Pub Date : 2026-01-20DOI: 10.1021/acs.chemmater.5c02831
Yoann Prado, Leonardo Curti, Aude Michel, Benoît Baptiste, Yanling Li, David Hrabovsky, Benoit Fleury, Vincent Dupuis, Laurent Lisnard, Jérôme Fresnais
Using cobalt(II) complexes and a simple coordination reaction at the surface of maghemite nanoparticles, molecule-driven control of the effective magnetic anisotropy can be achieved. This functionalization strategy is explored for nanoparticles ranging from 4 to 8 nm and performed under soft synthetic conditions (mild temperature and in air) and in aqueous media. It preserves colloidal stability and permits an acute control of the magnetic properties with an increase in the blocking temperature and of the coercive field values. This effect is correlated to the quantity of complexes coordinated at the surface and the increase in the surface anisotropy of the nanoparticles. Magnetometry studies show that the effective magnetic anisotropy constant, Keff, can be modulated from 32 to 168 kJ·m–3 and with a few kJ·m–3 accuracy.
{"title":"Molecule-Driven Control of the Magnetic Anisotropy of Surface-Functionalized Maghemite Nanoparticles","authors":"Yoann Prado, Leonardo Curti, Aude Michel, Benoît Baptiste, Yanling Li, David Hrabovsky, Benoit Fleury, Vincent Dupuis, Laurent Lisnard, Jérôme Fresnais","doi":"10.1021/acs.chemmater.5c02831","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c02831","url":null,"abstract":"Using cobalt(II) complexes and a simple coordination reaction at the surface of maghemite nanoparticles, molecule-driven control of the effective magnetic anisotropy can be achieved. This functionalization strategy is explored for nanoparticles ranging from 4 to 8 nm and performed under soft synthetic conditions (mild temperature and in air) and in aqueous media. It preserves colloidal stability and permits an acute control of the magnetic properties with an increase in the blocking temperature and of the coercive field values. This effect is correlated to the quantity of complexes coordinated at the surface and the increase in the surface anisotropy of the nanoparticles. Magnetometry studies show that the effective magnetic anisotropy constant, <i>K</i><sub>eff</sub>, can be modulated from 32 to 168 kJ·m<sup>–3</sup> and with a few kJ·m<sup>–3</sup> accuracy.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":" 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146005702","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 : 2026-01-20DOI: 10.1021/acs.chemmater.5c02233
Shaun Gallagher, Jessica Kline, Yunping Huang, Dylan M. Ladd, Benjamin F. Hammel, Ian Lyons, Jalen N. Pryor, Sadegh Yazdi, Gordana Dukovic, Michael F. Toney, Seth R. Marder, David S. Ginger
Improving the properties of perovskite quantum dots (QDs) for quantum-light applications such as single photon emission requires a systematic understanding of the influence of ligand surface chemistry on single particle properties including line width and photoluminescence (PL) blinking. Here, we investigate the influence of ligand exchange on both the optical and structural properties of the single QDs. We examine PL blinking using a wide-field fluorescence microscope with ligand-exchanged QDs. We find that the zwitterionic ligands lecithin and phosphoethanolamine (PEA-C8C12) reduce blinking compared to dodecylammonium bromide (DDAB) and a bidentate dicationic quaternary ammonium bromide (DC) ligands, which have mono- and bidentate cationic head groups, respectively. The champion PEA-C8C12 shows a nonblinking fraction of 0.21, compared to 0.01 for the cationic-capped QDs. We further investigate the effect of ligand capping on low-temperature line width. We probe single particle line widths and show that zwitterionic PEA-C8C12 and lecithin outperform the cationic surface ligands for ligand-exchanged samples, having a narrower average single particle line width (24 meV for lecithin and 18 meV for PEA-C8C12 compared to 39 meV for DC-capped and 42 meV for DDAB-capped QDs) over long integration times. We rationalize these findings by quantifying ligand surface coverage using nuclear magnetic resonance, observing that QDs capped by zwitterions have higher ligand surface coverage (6.5 ± 1.6 for lecithin and 7.4 ± 1.9 ligands/nm2 for PEA), consistent with their superior performance at the single particle level. These line width and blinking results show that zwitterionic ligands are a preferable design strategy for reducing PL blinking and improving single particle line widths.
{"title":"Influence of Ligand Exchange on Single Particle Properties of Cesium Lead Bromide Quantum Dots","authors":"Shaun Gallagher, Jessica Kline, Yunping Huang, Dylan M. Ladd, Benjamin F. Hammel, Ian Lyons, Jalen N. Pryor, Sadegh Yazdi, Gordana Dukovic, Michael F. Toney, Seth R. Marder, David S. Ginger","doi":"10.1021/acs.chemmater.5c02233","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c02233","url":null,"abstract":"Improving the properties of perovskite quantum dots (QDs) for quantum-light applications such as single photon emission requires a systematic understanding of the influence of ligand surface chemistry on single particle properties including line width and photoluminescence (PL) blinking. Here, we investigate the influence of ligand exchange on both the optical and structural properties of the single QDs. We examine PL blinking using a wide-field fluorescence microscope with ligand-exchanged QDs. We find that the zwitterionic ligands lecithin and phosphoethanolamine (PEA-C<sub>8</sub>C<sub>12</sub>) reduce blinking compared to dodecylammonium bromide (DDAB) and a bidentate dicationic quaternary ammonium bromide (DC) ligands, which have mono- and bidentate cationic head groups, respectively. The champion PEA-C<sub>8</sub>C<sub>12</sub> shows a nonblinking fraction of 0.21, compared to 0.01 for the cationic-capped QDs. We further investigate the effect of ligand capping on low-temperature line width. We probe single particle line widths and show that zwitterionic PEA-C<sub>8</sub>C<sub>12</sub> and lecithin outperform the cationic surface ligands for ligand-exchanged samples, having a narrower average single particle line width (24 meV for lecithin and 18 meV for PEA-C<sub>8</sub>C<sub>12</sub> compared to 39 meV for DC-capped and 42 meV for DDAB-capped QDs) over long integration times. We rationalize these findings by quantifying ligand surface coverage using nuclear magnetic resonance, observing that QDs capped by zwitterions have higher ligand surface coverage (6.5 ± 1.6 for lecithin and 7.4 ± 1.9 ligands/nm<sup>2</sup> for PEA), consistent with their superior performance at the single particle level. These line width and blinking results show that zwitterionic ligands are a preferable design strategy for reducing PL blinking and improving single particle line widths.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"96 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000638","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 : 2026-01-20DOI: 10.1021/acs.chemmater.5c03355
Lan Wang, Shu-Fang Li, Jing-Jing Zhao, Xin-Ran Hao, Ru-Ling Tang, Chu Chu, Bingbing Zhang, Dong Yan
Nonlinear optical (NLO) materials (especially second-order NLO crystals) enable pivotal technologies like laser frequency conversion and ultrafast electro-optic modulation. The functional performance of NLO crystals is predominantly governed by two interdependent factors: the ordered arrangement mode of constituent motifs and their inherent structural distortion characteristics. This work pioneers a coordination-driven structural manipulation strategy to regulate the NLO-active tetrahedral units. Leveraging ligands with different coordination capabilities to tetrahedral metal centers modulates the electron density distribution around metal sites through coordination-bond perturbation. Resulting electron redistribution asymmetrically influences the covalent bonds, inducing controlled tetrahedral distortion. Guided by the aforementioned strategy, we synthesized an isothiocyanate with mixed bonding configurations, namely, Zn4S(C2H2N3)3(NCS)3, which exhibits exceptional multifunctional optical properties: considerable second-harmonic generation (SHG) response [6.8 × KH2PO4 (KDP) @1064 nm], substantial birefringence (Δn = 0.32 @546 nm), high thermal stability (Td = 415 °C), and wide bandgap (4.72 eV). Theoretical calculations not only validate the efficacy of the coordination-driven structural manipulation strategy but also elucidate that synergistic interactions among constituent functional motifs govern the optical properties. A novel thiocyanate designated as Zn4S(C2H2N3)3(NCS)3 (ZSTN) was engineered through an effective coordination-driven structural distortion strategy, manifesting a mixed-chemical-bonding characteristic that concurrently delivers strong second-harmonic generation response (6.8 × KDP), substantial birefringence (Δn ≈ 0.32), wide bandgap (4.72 eV), and exceptional thermal stability (>400 °C).
{"title":"Zn4S(C2H2N3)3(NCS)3: Coordination-Driven Structural Distortion Engineering Triggers Exceptional NLO Effect in Mixed-Bonding Zinc Isothiocyanate","authors":"Lan Wang, Shu-Fang Li, Jing-Jing Zhao, Xin-Ran Hao, Ru-Ling Tang, Chu Chu, Bingbing Zhang, Dong Yan","doi":"10.1021/acs.chemmater.5c03355","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c03355","url":null,"abstract":"Nonlinear optical (NLO) materials (especially second-order NLO crystals) enable pivotal technologies like laser frequency conversion and ultrafast electro-optic modulation. The functional performance of NLO crystals is predominantly governed by two interdependent factors: the ordered arrangement mode of constituent motifs and their inherent structural distortion characteristics. This work pioneers a coordination-driven structural manipulation strategy to regulate the NLO-active tetrahedral units. Leveraging ligands with different coordination capabilities to tetrahedral metal centers modulates the electron density distribution around metal sites through coordination-bond perturbation. Resulting electron redistribution asymmetrically influences the covalent bonds, inducing controlled tetrahedral distortion. Guided by the aforementioned strategy, we synthesized an isothiocyanate with mixed bonding configurations, namely, Zn<sub>4</sub>S(C<sub>2</sub>H<sub>2</sub>N<sub>3</sub>)<sub>3</sub>(NCS)<sub>3</sub>, which exhibits exceptional multifunctional optical properties: considerable second-harmonic generation (SHG) response [6.8 × KH<sub>2</sub>PO<sub>4</sub> (KDP) @1064 nm], substantial birefringence (Δ<i>n</i> = 0.32 @546 nm), high thermal stability (<i>T</i><sub>d</sub> = 415 °C), and wide bandgap (4.72 eV). Theoretical calculations not only validate the efficacy of the coordination-driven structural manipulation strategy but also elucidate that synergistic interactions among constituent functional motifs govern the optical properties. A novel thiocyanate designated as Zn<sub>4</sub>S(C<sub>2</sub>H<sub>2</sub>N<sub>3</sub>)<sub>3</sub>(NCS)<sub>3</sub> (ZSTN) was engineered through an effective coordination-driven structural distortion strategy, manifesting a mixed-chemical-bonding characteristic that concurrently delivers strong second-harmonic generation response (6.8 × KDP), substantial birefringence (Δn ≈ 0.32), wide bandgap (4.72 eV), and exceptional thermal stability (>400 °C).","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"1 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000641","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 : 2026-01-19DOI: 10.1021/acs.chemmater.5c02745
Kai Zhang, Luhai Yuan, Dexuan Cai, Xihao Tang, Ziad Alsudairy, Shengrun Zheng, Mubiao Xie, Jun Fan, Yuwei Zhang, Weiguang Zhang, Xinle Li, Songliang Cai
Introducing macropores within chiral covalent organic frameworks (COFs) offers a potent solution to the low-efficiency mass transport common in micro- and mesoporous chiral COFs. Nevertheless, this attempt remains untapped to date. Here, we report the first hierarchically macro-mesoporous chiral COF, termed macro-L-DTPC-TP, using a template-assisted approach. Through this strategy, a β-ketoenamine-linked chiral COF bearing pyrrolidine moieties was assembled around monodisperse polystyrene (PS) nanospheres (∼200 nm), during which in situ deprotection of the tert-butoxycarbonyl (Boc) group occurred. Subsequent removal of the PS template produced macro-L-DTPC-TP COF with high crystallinity, macro-mesoporous structure, and inherent chiral pyrrolidine sites. The introduction of interconnected meso- and macropores significantly improved the catalytic efficiency of COF in the aqueous asymmetric aldol reaction. Compared to the pristine mesoporous L-DTPC-TP COF (51% yield), macro-L-DTPC-TP COF exhibited a remarkably high yield of 98%, underscoring the pivotal role of macropores in enhancing mass transport and substrate accessibility. This work presents the first example of a hierarchically macro-mesoporous chiral COF and establishes macropore incorporation as an effective strategy to overcome diffusion limitations and advance the performance of COF-based asymmetric catalysis.
{"title":"A Macro-mesoporous Chiral Covalent Organic Framework for Enhanced Asymmetric Catalysis in Water","authors":"Kai Zhang, Luhai Yuan, Dexuan Cai, Xihao Tang, Ziad Alsudairy, Shengrun Zheng, Mubiao Xie, Jun Fan, Yuwei Zhang, Weiguang Zhang, Xinle Li, Songliang Cai","doi":"10.1021/acs.chemmater.5c02745","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c02745","url":null,"abstract":"Introducing macropores within chiral covalent organic frameworks (COFs) offers a potent solution to the low-efficiency mass transport common in micro- and mesoporous chiral COFs. Nevertheless, this attempt remains untapped to date. Here, we report the first hierarchically macro-mesoporous chiral COF, termed macro-<i>L</i>-DTPC-TP, using a template-assisted approach. Through this strategy, a β-ketoenamine-linked chiral COF bearing pyrrolidine moieties was assembled around monodisperse polystyrene (PS) nanospheres (∼200 nm), during which <i>in situ</i> deprotection of the <i>tert</i>-butoxycarbonyl (Boc) group occurred. Subsequent removal of the PS template produced macro-<i>L</i>-DTPC-TP COF with high crystallinity, macro-mesoporous structure, and inherent chiral pyrrolidine sites. The introduction of interconnected meso- and macropores significantly improved the catalytic efficiency of COF in the aqueous asymmetric aldol reaction. Compared to the pristine mesoporous <i>L</i>-DTPC-TP COF (51% yield), macro-<i>L</i>-DTPC-TP COF exhibited a remarkably high yield of 98%, underscoring the pivotal role of macropores in enhancing mass transport and substrate accessibility. This work presents the first example of a hierarchically macro-mesoporous chiral COF and establishes macropore incorporation as an effective strategy to overcome diffusion limitations and advance the performance of COF-based asymmetric catalysis.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"272 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000876","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 : 2026-01-19DOI: 10.1021/acs.chemmater.5c02480
Sabin Aryal, Yiteng Tang, Dulanjan Harankahage, Mikhail Zamkov, Liangfeng Sun
We report colloidal PbS nanoplatelets synthesized in bromide-containing media that spontaneously form core/shell heterostructures with inorganic lead sulfobromide and lead bromide shells surrounding a PbS core. Band-structure measurements indicate a type-I alignment, which concentrates electrons and holes within the PbS core. These core–shell nanoplatelets exhibit near-infrared emission with a remarkably narrow photoluminescence peak of 78 meV at room temperature. The inorganic shells also act as robust passivating layers that suppress surface defect states, yielding an improved photoluminescence quantum yield and preserving emissive performance under ambient conditions. The resulting nanoplatelets are bright and air-stable, offering a solution-processable platform for infrared photonics and optoelectronics, including emitters, detectors, and integrated photonic components.
{"title":"Bright Infrared Colloidal PbS Nanoplatelets with Lead Sulfobromide Shells","authors":"Sabin Aryal, Yiteng Tang, Dulanjan Harankahage, Mikhail Zamkov, Liangfeng Sun","doi":"10.1021/acs.chemmater.5c02480","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c02480","url":null,"abstract":"We report colloidal PbS nanoplatelets synthesized in bromide-containing media that spontaneously form core/shell heterostructures with inorganic lead sulfobromide and lead bromide shells surrounding a PbS core. Band-structure measurements indicate a type-I alignment, which concentrates electrons and holes within the PbS core. These core–shell nanoplatelets exhibit near-infrared emission with a remarkably narrow photoluminescence peak of 78 meV at room temperature. The inorganic shells also act as robust passivating layers that suppress surface defect states, yielding an improved photoluminescence quantum yield and preserving emissive performance under ambient conditions. The resulting nanoplatelets are bright and air-stable, offering a solution-processable platform for infrared photonics and optoelectronics, including emitters, detectors, and integrated photonic components.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"315 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000642","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 : 2026-01-17DOI: 10.1021/acs.chemmater.5c02824
Kathryn E. Brockmeyer, Alexander J. Bologna, Matthew A. Wright, Josephine Wong, Cesar Rodriguez, Tianyu Li, Rachel A. Segalman, Ram Seshadri
Hard carbons are the leading anode material in Na-ion batteries due to their considerable ability to store Na, and the ease with which they can be produced from inexpensive precursors such as cellulose through pyrolysis in inert atmospheres. Here, we report a rapid one-step conversion of cellulose to hard carbons in under 15 min in a modified domestic microwave oven. This is in contrast to more conventional furnace-based pyrolysis which can take several hours. From optical pyrometry, we find that under different microwave power conditions, the hard carbons can be tunably formed at temperatures between 900 to 1250 °C under the conditions employed. The hard carbons produced here have been characterized by Raman spectroscopy, wide and small-angle X-ray diffraction, porosimetry, X-ray photoelectron spectroscopy, and X-ray pair distribution function analysis. As a function of increasing microwave power, the carbons are found to exhibit comparable local structure but enhanced crystallinity and evidence of an increased proportion of closed pores. The formation of closed pores appears to directly contribute to significant gains in Na storage capacity throughout the plateau region during electrochemical cycling. These results demonstrate a convenient and scalable strategy for rapidly producing hard carbons with tunable porosity.
{"title":"Direct Microwave Pyrolysis of Cellulose to Hard Carbon Anodes for Sodium-Ion Batteries","authors":"Kathryn E. Brockmeyer, Alexander J. Bologna, Matthew A. Wright, Josephine Wong, Cesar Rodriguez, Tianyu Li, Rachel A. Segalman, Ram Seshadri","doi":"10.1021/acs.chemmater.5c02824","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c02824","url":null,"abstract":"Hard carbons are the leading anode material in Na-ion batteries due to their considerable ability to store Na, and the ease with which they can be produced from inexpensive precursors such as cellulose through pyrolysis in inert atmospheres. Here, we report a rapid one-step conversion of cellulose to hard carbons in under 15 min in a modified domestic microwave oven. This is in contrast to more conventional furnace-based pyrolysis which can take several hours. From optical pyrometry, we find that under different microwave power conditions, the hard carbons can be tunably formed at temperatures between 900 to 1250 °C under the conditions employed. The hard carbons produced here have been characterized by Raman spectroscopy, wide and small-angle X-ray diffraction, porosimetry, X-ray photoelectron spectroscopy, and X-ray pair distribution function analysis. As a function of increasing microwave power, the carbons are found to exhibit comparable local structure but enhanced crystallinity and evidence of an increased proportion of closed pores. The formation of closed pores appears to directly contribute to significant gains in Na storage capacity throughout the plateau region during electrochemical cycling. These results demonstrate a convenient and scalable strategy for rapidly producing hard carbons with tunable porosity.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"144 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986667","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 : 2026-01-17DOI: 10.1021/acs.chemmater.5c03006
Kento Imamura, Kosuke Sato, Shinsuke Inagi
Covalent organic frameworks (COFs) are crystalline, porous materials with tunable structures and significant potential for applications, such as molecular separation and sensing. However, the fabrication of large-area, uniform, and defect-free COF films with controlled thickness and high crystallinity remains a major challenge. This study presents a rapid, scalable, two-step strategy for fabricating oriented crystalline fluorinated COF (F-COF) films. The process combines electrochemical deposition of an amorphous intermediate film induced by electrogenerated acid with subsequent annealing with acid vapor to achieve solid-state crystallization. Under mild conditions, this method produces free-standing, micrometer-thick F-COF films with crystallinity over centimeter-scale areas with a significantly shortened reaction time. The resulting F-COF films exhibit high crystallinity and orientation, thereby enhancing electron transport and enabling selective molecular sieving. These films can effectively discriminate small molecules such as alkylamines, even in the presence of interfering metal ions, highlighting their potential as contamination-resistant electrochemical sensors. The proposed approach provides a practical methodology for fabricating functional F-COF films and establishes a model for their electrochemical application.
{"title":"Electrochemically Controlled Deposition of Oriented Fluorinated Covalent Organic Framework Films for Selective Electrochemical Sensing","authors":"Kento Imamura, Kosuke Sato, Shinsuke Inagi","doi":"10.1021/acs.chemmater.5c03006","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c03006","url":null,"abstract":"Covalent organic frameworks (COFs) are crystalline, porous materials with tunable structures and significant potential for applications, such as molecular separation and sensing. However, the fabrication of large-area, uniform, and defect-free COF films with controlled thickness and high crystallinity remains a major challenge. This study presents a rapid, scalable, two-step strategy for fabricating oriented crystalline fluorinated COF (F-COF) films. The process combines electrochemical deposition of an amorphous intermediate film induced by electrogenerated acid with subsequent annealing with acid vapor to achieve solid-state crystallization. Under mild conditions, this method produces free-standing, micrometer-thick F-COF films with crystallinity over centimeter-scale areas with a significantly shortened reaction time. The resulting F-COF films exhibit high crystallinity and orientation, thereby enhancing electron transport and enabling selective molecular sieving. These films can effectively discriminate small molecules such as alkylamines, even in the presence of interfering metal ions, highlighting their potential as contamination-resistant electrochemical sensors. The proposed approach provides a practical methodology for fabricating functional F-COF films and establishes a model for their electrochemical application.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"21 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986668","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 : 2026-01-16DOI: 10.1021/acs.chemmater.5c02528
Malte Sachs, Antti J. Karttunen, Florian Kraus
We present a systematic first-principles screening of metal fluorides reported in polar crystallographic point groups to identify new candidates for ferroelectric materials. From an initial set of 57 distinct polar structure types collected from crystallographic databases, we classified each entry by crystallographic group-subgroup analysis, hybrid density functional theory (DFT) calculations, and machine-learning-based similarity search into one of the three categories: potentially ferroelectric structures, pyroelectric but nonferroelectric compounds, and structures likely based on wrong polar structure models. Our analysis yields 20 potentially ferroelectric compounds, including 14 new structure types that are further ranked by a one-class support vector machine (SVM) similarity analysis. Promising ferroelectric candidates include KNaSnF6, NaSrAlF6, KYF4 and the possibly multiferroic RbCrF5. With tetragonal antiprismatic coordinated Hf atoms the compound Pb2HfF8 introduces a new structural motive for ferroelectricity, whereas Mn3F8 is a new candidate for a charge-ordered ferroelectric. Together, these compounds expand the structural chemistry of fluoride ferroelectrics beyond the classical BaZnF4 type. We further report 14 pyroelectric candidates that lack centrosymmetric reference phases and are therefore structurally precluded from ferroelectric switching. In addition, we identified 23 structure types based on possibly wrong polar models. For these compounds, DFT structure optimizations systematically relax into centrosymmetric crystal structures, in line with earlier corrections reported in the literature. Among them, Sr4Zn3F14, NaMn3F10, RbTlF4 and δ-Na2UF6 remain uncorrected in crystallographic databases and require experimental reinvestigation. Our findings highlight that about 40% of the reported polar fluorides are likely misassigned, underlining the need for critical crystal structure validation prior to high-throughput searches. At the same time, the newly identified ferroelectric candidates offer promising directions for expanding the family of fluoride-based functional materials.
{"title":"A First-Principles Analysis of Metal Fluorides with Polar Crystal Structures as Candidates for New Ferroelectric Materials","authors":"Malte Sachs, Antti J. Karttunen, Florian Kraus","doi":"10.1021/acs.chemmater.5c02528","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c02528","url":null,"abstract":"We present a systematic first-principles screening of metal fluorides reported in polar crystallographic point groups to identify new candidates for ferroelectric materials. From an initial set of 57 distinct polar structure types collected from crystallographic databases, we classified each entry by crystallographic group-subgroup analysis, hybrid density functional theory (DFT) calculations, and machine-learning-based similarity search into one of the three categories: potentially ferroelectric structures, pyroelectric but nonferroelectric compounds, and structures likely based on wrong polar structure models. Our analysis yields 20 potentially ferroelectric compounds, including 14 new structure types that are further ranked by a one-class support vector machine (SVM) similarity analysis. Promising ferroelectric candidates include KNaSnF<sub>6</sub>, NaSrAlF<sub>6</sub>, KYF<sub>4</sub> and the possibly multiferroic RbCrF<sub>5</sub>. With tetragonal antiprismatic coordinated Hf atoms the compound Pb<sub>2</sub>HfF<sub>8</sub> introduces a new structural motive for ferroelectricity, whereas Mn<sub>3</sub>F<sub>8</sub> is a new candidate for a charge-ordered ferroelectric. Together, these compounds expand the structural chemistry of fluoride ferroelectrics beyond the classical BaZnF<sub>4</sub> type. We further report 14 pyroelectric candidates that lack centrosymmetric reference phases and are therefore structurally precluded from ferroelectric switching. In addition, we identified 23 structure types based on possibly wrong polar models. For these compounds, DFT structure optimizations systematically relax into centrosymmetric crystal structures, in line with earlier corrections reported in the literature. Among them, Sr<sub>4</sub>Zn<sub>3</sub>F<sub>14</sub>, NaMn<sub>3</sub>F<sub>10</sub>, RbTlF<sub>4</sub> and δ-Na<sub>2</sub>UF<sub>6</sub> remain uncorrected in crystallographic databases and require experimental reinvestigation. Our findings highlight that about 40% of the reported polar fluorides are likely misassigned, underlining the need for critical crystal structure validation prior to high-throughput searches. At the same time, the newly identified ferroelectric candidates offer promising directions for expanding the family of fluoride-based functional materials.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"30 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972385","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 : 2026-01-16DOI: 10.1021/acs.chemmater.5c02732
Anika Tabassum Promi, Jaeyoung Lee, Katelyn Meyer, Dawei Xia, Chenguang Shi, Yang Yang, Andrew M. Kiss, Luxi Li, Chengjun Sun, Dennis Nordlund, F. Marc Michel, Hongxiao Zhu, Feng Lin
Transition metal dissolution and redeposition (D/R) kinetics in alkaline media play a critical role in various chemical and electrochemical processes. Competitive reaction kinetics between different transition metals can modulate individual metal behavior in these processes. To date, these phenomena have remained largely unmeasured, and even when captured, they are difficult to statistically characterize due to their dynamic nature, simultaneous occurrence, and spatially heterogeneous nature. Here, we develop a statistical analysis framework based on in situ and operando X-ray fluorescence microscopy (XFM) to investigate the relative D/R kinetics of multiple transition metals in alkaline media. By employing statistical analysis, we quantify the spatial distribution of D/R species and assess the rate at which the system reaches equilibrium under varying reaction conditions. We show that pH does not simply change the rate of dissolution and redeposition, but reorganizes the cross-element kinetic correlations among Ni, Fe, and Mn and accelerates the spatial equilibration of D/R events, as quantified through correlation analysis, reaction-rate estimation, probability function distributions, and texture-based monitoring statistics. Additionally, we demonstrate how modifying the solvent environment can influence D/R kinetics, providing a pathway for tuning materials synthesis and process optimization. Our study offers valuable insights into the complex interplay between different transition metals and provides a reliable statistical framework for spatial analysis of diverse imaging data sets, enabling deeper extraction of latent information across multiple modalities.
{"title":"Spatiotemporal and Statistical Mapping of Transition Metal Equilibria in Alkaline Media","authors":"Anika Tabassum Promi, Jaeyoung Lee, Katelyn Meyer, Dawei Xia, Chenguang Shi, Yang Yang, Andrew M. Kiss, Luxi Li, Chengjun Sun, Dennis Nordlund, F. Marc Michel, Hongxiao Zhu, Feng Lin","doi":"10.1021/acs.chemmater.5c02732","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c02732","url":null,"abstract":"Transition metal dissolution and redeposition (D/R) kinetics in alkaline media play a critical role in various chemical and electrochemical processes. Competitive reaction kinetics between different transition metals can modulate individual metal behavior in these processes. To date, these phenomena have remained largely unmeasured, and even when captured, they are difficult to statistically characterize due to their dynamic nature, simultaneous occurrence, and spatially heterogeneous nature. Here, we develop a statistical analysis framework based on in situ and operando X-ray fluorescence microscopy (XFM) to investigate the relative D/R kinetics of multiple transition metals in alkaline media. By employing statistical analysis, we quantify the spatial distribution of D/R species and assess the rate at which the system reaches equilibrium under varying reaction conditions. We show that pH does not simply change the rate of dissolution and redeposition, but reorganizes the cross-element kinetic correlations among Ni, Fe, and Mn and accelerates the spatial equilibration of D/R events, as quantified through correlation analysis, reaction-rate estimation, probability function distributions, and texture-based monitoring statistics. Additionally, we demonstrate how modifying the solvent environment can influence D/R kinetics, providing a pathway for tuning materials synthesis and process optimization. Our study offers valuable insights into the complex interplay between different transition metals and provides a reliable statistical framework for spatial analysis of diverse imaging data sets, enabling deeper extraction of latent information across multiple modalities.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"23 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972386","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 : 2026-01-16DOI: 10.1021/acs.chemmater.5c03173
Shunta Iwamoto, Ryohei Akiyoshi, Sora Nakasone, Chomponoot Suppaso, Megumi Okazaki, Kazuhide Kamiya, Yuta Tsuji, Daisuke Tanaka, Kazuhiko Maeda
Developing electrocatalysts for CO2 reduction is essential for the effective use of renewable energy. Materials containing molecules such as coordination polymers have strong potential to exhibit high activity and selectivity. However, a critical shortcoming is that they often decompose into metals or metal oxides during reactions, thereby preventing the manifestation of functions unique to molecular structures. In this study, we compare a series of Pb–S-based coordination polymers, [Pb(x-SPhOMe)2]n (HSPhOMe = methoxybenzenethiol, x = ortho (KGF-32), meta (KGF-33), and para (KGF-34)), as model electrocatalysts to investigate the design guidelines. They have different crystal structures in terms of dimensionality and coordination environment. Among them, KGF-32 shows the highest Faradaic efficiency for formate production: 96.6 ± 2.9% at −1.0 V vs RHE with a partial current density of −9.76 ± 2.1 mA cm–2. By contrast, KGF-33 and -34 show lower Faradaic efficiencies for formate production, along with more pronounced decomposition to PbCO3. We use scanning electron microscopy, X-ray diffraction, and Raman spectroscopy to confirm that KGF-32 retains much of its crystal structure during operation, whereas KGF-33 and -34 decompose extensively. In addition, density functional theory calculations reveal that the energy barrier for formate production on KGF-32 is lower than that on PbCO3, which explains its superior catalytic activity. Our work demonstrates the inherent advantages of coordination-polymer-based electrocatalysts and provides valuable guidelines for designing more efficient and stable systems for CO2 reduction.
开发减少二氧化碳的电催化剂对于有效利用可再生能源至关重要。含有配位聚合物等分子的材料具有表现出高活性和选择性的强大潜力。然而，一个关键的缺点是它们在反应过程中经常分解成金属或金属氧化物，从而阻碍了分子结构特有功能的表现。在这项研究中，我们比较了一系列基于铅的配位聚合物[Pb(x- sphome)2]n （HSPhOMe =甲氧基苯硫醇，x =邻位（KGF-32），元（KGF-33）和段（KGF-34））作为模型电催化剂，以探讨设计指南。它们在维数和配位环境方面具有不同的晶体结构。其中，KGF-32在−1.0 V vs RHE条件下，产甲酸的法拉第效率最高，为96.6±2.9%，分电流密度为−9.76±2.1 mA cm-2。相比之下，KGF-33和-34在生成甲酸方面的法拉第效率较低，同时分解成PbCO3的效果更明显。我们使用扫描电子显微镜、x射线衍射和拉曼光谱来证实KGF-32在运行过程中保留了大部分晶体结构，而KGF-33和-34则大量分解。此外，密度泛函理论计算表明，KGF-32生成甲酸的能垒低于PbCO3，这解释了KGF-32具有更强的催化活性。我们的工作证明了基于配位聚合物的电催化剂的固有优势，并为设计更有效和稳定的CO2还原系统提供了有价值的指导。
{"title":"Substituent-Position-Dependent Electrochemical CO2 Reduction Activity of Pb–S-Based Coordination Polymers","authors":"Shunta Iwamoto, Ryohei Akiyoshi, Sora Nakasone, Chomponoot Suppaso, Megumi Okazaki, Kazuhide Kamiya, Yuta Tsuji, Daisuke Tanaka, Kazuhiko Maeda","doi":"10.1021/acs.chemmater.5c03173","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c03173","url":null,"abstract":"Developing electrocatalysts for CO<sub>2</sub> reduction is essential for the effective use of renewable energy. Materials containing molecules such as coordination polymers have strong potential to exhibit high activity and selectivity. However, a critical shortcoming is that they often decompose into metals or metal oxides during reactions, thereby preventing the manifestation of functions unique to molecular structures. In this study, we compare a series of Pb–S-based coordination polymers, [Pb(<i>x</i>-SPhOMe)<sub>2</sub>]<sub><i>n</i></sub> (HSPhOMe = methoxybenzenethiol, <i>x</i> = <i>ortho</i> (KGF-32), <i>meta</i> (KGF-33), and <i>para</i> (KGF-34)), as model electrocatalysts to investigate the design guidelines. They have different crystal structures in terms of dimensionality and coordination environment. Among them, KGF-32 shows the highest Faradaic efficiency for formate production: 96.6 ± 2.9% at −1.0 V vs RHE with a partial current density of −9.76 ± 2.1 mA cm<sup>–2</sup>. By contrast, KGF-33 and -34 show lower Faradaic efficiencies for formate production, along with more pronounced decomposition to PbCO<sub>3</sub>. We use scanning electron microscopy, X-ray diffraction, and Raman spectroscopy to confirm that KGF-32 retains much of its crystal structure during operation, whereas KGF-33 and -34 decompose extensively. In addition, density functional theory calculations reveal that the energy barrier for formate production on KGF-32 is lower than that on PbCO<sub>3</sub>, which explains its superior catalytic activity. Our work demonstrates the inherent advantages of coordination-polymer-based electrocatalysts and provides valuable guidelines for designing more efficient and stable systems for CO<sub>2</sub> reduction.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"57 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972387","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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