Pub Date : 2025-02-25DOI: 10.1021/acs.chemmater.5c0002310.1021/acs.chemmater.5c00023
Raffaella Buonsanti*, and , Brandi Cossairt*,
{"title":"The Future of Colloidal Semiconductor Nanocrystals","authors":"Raffaella Buonsanti*, and , Brandi Cossairt*, ","doi":"10.1021/acs.chemmater.5c0002310.1021/acs.chemmater.5c00023","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00023https://doi.org/10.1021/acs.chemmater.5c00023","url":null,"abstract":"","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"37 4","pages":"1333–1334 1333–1334"},"PeriodicalIF":7.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143478249","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 : 2025-02-25DOI: 10.1021/acs.chemmater.5c00023
Raffaella Buonsanti, Brandi Cossairt
Figure 1. Pie chart showing the distribution of votes for various future applications of colloidal quantum dots based on a social media survey. This article has not yet been cited by other publications.
{"title":"The Future of Colloidal Semiconductor Nanocrystals","authors":"Raffaella Buonsanti, Brandi Cossairt","doi":"10.1021/acs.chemmater.5c00023","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00023","url":null,"abstract":"Figure 1. Pie chart showing the distribution of votes for various future applications of colloidal quantum dots based on a social media survey. This article has not yet been cited by other publications.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"10 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143486600","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 : 2025-02-25DOI: 10.1021/acs.chemmater.5c00183
Paul D. Goring, Sara E. Skrabalak
Colloidal semiconductor nanocrystals have been hailed as the building blocks of next-generation nanotechnology. These solution-processed nanocrystals exhibit size-tunable optical and electronic properties, making them valuable for applications ranging from high-performance quantum dot displays to advanced biomedical imaging and even in photovoltaics. Their ability to bridge the gap between molecular chemistry and solid-state physics is central to such innovation, with the 2023 Nobel Prize in Chemistry recognizing the discovery and synthesis of quantum-confined colloidal semiconductor nanocrystals. Yet, as researchers push the frontiers of their potential, challenges persist that must be addressed to unlock their full potential in commercial and scientific pursuits. This Collection of recent papers on <i>Colloidal Semiconductor Nanocrystals</i> from <i>Chemistry of Materials</i> includes an invited editorial by Raffaella Buonsanti and Brandi Cossairt (DOI: 10.1021/acs.chemmater.5c00023), where they ask: What is next? This collection is built from their insight, with papers selected that emphasize (1) Mechanistic Insight and Synthetic Design, (2) Stability and the Nanocrystal Surface, (3) New Materials and the Use of Less Toxic Elements, and (4) Translation from Fundamental Science to Application. The synthetic design of colloidal semiconductor nanocrystals relies on precise control over nucleation and growth processes to achieve nanocrystals with uniform size, shape, and composition. This achievement provides nanocrystals with precisely tuned properties. Such nanocrystals are commonly prepared by the hot-injection method, with Kenis and co-workers (DOI: 10.1021/acs.chemmater.3c02751) providing insight into this method using an automated high-throughput experimental platform to collect a large experimental data set that could be used to train models for predicting synthetic outcomes using machine learning. This method focused on the widely studied CdSe system, which has also been advanced with the synthesis of CdSe-based heterostructures. These heterostructures include CdSe-Dot/CdS-Rod/PbS-Dot nanocrystals (DOI: 10.1021/acs.chemmater.4c02553) that are dual-emissive as well as CdSe/ZnSe Core/Shell and CdSe/ZnSe/ZnS Core/Shell/Shell nanocrystals (DOI: 10.1021/acs.chemmater.3c01333), where the latter quantum dots are green-emitting with a near-unity photoluminescence quantum yield. Heterostructured nanocrystals can be achieved through seeded methods as well as through chemical transformations, such as cation exchange, which in addition to producing the dual-emissive CdS-Rod system, was used to synthesize ZnSe-Dot/CdS-Rod nanocrystals (DOI: 10.1021/acs.chemmater.2c03278) as well as wurtzite InP nanocrystals (DOI: 10.1021/acs.chemmater.3c02226) from Cu<sub>3–<i>x</i></sub>P nanocrystals. Mechanistic studies that reveal the intricacies of colloidal chemistry are central to achieving such structurally complex semiconductor nanocrystals, with advances also
{"title":"Chemistry of Materials Highlights Colloidal Semiconductor Nanocrystals","authors":"Paul D. Goring, Sara E. Skrabalak","doi":"10.1021/acs.chemmater.5c00183","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00183","url":null,"abstract":"Colloidal semiconductor nanocrystals have been hailed as the building blocks of next-generation nanotechnology. These solution-processed nanocrystals exhibit size-tunable optical and electronic properties, making them valuable for applications ranging from high-performance quantum dot displays to advanced biomedical imaging and even in photovoltaics. Their ability to bridge the gap between molecular chemistry and solid-state physics is central to such innovation, with the 2023 Nobel Prize in Chemistry recognizing the discovery and synthesis of quantum-confined colloidal semiconductor nanocrystals. Yet, as researchers push the frontiers of their potential, challenges persist that must be addressed to unlock their full potential in commercial and scientific pursuits. This Collection of recent papers on <i>Colloidal Semiconductor Nanocrystals</i> from <i>Chemistry of Materials</i> includes an invited editorial by Raffaella Buonsanti and Brandi Cossairt (DOI: 10.1021/acs.chemmater.5c00023), where they ask: What is next? This collection is built from their insight, with papers selected that emphasize (1) Mechanistic Insight and Synthetic Design, (2) Stability and the Nanocrystal Surface, (3) New Materials and the Use of Less Toxic Elements, and (4) Translation from Fundamental Science to Application. The synthetic design of colloidal semiconductor nanocrystals relies on precise control over nucleation and growth processes to achieve nanocrystals with uniform size, shape, and composition. This achievement provides nanocrystals with precisely tuned properties. Such nanocrystals are commonly prepared by the hot-injection method, with Kenis and co-workers (DOI: 10.1021/acs.chemmater.3c02751) providing insight into this method using an automated high-throughput experimental platform to collect a large experimental data set that could be used to train models for predicting synthetic outcomes using machine learning. This method focused on the widely studied CdSe system, which has also been advanced with the synthesis of CdSe-based heterostructures. These heterostructures include CdSe-Dot/CdS-Rod/PbS-Dot nanocrystals (DOI: 10.1021/acs.chemmater.4c02553) that are dual-emissive as well as CdSe/ZnSe Core/Shell and CdSe/ZnSe/ZnS Core/Shell/Shell nanocrystals (DOI: 10.1021/acs.chemmater.3c01333), where the latter quantum dots are green-emitting with a near-unity photoluminescence quantum yield. Heterostructured nanocrystals can be achieved through seeded methods as well as through chemical transformations, such as cation exchange, which in addition to producing the dual-emissive CdS-Rod system, was used to synthesize ZnSe-Dot/CdS-Rod nanocrystals (DOI: 10.1021/acs.chemmater.2c03278) as well as wurtzite InP nanocrystals (DOI: 10.1021/acs.chemmater.3c02226) from Cu<sub>3–<i>x</i></sub>P nanocrystals. Mechanistic studies that reveal the intricacies of colloidal chemistry are central to achieving such structurally complex semiconductor nanocrystals, with advances also","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"38 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143486601","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 : 2025-02-24DOI: 10.1021/acs.chemmater.4c03238
Landon J. Keller, Seung Keun Song, Hannah R. M. Margavio, Sarah Atanasov, Jiun-Ruey Chen, Gregory N. Parsons
The development of new material–substrate systems and methods for area selective deposition (ASD) is vital to the manufacturing of next-generation microelectronics. Atomic layer deposition (ALD) and atomic layer etching (ALE) have been integrated to achieve ASD by reintroducing the initial nucleation delay during ALD on the surface, where no growth is desired, but many ALD processes show minimal nucleation delay on some materials. This work demonstrates the integration of HfO2 thermal ALD (TDMAHf and H2O) and thermal ALE (WF6 and BCl3) for HfO2 ASD on Co/Si–H versus Ru/SiO2 via the substrate-dependent film structuring and etching rate. At 275 °C, the quartz crystal microbalance shows the same growth rate on Co and Al2O3 during HfO2 ALD, but significantly more HfO2 is removed on Al2O3 than Co during HfO2 ALE before etching stops on each surface. Ultrathin HfO2 films deposited at 275 °C are amorphous on SiO2 and partially structured on Co. After annealing at 600 °C, the ⟨−111⟩ monoclinic crystalline plane is observed in HfO2 on SiO2 and Co with additional orthorhombic and tetragonal crystalline planes observed on only Co. Spectroscopic ellipsometry and transmission electron microscopy show >4 nm HfO2 selectively grown via integrated ALD/ALE on metal versus dielectric without the use of organic nucleation inhibition. This work provides novel insights into chemical patterning of dielectric materials via integrated ALD/ALE and low-temperature control of structured materials for advanced atomic scale processing.
{"title":"HfO2 Area Selective Deposition via Substrate-Dependent Area Selective Atomic Layer Etching","authors":"Landon J. Keller, Seung Keun Song, Hannah R. M. Margavio, Sarah Atanasov, Jiun-Ruey Chen, Gregory N. Parsons","doi":"10.1021/acs.chemmater.4c03238","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c03238","url":null,"abstract":"The development of new material–substrate systems and methods for area selective deposition (ASD) is vital to the manufacturing of next-generation microelectronics. Atomic layer deposition (ALD) and atomic layer etching (ALE) have been integrated to achieve ASD by reintroducing the initial nucleation delay during ALD on the surface, where no growth is desired, but many ALD processes show minimal nucleation delay on some materials. This work demonstrates the integration of HfO<sub>2</sub> thermal ALD (TDMAHf and H<sub>2</sub>O) and thermal ALE (WF<sub>6</sub> and BCl<sub>3</sub>) for HfO<sub>2</sub> ASD on Co/Si–H versus Ru/SiO<sub>2</sub> via the substrate-dependent film structuring and etching rate. At 275 °C, the quartz crystal microbalance shows the same growth rate on Co and Al<sub>2</sub>O<sub>3</sub> during HfO<sub>2</sub> ALD, but significantly more HfO<sub>2</sub> is removed on Al<sub>2</sub>O<sub>3</sub> than Co during HfO<sub>2</sub> ALE before etching stops on each surface. Ultrathin HfO<sub>2</sub> films deposited at 275 °C are amorphous on SiO<sub>2</sub> and partially structured on Co. After annealing at 600 °C, the ⟨−111⟩ monoclinic crystalline plane is observed in HfO<sub>2</sub> on SiO<sub>2</sub> and Co with additional orthorhombic and tetragonal crystalline planes observed on only Co. Spectroscopic ellipsometry and transmission electron microscopy show >4 nm HfO<sub>2</sub> selectively grown via integrated ALD/ALE on metal versus dielectric without the use of organic nucleation inhibition. This work provides novel insights into chemical patterning of dielectric materials via integrated ALD/ALE and low-temperature control of structured materials for advanced atomic scale processing.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"65 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143477678","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 : 2025-02-23DOI: 10.1021/acs.chemmater.4c02529
Pablo A. Leon, Avni Singhal, Jurgis Ruza, Jeremiah A. Johnson, Yang Shao-Horn, Rafael Gomez-Bombarelli
Solid polymer electrolytes are an exciting solution for safe and stable solid lithium electrode battery systems but are hindered by low ionic conductivity and low lithium transference. All-atom molecular dynamics simulation has become an invaluable tool to probe lithium diffusion mechanisms and accelerate the discovery of promising polymer chemistries. Because of their low computational cost and despite their approximate nature, only classical interatomic potentials can access the time and length scales for appropriate statistics of polymer kinetics. Machine learning (ML) potentials trained end-to-end on ab initio data have proven more accurate but cannot be scaled to the necessary time- and length- scales yet. Historical approaches to parametrize classical force fields have been incremental, reliant on a manual combination of top-down and bottom-up fitting, and are often paywalled and hard to reproduce. We introduce a computational learning workflow to predict classical interatomic potential parameters using quantum mechanical computations as training data that combines the automation and end-to-end fitting of ML with traditional class 1 and class 2 functional forms. The fitting strategy produced potentials whose simulations improved the accuracy of lithium coordination environments, diffusivities, and conductivities relative to experimental approaches when compared to both naive and hand-tuned parameters for liquid and solid organic electrolyte systems. We show that chemistry-informed regularization is necessary to constrain predicted parameters in order to reproduce experimental solvation and kinetic properties. Finally, we explore the limitations of nonpolarizable, fixed point-charge schemes in describing electrolyte anions and compare the effects of two alternative schemes to fit point-charge distributions. The two strategies result in distinct lithium coordination mechanisms and highlight that closest parity to DFT forces and energies does not correlate to correct trends with lithium salt concentration in kinetic and solvation properties for fixed-point-charge classical interatomic potentials.
固态聚合物电解质是安全稳定的固态锂电极电池系统的一种令人兴奋的解决方案，但却受到低离子传导性和低锂转移性的阻碍。全原子分子动力学模拟已成为探究锂扩散机制和加速发现有前途的聚合物化学成分的宝贵工具。由于计算成本低，尽管具有近似性质，但只有经典的原子间势能才能获得时间和长度尺度，从而对聚合物动力学进行适当的统计。事实证明，在 ab initio 数据上进行端到端训练的机器学习（ML）电势更为精确，但还不能扩展到必要的时间和长度尺度。对经典力场进行参数化的历史方法一直是渐进式的，依赖于自上而下和自下而上拟合的人工组合，而且往往是付费的，难以复制。我们介绍了一种利用量子力学计算作为训练数据预测经典原子间势参数的计算学习工作流程，它将 ML 的自动化和端到端拟合与传统的 1 类和 2 类函数形式相结合。与液态和固态有机电解质系统的原始参数和人工调整参数相比，该拟合策略产生的电位模拟提高了锂配位环境、扩散性和电导率的准确性。我们表明，为了再现实验溶解和动力学特性，化学信息正则化是约束预测参数的必要条件。最后，我们探讨了非极化、固定点电荷方案在描述电解质阴离子方面的局限性，并比较了拟合点电荷分布的两种替代方案的效果。这两种策略产生了不同的锂配位机制，并突出表明，对于固定点电荷经典原子间电位，与 DFT 力和能量最接近的奇偶性与锂盐浓度在动力学和溶解特性方面的正确趋势并不相关。
{"title":"End-To-End Learning of Classical Interatomic Potentials for Benchmarking Anion Polarization Effects in Lithium Polymer Electrolytes","authors":"Pablo A. Leon, Avni Singhal, Jurgis Ruza, Jeremiah A. Johnson, Yang Shao-Horn, Rafael Gomez-Bombarelli","doi":"10.1021/acs.chemmater.4c02529","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02529","url":null,"abstract":"Solid polymer electrolytes are an exciting solution for safe and stable solid lithium electrode battery systems but are hindered by low ionic conductivity and low lithium transference. All-atom molecular dynamics simulation has become an invaluable tool to probe lithium diffusion mechanisms and accelerate the discovery of promising polymer chemistries. Because of their low computational cost and despite their approximate nature, only classical interatomic potentials can access the time and length scales for appropriate statistics of polymer kinetics. Machine learning (ML) potentials trained end-to-end on ab initio data have proven more accurate but cannot be scaled to the necessary time- and length- scales yet. Historical approaches to parametrize classical force fields have been incremental, reliant on a manual combination of top-down and bottom-up fitting, and are often paywalled and hard to reproduce. We introduce a computational learning workflow to predict classical interatomic potential parameters using quantum mechanical computations as training data that combines the automation and end-to-end fitting of ML with traditional class 1 and class 2 functional forms. The fitting strategy produced potentials whose simulations improved the accuracy of lithium coordination environments, diffusivities, and conductivities relative to experimental approaches when compared to both naive and hand-tuned parameters for liquid and solid organic electrolyte systems. We show that chemistry-informed regularization is necessary to constrain predicted parameters in order to reproduce experimental solvation and kinetic properties. Finally, we explore the limitations of nonpolarizable, fixed point-charge schemes in describing electrolyte anions and compare the effects of two alternative schemes to fit point-charge distributions. The two strategies result in distinct lithium coordination mechanisms and highlight that closest parity to DFT forces and energies does not correlate to correct trends with lithium salt concentration in kinetic and solvation properties for fixed-point-charge classical interatomic potentials.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"110 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143477680","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 : 2025-02-21DOI: 10.1021/acs.chemmater.5c00103
Jaehoon Kwon, Hyunsoo Lee, Logeshwaran Natarajan, Sangyong Shin, Jaeyoung Choi, Sungho Lee, Bumjoon J. Kim, Hyunjoo Lee, Young Jun Lee
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 mgPt 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.
{"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<sub>Pt</sub> cm<sup>–2</sup>. 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}
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.
{"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 CO<sub>2</sub> to CH<sub>4</sub> is a highly beneficial option from the perspective of both energy and the environment. Several promising photocatalysts that selectively produce CH<sub>4</sub> (C1) mainly comprise Cu in different oxidation states. Since the CO<sub>2</sub> reduction to CH<sub>4</sub> 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 TiO<sub>2</sub> photocatalyst is able to selectively reduce CO<sub>2</sub> to CH<sub>4</sub> with very good yield. The present article reports detailed in situ FT-IR studies to delineate the different intermediates formed by exposure to CO<sub>2</sub> and moisture over the Cu-doped TiO<sub>2</sub> catalysts like bidentate carbonates, monodentate carbonates, bicarbonates, and carboxylates identified over different Cu-doped TiO<sub>2</sub> 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 Cu<sup>1+</sup>, Ti<sup>3+</sup>, 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 CO<sub>2</sub> 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 CO<sub>2</sub>. This study principally delineates the effect of Cu sites for the photocatalytic CO<sub>2</sub> 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 CO<sub>2</sub>.","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}
Pub Date : 2025-02-21DOI: 10.1021/acs.chemmater.4c03185
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
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 P21/m 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 b-axis. Electronic resistivity assessments indicate that Eu4Bi6Se13 exhibits metallic behavior. As the magnetic field is oriented along the b-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.
{"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 Eu<sub>4</sub>Bi<sub>6</sub>Se<sub>13</sub>, with particular focus on its magnetic anisotropy. This compound adopts a monoclinic crystal structure classified under the <i>P</i>2<sub>1</sub>/<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 Eu<sub>4</sub>Bi<sub>6</sub>Se<sub>13</sub> 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}
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: Co4Ge3.19Al0.81 and Co2Al1.26Ge1.74.
{"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: Co<sub>4</sub>Ge<sub>3.19</sub>Al<sub>0.81</sub> and Co<sub>2</sub>Al<sub>1.26</sub>Ge<sub>1.74</sub>.","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}
Pub Date : 2025-02-20DOI: 10.1021/acs.chemmater.4c02959
Gourab K. Dam, Vartika Jaiswal, Sumanta Let, Anirban Roy, Sudip Maity, Shalu Rana, Sujit K. Ghosh
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 t1/2 = 4.9 min in O2-saturated and t1/2 = 5.7 min under aerobic atmosphere, respectively, utilizing MeOH as the suitable solvent system. Additionally, ITC analysis revealed a favorable thermodynamic interaction (ΔG = −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.
{"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><sub>1/2</sub> = 4.9 min in O<sub>2</sub>-saturated and <i>t</i><sub>1/2</sub> = 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}
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