy(Gal)₃·4H₂O. These complexes were synthesized under optimized conditions (60 °C, pH 4–5) and characterized using the Ln³⁺ elemental content method, infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), mass spectrometry (MS), and fluorescence spectroscopy. IR spectra confirmed the coordination of rare earth ions (Ln³⁺) with gallic acid through carboxylate oxygen atoms. TGA revealed the thermal decomposition pathways, while MS identified the molecular ion peaks and fragmentation patterns. All complexes exhibited strong luminescence under UV excitation, with emission peaks corresponding to characteristic transitions of Sm³⁺, Eu³⁺, Tb³⁺, and Dy³⁺. Biological assays demonstrated significant antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, with Dy(Gal)₃·4H₂O showing the highest efficacy. Additionally, the complexes displayed inhibitory effects on MCF7 breast cancer cells, with Tb(Gal)₃·4H₂O exhibiting the lowest IC₅₀ value (11.3 µM). These findings suggest that rare earth metal complexes with gallic acid have potential applications in biomedical fields, particularly as antimicrobial and anticancer agents. Full article

(This article belongs to the Special Issue Synthesis, Structural Analysis and Biological Activity of Metal Complexes)

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13 pages, 1551 KiB

Open AccessArticle

Experimental Attempts at and Theoretical Study of the Thermal Generation of o-Carborane-Supported N-Heterocyclic Carbenes

by Mei-Juan Liang, Ke-Cheng Chen, Zhongzheng Cui, Yan-Chang Zhou, Yan Wang, Fan Qi and Xu-Qiong Xiao

Inorganics 2025, 13(6), 179; https://doi.org/10.3390/inorganics13060179 - 25 May 2025

Abstract

N-Heterocyclic carbenes (NHCs) have been widely utilized over the past three decades due to their broad applications, yet synthetic methods for their preparation remain limited. A promising approach for NHC generation involves the thermolysis of NHC adducts. Herein, we report the synthesis of [...] Read more.

N-Heterocyclic carbenes (NHCs) have been widely utilized over the past three decades due to their broad applications, yet synthetic methods for their preparation remain limited. A promising approach for NHC generation involves the thermolysis of NHC adducts. Herein, we report the synthesis of NHC pentafluorobenzene adducts featuring an o-carboranyl group in the backbone (2), which, unlike previously studied systems, resists thermal decomposition. Density functional theory (DFT) calculations were used to investigate the discrepancy, revealing that the decomposition reaction is kinetically controlled. For widely studied NHC systems like IMes and SIMes, the activation barriers were calculated to be 246.3 kJ/mol and 267.3 kJ/mol, respectively, aligning with reactions requiring heating. In contrast, the o-carborane system exhibited a significantly higher barrier of 320.5 kJ/mol, primarily due to the structural influence of the o-carborane backbone. Further analysis indicates that delocalization of π-electrons from the backbone into the NHC’s p-orbitals lowers the activation barrier, whereas delocalization into an exo-NHC ring increases it. These findings provide new insights into the thermal generation of NHCs and we hope it can offer guidance for future NHC design and synthesis. Full article

(This article belongs to the Topic Heterocyclic Carbene Catalysis)

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16 pages, 3874 KiB

Open AccessArticle

Efficacy of Stenocereus queretaroensis-Derived Silver Nanoparticles Against Methicillin-Resistant Staphylococcus aureus Biofilms: Synthesis and Antibiofilm Activity

by Angélica Sofía González-Garibay, Iván Moisés Sánchez-Hernández, Ariadna Abigail Villarreal-Amézquita, Omar Ricardo Torres-González and Eduardo Padilla-Camberos

Inorganics 2025, 13(6), 178; https://doi.org/10.3390/inorganics13060178 - 24 May 2025

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for many infections, primarily due to its ability to form biofilms. Nanotechnology has recently been proposed as an alternative for controlling MRSA. In the present work, we evaluated the antimicrobial and antibiofilm activities of silver nanoparticles synthesized [...] Read more.

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for many infections, primarily due to its ability to form biofilms. Nanotechnology has recently been proposed as an alternative for controlling MRSA. In the present work, we evaluated the antimicrobial and antibiofilm activities of silver nanoparticles synthesized with Stenocereus queretaroensis peel extract (SAgNPs). The biosynthesis process was optimized using a response surface design. The results showed antimicrobial activity against MRSA bacteria, with a minimum inhibitory concentration and minimum bactericidal concentration of 0.15 and 0.31 µg/mL, respectively. SAgNPs inhibited biofilm formation in multi-well plates and Congo red agar. Molecular docking analysis revealed that the presence of quercetin, one of the chemical components of S. queretaroensis peel, forms hydrogen bonds with six interacting amino acids. This suggests that quercetin presents a stable binding to this site, which in turn suggests that the mechanism of action of SAgNPs is related to their binding to PBP2a. Therefore, these findings suggest a promising, environmentally friendly approach to combating antibiotic-resistant infections, potentially reducing the reliance on traditional antibiotics. Full article

(This article belongs to the Special Issue Advances in Metallic Nanoparticles for Antibacterial and Antibiofilm Control)

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12 pages, 1740 KiB

Open AccessArticle

A 4-Methylbenzoylhydrazine Pt(II) Complex Inhibits the Proliferation of Breast Cancer Cells by Regulating the Cell Cycle and Inducing Apoptosis

by Huiping Wang, Xianguang Bai, Yarui Li and Kexin Chen

Inorganics 2025, 13(6), 177; https://doi.org/10.3390/inorganics13060177 - 23 May 2025

Abstract

In this study, a novel 4-methylbenzoylhydrazide·dimethyl sulfoxide·dichloro platinum(II) complex (Pt2) was synthesized and characterized, and its anti-tumor activity and action mechanism were explored. The molecular structure and spatial configuration of the complex were determined using X-ray diffraction. The results obtained using fluorescence spectroscopy [...] Read more.

In this study, a novel 4-methylbenzoylhydrazide·dimethyl sulfoxide·dichloro platinum(II) complex (Pt2) was synthesized and characterized, and its anti-tumor activity and action mechanism were explored. The molecular structure and spatial configuration of the complex were determined using X-ray diffraction. The results obtained using fluorescence spectroscopy demonstrate that this complex can effectively bind to DNA and affect its fluorescence properties. The experimental results show that Pt2 exhibited significant inhibitory effects on a variety of tumor cell lines (MCF-7, HepG-2, NCI-H460, T24, and A549), and its IC50 values were lower than those of cisplatin (DDP), indicating stronger anti-tumor activity. In addition, the complex not only significantly induced the apoptosis of MCF-7 cells but also inhibited cell cycle arrest at the G₂ phase, with the proportion of G₂-phase cells as high as 49.47%. In conclusion, the 4-methylbenzoylhydrazide platinum(II) complex exhibits good anti-tumor activity by inducing apoptosis and inhibiting the cell cycle, providing an important experimental basis for the development of novel platinum-based anti-tumor drugs. Full article

(This article belongs to the Special Issue Advances in Metal-Based Anticancer Drugs)

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15 pages, 2798 KiB

Open AccessArticle

The Synthesis and Characterisation of Ru(III)-Substituted Keggin-Type Phosphomolybdates

by Max Papajewski, Jan-Christian Raabe, Hamid Anwari, Dorothea Voß, Jakob Albert and Maximilian J. Poller

Inorganics 2025, 13(6), 176; https://doi.org/10.3390/inorganics13060176 - 23 May 2025

Abstract

Polyoxometalates are a promising family of compounds for the development of new catalyst materials, although up to now they have mainly been applied in acid catalysis and oxidative processes. In this study, we present the synthesis and characterisation of two new Keggin-type phosphomolybdates, [...] Read more.

Polyoxometalates are a promising family of compounds for the development of new catalyst materials, although up to now they have mainly been applied in acid catalysis and oxidative processes. In this study, we present the synthesis and characterisation of two new Keggin-type phosphomolybdates, H₆[PRuMo₁₁O₄₀] and H₉[PRu₂Mo₁₀O₄₀]. The successful synthesis was confirmed with ICP-OES (elemental composition) and infrared spectroscopy (structure). Furthermore, the molecular structure of H₆[PRuMo₁₁O₄₀] was determined by electron diffraction. The new compounds were comprehensively characterised using ³¹P-NMR spectroscopy, UV-Vis spectroscopy, and electrochemical methods. Square-Wave-Voltammetry revealed an additional RedOx peak for the Ru-substituted POMs compared to the unsubstituted phosphomolybdate at around 825 mV. In a test reaction, the new compounds showed promising catalytic activity for the hydrogenation of lactic acid. Full article

(This article belongs to the Special Issue State-of-the-Art Inorganic Chemistry in Germany)

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15 pages, 2403 KiB

Open AccessArticle

Accessing Bisphosphine Copper(I) Complexes with Recalcitrant Pterin–Phenanthroline Ligands Through Mechanochemistry

by Siva S. M. Bandaru, Christian Fischer, Jevy V. Correia, Anna-Lena Land and Carola Schulzke

Inorganics 2025, 13(6), 175; https://doi.org/10.3390/inorganics13060175 - 22 May 2025

Abstract

The synthesis of [Cu(PteN^˄N)(P^˄P)][BF₄] complexes with pterin-fused phenanthroline (PteN^˄N) derivatives and bisphosphine (P^˄P) co-ligands was achieved through a mechanochemical approach. Due to the extremely poor solubility of PteN^˄N ligands, traditional solution [...] Read more.

The synthesis of [Cu(PteN^˄N)(P^˄P)][BF₄] complexes with pterin-fused phenanthroline (PteN^˄N) derivatives and bisphosphine (P^˄P) co-ligands was achieved through a mechanochemical approach. Due to the extremely poor solubility of PteN^˄N ligands, traditional solution methods are ineffective, whereas solid-state mechanochemistry reliably yielded the targeted heteroleptic—rather than homoleptic—complexes with considerable stability even in solution. The transformation from ligand to complex increased the solubility dramatically. The ligands and complexes were comprehensively characterised with a mixture of routine spectroscopic and spectrometric methods, the applicability of which depended to some extent on the compounds’ solubility, e.g., in the case of NMR spectroscopy. The photophysical properties of the complexes, which were not as exciting as anticipated, were assessed by absorption and emission spectroscopic methods, showing that further improvements are needed in complex design if these species are to be developed towards photocatalysis in the future. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series in “Featuring Ligands and Their Applications in Coordination Chemistry”, 2nd Edition)

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