Phase transitions of the ionic liquid (IL) with a bulky cation were investigated at low temperature (LT) and high pressure (HP). The IL studied was trihexyl(tetradecyl)phosphonium hexafluorophosphate, [P666,14][PF6]. Upon cooling of 4.6 K/min, LT α phase was formed at 286 K. In the unit cell, void space was visualized. LT crystallization was influenced slightly by the cooling rate. Under HP, the crystal (α-phase) transformed into a flexible crystal (β phase) at 0.7 GPa by reducing void space. The HP α-β phase transition of [P666,14][PF6] was caused by compression of the void space within the unit cell. During the β phase with drastic volume contraction, the void fraction was almost constant. At 4.1 GPa, the flexible β phase transformed to a rigid ionic liquid crystal. Even at the maximum pressure of 7.2 GPa, a reversible volumetric phase transition was observed in the bulky [P666,14][PF6].
{"title":"Volumetric phase transitions in a bulky ionic liquid: trihexyl(tetradecyl)phosphonium hexafluorophosphate","authors":"Hiroshi Abe , Ryo Suzuki , Akihisa Aimi , Hiroaki Kishimura , Daisuke Okuyama , Hajime Sagayama","doi":"10.1016/j.chemphys.2025.113016","DOIUrl":"10.1016/j.chemphys.2025.113016","url":null,"abstract":"<div><div>Phase transitions of the ionic liquid (IL) with a bulky cation were investigated at low temperature (LT) and high pressure (HP). The IL studied was trihexyl(tetradecyl)phosphonium hexafluorophosphate, [P666,14][PF<sub>6</sub>]. Upon cooling of 4.6 K/min, LT α phase was formed at 286 K. In the unit cell, void space was visualized. LT crystallization was influenced slightly by the cooling rate. Under HP, the crystal (α-phase) transformed into a flexible crystal (β phase) at 0.7 GPa by reducing void space. The HP α-β phase transition of [P666,14][PF<sub>6</sub>] was caused by compression of the void space within the unit cell. During the β phase with drastic volume contraction, the void fraction was almost constant. At 4.1 GPa, the flexible β phase transformed to a rigid ionic liquid crystal. Even at the maximum pressure of 7.2 GPa, a reversible volumetric phase transition was observed in the bulky [P666,14][PF<sub>6</sub>].</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113016"},"PeriodicalIF":2.4,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555176","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 : 2025-11-14DOI: 10.1016/j.chemphys.2025.113028
Konok Chandro Roy , M. Riju Khandaker , M.N.H. Liton , M.M. Rahman , M.S.I. Sarker , M.K.R. Khan
Li2ZnSnO4, belongs to the quaternary (I2 − II − IV − O4) type of semiconductors. It is an essential candidate for solar cells and optoelectronic applications. In this study, our goal is to investigate the structural, electrical, and optical properties of Li2ZnSnO4. These properties are calculated using density functional theory (DFT), based on the first principles computational methods. The optimized lattice constants are found to be a = 5.46, b = 11.41, and c = 8.61 Å, with angle β = 129.0°. Li2ZnSnO4 compound demonstrates mechanical stability through its elastic tensor. It also exhibits soft, malleable, and highly machinable properties with poor elastic anisotropy. Two-dimensional and three-dimensional (2D and 3D) graphical visualizations are used to illustrate the elastic anisotropy. The material's stability is collectively ensured by its bond strength, Debye temperature, melting temperature, and Grüneisen parameter. Mülliken charge and bond analysis indicate a dominant ionic bonding character combined with covalent contributions. Li2ZnSnO4 exhibits a direct bandgap semiconductor with a bandgap energy of 2.01 eV. Various optical properties, such as dielectric response, absorption coefficient, reflectance, refractive index, photoconductivity, and energy loss characteristics have also been studied. The optical absorption coefficient is ∼105 cm−1 in the UV region. The low absorbance and reflectance of Li2ZnSnO4 compound in the infrared-to-visible region is a signature of transparent conducting oxide (TCO). Meeting redox potential conditions, Li2ZnSnO4 is considered as a promising photocatalyst for hydrogen generation and oxygen evolution.
Li2ZnSnO4，属于四元（I2−II−IV−O4）型半导体。它是太阳能电池和光电子应用的重要候选材料。在这项研究中，我们的目标是研究Li2ZnSnO4的结构、电学和光学性质。这些性质是利用密度泛函理论（DFT）计算的，基于第一性原理计算方法。优化后的晶格常数为a = 5.46, b = 11.41, c = 8.61 Å，角β = 129.0°。Li2ZnSnO4化合物通过弹性张量表现出力学稳定性。它还表现出柔软，延展性和高度可加工性能，弹性各向异性差。采用二维和三维（二维和三维）图形可视化来说明弹性各向异性。材料的稳定性由其结合强度、德拜温度、熔化温度和格力尼森参数共同保证。m lliken电荷和键分析表明，主要的离子键特征结合共价贡献。Li2ZnSnO4表现为直接带隙半导体，带隙能量为2.01 eV。各种光学性质，如介电响应、吸收系数、反射率、折射率、光电导率和能量损失特性也进行了研究。在紫外区光学吸收系数为~ 105 cm−1。Li2ZnSnO4化合物在红外-可见光区具有较低的吸光度和反射率，是透明导电氧化物（TCO）的特征。在满足氧化还原电位条件下，Li2ZnSnO4被认为是一种很有前途的产氢析氧光催化剂。
{"title":"First-principles investigation of structural, elastic, electronic, optical and photocatalytic properties of Li2ZnSnO4","authors":"Konok Chandro Roy , M. Riju Khandaker , M.N.H. Liton , M.M. Rahman , M.S.I. Sarker , M.K.R. Khan","doi":"10.1016/j.chemphys.2025.113028","DOIUrl":"10.1016/j.chemphys.2025.113028","url":null,"abstract":"<div><div>Li<sub>2</sub>ZnSnO<sub>4</sub>, belongs to the quaternary (I<sub>2</sub> − II − IV − O<sub>4</sub>) type of semiconductors. It is an essential candidate for solar cells and optoelectronic applications. In this study, our goal is to investigate the structural, electrical, and optical properties of Li<sub>2</sub>ZnSnO<sub>4</sub>. These properties are calculated using density functional theory (DFT), based on the first principles computational methods. The optimized lattice constants are found to be <em>a</em> = 5.46, <em>b</em> = 11.41, and <em>c</em> = 8.61 Å, with angle β = 129.0<sup>°</sup>. Li<sub>2</sub>ZnSnO<sub>4</sub> compound demonstrates mechanical stability through its elastic tensor. It also exhibits soft, malleable, and highly machinable properties with poor elastic anisotropy. Two-dimensional and three-dimensional (2D and 3D) graphical visualizations are used to illustrate the elastic anisotropy. The material's stability is collectively ensured by its bond strength, Debye temperature, melting temperature, and Grüneisen parameter. Mülliken charge and bond analysis indicate a dominant ionic bonding character combined with covalent contributions. Li<sub>2</sub>ZnSnO<sub>4</sub> exhibits a direct bandgap semiconductor with a bandgap energy of 2.01 eV. Various optical properties, such as dielectric response, absorption coefficient, reflectance, refractive index, photoconductivity, and energy loss characteristics have also been studied. The optical absorption coefficient is ∼10<sup>5</sup> cm<sup>−1</sup> in the UV region. The low absorbance and reflectance of Li<sub>2</sub>ZnSnO<sub>4</sub> compound in the infrared-to-visible region is a signature of transparent conducting oxide (TCO). Meeting redox potential conditions, Li<sub>2</sub>ZnSnO<sub>4</sub> is considered as a promising photocatalyst for hydrogen generation and oxygen evolution.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113028"},"PeriodicalIF":2.4,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576687","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 : 2025-11-14DOI: 10.1016/j.chemphys.2025.113029
I. Armenise , F. Esposito , G. Bonasia , G. Micca Longo , S. Longo
The application of multilayer feedforward backpropagation neural network is investigated for the implementation of state-to-state rate coefficients in a chemically reacting air system, which includes excited vibrational states and radicals. An oxygen dissociation reaction is chosen as a case study because of its importance, and also to compare it with a high-end traditional fit in terms of various performances in isolation and within a kinetic model. Different network architectures are experimented and compared, by varying the number of layers and neurons. The indications provided are relevant for practical use of different data implementation techniques in complex kinetic models.
{"title":"Evaluation of neural network in multivariate interpolation of rate coefficients in air kinetics","authors":"I. Armenise , F. Esposito , G. Bonasia , G. Micca Longo , S. Longo","doi":"10.1016/j.chemphys.2025.113029","DOIUrl":"10.1016/j.chemphys.2025.113029","url":null,"abstract":"<div><div>The application of multilayer feedforward backpropagation neural network is investigated for the implementation of state-to-state rate coefficients in a chemically reacting air system, which includes excited vibrational states and radicals. An oxygen dissociation reaction is chosen as a case study because of its importance, and also to compare it with a high-end traditional fit in terms of various performances in isolation and within a kinetic model. Different network architectures are experimented and compared, by varying the number of layers and neurons. The indications provided are relevant for practical use of different data implementation techniques in complex kinetic models.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113029"},"PeriodicalIF":2.4,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576688","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 : 2025-11-13DOI: 10.1016/j.chemphys.2025.113025
Carlos L. Di Prinzio , Luis N. Gerez , Esteban Druetta , Pastor I. Achával , Guillermo G. Aguirre Varela
The temporal evolution of the width of a scratch on the basal plane (0001) of a pure ice single crystal was analyzed under hydrostatic pressures of 0.1 MPa and 10 MPa. The sample was immersed in ultrapure silicone oil at −5 °C to suppress sublimation. A custom-designed pressurized cell enabled the application of controlled hydrostatic pressure, while time-lapse imaging was conducted using an optical microscope equipped with a digital camera. Images of the scratch were acquired at 30-min intervals over a 24-h period. Quantitative analysis of the scratch profiles was performed using image processing software, allowing for the extraction of the time-dependent broadening of the scratch under the specified hydrostatic pressures. From this, the surface self-diffusion coefficient was determined, providing insight into pressure-dependent surface mass transport mechanisms in ice.
{"title":"Surface self-diffusion of ice under high hydrostatic pressure","authors":"Carlos L. Di Prinzio , Luis N. Gerez , Esteban Druetta , Pastor I. Achával , Guillermo G. Aguirre Varela","doi":"10.1016/j.chemphys.2025.113025","DOIUrl":"10.1016/j.chemphys.2025.113025","url":null,"abstract":"<div><div>The temporal evolution of the width of a scratch on the basal plane (0001) of a pure ice single crystal was analyzed under hydrostatic pressures of 0.1 <em>MPa</em> and 10 <em>MPa</em>. The sample was immersed in ultrapure silicone oil at −5 <em>°C</em> to suppress sublimation. A custom-designed pressurized cell enabled the application of controlled hydrostatic pressure, while time-lapse imaging was conducted using an optical microscope equipped with a digital camera. Images of the scratch were acquired at 30-min intervals over a 24-h period. Quantitative analysis of the scratch profiles was performed using image processing software, allowing for the extraction of the time-dependent broadening of the scratch under the specified hydrostatic pressures. From this, the surface self-diffusion coefficient was determined, providing insight into pressure-dependent surface mass transport mechanisms in ice.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113025"},"PeriodicalIF":2.4,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576689","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 : 2025-11-13DOI: 10.1016/j.chemphys.2025.113027
Masato Kondoh , Saya Suzuki, Taka-aki Ishibashi
We investigated the interaction of an antimicrobial peptide, gramicidin A (gA), with supported lipid bilayers (SLBs) at a CaF2/water interface using total internal reflection-Raman spectroscopy. The gA-addition and premixed experiments were performed, monitoring the CH stretching and amide I regions. In the gA-addition experiment, gA was introduced into the aqueous phase after SLB preparation, and resulting spectral changes were monitored. In the premixed experiment, SLBs were formed from lipid-gA mixtures and spectra were measured. At low peptide concentrations in the premixed experiment, the gA-derived component after subtracting the SLB contribution resembled the changes observed in the gA-addition experiment, confirming that these signals originate from gA interacting with the SLB. At higher peptide concentrations, the spectra changed significantly, suggesting structural alterations of gA due to peptide–peptide interactions. These behaviors were consistent with previously reported gA spectra in vesicles, supporting the validity of SLBs as a model for peptide–lipid interactions.
我们利用全内反射-拉曼光谱研究了抗菌肽gramicidin A （gA）与负载脂质双分子层（slb）在CaF2/水界面上的相互作用。进行了ga添加和预混实验，监测了CH拉伸和酰胺I区。在添加gA的实验中，在制备SLB后，将gA引入水相，并监测其光谱变化。在预混合实验中，脂质- ga混合物形成了slb，并测量了光谱。在低肽浓度预混实验中，减去SLB贡献后的gA衍生成分与添加gA实验中观察到的变化相似，证实了这些信号来自gA与SLB相互作用。在较高的肽浓度下，光谱发生显著变化，表明由于肽-肽相互作用导致gA的结构改变。这些行为与先前报道的囊泡中的gA光谱一致，支持slb作为肽-脂质相互作用模型的有效性。
{"title":"Raman spectra of gramicidin A in a supported lipid bilayer at the CaF2/water interface","authors":"Masato Kondoh , Saya Suzuki, Taka-aki Ishibashi","doi":"10.1016/j.chemphys.2025.113027","DOIUrl":"10.1016/j.chemphys.2025.113027","url":null,"abstract":"<div><div>We investigated the interaction of an antimicrobial peptide, gramicidin A (gA), with supported lipid bilayers (SLBs) at a CaF<sub>2</sub>/water interface using total internal reflection-Raman spectroscopy. The gA-addition and premixed experiments were performed, monitoring the CH stretching and amide I regions. In the gA-addition experiment, gA was introduced into the aqueous phase after SLB preparation, and resulting spectral changes were monitored. In the premixed experiment, SLBs were formed from lipid-gA mixtures and spectra were measured. At low peptide concentrations in the premixed experiment, the gA-derived component after subtracting the SLB contribution resembled the changes observed in the gA-addition experiment, confirming that these signals originate from gA interacting with the SLB. At higher peptide concentrations, the spectra changed significantly, suggesting structural alterations of gA due to peptide–peptide interactions. These behaviors were consistent with previously reported gA spectra in vesicles, supporting the validity of SLBs as a model for peptide–lipid interactions.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113027"},"PeriodicalIF":2.4,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571118","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}
The transformation of NO into NH3 (nitric oxide reduction, NORR) provides a potential solution to mitigate NOx emissions and synthesis NH3. To develop catalysts with high catalytic activity and selectivity is still a great challenge. DFT calculations are employed to conduct a thorough investigation into the potential of DACs with a cage-structure on defective graphene for NORR. The results indicate that NO molecule predominantly adsorb onto the catalyst surface in an N-end mode. The stability of the catalyst is confirmed through AIMD simulations, which verify that both homonuclear and heteronuclear bimetallic structures can sustain stable geometric configurations. Upon analyzing the NORR pathways, the N-end enzymatic pathway is the most favorable for the majority of catalysts. Moreover, the investigated DACs catalysts have higher NH3 selectivity than HER. 2Pt@gra catalyst exhibits the lowest limiting potential (−0.07 V) and can effectively suppress the generation of by-products N2, demonstrating superior catalytic performance.
{"title":"Theoretical study of bimetallic catalysts for NO reduction to ammonia on defective graphene","authors":"Wenlong Guo , Xinlin Tang , Shirui Xiao , Xuanjun Shen , Haiyue Liao , Jia Peng , Xin Lian","doi":"10.1016/j.chemphys.2025.113021","DOIUrl":"10.1016/j.chemphys.2025.113021","url":null,"abstract":"<div><div>The transformation of NO into NH<sub>3</sub> (nitric oxide reduction, NORR) provides a potential solution to mitigate NO<sub>x</sub> emissions and synthesis NH<sub>3</sub>. To develop catalysts with high catalytic activity and selectivity is still a great challenge. DFT calculations are employed to conduct a thorough investigation into the potential of DACs with a cage-structure on defective graphene for NORR. The results indicate that NO molecule predominantly adsorb onto the catalyst surface in an N-end mode. The stability of the catalyst is confirmed through AIMD simulations, which verify that both homonuclear and heteronuclear bimetallic structures can sustain stable geometric configurations. Upon analyzing the NORR pathways, the N-end enzymatic pathway is the most favorable for the majority of catalysts. Moreover, the investigated DACs catalysts have higher NH<sub>3</sub> selectivity than HER. 2Pt@gra catalyst exhibits the lowest limiting potential (−0.07 V) and can effectively suppress the generation of by-products N<sub>2</sub>, demonstrating superior catalytic performance.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113021"},"PeriodicalIF":2.4,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526349","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}
The density, structures, dynamical properties and hydrogen bond (HB) dynamics of protic [EtNH3][NO3] and aprotic [Emim][NTF2] ionic liquid mixtures forming {[Emim][NTF2]}x{[EtNH3][NO3]}(1-x) with the molar fraction x = 0.00, 0.25, 0.50, 0.75 and 1.00 have been systematically investigated by using molecular dynamics simulations and a series of ab initio calculations. Our simulation results demonstrate that the studied IL mixtures is a quasi-ideal system, where two positive deviations (x = 0.25 and 0.50) and one negative deviation (x = 0.75) of the excess molar volume are less than 0.18 cm3·mol−1. Further analysis indicates that the translational as well as rotational motions of [Emim]+ and [NTF2]− are restricted significantly with the decreasing the molar fractions. However, for [EtNH3]+ and [NO3]−, they display similar restrictions with the increasing the molar fractions in IL mixtures. Such restrictions can be attributed to the enhanced HB dynamics between [EtNH3]+ and [NO3]− in the IL mixtures. Moreover, the HB strength of [Emim]+-[NTF2]− is enhanced with decreasing molar fractions in the IL mixtures, which can be better explained by the slower translational and rotational motions for [Emim]+ and [NTF₂]− ions. More importantly, the binding energies for above cations and anions ion-pairs were determined by the ab initio calculations, which are in accordance with the MD simulation results. Our simulation results provide a molecular-level understanding the structures and dynamics of protic [EtNH3][NO3] and aprotic [Emim][NTF2] ionic liquid mixtures, and will be a bit favorable to design and synthesis IL mixtures with specific properties.
{"title":"Understanding the structures and dynamics of protic [EtNH3][NO3] and aprotic [Emim][NTF₂] ionic liquid mixtures from molecular dynamics simulation","authors":"Wenshu Liang, Dong Wang, Jia-ni Fan, Guangli Zhou, Qiying Xia, Xia Leng, Yunzhi Li","doi":"10.1016/j.chemphys.2025.113020","DOIUrl":"10.1016/j.chemphys.2025.113020","url":null,"abstract":"<div><div>The density, structures, dynamical properties and hydrogen bond (HB) dynamics of protic [EtNH<sub>3</sub>][NO<sub>3</sub>] and aprotic [Emim][NTF<sub>2</sub>] ionic liquid mixtures forming {[Emim][NTF<sub>2</sub>]}<sub>x</sub>{[EtNH<sub>3</sub>][NO<sub>3</sub>]}<sub>(1-x)</sub> with the molar fraction x = 0.00, 0.25, 0.50, 0.75 and 1.00 have been systematically investigated by using molecular dynamics simulations and a series of ab initio calculations. Our simulation results demonstrate that the studied IL mixtures is a quasi-ideal system, where two positive deviations (x = 0.25 and 0.50) and one negative deviation (x = 0.75) of the excess molar volume are less than 0.18 cm<sup>3</sup>·mol<sup>−1</sup>. Further analysis indicates that the translational as well as rotational motions of [Emim]<sup>+</sup> and [NTF<sub>2</sub>]<sup>−</sup> are restricted significantly with the decreasing the molar fractions. However, for [EtNH<sub>3</sub>]<sup>+</sup> and [NO<sub>3</sub>]<sup>−</sup>, they display similar restrictions with the increasing the molar fractions in IL mixtures. Such restrictions can be attributed to the enhanced HB dynamics between [EtNH<sub>3</sub>]<sup>+</sup> and [NO<sub>3</sub>]<sup>−</sup> in the IL mixtures. Moreover, the HB strength of [Emim]<sup>+</sup>-[NTF<sub>2</sub>]<sup>−</sup> is enhanced with decreasing molar fractions in the IL mixtures, which can be better explained by the slower translational and rotational motions for [Emim]<sup>+</sup> and [NTF₂]<sup>−</sup> ions. More importantly, the binding energies for above cations and anions ion-pairs were determined by the ab initio calculations, which are in accordance with the MD simulation results. Our simulation results provide a molecular-level understanding the structures and dynamics of protic [EtNH<sub>3</sub>][NO<sub>3</sub>] and aprotic [Emim][NTF<sub>2</sub>] ionic liquid mixtures, and will be a bit favorable to design and synthesis IL mixtures with specific properties.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113020"},"PeriodicalIF":2.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526350","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}
NiTe nanorods with varying levels of Molybdenum substitution were grown by a facile hydrothermal process, and their performance as electrocatalysts for hydrogen evolution reaction (HER) was evaluated. The 5% Mo-substituted NiTe was found to have the best performance as HER electrocatalyst with the lowest overpotential among pristine and substituted NiTe. Density functional theory studies further corroborate our experimental findings, showing that an optimum substitution of Mo in NiTe enhances the electrocatalytic property of NiTe. Our findings shed light on the factors determining the optimum substitution levels in electrocatalysts based on transition metal dichalcogenides.
{"title":"Enhanced electrocatalytic activity of optimally Mo-substituted NiTe2 nanorods for hydrogen evolution","authors":"Joyal Sunny , Karuna Sharma , Poonam Moar , Imtiaz Ahmed , Krishna Kanta Haldar , Krishnakanta Mondal , Sourabh Barua","doi":"10.1016/j.chemphys.2025.113018","DOIUrl":"10.1016/j.chemphys.2025.113018","url":null,"abstract":"<div><div>NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> nanorods with varying levels of Molybdenum substitution were grown by a facile hydrothermal process, and their performance as electrocatalysts for hydrogen evolution reaction (HER) was evaluated. The 5% Mo-substituted NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> was found to have the best performance as HER electrocatalyst with the lowest overpotential among pristine and substituted NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. Density functional theory studies further corroborate our experimental findings, showing that an optimum substitution of Mo in NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> enhances the electrocatalytic property of NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. Our findings shed light on the factors determining the optimum substitution levels in electrocatalysts based on transition metal dichalcogenides.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113018"},"PeriodicalIF":2.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576680","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 : 2025-11-10DOI: 10.1016/j.chemphys.2025.113019
K.L. Ngai , Yanhui Zhang , Li-Min Wang , S. Capaccioli
In many studies of the dynamics of glass-forming materials pressure P and temperature T were varied while keeping the structural α-relaxation time τα(T,P) constant. Found generally by experiments and simulations is the frequency dispersion of the α-relaxation, or the exponent βK of its Kohlrausch-Williams-Watts correlation function, remains the same. Moreover, the Johari-Goldstein (JG) β-relaxation time τβ(T,P) is also constant. This remarkable and ubiquitous property of invariance of τα(T,P), βK(T,P), and τβ(T,P) collectively to varying P and T at constant τα(T,P) originates from the inseparable connection between the JGβ relaxation and the α-relaxation as predicted by the Coupling Model. Not considered before in this property is the caged dynamics, which has all molecules confined within cages via the intermolecular potential, and it is the precursor of the JGβ relaxation. The caged dynamics is strongly coupled to the JGβ and α relaxations as indicated by its decay and eventual termination by the onset of the JGβ relaxation, and its change of temperature dependence on crossing the glass transition temperatures Tgβ and Tgα of the JGβ and α relaxations. The strong connections of the caged dynamics to the JGβ and α relaxations suggest it is also invariant to changes of P and T at constant τα(T,P). Collected in this paper are data of caged dynamics from neutron scattering and dielectric relaxation experiments, and molecular dynamics simulations performed at different combinations of P and T at constant τα(T,P). The results clearly verify the invariance of the caged dynamics collectively with τα(T,P), βK(T,P), and τβ(T,P) to variations of P and T at constant τα(T,P). This co-invariance property extended to include the caged dynamics is expected to have repercussion on current research of the dynamics and thermodynamics of glass-forming materials.
{"title":"Co-invariance of caged dynamics with α and β relaxation to variation of temperature and pressure with the α-relaxation time kept constant","authors":"K.L. Ngai , Yanhui Zhang , Li-Min Wang , S. Capaccioli","doi":"10.1016/j.chemphys.2025.113019","DOIUrl":"10.1016/j.chemphys.2025.113019","url":null,"abstract":"<div><div>In many studies of the dynamics of glass-forming materials pressure <em>P</em> and temperature <em>T</em> were varied while keeping the structural α-relaxation time <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>) constant. Found generally by experiments and simulations is the frequency dispersion of the α-relaxation, or the exponent <em>β</em><sub><em>K</em></sub> of its Kohlrausch-Williams-Watts correlation function, remains the same. Moreover, the Johari-Goldstein (JG) <em>β</em>-relaxation time <em>τ</em><sub><em>β</em></sub>(<em>T,P</em>) is also constant. This remarkable and ubiquitous property of invariance of <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>), <em>β</em><sub><em>K</em></sub>(<em>T,P</em>), and <em>τ</em><sub><em>β</em></sub>(<em>T,P</em>) collectively to varying <em>P</em> and <em>T</em> at constant <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>) originates from the inseparable connection between the JG<em>β</em> relaxation and the α-relaxation as predicted by the Coupling Model. Not considered before in this property is the caged dynamics, which has all molecules confined within cages via the intermolecular potential, and it is the precursor of the JG<em>β</em> relaxation. The caged dynamics is strongly coupled to the JGβ and α relaxations as indicated by its decay and eventual termination by the onset of the JGβ relaxation, and its change of temperature dependence on crossing the glass transition temperatures <em>T</em><sub><em>gβ</em></sub> and <em>T</em><sub><em>gα</em></sub> of the JGβ and α relaxations. The strong connections of the caged dynamics to the JGβ and α relaxations suggest it is also invariant to changes of <em>P</em> and <em>T</em> at constant <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>). Collected in this paper are data of caged dynamics from neutron scattering and dielectric relaxation experiments, and molecular dynamics simulations performed at different combinations of <em>P</em> and <em>T</em> at constant <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>). The results clearly verify the invariance of the caged dynamics collectively with <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>), <em>β</em><sub><em>K</em></sub>(<em>T,P</em>), and <em>τ</em><sub><em>β</em></sub>(<em>T,P</em>) to variations of <em>P</em> and <em>T</em> at constant <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>). This co-invariance property extended to include the caged dynamics is expected to have repercussion on current research of the dynamics and thermodynamics of glass-forming materials.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113019"},"PeriodicalIF":2.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526351","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 : 2025-11-10DOI: 10.1016/j.chemphys.2025.113024
Pallavi D. Hambarde, Nitin P. Garad, Ashok C. Kumbharkhane
•
Investigated the dielectric properties and molecular interactions of isopropyl acetate (IPAc) and isoamyl acetate (IAA) with dimethyl sulfoxide (DMSO) binary mixtures using Time Domain Reflectometry (TDR) over 10 MHz–30 GHz.
•
Determined static dielectric constant (ε₀) and relaxation time (τ) by fitting complex permittivity spectra to the Cole–Davidson model with least squares fitting.
•
Evaluated molecular interactions and dielectric relaxation through Bruggeman factor, Kirkwood correlation factor, excess permittivity, and thermodynamic parameters.
•
Revealed structural differences and molecular interactions influenced by chain length and concentration, providing insights into dipole orientation and mixture behavior.
{"title":"Dielectric characterization and thermodynamic analysis of iso-propyl acetate and Iso-amyl acetate with dimethyl sulphoxide binary mixtures using time domain reflectometry","authors":"Pallavi D. Hambarde, Nitin P. Garad, Ashok C. Kumbharkhane","doi":"10.1016/j.chemphys.2025.113024","DOIUrl":"10.1016/j.chemphys.2025.113024","url":null,"abstract":"<div><div><ul><li><span>•</span><span><div>Investigated the dielectric properties and molecular interactions of isopropyl acetate (IPAc) and isoamyl acetate (IAA) with dimethyl sulfoxide (DMSO) binary mixtures using Time Domain Reflectometry (TDR) over 10 MHz–30 GHz.</div></span></li><li><span>•</span><span><div>Determined static dielectric constant (ε₀) and relaxation time (τ) by fitting complex permittivity spectra to the Cole–Davidson model with least squares fitting.</div></span></li><li><span>•</span><span><div>Evaluated molecular interactions and dielectric relaxation through Bruggeman factor, Kirkwood correlation factor, excess permittivity, and thermodynamic parameters.</div></span></li><li><span>•</span><span><div>Revealed structural differences and molecular interactions influenced by chain length and concentration, providing insights into dipole orientation and mixture behavior.</div></span></li></ul></div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113024"},"PeriodicalIF":2.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526392","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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