Pub Date : 2026-03-15DOI: 10.1021/acs.jpcc.6c00163
Yuchen Niu, Karen J. Gaskell, Janice E. Reutt-Robey
Knowledge of LiCoO2 surfaces enables fundamental electrochemical research and emerging applications in energy and electronic devices. In this work, the chemo-structural response of LiCoO2(001) surfaces from the meso-to-atomic scale under varied oxygen chemical potentials (μO) is investigated. Under a traditional ultrahigh-vacuum (UHV) processing regimen (−2.23 eV < μO < −1.48 eV), the LiCoO2(001) surface structure undergoes nanoscale roughening and initial ()R30° reconstruction. Emergent nanofeatures undergo 6-fold size increases under prolonged processing at low μO. The net surface stoichiometry, determined by X-ray photoelectron spectroscopy as Li0.6CoO1.5, consists of coexisting Li0.8CoO1.6(001) and CoO(111) phases. Scanning tunneling microscopy images of exposed flat regions reveal local R19.1° reconstruction of the Li-terminated LiCoO2(001) surface and ∼2% oxygen vacancies. Under a higher-pressure processing regimen at high μO (−1.26 eV < μO < −1.19 eV), reached with ambient air and oxygen gas, extended atomically flat LiCoO2(001) terraces of micron widths decorated with Co3O4(111) islands are routinely observed. Such high μO treatments yield a stoichiometric Li1.0CoO2.0(001) surface. The thermodynamic and kinetic impacts of μO on the chemo-structural evolution of LiCoO2(001) surfaces are described, providing new insights on LiCoO2 surface preparation and stability.
LiCoO2表面的知识使基本的电化学研究和新兴的应用在能源和电子设备。本文从中原子尺度研究了不同氧化学势（μO）下LiCoO2（001）表面的化学结构响应。在传统的超高真空（UHV）处理条件下（−2.23 eV < μO <−1.48 eV）， LiCoO2（001）表面结构经历了纳米级粗化和初始（3×3）R30°重构。在低μO条件下长时间处理，涌现纳米特征的尺寸增加了6倍。x射线光电子能谱测定净表面化学计量为Li0.6CoO1.5，由Li0.8CoO1.6（001）和CoO（111）相共存组成。暴露平面区域的扫描隧道显微镜图像显示局部（7×7）R19.1°重构的li端LiCoO2（001）表面和~ 2%的氧空位。在高μO（−1.26 eV < μO <−1.19 eV）的高压处理条件下，通常可以观察到以Co3O4（111）岛装饰的微米宽的原子平面LiCoO2（001）梯田。这种高μO处理得到化学计量Li1.0CoO2.0（001）表面。描述了μO对LiCoO2（001）表面化学结构演变的热力学和动力学影响，为LiCoO2表面制备和稳定性提供了新的见解。
{"title":"Chemo-Structural Evolution of LiCoO2(001) under Varied Oxygen Chemical Potentials","authors":"Yuchen Niu, Karen J. Gaskell, Janice E. Reutt-Robey","doi":"10.1021/acs.jpcc.6c00163","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00163","url":null,"abstract":"Knowledge of LiCoO<sub>2</sub> surfaces enables fundamental electrochemical research and emerging applications in energy and electronic devices. In this work, the chemo-structural response of LiCoO<sub>2</sub>(001) surfaces from the meso-to-atomic scale under varied oxygen chemical potentials (μ<sub>O</sub>) is investigated. Under a traditional ultrahigh-vacuum (UHV) processing regimen (−2.23 eV < μ<sub>O</sub> < −1.48 eV), the LiCoO<sub>2</sub>(001) surface structure undergoes nanoscale roughening and initial (<i></i><math display=\"inline\"><msqrt><mn>3</mn></msqrt><mo>×</mo><msqrt><mn>3</mn></msqrt></math>)R30° reconstruction. Emergent nanofeatures undergo 6-fold size increases under prolonged processing at low μ<sub>O</sub>. The net surface stoichiometry, determined by X-ray photoelectron spectroscopy as Li<sub>0.6</sub>CoO<sub>1.5</sub>, consists of coexisting Li<sub>0.8</sub>CoO<sub>1.6</sub>(001) and CoO(111) phases. Scanning tunneling microscopy images of exposed flat regions reveal local <i></i><math display=\"inline\"><mo>(</mo><msqrt><mrow><mn>7</mn></mrow></msqrt><mo>×</mo><msqrt><mrow><mn>7</mn></mrow></msqrt><mo>)</mo></math>R19.1° reconstruction of the Li-terminated LiCoO<sub>2</sub>(001) surface and ∼2% oxygen vacancies. Under a higher-pressure processing regimen at high μ<sub>O</sub> (−1.26 eV < μ<sub>O</sub> < −1.19 eV), reached with ambient air and oxygen gas, extended atomically flat LiCoO<sub>2</sub>(001) terraces of micron widths decorated with Co<sub>3</sub>O<sub>4</sub>(111) islands are routinely observed. Such high μ<sub>O</sub> treatments yield a stoichiometric Li<sub>1.0</sub>CoO<sub>2.0</sub>(001) surface. The thermodynamic and kinetic impacts of μ<sub>O</sub> on the chemo-structural evolution of LiCoO<sub>2</sub>(001) surfaces are described, providing new insights on LiCoO<sub>2</sub> surface preparation and stability.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"108 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147461885","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 : 2026-03-15DOI: 10.1021/acs.jpcc.6c00568
H. Martin R. Wilkening
Solid-state NMR is increasingly used to study Li+ ion dynamics in crystalline and amorphous electrolytes designed as electronically insulating components in electrochemical energy storage systems. Recently, Milan et al. (ACS Mater. Lett.2025, 7, 1187) reported diffusion-controlled 7Li NMR relaxation rates of Li2OHBr and analyzed them using BPP-type spectral density functions. However, their fitting procedure and results are difficult to follow and reproduce, especially regarding the treatment of BPP-type Lorentzian fits and background contributions in semilogarithmic representations. In this work, we reanalyze their rates while including an appropriate background contribution. For the X-ray amorphous, glassy Li2OHBr sample, two nearly ideal BPP processes are sufficient to describe the entire experimental response. Our extracted activation energies differ from those of Milan et al. and may alter the interpretation of their findings. Specifically, both the glassy and crystalline samples yield activation energies of 0.49 eV, independent of morphology. These values are in excellent agreement with recent (bulk) conductivity measurements and earlier NMR studies on Li2OHCl. The Arrhenius prefactors, reflecting attempt frequencies (3.8 × 1013 s–1 (glassy) and 1.8 × 1013 s–1 (crystalline)), vary only slightly but follow trends consistent with the observed 13 K shift of the main relaxation peaks. Notably, the slower motional process evident in the glassy sample is almost absent in the crystalline material.
{"title":"Interpretation of 7Li NMR Relaxation in Li2OHBr: Background Effects on Lorentzian Fits in Log Space","authors":"H. Martin R. Wilkening","doi":"10.1021/acs.jpcc.6c00568","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00568","url":null,"abstract":"Solid-state NMR is increasingly used to study Li<sup>+</sup> ion dynamics in crystalline and amorphous electrolytes designed as electronically insulating components in electrochemical energy storage systems. Recently, Milan et al. (<i>ACS Mater. Lett.</i> <b>2025</b>, 7, 1187) reported diffusion-controlled <sup>7</sup>Li NMR relaxation rates of Li<sub>2</sub>OHBr and analyzed them using BPP-type spectral density functions. However, their fitting procedure and results are difficult to follow and reproduce, especially regarding the treatment of BPP-type Lorentzian fits and background contributions in semilogarithmic representations. In this work, we reanalyze their rates while including an appropriate background contribution. For the X-ray amorphous, glassy Li<sub>2</sub>OHBr sample, two nearly ideal BPP processes are sufficient to describe the entire experimental response. Our extracted activation energies differ from those of Milan et al. and may alter the interpretation of their findings. Specifically, both the glassy and crystalline samples yield activation energies of 0.49 eV, independent of morphology. These values are in excellent agreement with recent (bulk) conductivity measurements and earlier NMR studies on Li<sub>2</sub>OHCl. The Arrhenius prefactors, reflecting attempt frequencies (3.8 × 10<sup>13</sup> s<sup>–1</sup> (glassy) and 1.8 × 10<sup>13</sup> s<sup>–1</sup> (crystalline)), vary only slightly but follow trends consistent with the observed 13 K shift of the main relaxation peaks. Notably, the slower motional process evident in the glassy sample is almost absent in the crystalline material.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"32 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147462108","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 : 2026-03-15DOI: 10.1021/acs.jpcc.5c08318
Partha Sarathi Dutta, Aditya Koneru, Adil Muhammed, Henry Chan, Karthik Balasubramanian, Sukriti Manna, Troy Loeffler, Kiran Sasikumar, Pierre Darancet, Subramanian K. R. S. Sankaranarayanan
Bismuthene is a heavy 2D material whose strong spin–orbit coupling and recently observed single-element ferroelectricity have intensified interest in its structural, vibrational, and transport properties. Accurate modeling of these behaviors requires a short-range interatomic potential that can reproduce the underlying bonding physics at a fraction of the computational cost of first-principles methods. However, such a potential is currently unavailable. In this work, we construct a Tersoff bond-order potential for β-bismuthene using a reinforcement-learning framework that integrates a continuous Monte Carlo Tree Search with a simplex-based local optimizer. The optimized parameter sets reproduce first-principles lattice constants, cohesive energy, the equation of state, elastic constants, and phonon dispersion. We validate the models by performing thermal-conductivity calculations and uniaxial fracture simulations─ our findings confirm the reliability of the resulting models across multiple thermomechanical regimes. Comparison of the three best solutions reveals how differences in pairwise interactions, angular terms, and bond-order behavior govern phonon features and mechanical responses. We demonstrate an interpretable and computationally efficient potential for bismuthene and demonstrate a general reinforcement-learning strategy for developing bond-order models in emerging 2D materials.
{"title":"Machine Learning an Ab-Initio Based Bond-Order Potential for Bismuthene","authors":"Partha Sarathi Dutta, Aditya Koneru, Adil Muhammed, Henry Chan, Karthik Balasubramanian, Sukriti Manna, Troy Loeffler, Kiran Sasikumar, Pierre Darancet, Subramanian K. R. S. Sankaranarayanan","doi":"10.1021/acs.jpcc.5c08318","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08318","url":null,"abstract":"Bismuthene is a heavy 2D material whose strong spin–orbit coupling and recently observed single-element ferroelectricity have intensified interest in its structural, vibrational, and transport properties. Accurate modeling of these behaviors requires a short-range interatomic potential that can reproduce the underlying bonding physics at a fraction of the computational cost of first-principles methods. However, such a potential is currently unavailable. In this work, we construct a Tersoff bond-order potential for β-bismuthene using a reinforcement-learning framework that integrates a continuous Monte Carlo Tree Search with a simplex-based local optimizer. The optimized parameter sets reproduce first-principles lattice constants, cohesive energy, the equation of state, elastic constants, and phonon dispersion. We validate the models by performing thermal-conductivity calculations and uniaxial fracture simulations─ our findings confirm the reliability of the resulting models across multiple thermomechanical regimes. Comparison of the three best solutions reveals how differences in pairwise interactions, angular terms, and bond-order behavior govern phonon features and mechanical responses. We demonstrate an interpretable and computationally efficient potential for bismuthene and demonstrate a general reinforcement-learning strategy for developing bond-order models in emerging 2D materials.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"7 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147461884","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 : 2026-03-14DOI: 10.1021/acs.jpcc.6c00900
Ruijuan Zhao, Lei Li, Chunhua Cui
The development of efficient CO2 reduction catalysts hinges on the precise control of intermediate binding strength to balance reactant adsorption and product desorption. Here, we demonstrate that NO microbubble gas−water interfaces can function as catalyst-like platforms for CO2 hydrogenation to methanol. By generating NO microbubbles in situ from acidified KNO2, we create a confined gas−water interface that triggers hydroxyl radical (•OH) and hydrated electrons (e−aq), while facilitating intermediate (CO2•−) formation. We show that lower KNO2 concentration favors redox radical formation, yet higher KNO2 concentration scavenges redox radicals thus producing NH4+ and NO3−. High-resolution mass spectroscopy and electron paramagnetic resonance reveal a domino reduction pathway involving sequential proton-coupled electron and hydrogen-atom transfers through key intermediates (CO2•−, •COH and •CH2OH). This system achieves methanol synthesis without traditional solid catalysts or external bias, showcasing gas−water interfaces as dynamic, self-sustaining alternatives for CO2 conversion.
{"title":"Domino CO2-to-Methanol Hydrogenation Enabled by a Catalyst-like Gas−Water Interface via NO Microbubble-Driven Redox Radicals","authors":"Ruijuan Zhao, Lei Li, Chunhua Cui","doi":"10.1021/acs.jpcc.6c00900","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00900","url":null,"abstract":"The development of efficient CO<sub>2</sub> reduction catalysts hinges on the precise control of intermediate binding strength to balance reactant adsorption and product desorption. Here, we demonstrate that NO microbubble gas−water interfaces can function as catalyst-like platforms for CO<sub>2</sub> hydrogenation to methanol. By generating NO microbubbles in situ from acidified KNO<sub>2</sub>, we create a confined gas−water interface that triggers hydroxyl radical (<sup>•</sup>OH) and hydrated electrons (e<sup>−</sup><sub>aq</sub>), while facilitating intermediate (CO<sub>2</sub><sup>•−</sup>) formation. We show that lower KNO<sub>2</sub> concentration favors redox radical formation, yet higher KNO<sub>2</sub> concentration scavenges redox radicals thus producing NH<sub>4</sub><sup>+</sup> and NO<sub>3</sub><sup>−</sup>. High-resolution mass spectroscopy and electron paramagnetic resonance reveal a domino reduction pathway involving sequential proton-coupled electron and hydrogen-atom transfers through key intermediates (CO<sub>2</sub><sup>•−</sup>, <sup>•</sup>COH and <sup>•</sup>CH<sub>2</sub>OH). This system achieves methanol synthesis without traditional solid catalysts or external bias, showcasing gas−water interfaces as dynamic, self-sustaining alternatives for CO<sub>2</sub> conversion.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"93 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448242","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}
Precise electronic regulation of platinum (Pt) catalysts is essential for optimizing key intermediate energy barriers in the methanol oxidation reaction (MOR). However, conventional coordination engineering strategies for electronic modulation are often hindered by size mismatch between ligands and metal active sites, leading to stochastic reaction mechanisms and suboptimal modulation. In this work, we designed a series of structurally well-defined Pt clusters coordinated with nitrogen-, phosphorus-, and sulfur-containing organic molecules, enabling single-variable manipulation and maximized coordination interactions. Our results reveal a pronounced coordination-dependent performance order of Pt–N > Pt–P > Pt–S. Notably, the N-coordinated catalyst achieves a 5-fold mass activity enhancement and enhanced stability. Mechanistic insights from in situ Fourier transform infrared and density functional theory calculations confirm that N-coordination optimizes Pt electron structure and lowers energy barriers for intermediate adsorption/desorption. This work elucidates the intrinsic modulation mechanism and offers valuable insights into the rational design of high-efficiency Pt-based MOR catalysts.
{"title":"Ligand-Modulated Electronic Structure of Pt Clusters for Enhanced Methanol Oxidation","authors":"Airong Xu, Hui Huang, Zihan Yang, Wenzhi Li, Lanyue Zhang, Mengyuan Liu, Dong Liu, Xiaokang Liu, Wei Zhang, Tao Yao, Tao Ding","doi":"10.1021/acs.jpcc.6c00729","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00729","url":null,"abstract":"Precise electronic regulation of platinum (Pt) catalysts is essential for optimizing key intermediate energy barriers in the methanol oxidation reaction (MOR). However, conventional coordination engineering strategies for electronic modulation are often hindered by size mismatch between ligands and metal active sites, leading to stochastic reaction mechanisms and suboptimal modulation. In this work, we designed a series of structurally well-defined Pt clusters coordinated with nitrogen-, phosphorus-, and sulfur-containing organic molecules, enabling single-variable manipulation and maximized coordination interactions. Our results reveal a pronounced coordination-dependent performance order of Pt–N > Pt–P > Pt–S. Notably, the N-coordinated catalyst achieves a 5-fold mass activity enhancement and enhanced stability. Mechanistic insights from in situ Fourier transform infrared and density functional theory calculations confirm that N-coordination optimizes Pt electron structure and lowers energy barriers for intermediate adsorption/desorption. This work elucidates the intrinsic modulation mechanism and offers valuable insights into the rational design of high-efficiency Pt-based MOR catalysts.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"54 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448241","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 : 2026-03-14DOI: 10.1021/acs.jpcc.6c00183
Marcos F. Gómez-Olivos, Fernando Plascencia-Hernández, Miguel A. Martínez-Cruz, Heriberto Pfeiffer
Dilithium nickel(II) oxide (Li2NiO2) was synthesized by a solid-state reaction and structurally and microstructurally characterized. Then, it was tested as a carbon dioxide (CO2) chemisorbent through dynamic and isothermal thermogravimetric analyses. Sample characterization indicated that the synthesized Li2NiO2 contained a small highly dispersed NiO phase as a secondary phase. CO2 capture performed on Li2NiO2, through dynamic experiments using different carbon dioxide partial pressures, showed that it had a low CO2 uptake at low temperatures (200–500 °C) but much higher uptakes at higher temperatures (550–700 °C) regardless of the CO2 concentration. Isothermal trends and solid product characterization allowed us to elucidate the reaction pathway, implying the lithium-deficient (Li1–xNixO2) crystal phase formation as reactive intermediates, as well as nickel oxide and lithium carbonate as final products. The reaction path evolution showed that low CO2 concentrations modified the external core–shell microstructure (porosity and specific surface area), which consequently favored CO2 capture. Complementarily, a kinetic analysis was performed via the Avrami–Erofeev model, the results of which were compared against different alkaline ceramics used for CO2 capture at high temperatures, revealing the positive performance of Li2NiO2.
{"title":"Thermokinetic Analysis of Carbon Dioxide Chemical Capture Using a Nickel-Containing Alkaline Ceramic (Li2NiO2)","authors":"Marcos F. Gómez-Olivos, Fernando Plascencia-Hernández, Miguel A. Martínez-Cruz, Heriberto Pfeiffer","doi":"10.1021/acs.jpcc.6c00183","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00183","url":null,"abstract":"Dilithium nickel(II) oxide (Li<sub>2</sub>NiO<sub>2</sub>) was synthesized by a solid-state reaction and structurally and microstructurally characterized. Then, it was tested as a carbon dioxide (CO<sub>2</sub>) chemisorbent through dynamic and isothermal thermogravimetric analyses. Sample characterization indicated that the synthesized Li<sub>2</sub>NiO<sub>2</sub> contained a small highly dispersed NiO phase as a secondary phase. CO<sub>2</sub> capture performed on Li<sub>2</sub>NiO<sub>2</sub>, through dynamic experiments using different carbon dioxide partial pressures, showed that it had a low CO<sub>2</sub> uptake at low temperatures (200–500 °C) but much higher uptakes at higher temperatures (550–700 °C) regardless of the CO<sub>2</sub> concentration. Isothermal trends and solid product characterization allowed us to elucidate the reaction pathway, implying the lithium-deficient (Li<sub>1–<i>x</i></sub>Ni<sub><i>x</i></sub>O<sub>2</sub>) crystal phase formation as reactive intermediates, as well as nickel oxide and lithium carbonate as final products. The reaction path evolution showed that low CO<sub>2</sub> concentrations modified the external core–shell microstructure (porosity and specific surface area), which consequently favored CO<sub>2</sub> capture. Complementarily, a kinetic analysis was performed via the Avrami–Erofeev model, the results of which were compared against different alkaline ceramics used for CO<sub>2</sub> capture at high temperatures, revealing the positive performance of Li<sub>2</sub>NiO<sub>2</sub>.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"23 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448240","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 : 2026-03-13DOI: 10.1021/acs.jpcc.5c08650
Ben Sun, Gui-Chang Wang
The preparation of propylene oxide (PO) by direct epoxidation of propylene with molecular oxygen using a Cu-based catalyst is one of the most important reactions in the chemical industry. Recent experimental studies have shown that the main product of propylene epoxidation catalyzed by rutile TiO2-supported CuOx clusters prepared by ultrahigh temperature calcination is PO. By combining global structural sampling, DFT calculations, and microkinetic modeling, we demonstrate that the high-performance rutile TiO2(110) support can stabilize geometrically diverse yet functionally unified CuOx configurations. Two representative configurations─an isolated cluster (CuOx_cluster/TiO2) and an extended chain (CuOx_chain/TiO2)─were identified. Interestingly, despite their distinct morphologies, both exhibit exceptionally high selectivity toward propylene oxide (PO), and much higher than that of Cu2O(111). Electronic structure analysis reveals that this common selectivity stems from a conserved Ti–O–Cu interface, which modulates the electronic state of adjacent Cu atoms. The strong covalent interaction at this interface pins the Cu d-band center deep below the Fermi level, thereby intrinsically limiting electron transfer to O2. This mechanism ensures the moderate activation of O2 while inhibiting its excessive reduction and dissociation, thereby stabilizing the molecular O2* species conducive to epoxidation and effectively blocking the allyl hydrogen removal (AHS) pathway that leads to combustion. On the other hand, the strong O2 activation on Cu2O(111) results in an O mechanism for DEP, which favors CO2 formation ultimately. This study elucidated the unified mechanism of the high performance of rutile TiO2-supported copper catalysts at the atomic scale, providing new insights for the design of selective oxidation catalysts.
{"title":"Direct Propylene Epoxidation over CuOx/TiO2: Unveiling the Common Ti–O–Cu Active Interface via DFT and Microkinetic Modeling","authors":"Ben Sun, Gui-Chang Wang","doi":"10.1021/acs.jpcc.5c08650","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08650","url":null,"abstract":"The preparation of propylene oxide (PO) by direct epoxidation of propylene with molecular oxygen using a Cu-based catalyst is one of the most important reactions in the chemical industry. Recent experimental studies have shown that the main product of propylene epoxidation catalyzed by rutile TiO<sub>2</sub>-supported CuO<sub><i>x</i></sub> clusters prepared by ultrahigh temperature calcination is PO. By combining global structural sampling, DFT calculations, and microkinetic modeling, we demonstrate that the high-performance rutile TiO<sub>2</sub>(110) support can stabilize geometrically diverse yet functionally unified CuO<sub><i>x</i></sub> configurations. Two representative configurations─an isolated cluster (CuO<sub><i>x</i></sub>_cluster/TiO<sub>2</sub>) and an extended chain (CuO<sub><i>x</i></sub>_chain/TiO<sub>2</sub>)─were identified. Interestingly, despite their distinct morphologies, both exhibit exceptionally high selectivity toward propylene oxide (PO), and much higher than that of Cu<sub>2</sub>O(111). Electronic structure analysis reveals that this common selectivity stems from a conserved Ti–O–Cu interface, which modulates the electronic state of adjacent Cu atoms. The strong covalent interaction at this interface pins the Cu d-band center deep below the Fermi level, thereby intrinsically limiting electron transfer to O<sub>2</sub>. This mechanism ensures the moderate activation of O<sub>2</sub> while inhibiting its excessive reduction and dissociation, thereby stabilizing the molecular O<sub>2</sub>* species conducive to epoxidation and effectively blocking the allyl hydrogen removal (AHS) pathway that leads to combustion. On the other hand, the strong O<sub>2</sub> activation on Cu<sub>2</sub>O(111) results in an O mechanism for DEP, which favors CO<sub>2</sub> formation ultimately. This study elucidated the unified mechanism of the high performance of rutile TiO<sub>2</sub>-supported copper catalysts at the atomic scale, providing new insights for the design of selective oxidation catalysts.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"7 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147440404","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}
Sodium-ion batteries present an attractive and abundant alternative to lithium-ion systems, utilizing ionic liquid electrolytes and carbon-based anodes to achieve high performance. Nonetheless, the stability can be influenced by interfacial chemical interactions. The present study employs a divide-and-conquer-type density-functional tight-binding molecular dynamics alongside Grimme’s DFT-D3 dispersion, to explore graphene oxide (GO) anodes in conjunction with NaFSA/[C3C1Pyr]FSA electrolytes. The level of concentration has a significant impact on the concentration, resulting in a decrease in the intensity of the RDF peaks. The hydroxyl-based GO demonstrates remarkable stability, as evidenced by the detection of only one new molecule at a concentration of 3 M. The interactions between sodium and FSA ions are predominant, with minor contributions from OH and H2O associated with hydroxyl-based GO. Sodium ions demonstrate significant diffusion across the graphene surface, where an epoxide-based GO reveals charge fluctuations while a hydroxide-based one exhibits charge delocalization.
{"title":"Density-Functional Tight-Binding Molecular Dynamics Simulation of Graphene Oxide-Ionic Liquid Electrolyte Interface in Sodium-Ion Batteries","authors":"Mirella Fonda Maahury, Aditya Wibawa Sakti, Hiromi Nakai","doi":"10.1021/acs.jpcc.5c07064","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c07064","url":null,"abstract":"Sodium-ion batteries present an attractive and abundant alternative to lithium-ion systems, utilizing ionic liquid electrolytes and carbon-based anodes to achieve high performance. Nonetheless, the stability can be influenced by interfacial chemical interactions. The present study employs a divide-and-conquer-type density-functional tight-binding molecular dynamics alongside Grimme’s DFT-D3 dispersion, to explore graphene oxide (GO) anodes in conjunction with NaFSA/[C<sub>3</sub>C<sub>1</sub>Pyr]FSA electrolytes. The level of concentration has a significant impact on the concentration, resulting in a decrease in the intensity of the RDF peaks. The hydroxyl-based GO demonstrates remarkable stability, as evidenced by the detection of only one new molecule at a concentration of 3 M. The interactions between sodium and FSA ions are predominant, with minor contributions from OH and H<sub>2</sub>O associated with hydroxyl-based GO. Sodium ions demonstrate significant diffusion across the graphene surface, where an epoxide-based GO reveals charge fluctuations while a hydroxide-based one exhibits charge delocalization.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"28 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448243","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 : 2026-03-13DOI: 10.1021/acs.jpcc.6c00244
Nagendra S. Kamath, Ashish Soni, Dipak Maity, Tharangattu N. Narayanan, Suman Kalyan Pal
Controlling the valley degree of freedom in two-dimensional transition metal dichalcogenides (TMDCs) is crucial for enabling valleytronic and optoelectronic applications. Herein, we investigate how substitutional-doping-induced defects influence valley properties and dynamics in monolayer MoS2. Using helicity-resolved transient absorption spectroscopy, we reveal that vanadium doping introduces local magnetic proximity effects that modify valley-polarized excitonic relaxation pathways. The vanadium-induced defect states are spin-polarized and exhibit valley-like characteristics, forming a three-valley system that sustains a finite degree of valley polarization (DVP) at room temperature. We observe significantly extended valley lifetimes in doped samples compared with pristine MoS2 and uncover a clear dependence of valley properties on vanadium concentration. Furthermore, we demonstrate that interband transitions can be harnessed to selectively manipulate excitonic relaxation, resulting in enhanced DVP. These findings establish a route for tuning valley lifetimes and intervalley scattering through targeted doping, offering new design strategies for next-generation spin-valleytronic devices.
{"title":"Spin-Selective Defect Coupling Drives Valley Polarization and Dynamics in Vanadium-Doped Monolayer MoS2","authors":"Nagendra S. Kamath, Ashish Soni, Dipak Maity, Tharangattu N. Narayanan, Suman Kalyan Pal","doi":"10.1021/acs.jpcc.6c00244","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00244","url":null,"abstract":"Controlling the valley degree of freedom in two-dimensional transition metal dichalcogenides (TMDCs) is crucial for enabling valleytronic and optoelectronic applications. Herein, we investigate how substitutional-doping-induced defects influence valley properties and dynamics in monolayer MoS<sub>2</sub>. Using helicity-resolved transient absorption spectroscopy, we reveal that vanadium doping introduces local magnetic proximity effects that modify valley-polarized excitonic relaxation pathways. The vanadium-induced defect states are spin-polarized and exhibit valley-like characteristics, forming a three-valley system that sustains a finite degree of valley polarization (DVP) at room temperature. We observe significantly extended valley lifetimes in doped samples compared with pristine MoS<sub>2</sub> and uncover a clear dependence of valley properties on vanadium concentration. Furthermore, we demonstrate that interband transitions can be harnessed to selectively manipulate excitonic relaxation, resulting in enhanced DVP. These findings establish a route for tuning valley lifetimes and intervalley scattering through targeted doping, offering new design strategies for next-generation spin-valleytronic devices.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"5 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147440405","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}
Optimizing the fill factor (FF) in ternary all-polymer blend solar cells is challenging because incorporating a third polymer changes the blend nanomorphology and charge-transport energy levels relative to those of the donor–acceptor (D:A) host binary device. In this study, two ternary blend systems, D2x:D1–x:A, were carefully designed based on two host D polymers─poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-c:4′,5′-c′]dithiophene-4,8-dione))] (PBDB-T) and its fluorinated derivative (PBDB-T-2F)─which exhibited comparable morphological characteristics but differed in their highest occupied molecular orbital (HOMO) energy-level alignment with a second polymer donor (D2), poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene))-alt-(2,2-ethyl-3(or 4)-carboxylate-thiophene)] (PTO2). The contribution of the HOMO energy difference (ΔHOMO) between D and D2 on charge transport and the FF was evaluated. For the ternary system with ΔHOMO = 0.26 eV, the FF decreased for D2 fractions (x) > 0.5, reaching a minimum at x = 0.9, owing to hole trapping within the insufficiently percolated D networks. In contrast, no reduction in the FF was observed for the ternary system where ΔHOMO = 0.08 eV because hole trapping was largely mitigated. These distinctly different FF dependences on the loading amounts of D2 underscore the importance of precise energy-level matching in maintaining a high FF in ternary all-polymer blend systems, providing a guideline for polymer selection with excellent FF tolerance across various blend compositions.
{"title":"Influence of HOMO Energy Alignment of Multiple Polymer Donors on Charge Transport and Fill Factor in Ternary All-Polymer Blend Solar Cells","authors":"Zhiyuan Liang, Divyanshu Raturi, Hiroaki Benten, Masakazu Nakamura","doi":"10.1021/acs.jpcc.6c00975","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00975","url":null,"abstract":"Optimizing the fill factor (FF) in ternary all-polymer blend solar cells is challenging because incorporating a third polymer changes the blend nanomorphology and charge-transport energy levels relative to those of the donor–acceptor (D:A) host binary device. In this study, two ternary blend systems, D2<sub><i>x</i></sub>:D<sub>1–<i>x</i></sub>:A, were carefully designed based on two host D polymers─poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-<i>b</i>:4,5-<i>b</i>′]dithiophene))-<i>alt</i>-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-<i>c</i>:4′,5′-<i>c</i>′]dithiophene-4,8-dione))] (PBDB-T) and its fluorinated derivative (PBDB-T-2F)─which exhibited comparable morphological characteristics but differed in their highest occupied molecular orbital (HOMO) energy-level alignment with a second polymer donor (D2), poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-<i>b</i>:4,5-<i>b</i>′]dithiophene))-<i>alt</i>-(2,2-ethyl-3(or 4)-carboxylate-thiophene)] (PTO2). The contribution of the HOMO energy difference (ΔHOMO) between D and D2 on charge transport and the FF was evaluated. For the ternary system with ΔHOMO = 0.26 eV, the FF decreased for D2 fractions (<i>x</i>) > 0.5, reaching a minimum at <i>x</i> = 0.9, owing to hole trapping within the insufficiently percolated D networks. In contrast, no reduction in the FF was observed for the ternary system where ΔHOMO = 0.08 eV because hole trapping was largely mitigated. These distinctly different FF dependences on the loading amounts of D2 underscore the importance of precise energy-level matching in maintaining a high FF in ternary all-polymer blend systems, providing a guideline for polymer selection with excellent FF tolerance across various blend compositions.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"308 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448428","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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