Pub Date : 2026-03-10DOI: 10.1021/acs.jpcc.5c07217
Shehu Adam Ibrahim,Jinxue Yang,Tan Shi,Chen Zhang,Da Chen,Jing Li,Yang Li,Jeremiah Chinonso Mbazor,Yizhuo Zhang,Zhengxiong Su,Chenyang Lu
Vacancy formation energy governs atomic transport, radiation defect evolution, and phase stability in high-entropy alloys (HEAs). To develop an efficient predictive framework for this critical property, we employ support vector regression (SVR) to model vacancy formation energies in both random solid solution (RSS) and locally chemically ordered (LCO) structures. Three classes of atomic descriptors─neighbor-specific descriptors, average structural metrics, and smooth overlap of atomic positions (SOAP)─were used to capture the complexity of local environments. Among these, SOAP, which capture many-body correlations and provides rotationally and translationally invariant fingerprints, consistently achieved the highest accuracy, with test R2 values of up to ∼0.89 for RSS and ∼0.96 for LCO. The enhanced predictability of LCO-based models results from compositional inhomogeneity, where regions such as Cr-rich clusters strengthen composition-energy correlations that simplify the learning task. While models trained on the more diverse RSS vacancy formation energies generalized better to LCO environments, a mixed training set containing RSS and LCO dataset was shown to maintain high performance on diverse atomic environments. These findings demonstrate that descriptor choice and structural representation are critical for machine learning predictability of defect energetics and provide a framework that can be extended to other defect properties in complex alloys.
{"title":"Machine Learning Prediction of Vacancy Formation Energies in CoNiCrFe High-Entropy Alloy: The Role of Atomic Descriptors and Local Chemical Order","authors":"Shehu Adam Ibrahim,Jinxue Yang,Tan Shi,Chen Zhang,Da Chen,Jing Li,Yang Li,Jeremiah Chinonso Mbazor,Yizhuo Zhang,Zhengxiong Su,Chenyang Lu","doi":"10.1021/acs.jpcc.5c07217","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c07217","url":null,"abstract":"Vacancy formation energy governs atomic transport, radiation defect evolution, and phase stability in high-entropy alloys (HEAs). To develop an efficient predictive framework for this critical property, we employ support vector regression (SVR) to model vacancy formation energies in both random solid solution (RSS) and locally chemically ordered (LCO) structures. Three classes of atomic descriptors─neighbor-specific descriptors, average structural metrics, and smooth overlap of atomic positions (SOAP)─were used to capture the complexity of local environments. Among these, SOAP, which capture many-body correlations and provides rotationally and translationally invariant fingerprints, consistently achieved the highest accuracy, with test R2 values of up to ∼0.89 for RSS and ∼0.96 for LCO. The enhanced predictability of LCO-based models results from compositional inhomogeneity, where regions such as Cr-rich clusters strengthen composition-energy correlations that simplify the learning task. While models trained on the more diverse RSS vacancy formation energies generalized better to LCO environments, a mixed training set containing RSS and LCO dataset was shown to maintain high performance on diverse atomic environments. These findings demonstrate that descriptor choice and structural representation are critical for machine learning predictability of defect energetics and provide a framework that can be extended to other defect properties in complex alloys.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"127 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383835","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 : 2026-03-10DOI: 10.1021/acs.jpcc.6c00028
Tuan M. Duong,Dmitry Aldakov,Wai Li Ling,Le Si Dang,Gilles Nogues,Peter Reiss
Lead halide perovskite nanocrystals, particularly CsPbBr3, are prime candidates for a variety of optical and optoelectronic applications. However, their poor stability, especially under strong irradiation, limits their practical use. In this work, we have developed a synthetic route for CsPbBr3/AlOx core/shell structures with near-unity photoluminescence quantum yield and improved photostability. The shell growth is realized through a water-free sol–gel reaction at room temperature. This approach reduces the risks of particle ripening at higher temperatures and of damaging the core nanocrystals during conventional oxide shell formation, which releases water and alcohol as side products. Moreover, the slow kinetics of the reaction allowed control of the shell thickness down to a monolayer. Finally, a nanopatch antenna structure was fabricated using the core/shell nanocrystals sandwiched between a gold surface and silver nanocubes, which led to a more than 2-fold accelerated carrier dynamics of the perovskite nanocrystals showing a fast photoluminescence decay component of 130 ps. These results contribute to the integration of CsPbBr3/AlOx core/shell nanocrystals into optoelectronic devices requiring a high emission rate, such as single-photon emitters.
{"title":"Bright and Photostable Alumina-Coated Perovskite Nanocrystals for Integration into Quantum Emitters","authors":"Tuan M. Duong,Dmitry Aldakov,Wai Li Ling,Le Si Dang,Gilles Nogues,Peter Reiss","doi":"10.1021/acs.jpcc.6c00028","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00028","url":null,"abstract":"Lead halide perovskite nanocrystals, particularly CsPbBr3, are prime candidates for a variety of optical and optoelectronic applications. However, their poor stability, especially under strong irradiation, limits their practical use. In this work, we have developed a synthetic route for CsPbBr3/AlOx core/shell structures with near-unity photoluminescence quantum yield and improved photostability. The shell growth is realized through a water-free sol–gel reaction at room temperature. This approach reduces the risks of particle ripening at higher temperatures and of damaging the core nanocrystals during conventional oxide shell formation, which releases water and alcohol as side products. Moreover, the slow kinetics of the reaction allowed control of the shell thickness down to a monolayer. Finally, a nanopatch antenna structure was fabricated using the core/shell nanocrystals sandwiched between a gold surface and silver nanocubes, which led to a more than 2-fold accelerated carrier dynamics of the perovskite nanocrystals showing a fast photoluminescence decay component of 130 ps. These results contribute to the integration of CsPbBr3/AlOx core/shell nanocrystals into optoelectronic devices requiring a high emission rate, such as single-photon emitters.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"68 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383838","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 : 2026-03-10DOI: 10.1021/acs.jpcc.5c07498
Bach Pham,Natasha W. Pettinger,Bern Kohler
The dynamics of charge carriers formed by UV excitation of few nm CeO2 nanoparticles (nanoceria) were studied by femtosecond transient absorption spectroscopy. Transient absorption bands of photogenerated electrons and holes are spectrally well separated greatly aiding the elucidation of their localization and trapping dynamics. Excitation above the optical band gap forms an electron small polaron (ESP) in the bulk of the nanoparticle and a localized hole at the surface in hundreds of fs. Ultrafast charge separation occurs because holes have much greater mobility than electrons in crystalline CeO2. From the mean first passage time for ESPs to diffuse to the particle surface, an activation barrier of 0.15 eV was determined for thermal hopping. While self-trapped excitons are not formed in the bulk of the nanoparticle, they form easily at the defect-rich surface when exciting below the optical band gap. The resulting surface polaron exciton decays nonradiatively with a half-life of 5 ps. This work offers the insight that the effectiveness of nanoceria, and possibly other metal oxides such as TiO2, as a photocatalyst arises from the self-trapping of just one of the carriers in the nanoparticle interior. It also shows that strategies that extend absorption to longer wavelengths by creating surface defects spoil the asymmetry and will likely not be productive for improving photocatalyst performance.
{"title":"Ultrafast Dynamics of Photogenerated Carriers in Cerium Oxide Nanoparticles","authors":"Bach Pham,Natasha W. Pettinger,Bern Kohler","doi":"10.1021/acs.jpcc.5c07498","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c07498","url":null,"abstract":"The dynamics of charge carriers formed by UV excitation of few nm CeO2 nanoparticles (nanoceria) were studied by femtosecond transient absorption spectroscopy. Transient absorption bands of photogenerated electrons and holes are spectrally well separated greatly aiding the elucidation of their localization and trapping dynamics. Excitation above the optical band gap forms an electron small polaron (ESP) in the bulk of the nanoparticle and a localized hole at the surface in hundreds of fs. Ultrafast charge separation occurs because holes have much greater mobility than electrons in crystalline CeO2. From the mean first passage time for ESPs to diffuse to the particle surface, an activation barrier of 0.15 eV was determined for thermal hopping. While self-trapped excitons are not formed in the bulk of the nanoparticle, they form easily at the defect-rich surface when exciting below the optical band gap. The resulting surface polaron exciton decays nonradiatively with a half-life of 5 ps. This work offers the insight that the effectiveness of nanoceria, and possibly other metal oxides such as TiO2, as a photocatalyst arises from the self-trapping of just one of the carriers in the nanoparticle interior. It also shows that strategies that extend absorption to longer wavelengths by creating surface defects spoil the asymmetry and will likely not be productive for improving photocatalyst performance.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"264 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383834","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 : 2026-03-10DOI: 10.1021/acs.jpcc.5c08242
Filip Vuković,Anna Niggas,Levin Mihlan,Zhen Yao,Armin Gölzhäuser,Louise Fréville,Vladislav Stroganov,Andrey Turchanin,Jürgen Schnack,Nigel A. Marks,Richard A. Wilhelm
Carbon nanomembranes (CNMs) are nanometer-thin disordered carbon materials that are suitable for a range of applications, from energy generation and storage through to water filtration. The structure–property relationships of these nanomembranes are challenging to study using traditional experimental characterization techniques, primarily due to the radiation sensitivity of the free-standing membrane. Highly charged ion spectroscopy is a novel characterization method that is able to infer structural details of the carbon nanomembrane without concern about induced damage affecting the measurements. Here we employ molecular dynamics simulations to produce candidate structural models of terphenylthiol-based CNMs with varying degrees of nanoscale porosity and compare predicted ion charge exchange data and tensile moduli to experiment. The results suggest that the in-vacuum CNM composition likely comprises a significant fraction of under-coordinated carbon, with an open subnanometer porous structure. Such a carbon network would be reactive in the atmosphere and would be presumably stabilized by hydrogen and oxygen groups under atmospheric conditions.
{"title":"Revealing the Innate Subnanometer Porous Structure of Carbon Nanomembranes with Molecular Dynamics Simulations and Highly-Charged Ion Spectroscopy","authors":"Filip Vuković,Anna Niggas,Levin Mihlan,Zhen Yao,Armin Gölzhäuser,Louise Fréville,Vladislav Stroganov,Andrey Turchanin,Jürgen Schnack,Nigel A. Marks,Richard A. Wilhelm","doi":"10.1021/acs.jpcc.5c08242","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08242","url":null,"abstract":"Carbon nanomembranes (CNMs) are nanometer-thin disordered carbon materials that are suitable for a range of applications, from energy generation and storage through to water filtration. The structure–property relationships of these nanomembranes are challenging to study using traditional experimental characterization techniques, primarily due to the radiation sensitivity of the free-standing membrane. Highly charged ion spectroscopy is a novel characterization method that is able to infer structural details of the carbon nanomembrane without concern about induced damage affecting the measurements. Here we employ molecular dynamics simulations to produce candidate structural models of terphenylthiol-based CNMs with varying degrees of nanoscale porosity and compare predicted ion charge exchange data and tensile moduli to experiment. The results suggest that the in-vacuum CNM composition likely comprises a significant fraction of under-coordinated carbon, with an open subnanometer porous structure. Such a carbon network would be reactive in the atmosphere and would be presumably stabilized by hydrogen and oxygen groups under atmospheric conditions.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"14 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383831","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 : 2026-03-10DOI: 10.1021/acs.jpcc.5c07927
Sara T. Gebre,Heungsoo Kim,Daniel C. Ratchford,William A. Maza,Viktoriia E. Babicheva,Evgeniya Lock,Jeffrey C. Owrutsky,Adam D. Dunkelberger
Epsilon near zero (ENZ) materials have potential in various applications such as all-optical switching and quantum information. Materials that support ENZ modes include metamaterials, semiconductors, and transparent conducting oxides (TCOs) like indium tin oxide (ITO). ITO supports an ENZ mode in the near-infrared (IR), giving rise to large nonlinearities and enabling strong optically induced changes in its refractive index. Recently, a perovskite TCO, La-doped BaSnO3 (LBSO) has demonstrated wide tunability of the ENZ wavelength ranging from the near IR to mid-IR regions. In this work, we use a reflective gold layer to access the Ferrell-Berreman (FB) mode of LBSO, a special class of leaky optical mode that occurs at the material’s ENZ wavelength. The FB mode has strong extinction, making it an ideal candidate for reflection modulation. Here, we interrogate the charge carrier dynamics of multiple Au-coated LBSO samples with varying ENZ wavelengths, paying special attention to the tuning behavior of the FB mode. We find that, upon UV excitation, injected charge carriers are long-lived compared to other transparent conducting oxides and that the photoexcited carriers induce strong modulation of the FB mode. This Au-coated LBSO shows promise for infrared optical switching applications, especially those requiring high thermal stability.
{"title":"Active Tuning of the Ferrell-Berreman Mode of La-Doped BaSnO3","authors":"Sara T. Gebre,Heungsoo Kim,Daniel C. Ratchford,William A. Maza,Viktoriia E. Babicheva,Evgeniya Lock,Jeffrey C. Owrutsky,Adam D. Dunkelberger","doi":"10.1021/acs.jpcc.5c07927","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c07927","url":null,"abstract":"Epsilon near zero (ENZ) materials have potential in various applications such as all-optical switching and quantum information. Materials that support ENZ modes include metamaterials, semiconductors, and transparent conducting oxides (TCOs) like indium tin oxide (ITO). ITO supports an ENZ mode in the near-infrared (IR), giving rise to large nonlinearities and enabling strong optically induced changes in its refractive index. Recently, a perovskite TCO, La-doped BaSnO3 (LBSO) has demonstrated wide tunability of the ENZ wavelength ranging from the near IR to mid-IR regions. In this work, we use a reflective gold layer to access the Ferrell-Berreman (FB) mode of LBSO, a special class of leaky optical mode that occurs at the material’s ENZ wavelength. The FB mode has strong extinction, making it an ideal candidate for reflection modulation. Here, we interrogate the charge carrier dynamics of multiple Au-coated LBSO samples with varying ENZ wavelengths, paying special attention to the tuning behavior of the FB mode. We find that, upon UV excitation, injected charge carriers are long-lived compared to other transparent conducting oxides and that the photoexcited carriers induce strong modulation of the FB mode. This Au-coated LBSO shows promise for infrared optical switching applications, especially those requiring high thermal stability.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"16 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383833","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 : 2026-03-10DOI: 10.1021/acs.jpcc.5c08550
Paweł Szabelski
Creation of low-dimensional molecular superstructures using two-in-one building blocks has been recently recognized as a practical alternative to conventional methods based on the self-assembly of binary (or multicomponent) mixtures of simple functional tectons. In this contribution, by means of coarse-grained Monte Carlo modeling, we study the on-surface self-assembly of functional tripod molecules equipped with terminal active centers of two types (1 and 2), providing directional intermolecular interactions. Our studies focus on the effect of preferred homotypic (1–1, 2–2) vs heterotypic (1–2) interaction mode on the structural properties of the resulting assemblies. Moreover, the role of the directionality of interactions on the self-assembly is examined for a complete set of isomers differing in the intramolecular distribution of the active centers. The results of the simulations demonstrate the formation of diverse superstructures, ranging from oligomers to networks, that can be directed by a suitable choice of the interaction mode and the intrinsic properties of a tecton at play. One of the general observations from these calculations is that under the heterotypic interaction mode, the growth of extended ordered molecular structures is greatly hindered, regardless of the type of isomer. The results of our theoretical investigations can be helpful in preliminary screening of molecular libraries to select optimal building blocks for the orthogonal self-assembly of molecular systems with presumed architecture and functions.
{"title":"Orthogonal Self-Assembly of Functional Molecules on Surfaces: Theoretical Modeling of Two-in-One Building Blocks","authors":"Paweł Szabelski","doi":"10.1021/acs.jpcc.5c08550","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08550","url":null,"abstract":"Creation of low-dimensional molecular superstructures using two-in-one building blocks has been recently recognized as a practical alternative to conventional methods based on the self-assembly of binary (or multicomponent) mixtures of simple functional tectons. In this contribution, by means of coarse-grained Monte Carlo modeling, we study the on-surface self-assembly of functional tripod molecules equipped with terminal active centers of two types (1 and 2), providing directional intermolecular interactions. Our studies focus on the effect of preferred homotypic (1–1, 2–2) vs heterotypic (1–2) interaction mode on the structural properties of the resulting assemblies. Moreover, the role of the directionality of interactions on the self-assembly is examined for a complete set of isomers differing in the intramolecular distribution of the active centers. The results of the simulations demonstrate the formation of diverse superstructures, ranging from oligomers to networks, that can be directed by a suitable choice of the interaction mode and the intrinsic properties of a tecton at play. One of the general observations from these calculations is that under the heterotypic interaction mode, the growth of extended ordered molecular structures is greatly hindered, regardless of the type of isomer. The results of our theoretical investigations can be helpful in preliminary screening of molecular libraries to select optimal building blocks for the orthogonal self-assembly of molecular systems with presumed architecture and functions.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"45 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383829","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 : 2026-03-09DOI: 10.1021/acs.jpcc.5c08169
He Dong, Rui Yang, Xiang Yu, Yaping Cui, Sidi Fan
The development of thermal interface materials (TIMs) is pivotal for addressing thermal management challenges in advanced electronic systems. While the aramid nanoribbon (ANR) films exhibit exceptional in-plane thermal conductivity (k∥), their out-of-plane thermal conductivity (k⊥) remains constrained by inherent structural anisotropy. To overcome this limitation, nanodiamond (ND) fillers are incorporated into the ANR matrix. The polydopamine (PDA) surface modification realizes dual-functional interfacial engineering: (i) suppressing ND agglomeration through enhanced electrostatic repulsion to achieve uniform filler dispersion; (ii) forming hydrogen bonds at the interfaces between ANR and ND to reduce interfacial thermal resistance. The ANR/ND@PDA film exhibits a k⊥ of 0.45 W/(m·K) and a k∥ of 16.85 W/(m·K), representing 462.5% and 879.7% increase, respectively, compared to the pristine ANR film. A practical test to assess the performance as a thermal interface material (TIM) is performed by observing light-emitting diode (LED) heat dissipation, highlighting immediate and rapid heat dissipation achieved with the ANR/ND@PDA film. Multiscale simulations, including molecular dynamics (MD) and finite element analysis (FEA), quantitatively investigate the roles of hydrogen-bonded interfacial interactions and uniform filler distribution in facilitating heat transfer. These findings position the ANR/ND@PDA films as high-potential polymer-based TIM candidates for next-generation thermal management applications.
{"title":"Dual-Functional Interfacial Engineering of Aramid-Based Composite Films as High-Performance Thermal Interface Materials","authors":"He Dong, Rui Yang, Xiang Yu, Yaping Cui, Sidi Fan","doi":"10.1021/acs.jpcc.5c08169","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08169","url":null,"abstract":"The development of thermal interface materials (TIMs) is pivotal for addressing thermal management challenges in advanced electronic systems. While the aramid nanoribbon (ANR) films exhibit exceptional in-plane thermal conductivity (<i>k</i><sub>∥</sub>), their out-of-plane thermal conductivity (<i>k</i><sub>⊥</sub>) remains constrained by inherent structural anisotropy. To overcome this limitation, nanodiamond (ND) fillers are incorporated into the ANR matrix. The polydopamine (PDA) surface modification realizes dual-functional interfacial engineering: (i) suppressing ND agglomeration through enhanced electrostatic repulsion to achieve uniform filler dispersion; (ii) forming hydrogen bonds at the interfaces between ANR and ND to reduce interfacial thermal resistance. The ANR/ND@PDA film exhibits a <i>k</i><sub>⊥</sub> of 0.45 W/(m·K) and a <i>k</i><sub>∥</sub> of 16.85 W/(m·K), representing 462.5% and 879.7% increase, respectively, compared to the pristine ANR film. A practical test to assess the performance as a thermal interface material (TIM) is performed by observing light-emitting diode (LED) heat dissipation, highlighting immediate and rapid heat dissipation achieved with the ANR/ND@PDA film. Multiscale simulations, including molecular dynamics (MD) and finite element analysis (FEA), quantitatively investigate the roles of hydrogen-bonded interfacial interactions and uniform filler distribution in facilitating heat transfer. These findings position the ANR/ND@PDA films as high-potential polymer-based TIM candidates for next-generation thermal management applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"45 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147381085","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 : 2026-03-09DOI: 10.1021/acs.jpcc.5c08594
Pablo F. Garcia, Pablo A. Mercadal, Gastón Godoy, Akira Branca, Angel Anzani, Pedro D. Gara, Gabriel Bilmes, Maxi Alberto Burgos Paci, Eduardo A. Coronado
Plasmonic nanoparticles are widely used as contrast agents in photoacoustic (PA) imaging owing to their efficient conversion of optical absorption into acoustic energy. In this work, we investigate the extinction and absorption properties of quasi-linear gold nanoparticle (AuNP) aggregates formed by self-assembly induced by the [Ru(phen)3]2+ complex. Spherical citrate-stabilized AuNPs with an average diameter of 25 ± 5 nm were synthesized and characterized by transmission electron microscopy, UV–Vis spectroscopy, and photoacoustic spectroscopy. Upon addition of [Ru(phen)3]2+, rapid aggregation occurs, giving rise to predominantly one-dimensional quasi-linear chains with controlled interparticle spacing and varying numbers of nanoparticles per aggregate. The aggregation process was monitored in real time by UV–Vis spectroscopy, while the absorption spectra of both isolated AuNPs and aggregates were independently measured using a calibrated photoacoustic setup. Rigorous electrodynamics simulations based on Mie theory and generalized multiparticle Mie theory, incorporating electronic confinement effects and an effective medium description of the nanoparticle environment, were employed to model the optical response. By combining experimental extinction and photoacoustic absorption spectra with theoretical simulations, we developed a quantitative methodology to determine the concentration and size distribution of AuNP aggregates in the colloidal dispersion. Despite their low abundance, larger aggregates were found to dominate the absorption response due to their significantly enhanced cross sections. The proposed approach provides a robust framework for quantitatively assessing the cluster-size composition of plasmonic nanoparticle assemblies and has important implications for the rational design and optimization of photoacoustic contrast agents for biomedical imaging applications.
{"title":"Disentangling the Concentration of Au Nanoparticles Aggregates by Extinction, Photoacoustic Spectroscopy and Electrodynamics Modeling","authors":"Pablo F. Garcia, Pablo A. Mercadal, Gastón Godoy, Akira Branca, Angel Anzani, Pedro D. Gara, Gabriel Bilmes, Maxi Alberto Burgos Paci, Eduardo A. Coronado","doi":"10.1021/acs.jpcc.5c08594","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08594","url":null,"abstract":"Plasmonic nanoparticles are widely used as contrast agents in photoacoustic (PA) imaging owing to their efficient conversion of optical absorption into acoustic energy. In this work, we investigate the extinction and absorption properties of quasi-linear gold nanoparticle (AuNP) aggregates formed by self-assembly induced by the [Ru(phen)<sub>3</sub>]<sup>2+</sup> complex. Spherical citrate-stabilized AuNPs with an average diameter of 25 ± 5 nm were synthesized and characterized by transmission electron microscopy, UV–Vis spectroscopy, and photoacoustic spectroscopy. Upon addition of [Ru(phen)<sub>3</sub>]<sup>2+</sup>, rapid aggregation occurs, giving rise to predominantly one-dimensional quasi-linear chains with controlled interparticle spacing and varying numbers of nanoparticles per aggregate. The aggregation process was monitored in real time by UV–Vis spectroscopy, while the absorption spectra of both isolated AuNPs and aggregates were independently measured using a calibrated photoacoustic setup. Rigorous electrodynamics simulations based on Mie theory and generalized multiparticle Mie theory, incorporating electronic confinement effects and an effective medium description of the nanoparticle environment, were employed to model the optical response. By combining experimental extinction and photoacoustic absorption spectra with theoretical simulations, we developed a quantitative methodology to determine the concentration and size distribution of AuNP aggregates in the colloidal dispersion. Despite their low abundance, larger aggregates were found to dominate the absorption response due to their significantly enhanced cross sections. The proposed approach provides a robust framework for quantitatively assessing the cluster-size composition of plasmonic nanoparticle assemblies and has important implications for the rational design and optimization of photoacoustic contrast agents for biomedical imaging applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"76 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147381100","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 : 2026-03-09DOI: 10.1021/acs.jpcc.5c07465
Ying Liu, Jinbao Wang, Xin Qu
Two-dimensional (2D) intrinsic half-metal materials facilitate spin filtering, low-energy dissipation, and enhanced signal integrity, making them highly desirable for next-generation nanoelectronics and quantum technologies. In this work, we constructed two novel 2D half-metallic materials, α1-ScSi2N4 and α2-ScSi2N4, with unconventional ferromagnetism originating from N atoms rather than the transition metal Sc. First-principles calculations confirm their dynamic and thermal stability, as well as their intrinsic half-metallicity. We further demonstrate that their electronic and optical properties can be effectively tuned via strain, atomic adsorption, and external electric fields. A half-metal-to-metal transition occurs under compressive strain (α1: 10%; α2: 6–10%), while H/F adsorption induces a metallic state in α1, and H adsorption does so in α2. Furthermore, α1 becomes metallic at electric fields of −0.2 to −0.5 V/Å and 0.2 to 0.5 V/Å, while α2 undergoes a similar transition at electric fields of −0.3 to −0.5 V/Å and 0.3 to 0.5 V/Å. Both materials exhibit strong deep-ultraviolet absorption, indicating their potential in optoelectronic applications. Symmetry breaking, charge transfer, and energy level shifting may serve as tunable mechanisms driving the transition from half-metal to metal. These findings not only expand the family of two-dimensional half-metals with nonmetal-dominated magnetism but also potentially open new avenues for the design of tunable magnetic materials in reconfigurable electronic, spintronic, and photonic devices.
{"title":"Half-Metallic 2D ScSi2N4 Phases with Non-metal-Induced Ferromagnetism and Tunable Electronic and Optical Properties","authors":"Ying Liu, Jinbao Wang, Xin Qu","doi":"10.1021/acs.jpcc.5c07465","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c07465","url":null,"abstract":"Two-dimensional (2D) intrinsic half-metal materials facilitate spin filtering, low-energy dissipation, and enhanced signal integrity, making them highly desirable for next-generation nanoelectronics and quantum technologies. In this work, we constructed two novel 2D half-metallic materials, α<sub>1</sub>-ScSi<sub>2</sub>N<sub>4</sub> and α<sub>2</sub>-ScSi<sub>2</sub>N<sub>4</sub>, with unconventional ferromagnetism originating from N atoms rather than the transition metal Sc. First-principles calculations confirm their dynamic and thermal stability, as well as their intrinsic half-metallicity. We further demonstrate that their electronic and optical properties can be effectively tuned via strain, atomic adsorption, and external electric fields. A half-metal-to-metal transition occurs under compressive strain (α<sub>1</sub>: 10%; α<sub>2</sub>: 6–10%), while H/F adsorption induces a metallic state in α<sub>1</sub>, and H adsorption does so in α<sub>2</sub>. Furthermore, α<sub>1</sub> becomes metallic at electric fields of −0.2 to −0.5 V/Å and 0.2 to 0.5 V/Å, while α<sub>2</sub> undergoes a similar transition at electric fields of −0.3 to −0.5 V/Å and 0.3 to 0.5 V/Å. Both materials exhibit strong deep-ultraviolet absorption, indicating their potential in optoelectronic applications. Symmetry breaking, charge transfer, and energy level shifting may serve as tunable mechanisms driving the transition from half-metal to metal. These findings not only expand the family of two-dimensional half-metals with nonmetal-dominated magnetism but also potentially open new avenues for the design of tunable magnetic materials in reconfigurable electronic, spintronic, and photonic devices.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"31 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147381083","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 : 2026-03-09DOI: 10.1021/acs.jpcc.5c07889
Jibo Miao, Wenqing Li
Although the combined use of MoS2 and carbon nanotubes (CNTs) has been known to work as superior anodes for Li+ intercalation/deintercalation, the essential contribution was still blurred provided by the so-called synergistic effects. To make this question clearer, we fabricated coaxial coated CNTs by MoS2 of single- and multiple-layered sheets via a solution-based method implemented by ultrasonic agitation and co-use of the nonionic surfactant polyethylene glycol (PEG400). The synthetic conditions were found as concentrations >2.0 M of the precursor (NH4)2MoS4, a lower ultrasonic power (<500 W), and less ultrasonic treatment time (10–30 min), which yielded hybrids with multiple layers of MoS2-coated CNTs (multi MoS2@CNTs). The lower concentration of (NH4)2MoS4 (0.5–1.0 M) produced monolayer MoS2-coated NTs (mono MoS2@CNTs). The mono MoS2@CNTs were proved to have a reversible capacity >750 mA·h·g–1 for at least 100 cycles, and no decaying of Li+ intercalation/deintercalation capacity was observed. The multi MoS2@CNTs delivered a higher capacity (∼1050 mA·h·g–1) but suffered from a gradual fading in Li+ storage/release capacity. DFT calculations demonstrated that the typical Li+ diffusion energy barrier (0.5 eV) from Oh to Th sites between two sheets of MoS2 constructed in the multi MoS2@CNTs was greatly decreased to 0.20 eV for lithium transfer from H to T sites between the MoS2 sheet and the CNT surface which was constructed in mono MoS2@CNTs. The superior cyclability and high rate of lithiation for the hybrid of MoS2@CNTs were confirmed to stem mainly from the first layer of MoS2 that was conjugated with the sp2 surface of graphene.
{"title":"Essential Contribution of Li+ Intercalation/Deintercalation Afforded by the First Layer of Coaxial Coated MoS2 Sheets on Carbon Nanotubes","authors":"Jibo Miao, Wenqing Li","doi":"10.1021/acs.jpcc.5c07889","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c07889","url":null,"abstract":"Although the combined use of MoS<sub>2</sub> and carbon nanotubes (CNTs) has been known to work as superior anodes for Li<sup>+</sup> intercalation/deintercalation, the essential contribution was still blurred provided by the so-called synergistic effects. To make this question clearer, we fabricated coaxial coated CNTs by MoS<sub>2</sub> of single- and multiple-layered sheets via a solution-based method implemented by ultrasonic agitation and co-use of the nonionic surfactant polyethylene glycol (PEG400). The synthetic conditions were found as concentrations >2.0 M of the precursor (NH<sub>4</sub>)<sub>2</sub>MoS<sub>4</sub>, a lower ultrasonic power (<500 W), and less ultrasonic treatment time (10–30 min), which yielded hybrids with multiple layers of MoS<sub>2</sub>-coated CNTs (multi MoS<sub>2</sub>@CNTs). The lower concentration of (NH<sub>4</sub>)<sub>2</sub>MoS<sub>4</sub> (0.5–1.0 M) produced monolayer MoS<sub>2</sub>-coated NTs (mono MoS<sub>2</sub>@CNTs). The mono MoS<sub>2</sub>@CNTs were proved to have a reversible capacity >750 mA·h·g<sup>–1</sup> for at least 100 cycles, and no decaying of Li<sup>+</sup> intercalation/deintercalation capacity was observed. The multi MoS<sub>2</sub>@CNTs delivered a higher capacity (∼1050 mA·h·g<sup>–1</sup>) but suffered from a gradual fading in Li<sup>+</sup> storage/release capacity. DFT calculations demonstrated that the typical Li<sup>+</sup> diffusion energy barrier (0.5 eV) from Oh to Th sites between two sheets of MoS<sub>2</sub> constructed in the multi MoS<sub>2</sub>@CNTs was greatly decreased to 0.20 eV for lithium transfer from H to T sites between the MoS<sub>2</sub> sheet and the CNT surface which was constructed in mono MoS<sub>2</sub>@CNTs. The superior cyclability and high rate of lithiation for the hybrid of MoS<sub>2</sub>@CNTs were confirmed to stem mainly from the first layer of MoS<sub>2</sub> that was conjugated with the sp<sup>2</sup> surface of graphene.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"263 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147381084","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：