Spinel oxides generally show subpar activity for electrochemical water splitting because of low electronic conductivity, suboptimal adsorption energies, and poor operational stability. To overcome these limitations, Pd2+ is introduced to induce lattice strain in a metastable Co3O4 phase featuring off-centered cobalt and oxygen atoms. While pristine Co3O4 typically crystallizes in the centrosymmetric Fd3̅m space group, 1.2 at % Pd transforms it to the dominant non-centrosymmetric F4̅3m space group. This unconventional lattice contains two non-equivalent tetrahedral sites and one octahedral site. Pd2+ preferentially substitutes the Co1 atom at the (0, 0, 0) 4a tetrahedral position, with a relative stabilization of −1.02 eV. Pd2+-induced enhancement of the density of states near the Fermi level tunes the d-band center, while Co-to-Pd charge redistribution activates the otherwise less active tetrahedral site alongside the intrinsically active octahedral site, thereby enhancing alkaline water electrolysis. For oxygen and hydrogen evolution, this bifunctional catalyst delivers mass activities of 60.6 and 31.0 A/g and turnover frequencies of 0.32 and 0.28 H2 s−1 at 300 and 250 mV overpotentials, respectively. In a two-electrode configuration, it reaches 50 mA/cm2 at an iR-uncorrected cell voltage of 1.85 V, while at 200 mA/cm2, it produces 25.4 mL/h H2 at a cell voltage of 2.31 V.
尖晶石氧化物由于电子电导率低、吸附能不理想和操作稳定性差，通常表现出较差的电化学水分解活性。为了克服这些限制，Pd2+被引入到以偏离中心的钴原子和氧原子为特征的亚稳Co3O4相中诱导晶格应变。原始的Co3O4通常在中心对称的Fd3′m空间群中结晶，1.2 at % Pd将其转变为主要的非中心对称的F4′m空间群。这种非常规晶格包含两个非等效四面体位点和一个八面体位点。Pd2+优先取代（0,0,0）4a四面体位置的Co1原子，相对稳定度为- 1.02 eV。Pd2+诱导的费米能级附近态密度的增强调节了d带中心，而Co-to-Pd电荷的重新分配激活了原本活性较低的四面体位点和本质活性的八面体位点，从而增强了碱性水电解。对于氧和氢的释放，该双功能催化剂在300和250 mV过电位下的质量活性分别为60.6和31.0 A/g，周转频率分别为0.32和0.28 H2 s - 1。在双电极配置下，在未经ir校正的1.85 V电池电压下，它能达到50 mA/cm2，而在200 mA/cm2电池电压为2.31 V时，它能产生25.4 mL/h的H2。
{"title":"Symmetry-Broken Co3O4 via Site-Selective Pd Substitution for Bifunctional Water Electrolysis","authors":"Maglu Mura,Sougata Saha,Rahul Majee,Saumil Ghosh,Arghyadeb Roy,Mamoni Maji,Vishwadeepa Hazra,Swapan K. Pati,Sayan Bhattacharyya","doi":"10.1021/acs.chemmater.6c01407","DOIUrl":"https://doi.org/10.1021/acs.chemmater.6c01407","url":null,"abstract":"Spinel oxides generally show subpar activity for electrochemical water splitting because of low electronic conductivity, suboptimal adsorption energies, and poor operational stability. To overcome these limitations, Pd2+ is introduced to induce lattice strain in a metastable Co3O4 phase featuring off-centered cobalt and oxygen atoms. While pristine Co3O4 typically crystallizes in the centrosymmetric Fd3̅m space group, 1.2 at % Pd transforms it to the dominant non-centrosymmetric F4̅3m space group. This unconventional lattice contains two non-equivalent tetrahedral sites and one octahedral site. Pd2+ preferentially substitutes the Co1 atom at the (0, 0, 0) 4a tetrahedral position, with a relative stabilization of −1.02 eV. Pd2+-induced enhancement of the density of states near the Fermi level tunes the d-band center, while Co-to-Pd charge redistribution activates the otherwise less active tetrahedral site alongside the intrinsically active octahedral site, thereby enhancing alkaline water electrolysis. For oxygen and hydrogen evolution, this bifunctional catalyst delivers mass activities of 60.6 and 31.0 A/g and turnover frequencies of 0.32 and 0.28 H2 s−1 at 300 and 250 mV overpotentials, respectively. In a two-electrode configuration, it reaches 50 mA/cm2 at an iR-uncorrected cell voltage of 1.85 V, while at 200 mA/cm2, it produces 25.4 mL/h H2 at a cell voltage of 2.31 V.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"22 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-27DOI: 10.1021/acs.chemmater.6c02485
Junfeng Li,Min Gao,Gaoyun Ren,Qi Qi,Wen-Yong Lai
Hierarchical architectures are ubiquitous in nature; however, the bottom-up construction of multilevel chiral macroscopic assemblies from small organic molecules remains highly challenging. Herein, we report an unprecedented assembly strategy for constructing hierarchically organized particles (HOPs) through the co-assembly of achiral o-carborane-based molecules (C-1 and C-2) with chiral (R/S)-limonene. Intriguingly, C-1-(S)-limonene forms microscale cocoon-like superstructures, whereas C-1-(R)-limonene undergoes self-assembly into fibrous architectures that ultimately evolve into random aggregates at the micrometer scale. In contrast, C-2-(R/S)-limonene assembles into bowtie-shaped microarchitectures. Graph Theory (GT) analysis reveals structural complexity indices (CIs) of 5.5 and 54 for the C-1-(S)-limonene- and C-2-(S)-limonene-based HOPs, respectively, indicating significantly higher architectural complexity for the latter. These assemblies exhibit distinct circularly polarized luminescence (CPL) properties: C-1-(S)-limonene displays intense CPL emission at 504 nm with a high luminescence dissymmetry factor (glum) of +0.006, whereas C-2-(S)-limonene exhibits CPL emission at 560 nm with a glum value of +0.002. These results demonstrate that chirality signals are transferred across multiple length scales from the molecular level to macroscopic architectures. The observed structural divergence originates from the synergistic effects of nonclassical dihydrogen bonding (Bδ+−Hδ−···Hδ+−Cδ−) between achiral o-carborane derivatives and chiral limonene, together with molecular polarity and elasticity effects. This study establishes a paradigm for fabricating chiral o-carborane-based hierarchical aggregates with programmable architectures and tailored chiroptical properties.
{"title":"Nonclassical Dihydrogen Bond-Directed Assembly of o-Carborane-Based Molecules into Macroscopic Architectures with Circularly Polarized Luminescence","authors":"Junfeng Li,Min Gao,Gaoyun Ren,Qi Qi,Wen-Yong Lai","doi":"10.1021/acs.chemmater.6c02485","DOIUrl":"https://doi.org/10.1021/acs.chemmater.6c02485","url":null,"abstract":"Hierarchical architectures are ubiquitous in nature; however, the bottom-up construction of multilevel chiral macroscopic assemblies from small organic molecules remains highly challenging. Herein, we report an unprecedented assembly strategy for constructing hierarchically organized particles (HOPs) through the co-assembly of achiral o-carborane-based molecules (C-1 and C-2) with chiral (R/S)-limonene. Intriguingly, C-1-(S)-limonene forms microscale cocoon-like superstructures, whereas C-1-(R)-limonene undergoes self-assembly into fibrous architectures that ultimately evolve into random aggregates at the micrometer scale. In contrast, C-2-(R/S)-limonene assembles into bowtie-shaped microarchitectures. Graph Theory (GT) analysis reveals structural complexity indices (CIs) of 5.5 and 54 for the C-1-(S)-limonene- and C-2-(S)-limonene-based HOPs, respectively, indicating significantly higher architectural complexity for the latter. These assemblies exhibit distinct circularly polarized luminescence (CPL) properties: C-1-(S)-limonene displays intense CPL emission at 504 nm with a high luminescence dissymmetry factor (glum) of +0.006, whereas C-2-(S)-limonene exhibits CPL emission at 560 nm with a glum value of +0.002. These results demonstrate that chirality signals are transferred across multiple length scales from the molecular level to macroscopic architectures. The observed structural divergence originates from the synergistic effects of nonclassical dihydrogen bonding (Bδ+−Hδ−···Hδ+−Cδ−) between achiral o-carborane derivatives and chiral limonene, together with molecular polarity and elasticity effects. This study establishes a paradigm for fabricating chiral o-carborane-based hierarchical aggregates with programmable architectures and tailored chiroptical properties.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"21 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-27DOI: 10.1021/acs.chemmater.6c01705
Abraham A. Rosenberg,Georgiy Akopov,Michael T. Yeung
For nearly a century, alloy design has been guided by the Hume-Rothery rules, which describe the conditions required for solid solution formation and have traditionally constrained the compositional space available to materials scientists. The emergence of high-entropy alloys fundamentally altered this paradigm by demonstrating that configurational entropy can stabilize compositions that would otherwise be thermodynamically unfavorable. Since their discovery, high-entropy concepts have expanded beyond metallic systems into ceramics, including oxides, carbides, silicides, nitrides, and borides, creating new opportunities to access unconventional chemistries and local atomic environments. This review examines how high-entropy alloying can be used to transcend classical alloying limitations and stabilize elements in coordination environments that are inaccessible in conventional materials. Particular emphasis is placed on high-entropy borides, where ordered boron frameworks provide a structural scaffold that accommodates chemically disparate elements while preserving phase stability. Recent examples, including Pt- and Si-containing high-entropy diborides, demonstrate how entropy stabilization enables the incorporation of elements that do not form stable binary diborides (MB2), resulting in unique electronic structures, bonding environments, and functional properties. More broadly, these systems illustrate how the interplay between disorder and local order can be leveraged to design next-generation materials beyond the boundaries imposed by traditional alloying rules.
{"title":"Structure-Directing Agents of Chaordic Materials Using High-Entropy Alloying","authors":"Abraham A. Rosenberg,Georgiy Akopov,Michael T. Yeung","doi":"10.1021/acs.chemmater.6c01705","DOIUrl":"https://doi.org/10.1021/acs.chemmater.6c01705","url":null,"abstract":"For nearly a century, alloy design has been guided by the Hume-Rothery rules, which describe the conditions required for solid solution formation and have traditionally constrained the compositional space available to materials scientists. The emergence of high-entropy alloys fundamentally altered this paradigm by demonstrating that configurational entropy can stabilize compositions that would otherwise be thermodynamically unfavorable. Since their discovery, high-entropy concepts have expanded beyond metallic systems into ceramics, including oxides, carbides, silicides, nitrides, and borides, creating new opportunities to access unconventional chemistries and local atomic environments. This review examines how high-entropy alloying can be used to transcend classical alloying limitations and stabilize elements in coordination environments that are inaccessible in conventional materials. Particular emphasis is placed on high-entropy borides, where ordered boron frameworks provide a structural scaffold that accommodates chemically disparate elements while preserving phase stability. Recent examples, including Pt- and Si-containing high-entropy diborides, demonstrate how entropy stabilization enables the incorporation of elements that do not form stable binary diborides (MB2), resulting in unique electronic structures, bonding environments, and functional properties. More broadly, these systems illustrate how the interplay between disorder and local order can be leveraged to design next-generation materials beyond the boundaries imposed by traditional alloying rules.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"10 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-26DOI: 10.1021/acs.chemmater.6c01699
Brent Motmans,Digvijay Ghogare,Thijs G. I. van Wijk,Joren Van Herck,Saba Heidarian,Pieter De Meyer,Berend Smit,An Hardy,Danny E. P. Vanpoucke
Copper nanoparticles (Cu NPs) have a broad applicability, yet their synthesis is sensitive to subtle changes in reaction parameters. This sensitivity, combined with the time- and resource-intensive nature of experimental optimization, poses a major challenge in achieving reproducible and size-controlled synthesis. While machine learning (ML) shows promise in materials research, its application is often limited by scarcity of large high-quality experimental data sets. This study explores ML to predict the DLS-derived hydrodynamic diameter of Cu NPs from microwave-assisted polyol synthesis using a small data set of 25 in-house performed syntheses. Latin hypercube sampling is used to efficiently cover the parameter space while creating the experimental data set. Ensemble regression models successfully predict hydrodynamic diameters with good predictive performance given the limited data set. Since quantitative regression requires a unique DLS-derived hydrodynamic diameter, the regression model is restricted to monomodal DLS distributions, while a complementary classification model identifies synthesis conditions for which quantitative prediction is applicable. Using equivalent out-of-sample validation (OOB and LOOCV), the ML and DoE models showed comparable generalization (MAE = 40.92 and 40.46 nm, respectively). The final ensemble model achieved an R2 of 0.74, an MAE of 23.81 nm, compared to an R2 of 0.60, an MAE of 33.54 nm for the DoE model, while retaining the complete synthesis parameter space, making it better suited for synthesis guidance. Additionally, classification models using both random forests and large language models (LLMs) are evaluated to distinguish between large and small particles. These classification models exhibited only modest predictive performance, indicating that this small data set is insufficient to fully exploit the capabilities of complex LLMs. Overall, this study demonstrates that carefully curated small data sets, paired with robust classical ML, can effectively support the synthesis of Cu NPs and highlights that for lab-scale studies, complex models like LLMs may offer limited benefits. The validation experiments further indicate the potential of ML guided synthesis to improve the efficiency of experimental optimization and reduce resource consumption.
{"title":"Predictive Inorganic Synthesis Based on Machine Learning Using Small Data Sets: A Case Study of Hydrodynamic Diameter-Controlled Copper Nanoparticles","authors":"Brent Motmans,Digvijay Ghogare,Thijs G. I. van Wijk,Joren Van Herck,Saba Heidarian,Pieter De Meyer,Berend Smit,An Hardy,Danny E. P. Vanpoucke","doi":"10.1021/acs.chemmater.6c01699","DOIUrl":"https://doi.org/10.1021/acs.chemmater.6c01699","url":null,"abstract":"Copper nanoparticles (Cu NPs) have a broad applicability, yet their synthesis is sensitive to subtle changes in reaction parameters. This sensitivity, combined with the time- and resource-intensive nature of experimental optimization, poses a major challenge in achieving reproducible and size-controlled synthesis. While machine learning (ML) shows promise in materials research, its application is often limited by scarcity of large high-quality experimental data sets. This study explores ML to predict the DLS-derived hydrodynamic diameter of Cu NPs from microwave-assisted polyol synthesis using a small data set of 25 in-house performed syntheses. Latin hypercube sampling is used to efficiently cover the parameter space while creating the experimental data set. Ensemble regression models successfully predict hydrodynamic diameters with good predictive performance given the limited data set. Since quantitative regression requires a unique DLS-derived hydrodynamic diameter, the regression model is restricted to monomodal DLS distributions, while a complementary classification model identifies synthesis conditions for which quantitative prediction is applicable. Using equivalent out-of-sample validation (OOB and LOOCV), the ML and DoE models showed comparable generalization (MAE = 40.92 and 40.46 nm, respectively). The final ensemble model achieved an R2 of 0.74, an MAE of 23.81 nm, compared to an R2 of 0.60, an MAE of 33.54 nm for the DoE model, while retaining the complete synthesis parameter space, making it better suited for synthesis guidance. Additionally, classification models using both random forests and large language models (LLMs) are evaluated to distinguish between large and small particles. These classification models exhibited only modest predictive performance, indicating that this small data set is insufficient to fully exploit the capabilities of complex LLMs. Overall, this study demonstrates that carefully curated small data sets, paired with robust classical ML, can effectively support the synthesis of Cu NPs and highlights that for lab-scale studies, complex models like LLMs may offer limited benefits. The validation experiments further indicate the potential of ML guided synthesis to improve the efficiency of experimental optimization and reduce resource consumption.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"43 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-26DOI: 10.1021/acs.chemmater.6c00920
Patricia E. Meza,Tyler J. Slade,Adam Balvanz,Abishek K. Iyer,Hengdi Zhao,Andrew Kindseth,Yukun Liu,Roberto dos Reis,Jeremy Lee,Alexander A. High,Mercouri G. Kanatzidis,Vinayak P. Dravid
Vanadium-based thiophosphates in the MPQ3/M2P2Q6 family provide an unusual platform for coupling mixed-metal valence, metal vacancies, and 2D magnetism, but access to phase-pure multimetal solid solutions with verified chemical homogeneity remains limited. Here, we show that multication alloying provides a route to incorporating V into layered thiophosphates while retaining the mixed-valent, vacancy-containing character of V2−xP2S6. This approach yields Fe1.25V0.6P2S6, Ni1.25V0.6P2S6, Co1.25V0.6P2S6, and high-entropy V-containing compositions. Single-crystal X-ray diffraction (scXRD) and electron energy-loss spectroscopy (EELS) mapping confirm formation of layered single-phase alloys and chemical uniformity both across the surface and through the flake thickness. Optical measurements show semiconducting band gaps spanning ∼1.33−1.66 eV, while temperature-dependent transport reveals markedly enhanced conductivity and low activation energies (∼0.2−0.3 eV) relative to conventional divalent TM2P2S6 analogs. Oxidation-state mapping indicates robust mixed-valent V2+/V3+ character consistent with defect-assisted hopping and self-doping linked to vanadium vacancies, likely causing enhanced conductivity. Magnetic measurements further show composition-dependent behavior, consistent with magnetic frustration and glassy components in Fe1.25V0.6P2S6 and (VMnFeCoNi)2P2S6, highlighting the role of multimetal disorder in shaping exchange interactions. Together, these results establish a route to phase-pure, conductive V-containing thiophosphate alloys and expand the tunable design space for coupled transport and magnetism in layered chalcophosphates.
{"title":"Alloy-Assisted Formation of Vanadium-Rich Thiophosphates with Enhanced Charge Transport and Glassy Magnetism","authors":"Patricia E. Meza,Tyler J. Slade,Adam Balvanz,Abishek K. Iyer,Hengdi Zhao,Andrew Kindseth,Yukun Liu,Roberto dos Reis,Jeremy Lee,Alexander A. High,Mercouri G. Kanatzidis,Vinayak P. Dravid","doi":"10.1021/acs.chemmater.6c00920","DOIUrl":"https://doi.org/10.1021/acs.chemmater.6c00920","url":null,"abstract":"Vanadium-based thiophosphates in the MPQ3/M2P2Q6 family provide an unusual platform for coupling mixed-metal valence, metal vacancies, and 2D magnetism, but access to phase-pure multimetal solid solutions with verified chemical homogeneity remains limited. Here, we show that multication alloying provides a route to incorporating V into layered thiophosphates while retaining the mixed-valent, vacancy-containing character of V2−xP2S6. This approach yields Fe1.25V0.6P2S6, Ni1.25V0.6P2S6, Co1.25V0.6P2S6, and high-entropy V-containing compositions. Single-crystal X-ray diffraction (scXRD) and electron energy-loss spectroscopy (EELS) mapping confirm formation of layered single-phase alloys and chemical uniformity both across the surface and through the flake thickness. Optical measurements show semiconducting band gaps spanning ∼1.33−1.66 eV, while temperature-dependent transport reveals markedly enhanced conductivity and low activation energies (∼0.2−0.3 eV) relative to conventional divalent TM2P2S6 analogs. Oxidation-state mapping indicates robust mixed-valent V2+/V3+ character consistent with defect-assisted hopping and self-doping linked to vanadium vacancies, likely causing enhanced conductivity. Magnetic measurements further show composition-dependent behavior, consistent with magnetic frustration and glassy components in Fe1.25V0.6P2S6 and (VMnFeCoNi)2P2S6, highlighting the role of multimetal disorder in shaping exchange interactions. Together, these results establish a route to phase-pure, conductive V-containing thiophosphate alloys and expand the tunable design space for coupled transport and magnetism in layered chalcophosphates.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"5 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-26DOI: 10.1021/acs.chemmater.6c01078
Lena K. Mathies,Asya Mazzucco,Giovanna Nicol,Mattia Giuliano,Adrian Jonas,Burkhard Beckhoff
Transition metal (TM) dissolution from the cathode and deposition on the anode in lithium−ion batteries is a key degradation mechanism, yet its spatial distribution in commercial cylindrical automotive-grade cells remains insufficiently understood. In this study on lithium−ion cells 18650 with a NMC811/graphite technology, we reveal a pronounced radial inhomogeneity in cathode metal deposition on the anode, with significantly higher accumulation in the inner windings of the jelly roll compared to the outer regions, identifying a critical vulnerability in the cell design while operating in overvoltage conditions. Spatially resolved near-edge edge X-ray absorption fine structure measurements further highlight this geometry dependence, revealing a higher fraction of Ni4+ in the inner windings, whereas the outer regions are dominated by Ni2+. This radial gradient correlates with intrinsic geometric characteristics of cylindrical cells, where the smaller bending radius in the inner windings may plausibly contribute to elevated mechanical stress, higher compressive pressure, and reduced heat dissipation in the cell core. The findings directly link cell geometry to both the extent and chemical state of TM deposition, proving its central role in degradation processes.
{"title":"Quantitative Investigation of Spatial Inhomogeneity of Transition Metal Deposition in Commercial Automotive Cylindrical Cells under Overvoltage Conditions","authors":"Lena K. Mathies,Asya Mazzucco,Giovanna Nicol,Mattia Giuliano,Adrian Jonas,Burkhard Beckhoff","doi":"10.1021/acs.chemmater.6c01078","DOIUrl":"https://doi.org/10.1021/acs.chemmater.6c01078","url":null,"abstract":"Transition metal (TM) dissolution from the cathode and deposition on the anode in lithium−ion batteries is a key degradation mechanism, yet its spatial distribution in commercial cylindrical automotive-grade cells remains insufficiently understood. In this study on lithium−ion cells 18650 with a NMC811/graphite technology, we reveal a pronounced radial inhomogeneity in cathode metal deposition on the anode, with significantly higher accumulation in the inner windings of the jelly roll compared to the outer regions, identifying a critical vulnerability in the cell design while operating in overvoltage conditions. Spatially resolved near-edge edge X-ray absorption fine structure measurements further highlight this geometry dependence, revealing a higher fraction of Ni4+ in the inner windings, whereas the outer regions are dominated by Ni2+. This radial gradient correlates with intrinsic geometric characteristics of cylindrical cells, where the smaller bending radius in the inner windings may plausibly contribute to elevated mechanical stress, higher compressive pressure, and reduced heat dissipation in the cell core. The findings directly link cell geometry to both the extent and chemical state of TM deposition, proving its central role in degradation processes.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"62 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-26DOI: 10.1021/acs.chemmater.6c00406
Chiranjib Gogoi,Nabanita Chatterjee,Clive L. Oliver
Two Zn(II)-based mixed-ligand metal−organic frameworks (MOFs) were synthesised using solvothermal methods and fully characterized (SCXRD, PXRD, TGA, DSC, FTIR, HSM). The MOFs are formulated as [Zn2(NDC)2(AzPy)2]n˙n(DMF)3 (ZNA150-DMF) and [Zn(NDC)(AzPy)0.5]n˙n(DMF)0.5 (ZNA90-DMF), where NDC2− = 2,6-naphthalene dicarboxylate, AzPy = 4,4′-azopyridine and DMF = N,N′-dimethylformamide, and are synthesized at 150 °C and 90 °C, respectively. Single crystal X-ray diffraction analysis confirmed that ZNA150-DMF and ZNA90-DMF are non-interpenetrated and triply interpenetrated, respectively. Both MOFs are highly flexible, displaying large changes in their unit cell parameters and void space features upon desolvation with the void space of both desolvated forms (ZNA150-act and ZNA90-act) consisting of isolated voids, thus leading to transient porosity, where these isolated pockets temporarily connect into channels to facilitate sorption. ZNA90-act carbon dioxide sorption isotherms have inflection points indicating a pressure-sustained structural change, as proven by variable-pressure single crystal and powder X-ray diffraction studies on ZNA90-act immersed in a CO2 gas environment. Variable-temperature single crystal X-ray diffraction studies on both activated MOFs, in the absence of gas, show that these are highly flexible, displaying colossal thermal expansion properties with changes in void space features. These changes tend towards what was observed for ZNA90-act under CO2 pressure, thus possibly linking flexible MOF behavior under the two sets of conditions.
{"title":"Linking Thermal Expansion to Transient Porosity in a Pair of Highly Flexible Activated 3D Zn(II)-Based MOFs","authors":"Chiranjib Gogoi,Nabanita Chatterjee,Clive L. Oliver","doi":"10.1021/acs.chemmater.6c00406","DOIUrl":"https://doi.org/10.1021/acs.chemmater.6c00406","url":null,"abstract":"Two Zn(II)-based mixed-ligand metal−organic frameworks (MOFs) were synthesised using solvothermal methods and fully characterized (SCXRD, PXRD, TGA, DSC, FTIR, HSM). The MOFs are formulated as [Zn2(NDC)2(AzPy)2]n˙n(DMF)3 (ZNA150-DMF) and [Zn(NDC)(AzPy)0.5]n˙n(DMF)0.5 (ZNA90-DMF), where NDC2− = 2,6-naphthalene dicarboxylate, AzPy = 4,4′-azopyridine and DMF = N,N′-dimethylformamide, and are synthesized at 150 °C and 90 °C, respectively. Single crystal X-ray diffraction analysis confirmed that ZNA150-DMF and ZNA90-DMF are non-interpenetrated and triply interpenetrated, respectively. Both MOFs are highly flexible, displaying large changes in their unit cell parameters and void space features upon desolvation with the void space of both desolvated forms (ZNA150-act and ZNA90-act) consisting of isolated voids, thus leading to transient porosity, where these isolated pockets temporarily connect into channels to facilitate sorption. ZNA90-act carbon dioxide sorption isotherms have inflection points indicating a pressure-sustained structural change, as proven by variable-pressure single crystal and powder X-ray diffraction studies on ZNA90-act immersed in a CO2 gas environment. Variable-temperature single crystal X-ray diffraction studies on both activated MOFs, in the absence of gas, show that these are highly flexible, displaying colossal thermal expansion properties with changes in void space features. These changes tend towards what was observed for ZNA90-act under CO2 pressure, thus possibly linking flexible MOF behavior under the two sets of conditions.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"4 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-23DOI: 10.1021/acs.chemmater.6c01542
Michael J. Brady,Hauke Glück,Jessica L. Andrews,Erica Truong,Alexander G. Squires,Ifeoluwa P. Oyekunle,Rachel C. Monger,Wolfgang G. Zeier,Yan-Yan Hu,David O. Scanlon,Benjamin J. Morgan,Brent C. Melot
Lithium-conducting fluoride garnets exhibit ionic conductivities of ∼10–10 S cm–1, far below those of their oxide counterparts. Here, we investigate the origin of this poor transport in Na3Ga2Li3F12 and Na3Al2Li3F12 through a combination of structural characterization and first-principles calculations. Both compounds are highly ordered, with no significant antisite disorder, and exhibit intrinsic ionic conductivities of ∼2 × 10–11 S cm–1 at 100 °C. Nudged elastic band calculations reveal low Li-ion migration barriers (0.16 to 0.29 eV), indicating that the fluoride garnet framework does not inherently restrict Li-ion diffusion. However, the formation energies for lithium Frenkel and Schottky defect pairs are high (1.9 to 2.4 eV), indicating that the intrinsic concentrations of mobile Li-ion defects are negligibly small. These results establish that the low conductivity of stoichiometric fluoride garnets arises from high defect-formation energies, rather than high migration barriers.
锂导电氟化物石榴石的离子电导率为~ 10-10 S cm-1，远低于它们的氧化物对应物。在这里，我们通过结构表征和第一性原理计算的结合来研究Na3Ga2Li3F12和Na3Al2Li3F12中这种低输运的起源。这两种化合物都是高度有序的，没有明显的反位无序，并且在100°C时表现出约2 × 10-11 S cm-1的固有离子电导率。轻推弹性带计算显示低锂离子迁移势垒（0.16至0.29 eV），表明氟化物石榴石框架本身并不限制锂离子扩散。然而，锂离子Frenkel和Schottky缺陷对的形成能很高（1.9 ~ 2.4 eV），表明可移动锂离子缺陷的本禀浓度可以忽略不计。这些结果表明，化学计量氟化物石榴石的低电导率是由高缺陷形成能引起的，而不是高迁移障碍。
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Pub Date : 2026-10-23DOI: 10.1021/acs.chemmater.6c02002
Carlo Gonzato,Loïc Buchon,Jean-Louis Clément,Yohann Guillaneuf,Olivier Soppera
Reversible-deactivation radical photopolymerization (photoRDRP) enables precise spatiotemporal control of polymer architectures. Because of embedded active chain ends, photoRDRP offers straightforward reactivation and chain extension, providing unmatched flexibility for fine-tuning structural, mechanical, and physicochemical properties for targeted applications. Nevertheless, its application to 3D printing remains limited by the cost and synthetic effort of the control agent, as well as by a limited reactivity under common near-UV and blue light sources, which requires printers working in the visible range and results in usually low printing rates. Herein, we show the unexpected ability of 2-isopropylthioxanthone (ITX) to promote both a direct acrylate photopolymerization, (with no need for any conventional co-initiator and a printing rate close to those of conventional photoinitiators) and a subsequent surface-initiated (SI) photopolymerization via reactivable surface-bound species, yielding postfunctionalization results that are equivalent to, or surpass, those of RAFT systems. Compared to benzyldithiocarbamate (BDC) and N-(tert-butyl)-N-(2-methyl-1-(4-benzoylphenyl)propyl)-O-(1-phenylethyl) hydroxylamine (MBA), two model photoinitiators for photoRDRP in the near-UV range, ITX enabled controlled SI photopolymerization of neat acrylate monomers over thicknesses of several hundred micrometers, with higher molar reactivity and a broader spectral response. This allowed for direct photopolymerization and photostructuring using wavelengths from 365 to 405 nm. This straightforward and scalable approach opens promising avenues for the on-demand functionalization and assembly of complex 3D-printed architectures and is expected to bridge the gap between academic precision and industrial accessibility.
可逆失活自由基光聚合（photoRDRP）实现了对聚合物结构的精确时空控制。由于嵌入了活性链端，photoRDRP提供了直接的再激活和链延伸，为目标应用的结构、机械和物理化学性质的微调提供了无与伦比的灵活性。然而，其在3D打印中的应用仍然受到控制剂的成本和合成努力的限制，以及在常见的近紫外线和蓝色光源下有限的反应性，这需要打印机在可见范围内工作，导致通常较低的打印速率。在此，我们展示了2-异丙基硫杂蒽酮（ITX）的意想不到的能力，既可以促进丙烯酸酯的直接光聚合（不需要任何传统的共引发剂，印刷速度接近传统的光引发剂），也可以通过可反应的表面结合物质促进随后的表面引发（SI）光聚合，产生相当于或超过RAFT系统的后功能化结果。与近紫外范围内的两种光引发剂苯二硫代氨基甲酸酯（BDC）和N-（叔丁基）-N-（2-甲基-1-（4-苯甲酰苯基）丙基）- o -（1-苯乙基）羟胺（MBA）相比，ITX能够在几百微米的厚度上控制纯丙烯酸酯单体的SI光聚合，具有更高的摩尔反应活性和更宽的光谱响应。这允许直接光聚合和光结构使用波长从365到405纳米。这种直接且可扩展的方法为复杂3d打印架构的按需功能化和组装开辟了有希望的途径，并有望弥合学术精度和工业可访问性之间的差距。
{"title":"Revisiting 2-Isopropylthioxanthone: Direct and Reactivable Photopolymerization of Acrylates from Near-UV to Blue Light. Efficient 3D Printing and Surface Modification","authors":"Carlo Gonzato,Loïc Buchon,Jean-Louis Clément,Yohann Guillaneuf,Olivier Soppera","doi":"10.1021/acs.chemmater.6c02002","DOIUrl":"https://doi.org/10.1021/acs.chemmater.6c02002","url":null,"abstract":"Reversible-deactivation radical photopolymerization (photoRDRP) enables precise spatiotemporal control of polymer architectures. Because of embedded active chain ends, photoRDRP offers straightforward reactivation and chain extension, providing unmatched flexibility for fine-tuning structural, mechanical, and physicochemical properties for targeted applications. Nevertheless, its application to 3D printing remains limited by the cost and synthetic effort of the control agent, as well as by a limited reactivity under common near-UV and blue light sources, which requires printers working in the visible range and results in usually low printing rates. Herein, we show the unexpected ability of 2-isopropylthioxanthone (ITX) to promote both a direct acrylate photopolymerization, (with no need for any conventional co-initiator and a printing rate close to those of conventional photoinitiators) and a subsequent surface-initiated (SI) photopolymerization via reactivable surface-bound species, yielding postfunctionalization results that are equivalent to, or surpass, those of RAFT systems. Compared to benzyldithiocarbamate (BDC) and N-(tert-butyl)-N-(2-methyl-1-(4-benzoylphenyl)propyl)-O-(1-phenylethyl) hydroxylamine (MBA), two model photoinitiators for photoRDRP in the near-UV range, ITX enabled controlled SI photopolymerization of neat acrylate monomers over thicknesses of several hundred micrometers, with higher molar reactivity and a broader spectral response. This allowed for direct photopolymerization and photostructuring using wavelengths from 365 to 405 nm. This straightforward and scalable approach opens promising avenues for the on-demand functionalization and assembly of complex 3D-printed architectures and is expected to bridge the gap between academic precision and industrial accessibility.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"13 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149241809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-23DOI: 10.1021/acs.chemmater.6c01940
Ko Marunouchi,Kodai Niitsu,Akira Chikamatsu,Hiroshi Kumigashira,Hiromichi Ohta,Tsukasa Katayama
The development of ferroelectric materials relies on cation engineering of pure oxide systems. However, the discovery of new polar frameworks in pure oxides has become increasingly difficult because of their chemical and structural limitations. We report an approach to realize ferroelectricity in the n = 1 Ruddlesden−Popper (RP) family (A2BX4), a structure that is typically nonpolar in the oxide form because of its high crystalline symmetry. To stabilize the polar order in this rigid framework, we utilized anion engineering, specifically the partial substitution of O2− with F−. Although traditional topochemical fluorination requires a stable crystalline parent oxide, the parent n = 1 oxide Pb2MO4 (M = Fe, Co, Ni) is thermodynamically unstable and cannot be synthesized as a crystalline template. A low-temperature fluorination method using amorphous oxide film precursors was used to overcome this challenge. c-Axis-oriented epitaxial thin films of metastable Pb2M(O,F)4 were obtained, because a stable parent crystal was not required. Scanning transmission electron microscopy (STEM) and electrical measurements (P−E) hysteresis and positive-up-negative-down (PUND) measurements confirmed that these layered oxyfluorides exhibited clear and switchable ferroelectricity. This behavior probably originates from the strong O/F anisotropy, which forces significant off-center cation displacements within the single perovskite layers. Thus, amorphous-based low-temperature fluorination provides a universal route for exploring novel functional materials across various mixed-anion systems.
{"title":"Ferroelectricity in Single-Layer Ruddlesden−Popper Oxyfluorides Enabled by Low-Temperature Fluorination of Amorphous Precursors","authors":"Ko Marunouchi,Kodai Niitsu,Akira Chikamatsu,Hiroshi Kumigashira,Hiromichi Ohta,Tsukasa Katayama","doi":"10.1021/acs.chemmater.6c01940","DOIUrl":"https://doi.org/10.1021/acs.chemmater.6c01940","url":null,"abstract":"The development of ferroelectric materials relies on cation engineering of pure oxide systems. However, the discovery of new polar frameworks in pure oxides has become increasingly difficult because of their chemical and structural limitations. We report an approach to realize ferroelectricity in the n = 1 Ruddlesden−Popper (RP) family (A2BX4), a structure that is typically nonpolar in the oxide form because of its high crystalline symmetry. To stabilize the polar order in this rigid framework, we utilized anion engineering, specifically the partial substitution of O2− with F−. Although traditional topochemical fluorination requires a stable crystalline parent oxide, the parent n = 1 oxide Pb2MO4 (M = Fe, Co, Ni) is thermodynamically unstable and cannot be synthesized as a crystalline template. A low-temperature fluorination method using amorphous oxide film precursors was used to overcome this challenge. c-Axis-oriented epitaxial thin films of metastable Pb2M(O,F)4 were obtained, because a stable parent crystal was not required. Scanning transmission electron microscopy (STEM) and electrical measurements (P−E) hysteresis and positive-up-negative-down (PUND) measurements confirmed that these layered oxyfluorides exhibited clear and switchable ferroelectricity. This behavior probably originates from the strong O/F anisotropy, which forces significant off-center cation displacements within the single perovskite layers. Thus, amorphous-based low-temperature fluorination provides a universal route for exploring novel functional materials across various mixed-anion systems.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"13 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149241559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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