Materials Chemistry and Physics最新文献

{"title":"Comprehensive Investigation Monolayers-dependent photocatalytic hydrogen evolution and optoelectronic properties of MXenes through DFT Study","authors":"E. Darkaoui , M. Maymoun , A. Zaghrane , A. Abbassi , S. Taj , B. Manaut","doi":"10.1016/j.matchemphys.2025.130922","DOIUrl":"10.1016/j.matchemphys.2025.130922","url":null,"abstract":"<div><div>This paper investigates the structural, electronic, optical, and photocatalytic properties of the <span><math><mrow><mi>S</mi><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>X</mi><msub><mrow><mi>T</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> MXene system <span><math><mrow><mo>(</mo><mi>X</mi><mo>=</mo><mi>C</mi><mspace></mspace><mi>o</mi><mi>r</mi><mspace></mspace><mi>N</mi><mo>;</mo><mi>T</mi><mo>=</mo><mi>C</mi><mi>l</mi><mspace></mspace><mi>o</mi><mi>r</mi><mspace></mspace><mi>H</mi><mo>)</mo></mrow></math></span> using density functional theory (DFT)-based theoretical calculations. Thermal and dynamic stabilities of all investigated monolayers were evaluated through ab initio molecular dynamics (AIMD) simulations and phonon dispersion calculations, confirming their structural stability under various conditions. Electronic band structure calculations, performed using both PBE-GGA and HSE06 exchange–correlation functionals, revealed that C-based MXenes <span><math><mrow><mo>(</mo><mi>S</mi><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>C</mi><mi>C</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msub><mspace></mspace><mi>and</mi><mspace></mspace><mi>S</mi><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>C</mi><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo></mrow></math></span> exhibit semiconducting behavior with HSE06 band gaps of 1.7214 eV and 1.8241 eV, respectively, while N-based MXenes <span><math><mrow><mo>(</mo><mi>S</mi><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>N</mi><mi>C</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msub><mspace></mspace><mi>and</mi><mspace></mspace><mi>S</mi><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>N</mi><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo></mrow></math></span> show metallic characteristics. Optical property analysis of <span><math><mrow><mi>S</mi><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>C</mi><mi>C</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> and <span><math><mrow><mi>S</mi><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>C</mi><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> monolayers demonstrated strong UV absorption and consistent reflectivity. These findings suggest high potential for UV-driven photocatalytic applications, particularly in environmental remediation and energy conversion processes utilizing both UV and visible light. All of the results show that <span><math><mrow><mi>S</mi><msub><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>C</mi><msub><mrow><mi>T</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> <span><math><mrow><mo>(</mo><mi>T</mi><mo>=</mo><mi>C</mi><mi>l</mi><mo>,</mo><mi>H</mi><mo>)</mo></mrow></math></span> MXenes monolayers are excellent candidates for optoelectronic an","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130922"},"PeriodicalIF":4.3,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143916760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A first-principles investigation of lead-free novel direct band gap double perovskite oxides X2AlBiO6 (X = Mg, Ca, Ba) for implementation in optoelectronic and thermoelectric technologies","authors":"Akteruzzaman Ashik ,&nbsp;Parartha Biswas ,&nbsp;Mashnon Hasan Fahim ,&nbsp;Muhammad Ruhul Amin","doi":"10.1016/j.matchemphys.2025.130911","DOIUrl":"10.1016/j.matchemphys.2025.130911","url":null,"abstract":"<div><div>In this study, the structural, electronic, optical, and thermoelectric properties of novel double perovskite oxide materials X<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>AlBiO<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span> (X = Mg, Ca, Ba) are investigated using the widely used density functional theory. The tolerance factor, octahedral factor, and cohesive energy provide evidence of the structural and thermodynamic stability of these novel cubic materials. The calculated band structures using the Trans-Blaha modified Becke–Johnson potential show that the compounds exhibit a direct energy gap of 2.42 eV for Mg<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>AlBiO<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span>, 2.15 eV for Ca<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>AlBiO<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span> and 1.3 eV for Ba<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>AlBiO<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span>. In particular, the band gap of Ba<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>AlBiO<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span> is very close to the Shockley-Quiesser band gap value of a single-junction solar cell. Furthermore, optical characteristics show that remarkable absorption occurs within the visible region for Ba<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>AlBiO<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span> as well as the ultraviolet region for X<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>AlBiO<span><math><msub><mrow></mrow><mrow><mn>6</mn></mrow></msub></math></span> (X= Mg, Ca). Finally, the compounds demonstrate notable thermoelectric properties, emphasizing the enhanced Seebeck coefficient at the golden range with a high figure of merit. Therefore, the calculated properties indicate that these materials are promising candidates for optoelectronic applications, such as photovoltaics, photocatalysts, and thermoelectric devices in the semiconductor industry.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130911"},"PeriodicalIF":4.3,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143916652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulate the Na content for structurally stable and high-performance sodium ion batteries","authors":"Yanxia Liu ,&nbsp;Ruixin Gao ,&nbsp;Nan Zhang ,&nbsp;Jiameng Feng","doi":"10.1016/j.matchemphys.2025.130971","DOIUrl":"10.1016/j.matchemphys.2025.130971","url":null,"abstract":"<div><div>The P2-type Ni/Mn layered oxide is a promising cathode material due to its high specific capacity and unique two-dimensional Na⁺ diffusion path. However, some drawbacks such as P2-O2 irreversible phase transition during charging/discharging, Na⁺/vacancy ordering transition, and poor air stability have seriously affected its commercialization. Based on above problems of layered oxides, a series of cathode materials Na_xLi_0.13Ni_0.20Mn_0.67O₂ (x = 0.6, 0.7, 0.8, 0.9, 1.0) with different sodium contents are prepared, correspondingly investigating the effect of sodium content on the crystal structure and electrochemical performance of cathode materials. The results show that the crystal structure is unstable and prone to P2-O2 irreversible phase transition when the sodium content is low. But the higher sodium content easily to bring Na⁺/vacancy ordering transition. Besides, the higher sodium content leads to poor air stability of cathode materials, which is not easy for subsequent wafer preparation and storage. Compared with other sodium content samples, the Na0.8 possesses the best cycling stability, which does not undergo P2-O2 irreversible phase transition and Na⁺/vacancy ordered transition, and the capacity retention rate is as high as 93.32 % after 100 cycles. The air stability of Na0.8 is also excellent, with the unbroken crystal structure, without impurity increasing on the surface, and still maintaining satisfactory cycling stability after exposed for 72 h in the air. This paper develops a new idea for the design of layered oxide cathode materials for sodium-ion batteries, and also provides a research basis for the effect of sodium content on the structure and performance of the materials.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130971"},"PeriodicalIF":4.3,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Core-mantle-shell framework for optimizing the distribution and size of metallic nanoparticles in dielectric spheres on light absorption and photoelectric efficiency","authors":"Yuting Luo,&nbsp;Ming Fu,&nbsp;Xiaoyu Liu,&nbsp;Jiefeng Li,&nbsp;Peixin Chu,&nbsp;Chenhui Wei,&nbsp;Yuting Zhang,&nbsp;Dawei He,&nbsp;Yongsheng Wang","doi":"10.1016/j.matchemphys.2025.130932","DOIUrl":"10.1016/j.matchemphys.2025.130932","url":null,"abstract":"<div><div>The composite structure of metallic nanoparticles and dielectric spheres, integrating metallic resonances with Mie resonance modes of dielectrics, shows great promise for efficient light absorption applications. However, the spatial distribution and size of metallic nanoparticles within dielectric spheres, aimed at maximizing optical absorption and minimizing photothermal energy loss, remain critical yet underexplored challenges. This work proposes a core–mantle–shell structure that boosts performance by incorporating metallic nanoparticles as a spherical mantle layer positioned in regions of strong electric fields induced by Mie resonances within the dielectric sphere, while enabling a fabrication process that is both straightforward and practical. With optimized spatial distribution and an increased number of nanoparticles, the average visible light absorption at the same Ag volume fraction is boosted to 2.67 times that of a single Ag particle at the sphere's center. The core-mantle-shell structure offers high flexibility in selecting core materials while allowing the shell to be porous. Based on plasmonic hot-electron charge generation and separation model calculations, Ag nanoparticles with a radius of ∼15 nm optimize photoelectric conversion efficiency, achieving 12.55 % under 1.5–3.1 eV light. The optimal metallic nanoparticle positions and sizes in core-mantle-shell structures were also consistent across other metal and dielectric materials, paralleling the results found in the SiO₂–Ag NPs-TiO₂ core-mantle-shell framework. The optimized structure, synthesized as SiO₂–Ag NPs-TiO₂ core-mantle-shell, exhibited significantly enhanced light absorption in the visible range. Compared with the SiO₂–TiO₂ core-shell, the photocatalytic degradation rate of methyl orange was improved by a factor of 4.5.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130932"},"PeriodicalIF":4.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143901890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drug loading and release from core-shell silicate particles: a case study for thiamine drug","authors":"M. Todea ,&nbsp;V. Simon ,&nbsp;L. Barbu ,&nbsp;C. Costinas ,&nbsp;M.D. Lazar ,&nbsp;M. Muresan-Pop ,&nbsp;Z.R. Tóth ,&nbsp;D.M. Petrisor ,&nbsp;S. Simon ,&nbsp;D. Eniu","doi":"10.1016/j.matchemphys.2025.130977","DOIUrl":"10.1016/j.matchemphys.2025.130977","url":null,"abstract":"<div><div>Spherical mesoporous silica and core-shell silicate particles loaded with thiamine hydrochloride water-soluble drug were investigated as new drug delivery platforms. The particles were synthesized by Stober method using dodecylamine as organic template, which was removed through a suitable heat treatment and left behind mesopores. A shell of aluminum oxide or a mixture of aluminum and iron oxides was developed on silica cores to extend the application fields of these particles. Both silica and core–shell particles were characterized as matrices for drug loading and release using various experimental techniques as scanning electron microscopy (SEM), specific surface area and porosity, particle size distributions and Zeta potential, X-ray diffraction (XRD), differential thermal analysis (DTA/TGA), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, as well as dissolution tests evaluated by UV-VIS spectrophotometry. Thiamine hydrochloride loaded onto these particles by solvent evaporation method was used as a model drug. The XRD results showed that the crystalline state of the loaded drug is thiamine hydrochloride monohydrate. According to DTA/TGA data, after the loading process the samples contain almost equal amounts of mesoporous particles and thiamine. The XPS analysis indicated the presence of thiamine on the surface of the spheres, but the low concentration of the elements entering the thiamine and the high concentration of the elements occurring from particles composition reveal that thiamine is mainly entrapped inside the pores of the particles. On the other hand, FTIR spectroscopy additionally indicated that thiamine is attached to the inner and/or outer surface of the particles via hydrogen bonds. A drug release delay was noticed for the investigated particles loaded with thiamine.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130977"},"PeriodicalIF":4.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143901984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanistic Interpretation of Thioglycolic Acid as a Depressant in the Differential Flotation of Molybdenite from Chalcopyrite","authors":"A. Mabudi ,&nbsp;R. Ahmadi","doi":"10.1016/j.matchemphys.2025.130964","DOIUrl":"10.1016/j.matchemphys.2025.130964","url":null,"abstract":"<div><div>This study explores the potential of thioglycolic acid (TGA) as an eco-friendly depressant for chalcopyrite in the differential flotation of molybdenite from chalcopyrite. Laboratory flotation experiments and molecular dynamics (MD) simulations were employed to evaluate TGA's effectiveness compared to sodium sulfide. The experiments demonstrated that TGA significantly enhanced chalcopyrite depression, achieving optimal molybdenite recovery (90.43%) and chalcopyrite depression (83.63%) under specific conditions: 2 kg/t TGA dosage, pH 11.5, and 28% solids. Statistical analysis highlighted TGA dosage and pH as the most influential parameters. However, excessive TGA concentrations led to froth destabilization, reducing separation efficiency. MD simulations confirmed TGA's stronger adsorption and hydrophilic modification of chalcopyrite surfaces, reducing its floatability while preserving molybdenite selectivity. The simulations revealed that TGA increases surface hydrophilicity by promoting denser water molecule packing and forming a robust adsorbed layer that prevents collector attachment. These findings were corroborated by surface energy and solvent-accessible surface area (SASA) analyses, which demonstrated TGA’s stronger interaction with chalcopyrite compared to sodium sulfide. The dual-scale approach of this study bridges the gap between laboratory-scale experimentation and molecular-level understanding, offering a comprehensive evaluation of TGA’s potential as a green depressant in mineral processing. By reducing reliance on toxic depressants like sodium sulfide, TGA represents a sustainable alternative for the selective flotation of molybdenite.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130964"},"PeriodicalIF":4.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coating of nonwoven polypropylene fabric by UV polymerization of styrene and maleic anhydride as a novel membrane and evaluation of its filtration properties","authors":"Aliasghar Kamyabi ,&nbsp;Mohammad Reza Miroliaei ,&nbsp;Hassan Sheibani","doi":"10.1016/j.matchemphys.2025.130969","DOIUrl":"10.1016/j.matchemphys.2025.130969","url":null,"abstract":"<div><div>Nonwoven polypropylene fabrics (NWPP) are a type of high-performance membrane consisting of entangled polypropylene microfibers. These membranes have gained attention in various applications such as water treatment due to their chemical resistance, excellent mechanical properties, and low cost. In this study, we investigated the effects of coating and modification on the filtration performance of the NWPP membrane for desalination. The NWPP fabric was coated with styrene-maleic anhydride copolymer (SMAnh) and then modified with poly(amidoamine) dendrimer (PAMAM) and functionalized multi-walled carbon nanotubes (f-MWCNTs). The membranes were characterized using different techniques and their filtration performance was evaluated. The results showed that surface coating with modification strategies significantly improved the performance of the NWPP membranes. Modifications with PAMAM and MWCNTs improved the hydrophilicity (WCA: 45.6°), the antifouling properties (88.5 %) and salt rejection of the coated membrane (96.5 %). The results of this study highlight the promising potential of surface modification techniques to customize the properties of NWPP membranes and improve their performance in desalination. The combination of SMAnh copolymer coating, PAMAM, and MWCNTs offers a successful approach for developing of high-performance NWPP membranes for sustainable desalination.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130969"},"PeriodicalIF":4.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fe-impregnated hydrochar catalysts prepared using liquor from hydrothermal carbonization of biomass as the reaction medium","authors":"Sebastian Ponce ,&nbsp;Raúl Alomoto ,&nbsp;Erick Cordero ,&nbsp;Daniela Armijos ,&nbsp;Carlos Loyo ,&nbsp;Karla Vizuete ,&nbsp;Alexis Debut ,&nbsp;Erika Cortés-Rojas ,&nbsp;Juan Gaibor-Chávez ,&nbsp;Pedro Ducos ,&nbsp;Darío Niebieskikwiat ,&nbsp;Herman A. Murillo","doi":"10.1016/j.matchemphys.2025.130980","DOIUrl":"10.1016/j.matchemphys.2025.130980","url":null,"abstract":"<div><div>This work presents a novel single-step approach for the synthesis of Fe-impregnated hydrochars using spent liquor from the hydrothermal carbonization (HTC) of residual biomass as a reaction radium. The resulting Fe-modified hydrochars were evaluated as catalysts for 4-nitrophenol (4-NP) removal via the Fenton reaction. Herein, it was demonstrated that incorporating HTC spent liquor significantly enhanced the hydrochar's catalytic activity, particularly at an HTC temperature of 250 °C with a 0.5 M metal-salt concentration. With the catalyst synthesized under these latter conditions, ∼88 % removal efficiency of 4-NP was achieved, including a reaction rate constant 17 times higher than at an HTC temperature of 220 °C. Characterization confirmed the in-situ formation of magnetite (Fe₃O₄) on the hydrochar surface, providing improved thermal stability and magnetic properties that enable catalyst recovery and reuse. The Fe reduction from the metal salt and subsequent impregnation may probably be attributed to the biomolecules in the spent liquor, especially in the liquor obtained from the HTC of Jatropha fruit husk. This single-step impregnation method forms the magnetite phase during HTC without requiring a post-pyrolysis treatment, as reported in previous studies. This energy-efficient and environmentally sustainable method provides valuable insights into the potential of HTC spent liquor as a renewable medium for functional material synthesis.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130980"},"PeriodicalIF":4.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis, characterization, structure refinement and dehydration behavior of sulfate-intercalated hydrocalumite-like layered double hydroxide","authors":"Anand N. Narayanappa,&nbsp;P. Vishnu Kamath","doi":"10.1016/j.matchemphys.2025.130952","DOIUrl":"10.1016/j.matchemphys.2025.130952","url":null,"abstract":"<div><div>The chloride-intercalated layered double hydroxide of Ca²⁺ and Al³⁺, better known as Friedel's salt, comprises positively charged metal hydroxide layers having the composition [Ca₂Al(OH)₆]⁺. The chloride ion is intercalated within all the available sites in the interlayer gallery. The perchlorate-intercalated phase is isotypic with Friedel's salt, and the perchlorate ions occupy all the anionic sites in the interlayer gallery. The sulfate ion has the same size as that of the perchlorate ion, but carries twice the charge. Thereby, the sulfate ions are expected to occupy only half the number of interlayer sites, leaving the rest vacant. With so much void space in the interlayer, the crystal is not expected to be stable. However, this work shows that a sulfate-intercalated layered double hydroxide of Ca²⁺ and Al³⁺ could be synthesized. Structure refinement shows that the sulfate ion is intercalated with one of its S–O bonds parallel to the <em>c</em>-axis of the crystal, which is also the stacking direction. The resultant coordination symmetry is <em>C</em>_3<em>v</em>. The crystal is stabilized by the incorporation of water molecules in voids not occupied by the sulfate ions. This additional water is hydrogen bonded to the sulfate ions and is lost at a higher temperature (160 °C) than the water molecules coordinated to the Ca²⁺ ion (100 °C). The former is structural water and its loss leads to the breakdown of the layered structure.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130952"},"PeriodicalIF":4.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailoring structural and electrical properties in cobalt-doped Ag0.2Na0.8NbO3 ceramics for advanced electronic applications","authors":"Meenu Rani ,&nbsp;Y.P. Singh ,&nbsp;Shristi Chaudhary ,&nbsp;Shilpi Jindal","doi":"10.1016/j.matchemphys.2025.130953","DOIUrl":"10.1016/j.matchemphys.2025.130953","url":null,"abstract":"<div><div>In this work, environment-friendly lead-free polycrystalline ceramic samples of cobalt doped silver sodium niobate with composition Ag_0.2Co_xNa_0.8-xNbO₃ (with x = 0, 0.02, 0.04, 0.06, 0.08) had been prepared by using solid-state reaction technique and effect of Co-doping on dielectric, electrical and ferroelectric properties had been reported. Analysis of X-ray diffraction (XRD) data confirmed the perovskite orthorhombic structure in all specimens with decreasing average crystallite size on increasing Co-content. Scanning Electron Microscopy (SEM) investigation indicated reduction in average grain size from 1.69 μm to 1.29 μm as concentration of cobalt grew from 0 to 0.08. Impedance analyzer had been used to measure dielectric constant and tangent loss over the frequency range from 20 Hz to 10 MHz for temperatures varying from 25⁰ C to 350⁰ C. Both the dielectric constant as well as tangent loss were found to follow a declining trend with the rising frequency as well as rising dopant content. Impedance had also been analyzed to get information on the conduction mechanism and role of grain boundaries over grains had been deduced to be dominant. Ferroelectric behavior of specimens had been assessed through polarization-electric field (P-E) loop measurements that depicted the presence of moderate polarization levels and relatively high coercive field in all specimens making them versatile for advanced electronic applications.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"342 ","pages":"Article 130953"},"PeriodicalIF":4.3,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143901985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}