Chemistry of Materials最新文献

{"title":"Highly Durable Fuel Cells Using Carbon-Bound Platinum Alloy Catalysts Derived from Upcycled Polystyrene","authors":"Jaehoon Kwon, Hyunsoo Lee, Logeshwaran Natarajan, Sangyong Shin, Jaeyoung Choi, Sungho Lee, Bumjoon J. Kim, Hyunjoo Lee, Young Jun Lee","doi":"10.1021/acs.chemmater.5c00103","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00103","url":null,"abstract":"Developing highly active and durable catalysts with minimal platinum (Pt) usage is crucial for reducing the overall cost of proton exchange membrane fuel cells (PEMFCs). Herein, we introduce a scalable synthesis of carbon-bound catalysts using the upcycling of the polystyrene (PS) polymer. Our approach utilizes solvent-based hyper-cross-linking techniques to spontaneously achieve a hierarchically porous structure in a single-step process. The Pt-loaded PS-derived carbon support features a mesopore structure that enhances mass transport for PEMFCs, despite a low Pt loading of 0.05 mg_Pt cm^–2. The catalyst exhibits excellent durability, retaining 92.1% of its initial power density after 30,000 cycles, owing to its carbon-bound structure and the strong interaction between catalyst and support. In contrast, the power density of commercial Pt/C retains only 35.8% after 30,000 cycles. This approach offers a cost-efficient and sustainable method for upcycling PS polymers into highly durable cathode materials for PEMFCs.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"25 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471027","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}

{"title":"Spin–Flop and Metamagnetic Transition in Monoclinic Eu4Bi6Se13","authors":"Mingyu Xu, Jose L. Gonzalez Jimenez, Greeshma C. Jose, Artittaya Boonkird, Chengkun Xing, Chelsea Harrod, Xinle Li, Haidong D. Zhou, Xianglin Ke, Wenli Bi, Mingda Li, Weiwei Xie","doi":"10.1021/acs.chemmater.4c03185","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c03185","url":null,"abstract":"This study explores an investigation of the crystallographic, electronic, and magnetic properties of the europium-based bismuth selenide compound Eu₄Bi₆Se₁₃, with particular focus on its magnetic anisotropy. This compound adopts a monoclinic crystal structure classified under the <i>P</i>2₁/<i>m</i> space group (#11). It exhibits distinctive structural features, including substantial Eu–Se coordination numbers (6 and 8), Bi–Se ladders, and linear chains of Eu atoms that propagate along the <i>b</i>-axis. Electronic resistivity assessments indicate that Eu₄Bi₆Se₁₃ exhibits metallic behavior. As the magnetic field is oriented along the <i>b</i>-axis, magnetic characterization reveals uniaxial magnetic anisotropy, with metamagnetic transitions appearing at approximately 12 kOe and a lower field. In the field below 10 kOe, the spin-flop transition is observed with possible domain-induced hysteresis. This behavior supports the identification of metamagnetic features in field-dependent measurements attributable to the europium spins.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"11 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471105","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}

{"title":"Elemental Reactivity Maps for Materials Discovery","authors":"Yuki Inada, Masaya Fujioka, Haruhiko Morito, Tohru Sugahara, Hisanori Yamane, Yukari Katsura","doi":"10.1021/acs.chemmater.4c02259","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02259","url":null,"abstract":"When searching for novel inorganic materials, limiting the combination of constituent elements can greatly improve the search efficiency. In this study, we used machine learning to predict elemental combinations with high reactivity for materials discovery. The essential issue for such prediction is the uncertainty of whether the unreported combinations are nonreactive or not just investigated, though the reactive combinations can be easily collected as positive data sets from the materials databases. To construct the negative data sets, we developed a process to select reliable nonreactive combinations by evaluating the similarity between unreported and reactive combinations. The machine learning models were trained by both data sets, and the prediction results were visualized by two-dimensional heatmaps: elemental reactivity maps to identify elemental combinations with high reactivity but no reported stable compounds. The maps predicted high reactivity (i.e., synthesizability) for the Co–Al–Ge ternary system, and two novel ternary compounds were synthesized: Co₄Ge_3.19Al_0.81 and Co₂Al_1.26Ge_1.74.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"18 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471099","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}

{"title":"High Selectivity toward Photoreduction of Carbon Dioxide to Methane over Copper-Doped Titania: Investigations Using Operando Techniques","authors":"Kaustava Bhattacharyya, Chandrani Nayak, Dibyendyu Bhattacharyya, Ahin Roy, Avesh K. Tyagi","doi":"10.1021/acs.chemmater.4c00748","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c00748","url":null,"abstract":"The photocatalytic reduction of CO₂ to CH₄ is a highly beneficial option from the perspective of both energy and the environment. Several promising photocatalysts that selectively produce CH₄ (C1) mainly comprise Cu in different oxidation states. Since the CO₂ reduction to CH₄ is an 8 electron reaction, the formation of the different intermediates upon adsorption and photocatalytic reaction had to be discerned individually. Earlier, it has been demonstrated by our group that the Cu-doped TiO₂ photocatalyst is able to selectively reduce CO₂ to CH₄ with very good yield. The present article reports detailed in situ FT-IR studies to delineate the different intermediates formed by exposure to CO₂ and moisture over the Cu-doped TiO₂ catalysts like bidentate carbonates, monodentate carbonates, bicarbonates, and carboxylates identified over different Cu-doped TiO₂ surfaces. These intermediates were correlated with the differential electron densities over Cu, Ti, and O vacancies ascertained from XANES/EXAFS (XAS) studies. These catalysts were then selectively reduced within the in situ FT-IR chamber to further ascertain the role of the Cu¹⁺, Ti³⁺, and O vacancies to rationalize the effect of different Lewis base sites in the photocatalysts. In situ XAS studies in correlation with the in situ FT-IR studies lead to a generic understanding of different adsorbate species formed over the Cu surfaces at the molecular level. The time-dependent XAS studies used for the photoreduction of CO₂ over the Cu-doped photocatalysts were undertaken to establish the precise role of Cu and to delineate the alteration in the bond distances on the photocatalytic reduction of CO₂. This study principally delineates the effect of Cu sites for the photocatalytic CO₂ reduction process in the presence of moisture as compared to the other probable active sites present in the photocatalyst. The effect of oxidation states and the formation of different intermediates for reactive adsorption and, in turn, their effect on photocatalysis will pave the way to formulate further better photocatalysts for the photoreduction of CO₂.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"72 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462197","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}

{"title":"Ultrafast Photocatalytic Decontamination of Mustard Gas Simulant and Thermodynamic Insights by a Metal-Free Imidazoline Porous Organic Polymer","authors":"Gourab K. Dam, Vartika Jaiswal, Sumanta Let, Anirban Roy, Sudip Maity, Shalu Rana, Sujit K. Ghosh","doi":"10.1021/acs.chemmater.4c02959","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02959","url":null,"abstract":"Detoxification of mustard gas through selective partial oxidation to sulfoxide is efficient yet challenging due to the hazardous nature of the overoxidized sulfone product. Metal-free imidazoline-based POPs, an emerging class of efficient photosensitizers with excellent chemical stability, incorporate both electron-rich and electron-deficient units with donor–acceptor junctions. In this study, we developed a highly photoactive protonated imidazoline-based POP, IPM-401, illustrating mild oxidizing power and enhanced ROS generation capability. Toward the detoxification of mustard gas simulant 2-chloroethyl ethyl sulfide (CEES), IPM-401 displayed excellent performance with ultrafast kinetics of <i>t</i>_1/2 = 4.9 min in O₂-saturated and <i>t</i>_1/2 = 5.7 min under aerobic atmosphere, respectively, utilizing MeOH as the suitable solvent system. Additionally, ITC analysis revealed a favorable thermodynamic interaction (Δ<i>G</i> = −6.39 kcal/mol) between IPM-401 and CEES. Density functional theory calculations further validated this interaction, confirming the favorable binding of CEES to the imidazoline moiety of IPM-401. The underlying detoxification mechanism in different solvent systems is further advocated by experimental data. IPM-401 also demonstrates its versatile photocatalytic activity toward sulfide and aromatic aldehyde oxidation reactions across a broad range of substrates. Furthermore, the practical relevance of chemically stable IPM-401 was also established from its satisfactory recyclability performance up to 10 cycles.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"29 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462234","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}

{"title":"Molecular Design in Area-Selective Atomic Layer Deposition: Understanding Inhibitors and Precursors","authors":"Yujin Lee, Amnon Rothman, Alexander B. Shearer, Stacey F. Bent","doi":"10.1021/acs.chemmater.4c02902","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02902","url":null,"abstract":"Area-selective atomic layer deposition (AS-ALD) has become an essential technique in precision patterning due to its ability to deposit thin films with high conformality and angstrom-level thickness control exclusively in targeted areas. This bottom-up approach offers significant advantages over conventional top-down patterning methods such as photolithography, which encounter challenges like edge placement error and require multiple processing steps. AS-ALD, with its precise control over nanostructure fabrication, supports the development of advanced devices and extends its applications to diverse fields such as sensing, catalysis, and energy. This Review considers molecular design in AS-ALD, highlighting the molecular-level interactions between atomic layer deposition (ALD) precursors and inhibitors with a focus on how variations in precursor ligands and inhibitor head and tail groups influence selectivity. Recent advancements and experimental insights are summarized to provide an understanding of the chemical mechanisms underlying AS-ALD processes. By offering detailed molecular insights, this Review aims to enhance the selection and design of precursor and inhibitor molecules, thereby advancing the development of AS-ALD across various technological fields.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"25 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462198","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}

{"title":"Robust Unusually High Valence Fe5+ State and Large Magnetic Interaction Change in the Double Perovskites La2–xCaxLiFeO6–0.5x","authors":"Masato Goto, Kazunori Sato, Wei-tin Chen, Wei-Hsiang Huang, Yuichi Shimakawa","doi":"10.1021/acs.chemmater.4c03494","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c03494","url":null,"abstract":"We successfully synthesized Ca-substituted <i>B</i>-site-ordered double perovskites La_2–<i>x</i>Ca<i>_<i>x</i></i>LiFeO₆ by using high-pressure techniques and investigated site-substitution effects on the stability of unusually high valence Fe ions and their magnetic properties. Our research revealed the robust Fe⁵⁺ state against the aliovalent substitution at the <i>A</i> site, as seen in the actual composition La_2–<i>x</i>Ca<i>_<i>x</i></i>LiFeO_{6–0.5<i>x</i>}. Introducing oxygen vacancies is a key factor in this discovery, as it significantly weakens the strong antiferromagnetic interaction for <i>x</i> = 0, transforming it into a weak ferromagnetic one for <i>x</i> &gt; 0.3. This significant interaction change, coupled with the partial randomness of the magnetic interactions, easily releases the geometrical spin frustration of Fe⁵⁺ located on a face-centered-cubic lattice with just 5% Ca substitution. These results deepen our understanding of the site-substitution effects in geometrically frustrated <i>B</i>-site-ordered double perovskites.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"31 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462199","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}

{"title":"Exploiting Dioxazaborocane Chemistry for Preparing Elastomeric Vitrimers with Enhanced Processability and Mechanical Properties","authors":"Alvaro Quinteros-Sedano, Brieuc Le Besnerais, Nathan J. Van Zee, Renaud Nicolaÿ","doi":"10.1021/acs.chemmater.5c00154","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00154","url":null,"abstract":"Boronic ester-based vitrimers have garnered significant attention in the polymer science community owing to their chemical stability, ease of synthesis, and recyclability. However, like most vitrimers, these materials tend to exhibit high viscosity at high temperature, making them difficult to process. Moreover, the dynamicity of boronic ester exchange at room temperature can result in poor creep resistance under service conditions for elastomeric vitrimers. Herein, we sought to address the balance of processability and mechanical performance by exploiting dioxazaborocane groups, which are a scarcely explored class of boronic esters featuring a dative nitrogen–boron bond. Both dioxazaborocane- and dioxaborolane-based vitrimers were prepared from low glass transition temperature (<i>T</i>_g) polymethacrylate precursors bearing pendant complementary functional groups. Compared to dioxaborolane vitrimers, dioxazaborocane vitrimers exhibit faster relaxation dynamics at high temperatures, leading to more processable materials. The dioxazaborocane vitrimers also display improved tensile properties and competitive creep resistance, especially when using highly entangled precursors. This combination of enhanced processability and mechanical performance renders the dioxazaborocane group as an attractive motif for implementing into vitrimers.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"44 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462235","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}

{"title":"Why Charge Added Using Transition Metals to Some Insulators, Including LK-99, Localizes and Does Not Yield a Metal","authors":"Alexandru B. Georgescu","doi":"10.1021/acs.chemmater.4c02817","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02817","url":null,"abstract":"While adding charge to semiconductors via dopants is a well-established method for tuning electronic properties, we demonstrate that introducing transition-metal impurities into certain insulators can lead to localized charge, assisted by a Jahn–Teller distortion. This leads to isolated charge and an insulating material, as opposed to emergent states, including superconductivity. We focus on Cu impurities added to Pb₁₀(PO₄)₆O (“LK-99”), replacing 10% of Cu ions, as discussed in recent literature. Our calculations show that the material remains a wide bandgap insulator with isolated, <i>S</i> = 1/2 localized charges on the Cu ions─similar to color centers, even within standard DFT, without the need for electron correlation corrections to the Cu d-orbitals. Superconductivity is excluded by known mechanisms that require the material to be metallic. We resolve previously observed inconsistencies between density functional theory results and experimental findings related to doping site energetics, crystal structure, and transparency. We find that Cu doping either Pb site leads to CuO₄ coordination and a similar unit cell volume contraction. Engineering materials with dopant sites that have different local symmetries can induce nonrelativistic spin splitting─often referred to as altermagnetism. However, in the case of localized charges, this may enable spins to be individually controlled.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"25 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451994","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}

{"title":"Drug-Loaded Janus Dressings Precipitated from PEG–PTMC Thermosensitive Hydrogel for Oral Ulcer Treatment","authors":"Geng Chen, Haoming Wu, Xingchen Zhao, Zhen Zhang, Xin Hu, Peijie Hou, Chengdong Xiong, Likun Guo, Lifang Zhang","doi":"10.1021/acs.chemmater.4c03077","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c03077","url":null,"abstract":"Oral ulcers, prevalent lesions of the oral mucosa, often stem from trauma, viral infections, and autoimmune diseases, necessitating effective treatment strategies to address both their physical and psychological impacts. Current treatments are often limited by issues such as poor adhesion and rapid dilution within the dynamic oral environment. To overcome these challenges, we have explored the application of thermosensitive hydrogels, specifically aqueous solutions of poly(ethylene glycol)–poly(trimethylene carbonate) (PEG–PTMC) copolymers. These copolymers are noted for their biocompatibility and temperature-responsive phase transition properties. We engineered a thermosensitive drug delivery system by fine-tuning the molecular weight and segment lengths of PEG–PTMC, which gels near 32 °C and precipitates at 37 °C. Utilizing the slight temperature differential between the oral mucosa and ambient air, the system forms a Janus structure with distinct gel and precipitate layers, ensuring sustained drug release and enhanced tissue adhesion. This innovative formulation not only acts as a protective, drug-laden dressing that promotes healing but is also designed for ease of use, allowing for self-administration. This study presents a significant advancement in the treatment of oral ulcers, offering a promising solution through the in situ formation of a bilayered, drug-loaded dressing, leveraging the unique properties of thermosensitive hydrogels.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"1 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443893","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}