Pub Date : 2024-11-14DOI: 10.1021/acs.jpcc.4c05841
Geet Gupta, Brandon C. Bukowski
Microporous catalysts are ubiquitous in chemical processes including sustainable transformations of biobased feedstocks into fuels and fine chemicals. The mechanistic insights needed to design next-generation microporous catalysts can be obtained with ab initio simulations coupled with microkinetic modeling, yet active site confinement complicates an accurate determination of adsorbate entropies, which, in turn, affect predictions of rate and equilibrium constants. In this study, we developed a machine learning force field (MLFF) strategy to rapidly predict temperature-dependent quasi-harmonic adsorbate entropies in zeolite Beta, reducing the number of compute-intensive ab initio molecular dynamics calculations needed to construct a microkinetic model. These entropies directly impacted the kinetics of a model parallel reaction mechanism. We chose lactic acid dehydration to acrylic acid on aluminosilicate zeolite Beta to explore the pathway dependence of unselective product formation and initial deactivation mechanisms using microkinetic modeling with our MLFF entropy strategy. The resulting quasi-harmonic entropy approximations led to shifts in steady-state coverages that impacted reaction orders and product selectivity. At low lactic acid partial pressures, concerted monomolecular decarbonylation is favored over Brønsted acid sites, which then shifts at high lactic acid partial pressures to concerted bimolecular condensations into lactic acid oligomers. Sequential pathways mediated by adsorbed alkoxide or carbonyl intermediates have no kinetic relevance at these conditions. These findings provide a strategy to integrate quasi-harmonic entropies into microkinetic modeling that is scalable with reaction temperature and applicable to a wide range of catalysts and catalytic cycles.
微孔催化剂在化学过程中无处不在，包括生物基原料向燃料和精细化学品的可持续转化。设计下一代微孔催化剂所需的机理认识可通过自证模拟与微动力学建模相结合的方法获得，但活性位点的封闭性使吸附剂熵的准确测定变得复杂，而吸附剂熵反过来又会影响速率常数和平衡常数的预测。在这项研究中，我们开发了一种机器学习力场（MLFF）策略，用于快速预测沸石 Beta 中与温度相关的准谐波吸附熵，从而减少了构建微动力学模型所需的计算密集型 ab initio 分子动力学计算的数量。这些熵直接影响了平行反应机制模型的动力学。我们选择了在铝硅酸盐沸石 Beta 上将乳酸脱水为丙烯酸的方法，利用微动力学模型和 MLFF 熵策略来探索非选择性产物形成的路径依赖性和初始失活机制。由此得出的准谐波熵近似值导致了稳态覆盖率的变化，从而影响了反应顺序和产物选择性。在低乳酸分压下，单分子脱羰基反应比布氏酸位点更有利，然后在高乳酸分压下转变为双分子缩合成乳酸低聚物的反应。在这些条件下，由吸附的烷氧基或羰基中间体介导的顺序途径与动力学无关。这些发现提供了一种将准谐波熵纳入微观动力学建模的策略，该策略可随着反应温度的升高而扩展，并适用于多种催化剂和催化循环。
{"title":"Kinetic Consequences of Quasi-Harmonic Entropies Calculated with Machine Learning Interatomic Potentials for Microkinetic Modeling","authors":"Geet Gupta, Brandon C. Bukowski","doi":"10.1021/acs.jpcc.4c05841","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05841","url":null,"abstract":"Microporous catalysts are ubiquitous in chemical processes including sustainable transformations of biobased feedstocks into fuels and fine chemicals. The mechanistic insights needed to design next-generation microporous catalysts can be obtained with <i>ab initio</i> simulations coupled with microkinetic modeling, yet active site confinement complicates an accurate determination of adsorbate entropies, which, in turn, affect predictions of rate and equilibrium constants. In this study, we developed a machine learning force field (MLFF) strategy to rapidly predict temperature-dependent quasi-harmonic adsorbate entropies in zeolite Beta, reducing the number of compute-intensive <i>ab initio</i> molecular dynamics calculations needed to construct a microkinetic model. These entropies directly impacted the kinetics of a model parallel reaction mechanism. We chose lactic acid dehydration to acrylic acid on aluminosilicate zeolite Beta to explore the pathway dependence of unselective product formation and initial deactivation mechanisms using microkinetic modeling with our MLFF entropy strategy. The resulting quasi-harmonic entropy approximations led to shifts in steady-state coverages that impacted reaction orders and product selectivity. At low lactic acid partial pressures, concerted monomolecular decarbonylation is favored over Brønsted acid sites, which then shifts at high lactic acid partial pressures to concerted bimolecular condensations into lactic acid oligomers. Sequential pathways mediated by adsorbed alkoxide or carbonyl intermediates have no kinetic relevance at these conditions. These findings provide a strategy to integrate quasi-harmonic entropies into microkinetic modeling that is scalable with reaction temperature and applicable to a wide range of catalysts and catalytic cycles.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"20 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1021/acs.jpcc.4c06417
Kyoungweon Park, Richard Sottie, Eva Yazmin Santiago, Oscar Avalos-Ovando, Alexander Govorov, Richard A. Vaia
Ensembles of large aspect ratio gold rods (AuNRs) are of technological interest due to their extreme optical cross-section at visible and near-infrared wavelengths (C ∼ 104–105 nm2), ultrafast plasmonic and excitonic character (τ ∼ fs–ps), and responsivity to external fields affording ensemble alignment (ns−μs). With increasing aspect ratio and nanorod volume, plasmonic modes beyond dipolar emerge due to phase retardation. Such multipole resonances exhibit larger quality factors due to greater electromagnetic field localization, which is advantageous for optical signal routing, photon manipulation, or multistep processes such as second-harmonic generation, bioimaging, and photocatalysis. However, polydispersity of most as-synthesized AuNRs obscures these physicochemical behaviors across an ensemble, and thus at the macroscale. Herein, we present synthesis procedures for single-crystal AuNRs that simultaneously satisfy production scalability and ultralow dispersity with geometric tunability (aspect ratio:5 to 10; structural dispersity <0.1). Quadrupole and octupole resonances are observed in solutions and nanocomposite films with >10 nM AuNRs. The relationship between multipole resonance, aspect ratio, dielectric environment, temperature, and polarization agrees with theoretical predictions, confirming the foundation for the use of these effects in future technologies.
{"title":"Optical Sensitivity of Multipole Resonant Gold Nanorods in Solution and Film","authors":"Kyoungweon Park, Richard Sottie, Eva Yazmin Santiago, Oscar Avalos-Ovando, Alexander Govorov, Richard A. Vaia","doi":"10.1021/acs.jpcc.4c06417","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06417","url":null,"abstract":"Ensembles of large aspect ratio gold rods (AuNRs) are of technological interest due to their extreme optical cross-section at visible and near-infrared wavelengths (<i>C</i> ∼ 10<sup>4</sup>–10<sup>5</sup> nm<sup>2</sup>), ultrafast plasmonic and excitonic character (τ ∼ fs–ps), and responsivity to external fields affording ensemble alignment (ns−μs). With increasing aspect ratio and nanorod volume, plasmonic modes beyond dipolar emerge due to phase retardation. Such multipole resonances exhibit larger quality factors due to greater electromagnetic field localization, which is advantageous for optical signal routing, photon manipulation, or multistep processes such as second-harmonic generation, bioimaging, and photocatalysis. However, polydispersity of most as-synthesized AuNRs obscures these physicochemical behaviors across an ensemble, and thus at the macroscale. Herein, we present synthesis procedures for single-crystal AuNRs that simultaneously satisfy production scalability and ultralow dispersity with geometric tunability (aspect ratio:5 to 10; structural dispersity <0.1). Quadrupole and octupole resonances are observed in solutions and nanocomposite films with >10 nM AuNRs. The relationship between multipole resonance, aspect ratio, dielectric environment, temperature, and polarization agrees with theoretical predictions, confirming the foundation for the use of these effects in future technologies.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"11 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oxygen evolution reaction (OER) is the counterpart in hydrogen production by water electrolysis. Further challenges have been required to bypass the energy consumption processes in the OER. It is still important to unveil the OER intermediates toward effective green hydrogen production. In this study, we conducted in situ Raman observation of the OER intermediates over Ni nanohole-array electrodes in the various electrolyte conditions. Ni nanohole-array electrodes were prepared with interference exposure methods. Intense Raman peaks were observed from Ni–OH, Ni-OOH, and active oxygen species as the OER intermediates. The OER behavior can be classified with the reactants, such as OH– and H2O. The presented study demonstrates the importance of the electrolyte for the designing active OER catalysis for the next generation energy society.
氧进化反应（OER）是水电解制氢的对应反应。要绕过氧进化反应中的能量消耗过程，还需要进一步的挑战。揭示氧进化反应的中间产物对于实现有效的绿色制氢仍然非常重要。在本研究中，我们对不同电解质条件下镍纳米孔阵列电极上的 OER 中间产物进行了原位拉曼观测。镍纳米孔阵列电极采用干涉曝光法制备。在 OER 中间产物 Ni-OH、Ni-OOH 和活性氧中观察到了强烈的拉曼峰。OER 行为可根据反应物（如 OH- 和 H2O）进行分类。这项研究表明，电解质对于设计下一代能源社会的活性 OER 催化非常重要。
{"title":"Raman Spectroscopic Observation of Electrolyte-Dependent Oxygen Evolution Reaction Intermediates in Nickel-Based Electrodes","authors":"Tomohiro Fukushima, Kenko Tsuchimoto, Nobuaki Oyamada, Daiki Sato, Hiro Minamimoto, Kei Murakoshi","doi":"10.1021/acs.jpcc.4c06732","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06732","url":null,"abstract":"Oxygen evolution reaction (OER) is the counterpart in hydrogen production by water electrolysis. Further challenges have been required to bypass the energy consumption processes in the OER. It is still important to unveil the OER intermediates toward effective green hydrogen production. In this study, we conducted in situ Raman observation of the OER intermediates over Ni nanohole-array electrodes in the various electrolyte conditions. Ni nanohole-array electrodes were prepared with interference exposure methods. Intense Raman peaks were observed from Ni–OH, Ni-OOH, and active oxygen species as the OER intermediates. The OER behavior can be classified with the reactants, such as OH<sup>–</sup> and H<sub>2</sub>O. The presented study demonstrates the importance of the electrolyte for the designing active OER catalysis for the next generation energy society.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"11 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1021/acs.jpcc.4c06337
Cuixia Bi, Xiaolong Yin, Zhixiu Wang, Hongyan Zhao, Guangqiang Liu
In this study, trimetallic Au@PdPt nanoparticles (NPs) were synthesized by a seed-mediated technique, possessing a hexoctahedral (HOH) Au core with a branched PdPt alloy shell. The fabrication process involved the synthesis of HOH Au NPs exhibiting high-index {651} facet as nanotemplates, followed by the epitaxial growth of Pd and Pt on these NPs to yield HOH Au@PdPt NPs. The size and composition of HOH Au@PdPt NPs as well as the thickness of PdPt alloy shells (from 2 to 4, 5, and 8 nm) can be precisely adjusted by varying the quantity of Pd and Pt precursors. The catalytic efficacy of these Au@PdPt NPs was significantly enhanced through the synergistic effect between Au, Pd, and Pt, along with the increased contact areas afforded by multibranched PdPt alloy shells. For methanol electro-oxidation, the catalytic activity of HOH Au@PdPt NPs depends on the Pt content showing a distinctive volcano-type pattern. Remarkably, the HOH Au@Pd0.3Pt0.3 NPs demonstrate optimum catalytic performance for methanol oxidation in acidic conditions, exhibiting superior electrocatalytic properties compared to commercial Pt black catalysts. Their ECSA value, mass, and specific activities are 47.21 m2 g–1, 0.93 A mg–1, and 1.97 mA cm–2, respectively. This research can be exploited to fabricate catalysts possessing exceptional properties by precisely designing and controlling the size, composition and morphology of the trimetallic Au@PdPt NPs.
{"title":"Facile Synthesis of Trimetallic Hexoctahedral Au@PdPt Nanoparticles for Electrocatalytic Oxidation of Methanol","authors":"Cuixia Bi, Xiaolong Yin, Zhixiu Wang, Hongyan Zhao, Guangqiang Liu","doi":"10.1021/acs.jpcc.4c06337","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06337","url":null,"abstract":"In this study, trimetallic Au@PdPt nanoparticles (NPs) were synthesized by a seed-mediated technique, possessing a hexoctahedral (HOH) Au core with a branched PdPt alloy shell. The fabrication process involved the synthesis of HOH Au NPs exhibiting high-index {651} facet as nanotemplates, followed by the epitaxial growth of Pd and Pt on these NPs to yield HOH Au@PdPt NPs. The size and composition of HOH Au@PdPt NPs as well as the thickness of PdPt alloy shells (from 2 to 4, 5, and 8 nm) can be precisely adjusted by varying the quantity of Pd and Pt precursors. The catalytic efficacy of these Au@PdPt NPs was significantly enhanced through the synergistic effect between Au, Pd, and Pt, along with the increased contact areas afforded by multibranched PdPt alloy shells. For methanol electro-oxidation, the catalytic activity of HOH Au@PdPt NPs depends on the Pt content showing a distinctive volcano-type pattern. Remarkably, the HOH Au@Pd<sub>0.3</sub>Pt<sub>0.3</sub> NPs demonstrate optimum catalytic performance for methanol oxidation in acidic conditions, exhibiting superior electrocatalytic properties compared to commercial Pt black catalysts. Their ECSA value, mass, and specific activities are 47.21 m<sup>2</sup> g<sup>–1</sup>, 0.93 A mg<sup>–1</sup>, and 1.97 mA cm<sup>–2</sup>, respectively. This research can be exploited to fabricate catalysts possessing exceptional properties by precisely designing and controlling the size, composition and morphology of the trimetallic Au@PdPt NPs.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"17 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1021/acs.jpcc.4c04873
Mythreyi Rayaluru, Anwesha Maitra, Anuj K. Pennathur, Jahan M. Dawlaty
Photothermal spectroscopy has proven to be an incisive analytical tool, with several offshoots and applications. It is desirable to extend this technique to interfacial spectroscopy to further broaden its scope. Toward that goal, we demonstrate photothermal infrared (IR) spectroscopy where a resonant IR beam heats an interface, while a visible beam probes the interface in the attenuated total internal reflection (ATR) geometry. The photothermal spectra of a test molecule show similar concentration dependence and solvatochromic shifts when compared to FTIR-ATR measurements. We also show that two mechanisms underpin the ATR photothermal signal. The first mechanism is polarization change of the probe beam due to the thermal refractive index change of the interface. This is confirmed by time-dependent changes in the polarization state of the probe beam due to heating. The second mechanism is deflection of the probe beam upon heating by the IR pump. Furthermore, we showed that the photothermal effect persists when a thin film of gold is added to the interface. Our work will open potential applications of this technique in interfacial sciences and electrochemistry and will guide new approaches to reach monolayer sensitivity.
{"title":"Photothermal Spectroscopy in Attenuated Total Internal Reflection Geometry by Polarization Rotation and Deflection","authors":"Mythreyi Rayaluru, Anwesha Maitra, Anuj K. Pennathur, Jahan M. Dawlaty","doi":"10.1021/acs.jpcc.4c04873","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c04873","url":null,"abstract":"Photothermal spectroscopy has proven to be an incisive analytical tool, with several offshoots and applications. It is desirable to extend this technique to interfacial spectroscopy to further broaden its scope. Toward that goal, we demonstrate photothermal infrared (IR) spectroscopy where a resonant IR beam heats an interface, while a visible beam probes the interface in the attenuated total internal reflection (ATR) geometry. The photothermal spectra of a test molecule show similar concentration dependence and solvatochromic shifts when compared to FTIR-ATR measurements. We also show that two mechanisms underpin the ATR photothermal signal. The first mechanism is polarization change of the probe beam due to the thermal refractive index change of the interface. This is confirmed by time-dependent changes in the polarization state of the probe beam due to heating. The second mechanism is deflection of the probe beam upon heating by the IR pump. Furthermore, we showed that the photothermal effect persists when a thin film of gold is added to the interface. Our work will open potential applications of this technique in interfacial sciences and electrochemistry and will guide new approaches to reach monolayer sensitivity.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"38 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1021/acs.jpcc.4c05104
Titus de Haas, Dario Calvani, Aegir Zaaruolo, Tjeerd de Jong, Jonas Rutgers, Bas Kreupeling, Huub J. M. de Groot, Francesco Buda
In the past decade, Ru-bda (bda = 2,2′-bipyridine-6,6′-dicarboxylic acid) complexes have emerged as extremely effective water oxidation catalysts, rendering them a potential candidate for incorporation into dye-sensitized photoelectrochemical cells. However, the performance of these catalysts declines dramatically when anchored to a photoanode surface due to their catalytic mechanism involving the interaction of two metal centers (I2M). This reduced performance prompts an investigation into the catalytic cycle following an alternative mechanism in which the O–O bond is formed through a water nucleophilic attack (WNA). In this work, we have performed hybrid-DFT based molecular dynamics simulations of the rate-determining O–O bond formation following the WNA mechanism in a [Ru-bda]–dye dyad model in explicit water solvation. In addition, our study probes oxygen dissociation from the RuIII–O2 intermediate, and the equilibrium dynamics of the low-valent RuIII–bda intermediate. Our simulations demonstrate that including a fraction of exact Hartree–Fock exchange impacts the electron and hole localizations in the catalyst–dye complex, which can in specific instances affect the dynamics of the system. This study contributes to a fundamental understanding of water oxidation catalysis with the Ru-bda catalyst family and highlights the relevance of modeling catalytic processes at the hybrid-DFT level.
{"title":"Hybrid-DFT Molecular Dynamics Simulations of Photocatalytic Water Oxidation in a [Ru-bda]–Dye Complex","authors":"Titus de Haas, Dario Calvani, Aegir Zaaruolo, Tjeerd de Jong, Jonas Rutgers, Bas Kreupeling, Huub J. M. de Groot, Francesco Buda","doi":"10.1021/acs.jpcc.4c05104","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05104","url":null,"abstract":"In the past decade, Ru-bda (bda = 2,2′-bipyridine-6,6′-dicarboxylic acid) complexes have emerged as extremely effective water oxidation catalysts, rendering them a potential candidate for incorporation into dye-sensitized photoelectrochemical cells. However, the performance of these catalysts declines dramatically when anchored to a photoanode surface due to their catalytic mechanism involving the interaction of two metal centers (I2M). This reduced performance prompts an investigation into the catalytic cycle following an alternative mechanism in which the O–O bond is formed through a water nucleophilic attack (WNA). In this work, we have performed hybrid-DFT based molecular dynamics simulations of the rate-determining O–O bond formation following the WNA mechanism in a [Ru-bda]–dye dyad model in explicit water solvation. In addition, our study probes oxygen dissociation from the Ru<sup>III</sup>–O<sub>2</sub> intermediate, and the equilibrium dynamics of the low-valent Ru<sup>III</sup>–bda intermediate. Our simulations demonstrate that including a fraction of exact Hartree–Fock exchange impacts the electron and hole localizations in the catalyst–dye complex, which can in specific instances affect the dynamics of the system. This study contributes to a fundamental understanding of water oxidation catalysis with the Ru-bda catalyst family and highlights the relevance of modeling catalytic processes at the hybrid-DFT level.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"16 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1021/acs.jpcc.4c05907
Olusayo J. Ogunyemi, Chanchal Rani, Oleg Varnavski, Rumaisa Wajahath, Michael Norscia, Brock Malaikal, Yunfan Qiu, Shichao Sun, Yonghao Gu, Shaul Mukamel, Michael R. Wasielewski, Theodore Goodson, III
Quantum-to-quantum transduction is the coherent exchange of information between quantum systems, which is an essential element of quantum information science (QIS). Molecular architectures provide unmatched flexibility for tailoring the properties that are critical to quantum transduction, and molecular synthesis affords the opportunity to build novel molecular materials from the bottom-up. Singlet fission (SF) in organic chromophore solids provides a potential means of executing photon-to-spin quantum transduction because absorption of a single photon results in formation of four entangled spins that constitute a triplet pair state (TT). We have demonstrated that SF in single crystals of 5,12-bis(tricyclohexylsilylethynyl)-tetracene (TCHS-tetracene) produces a long-lived quintet state 5(TT) that provides a promising new route to multiqubit systems for QIS. Here, we investigate the interaction of classical and entangled photons with TCHS-tetracene as well as the related TIPS-tetracene and tetracene to assess the molecular properties required for quantum transduction. From the classical two-photon absorption (TPA) experiment, we observed that TCHS-tetracene and TIPS-tetracene have a higher TPA cross-section than tetracene. The entangled TPA cross-sections of TCHS-tetracene and TIPS-tetracene (6.914 × 10–19 and 5.057 × 10–19 cm2/molecule, respectively) are about an order of magnitude larger than that of tetracene (5.146 × 10–20 cm2/molecule), making TCHS-tetracene and TIPS-tetracene excellent candidates for demonstrating photon-to-spin transduction using SF. We also observed a longer coherence time for the TCHS-tetracene in comparison to the tetracene molecular systems investigated, which suggests its suitability for possible QIS applications.
{"title":"Understanding the Correlation of the Quantum Dephasing Time and Entangled Photon Interaction in Crystalline Tetracene Derivatives","authors":"Olusayo J. Ogunyemi, Chanchal Rani, Oleg Varnavski, Rumaisa Wajahath, Michael Norscia, Brock Malaikal, Yunfan Qiu, Shichao Sun, Yonghao Gu, Shaul Mukamel, Michael R. Wasielewski, Theodore Goodson, III","doi":"10.1021/acs.jpcc.4c05907","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05907","url":null,"abstract":"Quantum-to-quantum transduction is the coherent exchange of information between quantum systems, which is an essential element of quantum information science (QIS). Molecular architectures provide unmatched flexibility for tailoring the properties that are critical to quantum transduction, and molecular synthesis affords the opportunity to build novel molecular materials from the bottom-up. Singlet fission (SF) in organic chromophore solids provides a potential means of executing photon-to-spin quantum transduction because absorption of a single photon results in formation of four entangled spins that constitute a triplet pair state (TT). We have demonstrated that SF in single crystals of 5,12-bis(tricyclohexylsilylethynyl)-tetracene (TCHS-tetracene) produces a long-lived quintet state <sup>5</sup>(TT) that provides a promising new route to multiqubit systems for QIS. Here, we investigate the interaction of classical and entangled photons with TCHS-tetracene as well as the related TIPS-tetracene and tetracene to assess the molecular properties required for quantum transduction. From the classical two-photon absorption (TPA) experiment, we observed that TCHS-tetracene and TIPS-tetracene have a higher TPA cross-section than tetracene. The entangled TPA cross-sections of TCHS-tetracene and TIPS-tetracene (6.914 × 10<sup>–19</sup> and 5.057 × 10<sup>–19</sup> cm<sup>2</sup>/molecule, respectively) are about an order of magnitude larger than that of tetracene (5.146 × 10<sup>–20</sup> cm<sup>2</sup>/molecule), making TCHS-tetracene and TIPS-tetracene excellent candidates for demonstrating photon-to-spin transduction using SF. We also observed a longer coherence time for the TCHS-tetracene in comparison to the tetracene molecular systems investigated, which suggests its suitability for possible QIS applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"10 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1021/acs.jpcc.4c05014
Purnima P. Balakrishnan, Qinwen Lu, Qing Wang, Shin Muramoto, Paige Quarterman, Michael R. Fitzsimmons, Timothy R. Charlton, Xiaofang Zhai, Alexander J. Grutter
We demonstrate an unexpected substrate dependence of the magnetic properties of complex oxide thin film membranes. While the tunable magnetism of complex oxides is attractive for many applications, device integration has long been limited by the strict substrate requirements necessary for high-quality film growth. Recently, water-soluble sacrificial layers have been used to separate oxide thin films from the substrate after growth, decoupling the structural and chemical degrees of freedom at the interface. This approach is hoped to enable integration with previously incompatible material platforms, but interface studies of transferred films remain limited. In this work, we use polarized neutron reflectometry and secondary ion mass spectroscopy to provide a detailed understanding of depth-dependent chemistry and magnetization of LaMnO3 membranes. We find that the final substrate plays a key role in either incorporating or excluding hydrogen species at the surfaces of transferred LaMnO3 thin films, modifying the magnetism in these interfacial regions. Despite elimination of the epitaxial relationship, the choice of substrate influences the magnetism within the transferred membranes to an unexpected degree, with important implications for integration into existing silicon-based technologies.
{"title":"Manipulating Interface Magnetism in Manganite Thin Film Membranes by Substrate Surface Chemistry","authors":"Purnima P. Balakrishnan, Qinwen Lu, Qing Wang, Shin Muramoto, Paige Quarterman, Michael R. Fitzsimmons, Timothy R. Charlton, Xiaofang Zhai, Alexander J. Grutter","doi":"10.1021/acs.jpcc.4c05014","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05014","url":null,"abstract":"We demonstrate an unexpected substrate dependence of the magnetic properties of complex oxide thin film membranes. While the tunable magnetism of complex oxides is attractive for many applications, device integration has long been limited by the strict substrate requirements necessary for high-quality film growth. Recently, water-soluble sacrificial layers have been used to separate oxide thin films from the substrate after growth, decoupling the structural and chemical degrees of freedom at the interface. This approach is hoped to enable integration with previously incompatible material platforms, but interface studies of transferred films remain limited. In this work, we use polarized neutron reflectometry and secondary ion mass spectroscopy to provide a detailed understanding of depth-dependent chemistry and magnetization of LaMnO<sub>3</sub> membranes. We find that the final substrate plays a key role in either incorporating or excluding hydrogen species at the surfaces of transferred LaMnO<sub>3</sub> thin films, modifying the magnetism in these interfacial regions. Despite elimination of the epitaxial relationship, the choice of substrate influences the magnetism within the transferred membranes to an unexpected degree, with important implications for integration into existing silicon-based technologies.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"11 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142609808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1021/acs.jpcc.4c07365
Luca Brugnoli, Maxime Ducamp, François-Xavier Coudert
Molecular dynamics simulations of zeolites are commonly employed for the characterization of their framework dynamics and response to the application of temperature and pressure. While classical interatomic potentials are commonly used for this task, they offer a description of the interactions in the system with limited accuracy. Density functional theory, meanwhile, is accurate, but its high computational expense limits its scalability for large systems or long dynamics. Recent advances in machine learning interatomic potentials, trained on computational data obtained at the quantum chemical level, offer a promising alternative combining high accuracy with computational efficiency. In this study, we developed an MLIP specifically for pure silica zeolites, trained on data from high-temperature ab initio MD simulations across various zeolitic topologies. This MLIP was then applied to predict structural properties, thermal expansion, and pressure response of different zeolites, demonstrating its potential for accuracy and generalizability in simulations of topologies beyond its initial training set.
沸石的分子动力学模拟通常用于表征其框架动力学以及对温度和压力的响应。虽然经典原子间位势常用于这项任务，但它们对系统中相互作用的描述精度有限。与此同时，密度泛函理论虽然精确，但其高昂的计算费用限制了其在大型系统或长动态过程中的可扩展性。机器学习原子间势的最新进展是在量子化学层面获得的计算数据基础上进行训练，它提供了一种兼具高精度和计算效率的有前途的替代方法。在本研究中，我们开发了一种专门针对纯硅沸石的 MLIP，该 MLIP 是根据各种沸石拓扑结构的高温 ab initio MD 模拟数据进行训练的。然后，我们将该 MLIP 应用于预测不同沸石的结构特性、热膨胀和压力响应，证明了它在模拟其初始训练集之外的拓扑结构时的准确性和通用性潜力。
{"title":"Neural Network-Based Interatomic Potential for the Study of Thermal and Mechanical Properties of Siliceous Zeolites","authors":"Luca Brugnoli, Maxime Ducamp, François-Xavier Coudert","doi":"10.1021/acs.jpcc.4c07365","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c07365","url":null,"abstract":"Molecular dynamics simulations of zeolites are commonly employed for the characterization of their framework dynamics and response to the application of temperature and pressure. While classical interatomic potentials are commonly used for this task, they offer a description of the interactions in the system with limited accuracy. Density functional theory, meanwhile, is accurate, but its high computational expense limits its scalability for large systems or long dynamics. Recent advances in machine learning interatomic potentials, trained on computational data obtained at the quantum chemical level, offer a promising alternative combining high accuracy with computational efficiency. In this study, we developed an MLIP specifically for pure silica zeolites, trained on data from high-temperature ab initio MD simulations across various zeolitic topologies. This MLIP was then applied to predict structural properties, thermal expansion, and pressure response of different zeolites, demonstrating its potential for accuracy and generalizability in simulations of topologies beyond its initial training set.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"98 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142609813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the past several years, the discoveries of multiple magnetic topological phases in MnBi2Te4 and its analogues have highlighted the research in modern condensed matter physics. The topological crystalline insulator (TCI) phase protected by space group symmetry is a valuable platform to understand the profound relation of crystalline symmetry and band topology in materials. Via first-principles calculations, we predict that the MnBi2Te4 analogues, MnBi4Te7, MnSb4Te7, Mn2Bi2Te5, and Eu2Bi2Te5, are all mirror-symmetry-protected TCI candidates when magnetized along the in-plane x orientation. Gapless surface states are expected for the van der Waals terminations in this phase. Particularly, the magnetic easy axis of Eu2Bi2Te5 is along the in-plane direction in our calculations. These findings open opportunities for research and application of magnetic TCIs and magnetically controllable topological quantum phase transitions.
{"title":"Topological Crystalline Insulator Phases in Magnetic van der Waals Crystal MnBi4Te7 and Mn2Bi2Te5 Families","authors":"Jia-Yi Lin, Zhipeng Cao, Zhong-Jia Chen, Wenxin He, Jiarui Zeng, Xiao-Bao Yang, Yichen Hua, Ji-Hai Liao, Yu-Jun Zhao","doi":"10.1021/acs.jpcc.4c05870","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05870","url":null,"abstract":"In the past several years, the discoveries of multiple magnetic topological phases in MnBi<sub>2</sub>Te<sub>4</sub> and its analogues have highlighted the research in modern condensed matter physics. The topological crystalline insulator (TCI) phase protected by space group symmetry is a valuable platform to understand the profound relation of crystalline symmetry and band topology in materials. Via first-principles calculations, we predict that the MnBi<sub>2</sub>Te<sub>4</sub> analogues, MnBi<sub>4</sub>Te<sub>7</sub>, MnSb<sub>4</sub>Te<sub>7</sub>, Mn<sub>2</sub>Bi<sub>2</sub>Te<sub>5</sub>, and Eu<sub>2</sub>Bi<sub>2</sub>Te<sub>5</sub>, are all mirror-symmetry-protected TCI candidates when magnetized along the in-plane <i>x</i> orientation. Gapless surface states are expected for the van der Waals terminations in this phase. Particularly, the magnetic easy axis of Eu<sub>2</sub>Bi<sub>2</sub>Te<sub>5</sub> is along the in-plane direction in our calculations. These findings open opportunities for research and application of magnetic TCIs and magnetically controllable topological quantum phase transitions.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"6 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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