Chemistry of Materials最新文献

{"title":"Impact of SO2 on NiFe Nanoparticle Exsolution and Dissolution from LaFe0.9Ni0.1O3 Perovskite Oxides","authors":"Musa Najimu, Matthew J. Hurlock, Sahanaz Parvin, Courtney Brea, Neelesh Kumar, Yoon Jin Cho, Yiqing Wu, Guoxiang Hu, Zili Wu, Eranda Nikolla, Jonas Baltrusaitis, Tina M. Nenoff, Israel E. Wachs, Kandis Leslie Gilliard-AbdulAziz","doi":"10.1021/acs.chemmater.4c03439","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c03439","url":null,"abstract":"Ni-doped LaFeO₃ perovskite oxide is a promising cathode material for solid oxide electrolysis cells (SOECs) designed for CO₂/H₂O coelectrolysis. The performance of LaFe_0.9Ni_0.1O₃ is being investigated under real-world conditions that include exposure to acid gases, such as SO₂, relevant to SOEC operation. Experiments show that LaFe_0.9Ni_0.1O₃ exsolves NiFe nanoparticles, along with the formation of surface SO₄^2– and SO₃^2– after being exposed to 200 ppm of SO₂. This suggests that the ionic diffusion of Ni³⁺ and Fe³⁺ between the bulk and the surface remains unaffected throughout the exsolution–dissolution–exsolution cycle. Thermochemical water splitting has been employed as a probe reaction to evaluate the catalytic properties of the exsolved NiFe nanoparticles. These nanoparticles demonstrated improved hydrogen production compared to bare perovskite oxide substrates. However, after exposure to SO₂, the formation of Fe-rich NiFe nanoparticles led to poor thermocatalytic performance and rapid deactivation of the perovskite at elevated temperatures. Density functional theory (DFT) analysis was utilized to validate the experimental findings, indicating a significantly negative reaction energy for water splitting over exsolved Fe, as well as stronger binding of SO₂ to Fe than to Ni. Computational analysis further suggests that the presence of surface sulfate promotes the formation of Fe-rich NiFe nanoparticles, aligning with the experimental results. Overall, this study clarifies how SO₂ affects the structure of SOEC perovskite oxide candidate materials. Future engineering efforts should focus on enhancing nanoparticle exsolution and sulfur resistance, which is crucial for improving the hydrogen production capacity of La-based perovskite oxides for electro- and thermocatalytic water splitting in real environments containing acid gases.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"18 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143561164","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":"Impact of SO2 on NiFe Nanoparticle Exsolution and Dissolution from LaFe0.9Ni0.1O3 Perovskite Oxides","authors":"Musa Najimu,&nbsp;Matthew J. Hurlock,&nbsp;Sahanaz Parvin,&nbsp;Courtney Brea,&nbsp;Neelesh Kumar,&nbsp;Yoon Jin Cho,&nbsp;Yiqing Wu,&nbsp;Guoxiang Hu,&nbsp;Zili Wu,&nbsp;Eranda Nikolla,&nbsp;Jonas Baltrusaitis,&nbsp;Tina M. Nenoff,&nbsp;Israel E. Wachs and Kandis Leslie Gilliard-AbdulAziz*,&nbsp;","doi":"10.1021/acs.chemmater.4c0343910.1021/acs.chemmater.4c03439","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c03439https://doi.org/10.1021/acs.chemmater.4c03439","url":null,"abstract":"<p >Ni-doped LaFeO₃ perovskite oxide is a promising cathode material for solid oxide electrolysis cells (SOECs) designed for CO₂/H₂O coelectrolysis. The performance of LaFe_0.9Ni_0.1O₃ is being investigated under real-world conditions that include exposure to acid gases, such as SO₂, relevant to SOEC operation. Experiments show that LaFe_0.9Ni_0.1O₃ exsolves NiFe nanoparticles, along with the formation of surface SO₄^2– and SO₃^2– after being exposed to 200 ppm of SO₂. This suggests that the ionic diffusion of Ni³⁺ and Fe³⁺ between the bulk and the surface remains unaffected throughout the exsolution–dissolution–exsolution cycle. Thermochemical water splitting has been employed as a probe reaction to evaluate the catalytic properties of the exsolved NiFe nanoparticles. These nanoparticles demonstrated improved hydrogen production compared to bare perovskite oxide substrates. However, after exposure to SO₂, the formation of Fe-rich NiFe nanoparticles led to poor thermocatalytic performance and rapid deactivation of the perovskite at elevated temperatures. Density functional theory (DFT) analysis was utilized to validate the experimental findings, indicating a significantly negative reaction energy for water splitting over exsolved Fe, as well as stronger binding of SO₂ to Fe than to Ni. Computational analysis further suggests that the presence of surface sulfate promotes the formation of Fe-rich NiFe nanoparticles, aligning with the experimental results. Overall, this study clarifies how SO₂ affects the structure of SOEC perovskite oxide candidate materials. Future engineering efforts should focus on enhancing nanoparticle exsolution and sulfur resistance, which is crucial for improving the hydrogen production capacity of La-based perovskite oxides for electro- and thermocatalytic water splitting in real environments containing acid gases.</p>","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"37 6","pages":"2268–2280 2268–2280"},"PeriodicalIF":7.2,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678508","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":"Metal-Free Nanozyme-Hydrogel Enabled by Conductive Polymer Nanofibers for Multimodal Antibacterial Therapy","authors":"Wenya Xu, Ziyi Zhu, Zhen Tan, Ziteng Fan, Shibing Wei, Kaili Yang, Lihui Yuwen, Wen Jing Yang, En-Tang Kang, Lianhui Wang","doi":"10.1021/acs.chemmater.4c02480","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02480","url":null,"abstract":"The nanozyme antibacterial materials have been of great interest due to their broad-spectrum activity and minimal drug resistance. A variety of metal-based nanozymes have been designed as bactericidal agents, whereas their biosafety issues are still serious concerns. Accordingly, the development of metal-free nanozymes and the corresponding hydrogel dressings is of great importance for antibacterial applications. Herein, a classical conductive polymer, polyaniline nanofibers (PANI NF), has been developed as a three-pronged metal-free enzyme-like antibacterial material. They exhibited high oxidase-like and peroxidase-like activities for reactive oxygen species (ROS) production, positively charged surfaces capable of capturing/trapping bacteria to reduce ROS diffusion distance, and unique photothermal ablation effect. By harnessing the intrinsic merits of PANI NF, a PANI/poly(vinyl alcohol) (PANI/PVA) nanocomposite hydrogel, with high stability, soft-tissue adhesion properties, self-healing capability, remoldability, and biocompatibility, has been fabricated as biomedical dressings to promote bacteria-infected wound healing. The studies on antibacterial activities of polyaniline nanofibers shed light on the conductive polymer as promising metal-free enzyme-like antibacterial materials. The prepared PANI/PVA hydrogel provides a stable hydrogel dressing without toxic metal leakage for biomedical applications.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"24 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143538809","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":"Twist-Induced Dimensional Crossover and Topological Phase Transitions in Bismuthene Quasicrystals","authors":"Sang Wook Han, Won Seok Yun, Gi-Beom Cha, Seungho Seong, Jong Chan Kim, Hu Young Jeong, Chang Won Ahn, Keisuke Fukutani, Roland Stania, Jeongsoo Kang","doi":"10.1021/acs.chemmater.5c00204","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00204","url":null,"abstract":"Twisted bismuthene homojunctions, comprised of a Bi(111) bilayer atop two Bi(110) monolayers, exhibit a distinct growth orientation that is facilitated by self-assembly. Our cross-sectional structural analysis reveals an unexpected growth alignment of Bi(110) layers on transition-metal dichalcogenides, deviating from the anticipated Bi(111) bilayer structure. This self-assembly process, driven by the crystal symmetry interplay, induces a topological phase transition beyond a critical thickness. The dimensional crossover in the Fermi surfaces marks the electronic transition from two-dimensional (2D) Bi(110) to 1D Bi(111) quasicrystals. Additionally, the emergence of the topologically nontrivial band structures, an enhanced 1D carrier density, and a metal–insulator transition through band inversion indicate that the twisted bismuthene quasicrystals are promising candidates for higher-order topological quasicrystalline insulators. These findings pave the way for low-resistance contacts in 2D transistors, advancing the development of next-generation electronic devices.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"32 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143538810","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":"Twist-Induced Dimensional Crossover and Topological Phase Transitions in Bismuthene Quasicrystals","authors":"Sang Wook Han*,&nbsp;Won Seok Yun,&nbsp;Gi-Beom Cha,&nbsp;Seungho Seong,&nbsp;Jong Chan Kim,&nbsp;Hu Young Jeong*,&nbsp;Chang Won Ahn,&nbsp;Keisuke Fukutani,&nbsp;Roland Stania and Jeongsoo Kang,&nbsp;","doi":"10.1021/acs.chemmater.5c0020410.1021/acs.chemmater.5c00204","DOIUrl":"https://doi.org/10.1021/acs.chemmater.5c00204https://doi.org/10.1021/acs.chemmater.5c00204","url":null,"abstract":"<p >Twisted bismuthene homojunctions, comprised of a Bi(111) bilayer atop two Bi(110) monolayers, exhibit a distinct growth orientation that is facilitated by self-assembly. Our cross-sectional structural analysis reveals an unexpected growth alignment of Bi(110) layers on transition-metal dichalcogenides, deviating from the anticipated Bi(111) bilayer structure. This self-assembly process, driven by the crystal symmetry interplay, induces a topological phase transition beyond a critical thickness. The dimensional crossover in the Fermi surfaces marks the electronic transition from two-dimensional (2D) Bi(110) to 1D Bi(111) quasicrystals. Additionally, the emergence of the topologically nontrivial band structures, an enhanced 1D carrier density, and a metal–insulator transition through band inversion indicate that the twisted bismuthene quasicrystals are promising candidates for higher-order topological quasicrystalline insulators. These findings pave the way for low-resistance contacts in 2D transistors, advancing the development of next-generation electronic devices.</p>","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"37 6","pages":"2358–2366 2358–2366"},"PeriodicalIF":7.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678491","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":"Metal-Free Nanozyme-Hydrogel Enabled by Conductive Polymer Nanofibers for Multimodal Antibacterial Therapy","authors":"Wenya Xu,&nbsp;Ziyi Zhu,&nbsp;Zhen Tan,&nbsp;Ziteng Fan,&nbsp;Shibing Wei,&nbsp;Kaili Yang,&nbsp;Lihui Yuwen,&nbsp;Wen Jing Yang*,&nbsp;En-Tang Kang* and Lianhui Wang*,&nbsp;","doi":"10.1021/acs.chemmater.4c0248010.1021/acs.chemmater.4c02480","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02480https://doi.org/10.1021/acs.chemmater.4c02480","url":null,"abstract":"<p >The nanozyme antibacterial materials have been of great interest due to their broad-spectrum activity and minimal drug resistance. A variety of metal-based nanozymes have been designed as bactericidal agents, whereas their biosafety issues are still serious concerns. Accordingly, the development of metal-free nanozymes and the corresponding hydrogel dressings is of great importance for antibacterial applications. Herein, a classical conductive polymer, polyaniline nanofibers (PANI NF), has been developed as a three-pronged metal-free enzyme-like antibacterial material. They exhibited high oxidase-like and peroxidase-like activities for reactive oxygen species (ROS) production, positively charged surfaces capable of capturing/trapping bacteria to reduce ROS diffusion distance, and unique photothermal ablation effect. By harnessing the intrinsic merits of PANI NF, a PANI/poly(vinyl alcohol) (PANI/PVA) nanocomposite hydrogel, with high stability, soft-tissue adhesion properties, self-healing capability, remoldability, and biocompatibility, has been fabricated as biomedical dressings to promote bacteria-infected wound healing. The studies on antibacterial activities of polyaniline nanofibers shed light on the conductive polymer as promising metal-free enzyme-like antibacterial materials. The prepared PANI/PVA hydrogel provides a stable hydrogel dressing without toxic metal leakage for biomedical applications.</p>","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"37 6","pages":"2106–2124 2106–2124"},"PeriodicalIF":7.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678912","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":"Confined Palladium Nanocrystals within Covalent Organic Framework-Intercalated MXene Nanoarchitectures toward Highly Efficient Methanol Electrooxidation","authors":"Lan Yue, Quanguo Jiang, Le Ma, Yanan Li, Lu Yang, Jian Zhang, Haiyan He, Huajie Huang","doi":"10.1021/acs.chemmater.4c02659","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02659","url":null,"abstract":"The rational design of high-performance electrocatalysts toward the methanol oxidation reaction plays a noticeable role in the progress of stimulating the industrial development of direct methanol fuel cells. In this study, ultrafine palladium nanocrystals are <i>in situ</i> confined within the hydrazone-linked covalent organic framework (COF-42)-intercalated Ti₃C₂T_<i>x</i> MXene nanoarchitectures (Pd/COF-MX) through a facile and robust stereoconstruction strategy. The existence of hydrangea-shaped COF-42 with abundant N species makes it possible to optimize the coordination environments for Pd nanocrystals to facilitate their size confinement and homogeneous dispersion, while the MXene nanosheets afford strong electronic interactions and contemporaneously reduce the overall charge-transfer resistance of the hybrid catalyst. As a result, the emerging Pd/COF-MX nanoarchitectures demonstrate a preferable catalytic methanol electrooxidation performance with an extensive electrochemically active surface area, superior mass activity, and dependable long-term stability, significantly outperforming the conventional Pd/carbon black, Pd/carbon nanotube, Pd/reduced graphene oxide, and Pd/MXene catalysts. Density functional theory simulation additionally discloses that the functionalization of COF-42 enables a stronger atomic interaction with the Pd component, which induces an obvious left shift of its d-band center and leads to a weaker adsorption ability toward the CO molecule.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"46 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143538852","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":"Ion Exchange Synthesizes a Metastable Layered Polymorph of MgZrN2 and MgHfN2 Semiconductors","authors":"Christopher L. Rom*,&nbsp;Matthew Jankousky,&nbsp;Maxwell Q. Phan,&nbsp;Shaun O’Donnell,&nbsp;Corlyn E. Regier,&nbsp;James R. Neilson,&nbsp;Vladan Stevanović and Andriy Zakutayev*,&nbsp;","doi":"10.1021/acs.chemmater.4c0274810.1021/acs.chemmater.4c02748","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02748https://doi.org/10.1021/acs.chemmater.4c02748","url":null,"abstract":"<p >The synthesis of ternary nitride materials is uniquely difficult, in large part because elemental N₂ is relatively inert. However, lithium reacts readily with other metals and N₂, making Li-M-N the most numerous subset of ternary nitrides. Here, we use Li₂ZrN₂, a ternary nitride compound with a simple synthesis recipe, as a precursor for ion exchange reactions toward AZrN₂ (A = Mg, Fe, Cu, Zn). In situ synchrotron powder X-ray diffraction studies show that Li⁺ and Mg²⁺ undergo ion exchange topochemically, preserving the layers of octahedral [ZrN₆]. This reaction yields a metastable layered polymorph of MgZrN₂ (space group <i>R</i>3̅<i>m</i>) rather than the calculated ground state structure (<i>I</i>4₁/<i>amd</i>). Diffuse reflectance measurements show an optical absorption onset near 2.0 eV, consistent with the calculated bandgap for this polymorph. Our experimental attempts to extend this ion exchange method toward FeZrN₂, CuZrN₂, and ZnZrN₂ resulted in decomposition products (<i></i><math><mi>A</mi><mo>+</mo><mrow><mi>Z</mi><mi>r</mi><mi>N</mi></mrow><mo>+</mo><mfrac><mn>1</mn><mn>6</mn></mfrac><msub><mi>N</mi><mn>2</mn></msub></math>). This experimental outcome is explained by our computational results via the higher metastability of these phases compared to MgZrN₂. We successfully extended this ion exchange method to other Li-M-N precursors by synthesizing MgHfN₂ from Li₂HfN₂. In addition to the experimental synthesis of metastable <i>R</i>3̅<i>m</i> polymorphs of MgZrN₂ and MgHfN₂, this work highlights the potential of the 63 known Li-M-N phases as precursors to synthesize many other ternary nitride materials.</p>","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"37 6","pages":"2136–2144 2136–2144"},"PeriodicalIF":7.2,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.chemmater.4c02748","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Confined Palladium Nanocrystals within Covalent Organic Framework-Intercalated MXene Nanoarchitectures toward Highly Efficient Methanol Electrooxidation","authors":"Lan Yue,&nbsp;Quanguo Jiang,&nbsp;Le Ma,&nbsp;Yanan Li,&nbsp;Lu Yang,&nbsp;Jian Zhang,&nbsp;Haiyan He* and Huajie Huang*,&nbsp;","doi":"10.1021/acs.chemmater.4c0265910.1021/acs.chemmater.4c02659","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02659https://doi.org/10.1021/acs.chemmater.4c02659","url":null,"abstract":"<p >The rational design of high-performance electrocatalysts toward the methanol oxidation reaction plays a noticeable role in the progress of stimulating the industrial development of direct methanol fuel cells. In this study, ultrafine palladium nanocrystals are <i>in situ</i> confined within the hydrazone-linked covalent organic framework (COF-42)-intercalated Ti₃C₂T_<i>x</i> MXene nanoarchitectures (Pd/COF-MX) through a facile and robust stereoconstruction strategy. The existence of hydrangea-shaped COF-42 with abundant N species makes it possible to optimize the coordination environments for Pd nanocrystals to facilitate their size confinement and homogeneous dispersion, while the MXene nanosheets afford strong electronic interactions and contemporaneously reduce the overall charge-transfer resistance of the hybrid catalyst. As a result, the emerging Pd/COF-MX nanoarchitectures demonstrate a preferable catalytic methanol electrooxidation performance with an extensive electrochemically active surface area, superior mass activity, and dependable long-term stability, significantly outperforming the conventional Pd/carbon black, Pd/carbon nanotube, Pd/reduced graphene oxide, and Pd/MXene catalysts. Density functional theory simulation additionally discloses that the functionalization of COF-42 enables a stronger atomic interaction with the Pd component, which induces an obvious left shift of its d-band center and leads to a weaker adsorption ability toward the CO molecule.</p>","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"37 6","pages":"2125–2135 2125–2135"},"PeriodicalIF":7.2,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678835","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":"Cyclic Voltammetry and Spectroelectrochemistry of Two Common Thiophene Polymers Reveals Ion Diffusion and Polaron Wave Function Extent","authors":"Alistair W. Bevan,&nbsp;Carol-Lynn Gee,&nbsp;Melissa Vermette,&nbsp;Harsimrat Kaur,&nbsp;Sepideh Saghafifar and Loren G. Kaake*,&nbsp;","doi":"10.1021/acs.chemmater.4c0328410.1021/acs.chemmater.4c03284","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c03284https://doi.org/10.1021/acs.chemmater.4c03284","url":null,"abstract":"<p >Cyclic voltammetry is a conventional characterization method for understanding the electronic structure of organic electronic materials. Despite the maturity of the field, and ubiquity of the technique, a fundamental understanding of the processes occurring during the collection of a typical cyclic voltammogram is still a matter of debate. We have collected scan rate dependent cyclic voltammograms using two common mixed ion-electron transporting polymers while varying the position of the electrical contact to the film. When electrical contact to the film is opposite the side in contact with the electrolyte, it may be possible for electric fields emanating from the contact to draw ions across the interface. When contact is made on the same side as the electrolyte, these fields are not present, and the ion transport is expected to be diffusive. Scan rate dynamics are independent of the position of the contact, providing clear evidence that drift under an applied field is not an appropriate model of ion transport. The technique also rules out carrier transport as the rate-limiting step in these materials. Instead, we have found that Fick’s law diffusion is sufficient to model the majority of the observations and extract density of states information. Comparison with steady-state UV–vis spectroelectrochemistry data analyzed using multivariate curve resolution (MCR) shows the voltage dependence of polaronic and neutral species in the film. Combining the two measurements allows the size of the charge carriers to be estimated in terms of the number of monomer units responsible for the UV–vis absorption features observed.</p>","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":"37 5","pages":"1949–1960 1949–1960"},"PeriodicalIF":7.2,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591184","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}