Pub Date : 2025-01-23DOI: 10.1021/acs.jpclett.4c03514
Kathiresan C., Sruthy Subash, Udhayakumar S., Varun Karthik M., Kamala Bharathi K.
Manganese oxides are a promising cathode material for aqueous zinc-ion batteries (AZIBs), but thin-film configurations remain underexplored. This study investigates the electrochemical dynamics of 60 nm thin Mn3O4 thin films, fabricated via RF magnetron reactive sputtering. It addresses the highest reported capacity (25 mAh/g) in thin film form, stability over 500 cycles, effective performance across varying current rates, surpassing previous studies and challenges such as phase stability, and capacity fading over extended cycling, aiming to enhance uniformity, minimizing diffusion barriers for improved performance. EIS reveals Zn2+ diffusion coefficients of 1.503 × 10–7, 1.336 × 10–16, and 1.947 × 10–20 cm2/s in precycle, charged, and discharged states, respectively, highlighting evolving diffusion dynamics during cycling. Structural instability during discharge leads to a decline in diffusion performance, emphasizing the need for material and interfacial optimizations to enhance stability and mitigate degradation. These findings underscore the critical role of interfacial engineering and structural stability in maintaining high ion diffusion rates and minimizing morphological degradation during cycling. The present study explores the critical role of targeted engineering in unlocking their full potential for lightweight, miniaturized, high-performance microbatteries for energy storage applications.
{"title":"Nanoengineered RF-Sputtered Mn3O4 Cathode Thin Films for Aqueous Zinc-Ion Batteries: Insights into Diffusion Dynamics and Application Potential","authors":"Kathiresan C., Sruthy Subash, Udhayakumar S., Varun Karthik M., Kamala Bharathi K.","doi":"10.1021/acs.jpclett.4c03514","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03514","url":null,"abstract":"Manganese oxides are a promising cathode material for aqueous zinc-ion batteries (AZIBs), but thin-film configurations remain underexplored. This study investigates the electrochemical dynamics of 60 nm thin Mn<sub>3</sub>O<sub>4</sub> thin films, fabricated via RF magnetron reactive sputtering. It addresses the highest reported capacity (25 mAh/g) in thin film form, stability over 500 cycles, effective performance across varying current rates, surpassing previous studies and challenges such as phase stability, and capacity fading over extended cycling, aiming to enhance uniformity, minimizing diffusion barriers for improved performance. EIS reveals Zn<sup>2</sup><sup>+</sup> diffusion coefficients of 1.503 × 10<sup>–</sup><sup>7</sup>, 1.336 × 10<sup>–</sup><sup>1</sup><sup>6</sup>, and 1.947 × 10<sup>–</sup><sup>2</sup><sup>0</sup> cm<sup>2</sup>/s in precycle, charged, and discharged states, respectively, highlighting evolving diffusion dynamics during cycling. Structural instability during discharge leads to a decline in diffusion performance, emphasizing the need for material and interfacial optimizations to enhance stability and mitigate degradation. These findings underscore the critical role of interfacial engineering and structural stability in maintaining high ion diffusion rates and minimizing morphological degradation during cycling. The present study explores the critical role of targeted engineering in unlocking their full potential for lightweight, miniaturized, high-performance microbatteries for energy storage applications.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"51 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Synthesis of 2D quasi-hexagonal phase C60 (qHP C60) has opened avenues for its application as a novel catalytic support. This study investigates the structure, stability, and anisotropic properties of Cu4 clusters anchored on the qHP C60 surface through density functional theory calculations. Our findings reveal that the Cu4 cluster preferentially occupies the intrinsic holes of the qHP C60 via one of its tetrahedral faces, resulting in enhanced stability and conductivity, with a significantly reduced band gap of 0.11 eV, compared to the semiconductor behavior of pristine qHP C60. The anisotropic mechanical properties are retained, affirming the robustness of the material under stress. Importantly, the interaction between qHP C60 and Cu4 not only modifies intramolecular bonding but also introduces additional active sites, thereby having a promising enhanced catalytic performance. This work underscores the potential of qHP C60 as an innovative support in catalysis, paving the way for further exploration of its capabilities in industrial applications.
{"title":"Harnessing Hole Sites in 2D Monolayer C60 for Metal Cluster Anchoring","authors":"Jianzhi Xu, Ya-Ke Li, Zhi-Xin Guo, Zhe Li, Gao-Lei Hou","doi":"10.1021/acs.jpclett.4c03316","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03316","url":null,"abstract":"Synthesis of 2D quasi-hexagonal phase C<sub>60</sub> (qHP C<sub>60</sub>) has opened avenues for its application as a novel catalytic support. This study investigates the structure, stability, and anisotropic properties of Cu<sub>4</sub> clusters anchored on the qHP C<sub>60</sub> surface through density functional theory calculations. Our findings reveal that the Cu<sub>4</sub> cluster preferentially occupies the intrinsic holes of the qHP C<sub>60</sub> via one of its tetrahedral faces, resulting in enhanced stability and conductivity, with a significantly reduced band gap of 0.11 eV, compared to the semiconductor behavior of pristine qHP C<sub>60</sub>. The anisotropic mechanical properties are retained, affirming the robustness of the material under stress. Importantly, the interaction between qHP C<sub>60</sub> and Cu<sub>4</sub> not only modifies intramolecular bonding but also introduces additional active sites, thereby having a promising enhanced catalytic performance. This work underscores the potential of qHP C<sub>60</sub> as an innovative support in catalysis, paving the way for further exploration of its capabilities in industrial applications.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"136 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-23DOI: 10.1021/acs.jpclett.4c03192
Lukas Kunze, Andreas Hansen, Stefan Grimme, Jan-Michael Mewes
With their narrow-band emission, high quantum yield, and good chemical stability, multiresonance thermally activated delayed fluorescence (MR-TADF) emitters are promising materials for OLED technology. However, accurately modeling key properties, such as the singlet–triplet (ST) energy gap and fluorescence energy, remains challenging. While time-dependent density functional theory (TD-DFT), the workhorse of computational materials science, suffers from fundamental issues, wave function-based coupled-cluster (CC) approaches, like approximate CC of second-order (CC2), are accurate but suffer from high computational cost and unfavorable scaling with system size. This work demonstrates that a state-specific ΔDFT approach based on unrestricted Kohn–Sham (ΔUKS) combines the best of both worlds: on a diverse benchmark set of 35 MR-TADF emitters, ΔUKS performs as good as or better than CC2, recovering experimental ST gaps with a mean absolute deviation (MAD) of 0.03 eV at a small fraction of the computational cost of CC2. When combined with a tuned range-separated LC-ωPBE functional, the excellent performance extends to fluorescence energies and ST gaps of MR- and donor–acceptor TADF emitters and even molecules with an inverted ST gap (INVEST), rendering this approach a jack of all trades for organic electronics.
{"title":"The Best of Both Worlds: ΔDFT Describes Multiresonance TADF Emitters with Wave-Function Accuracy at Density-Functional Cost","authors":"Lukas Kunze, Andreas Hansen, Stefan Grimme, Jan-Michael Mewes","doi":"10.1021/acs.jpclett.4c03192","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03192","url":null,"abstract":"With their narrow-band emission, high quantum yield, and good chemical stability, multiresonance thermally activated delayed fluorescence (MR-TADF) emitters are promising materials for OLED technology. However, accurately modeling key properties, such as the singlet–triplet (ST) energy gap and fluorescence energy, remains challenging. While time-dependent density functional theory (TD-DFT), the workhorse of computational materials science, suffers from fundamental issues, wave function-based coupled-cluster (CC) approaches, like approximate CC of second-order (CC2), are accurate but suffer from high computational cost and unfavorable scaling with system size. This work demonstrates that a state-specific ΔDFT approach based on unrestricted Kohn–Sham (ΔUKS) combines the best of both worlds: on a diverse benchmark set of 35 MR-TADF emitters, ΔUKS performs as good as or better than CC2, recovering experimental ST gaps with a mean absolute deviation (MAD) of 0.03 eV at a small fraction of the computational cost of CC2. When combined with a tuned range-separated LC-ωPBE functional, the excellent performance extends to fluorescence energies and ST gaps of MR- and donor–acceptor TADF emitters and even molecules with an inverted ST gap (INVEST), rendering this approach a jack of all trades for organic electronics.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"57 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-23DOI: 10.1021/acs.jpclett.4c03373
Chao-Yang Lin, Zi-Cheng Jiang, Bo-Han Chen, Isabella Wagner, Loïc Lavenu, Yoann Zaouter, Lin-Song Cui, Chih-Hsuang Lu, Marc Hanna, Justin M. Hodgkiss, Shang-Da Yang, Kai Chen
We demonstrate a high-performance ultrafast broadband time-resolved photoluminescence (TRPL) system based on the transient grating photoluminescence spectroscopy (TGPLS) technique. The core of the system is a Kerr effect-induced transient grating (TG) optical gate driven by high repetition rate ultrashort laser pulses at 1030 nm with micro-Joule pulse energy. Satisfying the demands of spectroscopy applications, the setup achieves high sensitivity, rapid data acquisition, ultrafast time resolution, and a wide spectral window from ultraviolet to near-infrared. The time resolution can be further improved to achieve <80 fs instrument response function by employing the multiple plate compression (MPC) technique to temporally compress the driving pulses. This work presents a new benchmark for ultrafast TRPL.
{"title":"Next-Generation Ultrafast Photoluminescence Spectroscopy: Integration of Transient Grating Optical Gate and Advanced Femtosecond Laser Technology","authors":"Chao-Yang Lin, Zi-Cheng Jiang, Bo-Han Chen, Isabella Wagner, Loïc Lavenu, Yoann Zaouter, Lin-Song Cui, Chih-Hsuang Lu, Marc Hanna, Justin M. Hodgkiss, Shang-Da Yang, Kai Chen","doi":"10.1021/acs.jpclett.4c03373","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03373","url":null,"abstract":"We demonstrate a high-performance ultrafast broadband time-resolved photoluminescence (TRPL) system based on the transient grating photoluminescence spectroscopy (TGPLS) technique. The core of the system is a Kerr effect-induced transient grating (TG) optical gate driven by high repetition rate ultrashort laser pulses at 1030 nm with micro-Joule pulse energy. Satisfying the demands of spectroscopy applications, the setup achieves high sensitivity, rapid data acquisition, ultrafast time resolution, and a wide spectral window from ultraviolet to near-infrared. The time resolution can be further improved to achieve <80 fs instrument response function by employing the multiple plate compression (MPC) technique to temporally compress the driving pulses. This work presents a new benchmark for ultrafast TRPL.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"17 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-23DOI: 10.1021/acs.jpclett.4c03506
Hao-Yu Wang, Yu Kevin Dai, Kang-Ming Liao, Shuguang Deng, Gui-Ping Dai
Lithium–sulfur batteries have been recognized as one of the excellent candidates for next-generation energy storage batteries because of their high energy density and low cost and low pollution. However, lithium–sulfur batteries have been challenged by low conductivity, low sulfur utilization, poor cycle life, and the shuttle effect of polysulfides. To address these problems, we report here an independent mixed sulfur host. First, NiCoAl-layered double hydroxide (LDH) nanosheets were uniformly grown on carbon cloth (CC) by a hydrothermal method. Then, vertical graphene (VG) was uniformly vertically grown on the composite structures to form VG@LDH/CC by a plasma enhanced chemical vapor deposition (PECVD) method. Graphene and LDH nanosheets forming a three-dimensional mesh structure can effectively physically block lithium polysulfides, store singlet sulfur, and improve the conductivity of the cathode. In addition, during the growth of graphene, the Ni and Co ions in the LDH nanosheets are reduced to NiCo nanoparticles, which can enhance the chemical adsorption of polysulfides, thus effectively mitigating the “shuttle effect” and improving the electrical conductivity of the material. The lithium sulfur batteries with derived sulfur anodes (VG@LDH/CC-S) exhibited excellent electrochemical properties, including excellent rate performance (780.8 mAh g–1 at 3C) and impressive cycling stability (capacity decay of about 0.0755% per cycle after 750 cycles at 0.5C).
锂硫电池以其高能量密度、低成本、低污染等优点被公认为下一代储能电池的优秀候选之一。然而，锂硫电池存在电导率低、硫利用率低、循环寿命差以及多硫化物的穿梭效应等问题。为了解决这些问题，我们在这里报道了一个独立的混合硫宿主。首先，采用水热法在碳布（CC）上均匀生长镍层双氢氧化物（LDH）纳米片。然后，采用等离子体增强化学气相沉积（PECVD）方法，在复合材料结构上均匀垂直生长垂直石墨烯（VG），形成VG@LDH/CC。石墨烯和LDH纳米片形成三维网状结构，可以有效地物理阻塞锂多硫化物，存储单线态硫，提高阴极的导电性。此外，在石墨烯生长过程中，LDH纳米片中的Ni和Co离子被还原为NiCo纳米粒子，可以增强对多硫化物的化学吸附，从而有效缓解“穿梭效应”，提高材料的导电性。采用衍生硫阳极的硫锂电池（VG@LDH/CC-S）表现出优异的电化学性能，包括优异的速率性能（在3C时为780.8 mAh g-1）和令人印象印象的循环稳定性（在0.5C下750次循环后，每循环容量衰减约0.0755%）。
{"title":"Vertical Graphene Growth on LDH Nanosheets and Carbon Cloth Nanofibers with NiCo Nanoparticles as a Freestanding Host for High-Performance Lithium–Sulfur Batteries","authors":"Hao-Yu Wang, Yu Kevin Dai, Kang-Ming Liao, Shuguang Deng, Gui-Ping Dai","doi":"10.1021/acs.jpclett.4c03506","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03506","url":null,"abstract":"Lithium–sulfur batteries have been recognized as one of the excellent candidates for next-generation energy storage batteries because of their high energy density and low cost and low pollution. However, lithium–sulfur batteries have been challenged by low conductivity, low sulfur utilization, poor cycle life, and the shuttle effect of polysulfides. To address these problems, we report here an independent mixed sulfur host. First, NiCoAl-layered double hydroxide (LDH) nanosheets were uniformly grown on carbon cloth (CC) by a hydrothermal method. Then, vertical graphene (VG) was uniformly vertically grown on the composite structures to form VG@LDH/CC by a plasma enhanced chemical vapor deposition (PECVD) method. Graphene and LDH nanosheets forming a three-dimensional mesh structure can effectively physically block lithium polysulfides, store singlet sulfur, and improve the conductivity of the cathode. In addition, during the growth of graphene, the Ni and Co ions in the LDH nanosheets are reduced to NiCo nanoparticles, which can enhance the chemical adsorption of polysulfides, thus effectively mitigating the “shuttle effect” and improving the electrical conductivity of the material. The lithium sulfur batteries with derived sulfur anodes (VG@LDH/CC-S) exhibited excellent electrochemical properties, including excellent rate performance (780.8 mAh g<sup>–1</sup> at 3C) and impressive cycling stability (capacity decay of about 0.0755% per cycle after 750 cycles at 0.5C).","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"1 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-23DOI: 10.1021/acs.jpclett.4c03478
Ying Zhang, Xiaoming Lyu, Yaowen Xing, Yinghe Ji, Li Zhang, Guangrun Wu, Xiaoyu Liu, Lei Qin, Yanli Wu, Xiaotong Wang, Jing Wu, Yang Li
Surface-enhanced Raman spectroscopy (SERS) has become an indispensable tool for biomolecular analysis, yet the detection of DNA signals remains hindered by spectral interference from citrate ions, which overlap with key DNA features. This study introduces an innovative, ultrasensitive SERS platform utilizing thiol-modified silver nanoparticles (Ag@SDCNPs) that overcomes this challenge by eliminating citrate interference. This platform enables direct, interference-free detection and structural characterization of a wide range of DNA conformations, including single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), i-motif, hairpin, G-quadruplex, and triple-stranded DNA (tsDNA). Employing calcium ions as aggregating agents and deuterated methanol as an internal standard, the system achieved high spectral quality and reproducibility. Machine learning (ML) techniques, such as linear discriminant analysis (LDA) and t-distributed stochastic neighbor embedding (t-SNE), were utilized for spectral classification, alongside support vector machines (SVM) for predictive modeling, yielding accuracies above 99%. These findings establish a robust and versatile platform for DNA structural analysis, offering transformative potential for applications in clinical diagnostics and biomedical research.
{"title":"Advancing DNA Structural Analysis: A SERS Approach Free from Citrate Interference Combined with Machine Learning","authors":"Ying Zhang, Xiaoming Lyu, Yaowen Xing, Yinghe Ji, Li Zhang, Guangrun Wu, Xiaoyu Liu, Lei Qin, Yanli Wu, Xiaotong Wang, Jing Wu, Yang Li","doi":"10.1021/acs.jpclett.4c03478","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03478","url":null,"abstract":"Surface-enhanced Raman spectroscopy (SERS) has become an indispensable tool for biomolecular analysis, yet the detection of DNA signals remains hindered by spectral interference from citrate ions, which overlap with key DNA features. This study introduces an innovative, ultrasensitive SERS platform utilizing thiol-modified silver nanoparticles (Ag@SDCNPs) that overcomes this challenge by eliminating citrate interference. This platform enables direct, interference-free detection and structural characterization of a wide range of DNA conformations, including single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), i-motif, hairpin, G-quadruplex, and triple-stranded DNA (tsDNA). Employing calcium ions as aggregating agents and deuterated methanol as an internal standard, the system achieved high spectral quality and reproducibility. Machine learning (ML) techniques, such as linear discriminant analysis (LDA) and t-distributed stochastic neighbor embedding (t-SNE), were utilized for spectral classification, alongside support vector machines (SVM) for predictive modeling, yielding accuracies above 99%. These findings establish a robust and versatile platform for DNA structural analysis, offering transformative potential for applications in clinical diagnostics and biomedical research.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"103 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.1021/acs.jpclett.4c03103
Unhyeok Jo, Kiun Cheong, Jae-Min Kim, Jun Yeob Lee
Controlling intermolecular interactions, such as triplet–triplet annihilation (TTA) and triplet–polaron annihilation (TPA), is crucial for achieving high quantum efficiency in organic light-emitting diodes (OLEDs) by suppressing exciton loss. This study investigates the molecular design of tetradentate Pt(II) complexes used for singlet exciton harvesting in fluorescent OLEDs to elucidate the relationship between the chemical structure of the ligands and exciton quenching mechanisms. It was discovered that the bulkiness of substituents is pivotal for maximizing quantum efficiency in these devices. An exciton dynamics study conducted during device operation quantitatively analyzed the contribution of substituents to the OLED operation mechanism, demonstrating that complexes with bulky 2,6-diisopropylphenyl and tert-butyl substituents enhance singlet exciton harvesting by suppressing TTA and TPA, thereby facilitating Förster energy transfer.
{"title":"Design Rule of Tetradentate Ligand-Based Pt(II) Complex for Efficient Singlet Exciton Harvesting in Fluorescent Organic Light-Emitting Diodes","authors":"Unhyeok Jo, Kiun Cheong, Jae-Min Kim, Jun Yeob Lee","doi":"10.1021/acs.jpclett.4c03103","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03103","url":null,"abstract":"Controlling intermolecular interactions, such as triplet–triplet annihilation (TTA) and triplet–polaron annihilation (TPA), is crucial for achieving high quantum efficiency in organic light-emitting diodes (OLEDs) by suppressing exciton loss. This study investigates the molecular design of tetradentate Pt(II) complexes used for singlet exciton harvesting in fluorescent OLEDs to elucidate the relationship between the chemical structure of the ligands and exciton quenching mechanisms. It was discovered that the bulkiness of substituents is pivotal for maximizing quantum efficiency in these devices. An exciton dynamics study conducted during device operation quantitatively analyzed the contribution of substituents to the OLED operation mechanism, demonstrating that complexes with bulky 2,6-diisopropylphenyl and <i>tert</i>-butyl substituents enhance singlet exciton harvesting by suppressing TTA and TPA, thereby facilitating Förster energy transfer.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"45 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The deposition of alkali metals on oxide surfaces has garnered significant interest due to their critical role in enhancing various catalytic processes. However, the atomic-scale characterization of these structures remains elusive, owing to the complex and competing interactions among the oxygen, the alkali metals, and the metal atoms within the oxides. In this work, we grew alkali metals (Na, K, Cs) on the copper oxide films on the Cu(111) surface and found the formation of hexagonally ordered monolayer films. Via noncontact atomic force microscopy (nc-AFM), we could directly identify the positions of alkali metal cations and the chemical structures of Cu3O building block in the hexagonal superstructure. In combination with density functional theory (DFT) calculations and AFM simulations, we demonstrated that the alkali metal cations (Na, K, Cs) are chemically bonded with the oxygens in the copper oxides, forming an ACu6O5 (A = Na, K, Cs) monolayer compound on the Cu(111) surface. Scanning tunneling spectroscopy (STS) measurement presents the increase of the density of states beyond zero bias (Fermi level, EF) and onset of conduction band at 0.5 eV. In addition, the alkali metal modified copper oxide film shows a lower work function (∼3.5 eV), which is quantitively assessed through field emission resonance (FER) and further confirmed by measuring the contact potential difference and I(z) curves. These electronic properties of the ACu6O5 ternary compound indicate the high chemical activity, which facilitates the adsorption of CO2 molecules with the oxygen binding with the alkali metal cations. These findings clarify the geometric and electronic structure of alkali metal modified copper oxide films and will contribute to unraveling its promoting reaction mechanism in heterogeneous catalysis at the molecular level.
{"title":"Identifying the Structure of Two-Dimensional ACu6O5 (A = Na, K, Cs) Film on Cu(111) with Atomic Resolution","authors":"Pu Yang, Mengyu Zhao, Xiayu Ran, Chen Zhang, Weiqiang Luo, Wenyu Sun, Jing Xie, Duanyun Cao, Jing Guo","doi":"10.1021/acs.jpclett.4c03093","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03093","url":null,"abstract":"The deposition of alkali metals on oxide surfaces has garnered significant interest due to their critical role in enhancing various catalytic processes. However, the atomic-scale characterization of these structures remains elusive, owing to the complex and competing interactions among the oxygen, the alkali metals, and the metal atoms within the oxides. In this work, we grew alkali metals (Na, K, Cs) on the copper oxide films on the Cu(111) surface and found the formation of hexagonally ordered monolayer films. Via noncontact atomic force microscopy (nc-AFM), we could directly identify the positions of alkali metal cations and the chemical structures of Cu<sub>3</sub>O building block in the hexagonal superstructure. In combination with density functional theory (DFT) calculations and AFM simulations, we demonstrated that the alkali metal cations (Na, K, Cs) are chemically bonded with the oxygens in the copper oxides, forming an ACu<sub>6</sub>O<sub>5</sub> (A = Na, K, Cs) monolayer compound on the Cu(111) surface. Scanning tunneling spectroscopy (STS) measurement presents the increase of the density of states beyond zero bias (Fermi level, <i>E</i><sub>F</sub>) and onset of conduction band at 0.5 eV. In addition, the alkali metal modified copper oxide film shows a lower work function (∼3.5 eV), which is quantitively assessed through field emission resonance (FER) and further confirmed by measuring the contact potential difference and I(z) curves. These electronic properties of the ACu<sub>6</sub>O<sub>5</sub> ternary compound indicate the high chemical activity, which facilitates the adsorption of CO<sub>2</sub> molecules with the oxygen binding with the alkali metal cations. These findings clarify the geometric and electronic structure of alkali metal modified copper oxide films and will contribute to unraveling its promoting reaction mechanism in heterogeneous catalysis at the molecular level.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"81 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.1021/acs.jpclett.4c03451
Xiaojing Teng, Wenbo Yu, Alexander D. MacKerell, Jr.
An improvement in the computational efficiency of polarizable force field simulations is made through the development of a polarizable Drude water model, SWM3, in combination with the use of Lennard-Jones Particle Mesh Ewald (LJPME) for the treatment of long-range LJ interactions. The experimental bulk properties, density, heat of vaporization, dielectric constant, and self-diffusion constant of the SWM3 model are accurately replicated at ambient condition. The temperature dependence of the bulk properties is also captured except for the density. Microscopic properties, such as hydration free energy, dimer properties, and binding energies of clusters are well represented. The SWM3 model is ∼40% faster than the SWM4 water model traditionally used with the Drude force field, and use of LJPME offers an additional 30% speedup in heterogeneous systems. This combination makes the SWM3-based Drude model only 2.6-fold slower than the TIP3P-based additive simulations.
{"title":"Computationally Efficient Polarizable MD Simulations: A Simple Water Model for the Classical Drude Oscillator Polarizable Force Field","authors":"Xiaojing Teng, Wenbo Yu, Alexander D. MacKerell, Jr.","doi":"10.1021/acs.jpclett.4c03451","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03451","url":null,"abstract":"An improvement in the computational efficiency of polarizable force field simulations is made through the development of a polarizable Drude water model, SWM3, in combination with the use of Lennard-Jones Particle Mesh Ewald (LJPME) for the treatment of long-range LJ interactions. The experimental bulk properties, density, heat of vaporization, dielectric constant, and self-diffusion constant of the SWM3 model are accurately replicated at ambient condition. The temperature dependence of the bulk properties is also captured except for the density. Microscopic properties, such as hydration free energy, dimer properties, and binding energies of clusters are well represented. The SWM3 model is ∼40% faster than the SWM4 water model traditionally used with the Drude force field, and use of LJPME offers an additional 30% speedup in heterogeneous systems. This combination makes the SWM3-based Drude model only 2.6-fold slower than the TIP3P-based additive simulations.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"137 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are considered to be the most important processes in metal–air batteries and regenerative fuel cell devices. Metal–organic polymers are attracting interest as promising precursors of advanced metal/carbon electrocatalysts because of their hierarchical porous structure along with the integrated metal–carbon framework. We developed carbon-coated CNTs with Ni/Fe and Cu/Fe as active sites. Experimental observations from X-ray photoelectron spectroscopy and X-ray absorption analysis suggest that C@CNT[Ni] outperforms C@CNT[Cu] in the ORR and OER, which is further supported by density functional theory calculations. C@CNT[Ni] exhibits a higher onset potential (0.99 V vs RHE) and a smaller Tafel slope (40.2 mV decade–1) compared to those of C@CNT/[Cu] in an alkaline electrolyte (0.94 V vs RHE and 46.5 mV decade–1, respectively). Such circumstances are attributed to the alloying effect between Ni and Fe in C@CNT[Ni], in contrast to the existing copper iron oxide phase in C@CNT/[Cu]. It is noteworthy that C@CNT[Ni] also displayed an improved OER, demanding its bifunctional property. As a proof of concept, C@CNT[Ni] was utilized in zinc–air batteries, which shows a high energy efficiency of ∼60%, a small charge–discharge voltage gap of 0.78 V, and excellent cycling performance (∼120 h) at 5 mA cm–2 and 25 °C. This protocol expands the utility of novel metal–organic hyper-cross-linked polymer-derived bimetallic electrocatalysts for clean energy research.
氧还原反应（ORR）和析氧反应（OER）被认为是金属空气电池和再生燃料电池装置中最重要的过程。金属-有机聚合物由于其层叠多孔结构和金属-碳一体化框架而成为先进金属/碳电催化剂的前驱体。我们开发了以Ni/Fe和Cu/Fe作为活性位点的碳包覆CNTs。x射线光电子能谱和x射线吸收分析的实验观测结果表明，C@CNT[Ni]在ORR和OER中优于C@CNT[Cu]，密度泛函理论计算进一步支持了这一结论。与C@CNT/[Cu]相比，C@CNT[Ni]在碱性电解质中表现出更高的起始电位（0.99 V vs RHE）和更小的Tafel斜率（40.2 mV decade-1）（分别为0.94 V vs RHE和46.5 mV decade-1）。这种情况归因于C@CNT[Ni]中Ni和Fe之间的合金化作用，而C@CNT/[Cu]中存在铜氧化铁相。值得注意的是，C@CNT[Ni]也显示出改进的OER，要求其双功能特性。作为概念验证，C@CNT[Ni]被用于锌空气电池中，该电池显示出高达60%的高能量效率，0.78 V的小充放电电压间隙，以及在5 mA cm-2和25°C下优异的循环性能（~ 120 h）。该协议扩大了新型金属-有机超交联聚合物衍生双金属电催化剂在清洁能源研究中的应用。
{"title":"Hyper-Cross-Linked Polymer-Derived Carbon-Coated Fe–Ni Alloy/CNT as a Bifunctional Electrocatalyst for Rechargeable Zinc–Air Batteries","authors":"Arindam Modak, Ankita Phutela, Aniruddha Kundu, Srijib Das, Vidha Bhasin, Dibyendu Bhattacharyya, Saswata Bhattacharya","doi":"10.1021/acs.jpclett.4c03361","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03361","url":null,"abstract":"The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are considered to be the most important processes in metal–air batteries and regenerative fuel cell devices. Metal–organic polymers are attracting interest as promising precursors of advanced metal/carbon electrocatalysts because of their hierarchical porous structure along with the integrated metal–carbon framework. We developed carbon-coated CNTs with Ni/Fe and Cu/Fe as active sites. Experimental observations from X-ray photoelectron spectroscopy and X-ray absorption analysis suggest that C@CNT[Ni] outperforms C@CNT[Cu] in the ORR and OER, which is further supported by density functional theory calculations. C@CNT[Ni] exhibits a higher onset potential (0.99 V vs RHE) and a smaller Tafel slope (40.2 mV decade<sup>–1</sup>) compared to those of C@CNT/[Cu] in an alkaline electrolyte (0.94 V vs RHE and 46.5 mV decade<sup>–1</sup>, respectively). Such circumstances are attributed to the alloying effect between Ni and Fe in C@CNT[Ni], in contrast to the existing copper iron oxide phase in C@CNT/[Cu]. It is noteworthy that C@CNT[Ni] also displayed an improved OER, demanding its bifunctional property. As a proof of concept, C@CNT[Ni] was utilized in zinc–air batteries, which shows a high energy efficiency of ∼60%, a small charge–discharge voltage gap of 0.78 V, and excellent cycling performance (∼120 h) at 5 mA cm<sup>–2</sup> and 25 °C. This protocol expands the utility of novel metal–organic hyper-cross-linked polymer-derived bimetallic electrocatalysts for clean energy research.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"59 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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