Pub Date : 2025-12-22DOI: 10.1016/j.chemphys.2025.113072
Xiao-Tian Quan , Wei Zeng , Zheng-Tang Liu , Wen-Guang Li
This study employs Lindemann's melting equation combined with first-principles calculations to predict material melting temperatures. Lindemann's melting law states that melting occurs when atomic thermal amplitudes reach a critical threshold causing chemical bond rupture. Li et al. proposed that melting occurs when the sum of adjacent atomic amplitudes reaches a specific critical value, with atomic amplitudes calculated using the mean square deviation (MSD) method. Using Li's MSD-based melting temperature model, we successfully predicted melting temperatures for a series of transition metal compounds, including covalent compounds such as transition metal nitrides and carbides. This successful prediction demonstrates the model's applicability in covalent systems.
{"title":"Extension of the atomic mean displacement melting model: Calculation of melting temperatures for transition metal carbides, nitrides and other compounds","authors":"Xiao-Tian Quan , Wei Zeng , Zheng-Tang Liu , Wen-Guang Li","doi":"10.1016/j.chemphys.2025.113072","DOIUrl":"10.1016/j.chemphys.2025.113072","url":null,"abstract":"<div><div>This study employs Lindemann's melting equation combined with first-principles calculations to predict material melting temperatures. Lindemann's melting law states that melting occurs when atomic thermal amplitudes reach a critical threshold causing chemical bond rupture. Li et al. proposed that melting occurs when the sum of adjacent atomic amplitudes reaches a specific critical value, with atomic amplitudes calculated using the mean square deviation (MSD) method. Using Li's MSD-based melting temperature model, we successfully predicted melting temperatures for a series of transition metal compounds, including covalent compounds such as transition metal nitrides and carbides. This successful prediction demonstrates the model's applicability in covalent systems.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113072"},"PeriodicalIF":2.4,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836594","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 : 2025-12-21DOI: 10.1016/j.chemphys.2025.113068
K.K. Purushothaman , B. Sethuraman , K. Karthikeyan , A. John Samuel , Sasikumar Moorthy , K. Jeyalakshmi
The development of high-power and high-energy supercapacitors (SCs) has long been pursued for use in transportation and energy storage systems. However, maintaining high rate performance, especially in integrated electrodes, is still challenging. In this work, we report a facile method to synthesize interconnected, flower-like and porous Co-doped NiO/MWCNT nanostructure. Benefiting from the synergistic effects of Co doping and MWCNT incorporation, the as-prepared electrode achieves a maximum specific capacitance of 1855 F g−1 at a current density of 1 A g−1 with the good cycling stability. Furthermore, the Dunn and Trasatti methods were employed to quantify the charge-storage contributions from surface-controlled and diffusion-controlled processes. An asymmetric supercapacitor (Co-doped NiO-MWCNT//rGO) achieves an energy density of 12.7 Wh kg−1 at a current density of 1 A g−1 and a maximum power density of 1246.5 W kg−1 at 5 A g−1.
大功率高能超级电容器（SCs）在交通运输和储能系统中的应用一直是人们追求的目标。然而，保持高速率性能，特别是集成电极，仍然具有挑战性。在这项工作中，我们报告了一种简单的方法来合成互连，花状和多孔共掺杂NiO/MWCNT纳米结构。得益于Co掺杂和MWCNT掺入的协同效应，所制备的电极在电流密度为1 a g−1时的最大比电容为1855 F g−1，并且具有良好的循环稳定性。此外，Dunn和Trasatti方法被用来量化表面控制和扩散控制过程的电荷存储贡献。非对称超级电容器（共掺杂NiO-MWCNT//rGO）在电流密度为1 a g−1时能量密度为12.7 Wh kg−1，在电流密度为5 a g−1时最大功率密度为1246.5 W kg−1。
{"title":"Cobalt doped NiO/MWCNT hybrid micro flowers for supercapacitor applications","authors":"K.K. Purushothaman , B. Sethuraman , K. Karthikeyan , A. John Samuel , Sasikumar Moorthy , K. Jeyalakshmi","doi":"10.1016/j.chemphys.2025.113068","DOIUrl":"10.1016/j.chemphys.2025.113068","url":null,"abstract":"<div><div>The development of high-power and high-energy supercapacitors (SCs) has long been pursued for use in transportation and energy storage systems. However, maintaining high rate performance, especially in integrated electrodes, is still challenging. In this work, we report a facile method to synthesize interconnected, flower-like and porous Co-doped NiO/MWCNT nanostructure. Benefiting from the synergistic effects of Co doping and MWCNT incorporation, the as-prepared electrode achieves a maximum specific capacitance of 1855 F g<sup>−1</sup> at a current density of 1 A g<sup>−1</sup> with the good cycling stability. Furthermore, the Dunn and Trasatti methods were employed to quantify the charge-storage contributions from surface-controlled and diffusion-controlled processes. An asymmetric supercapacitor (Co-doped NiO-MWCNT//rGO) achieves an energy density of 12.7 Wh kg<sup>−1</sup> at a current density of 1 A g<sup>−1</sup> and a maximum power density of 1246.5 W kg<sup>−1</sup> at 5 A g<sup>−1</sup>.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113068"},"PeriodicalIF":2.4,"publicationDate":"2025-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836593","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 : 2025-12-20DOI: 10.1016/j.chemphys.2025.113070
Asghar Hussain , Muhammad Khuram Shahzad , Muhammad Sagir , Adnan Khalil , Muhammad Bilal Tahir
The serious challenge of the modern era lies in identifying sustainable and cost-effective solutions for energy generation and utilization. Perovskite materials have emerged as a promising avenue to address these issues, offering efficient energy production at affordable costs. This study explores the properties of cubic inorganic perovskites Na2ScCuX6 (X = I, F) using Density Functional Theory (DFT). The investigations employ the ultrasoft pseudopotential plane wave (PW) method combined with the Perdew Burke Ernzerhof (PBE) exchange correlation functional within the Generalized Gradient Approximation (GGA) context. CASTEP code is utilized to analyze the structural, mechanical, electrical, and optical properties of these materials. The structural analysis exposes that these compounds crystallize in a cubic structure with a space group of 225 (Fmm). The formation energies of Na2ScCuF6, and Na2ScCuI6 are calculated to be −2.80 eV, and − 2.17 eV, respectively, while phonon dispersion calculations confirm their thermodynamic stability. The electronic band structure analysis indicates that both compounds exhibit indirect bandgaps, with values of 0.055 eV for Na2ScCuF6, and 1.528 eV for Na2ScCuI6, which means they behave like semiconductors. Mechanical properties, including Pugh's ratio (5.05, 3.47), Poisson's ratio (0.40, 0.37), and anisotropy factors (0.74, 1.74), further confirm the ductile nature of these perovskites. The thermodynamic features, including enthalpy, free energy, entropy, and heat capacity, were evaluated through phonon mode analysis. Based on their optical and thermodynamic performance, pure Na2ScCuF6 and Na2ScCuI6 compounds exhibit promising potential for use in optoelectronic and photovoltaic applications.
{"title":"Computational explorations of Lead-free double perovskite Na2ScCuX6 (X = F, I) compounds for optoelectronics applications","authors":"Asghar Hussain , Muhammad Khuram Shahzad , Muhammad Sagir , Adnan Khalil , Muhammad Bilal Tahir","doi":"10.1016/j.chemphys.2025.113070","DOIUrl":"10.1016/j.chemphys.2025.113070","url":null,"abstract":"<div><div>The serious challenge of the modern era lies in identifying sustainable and cost-effective solutions for energy generation and utilization. Perovskite materials have emerged as a promising avenue to address these issues, offering efficient energy production at affordable costs. This study explores the properties of cubic inorganic perovskites Na<sub>2</sub>ScCuX<sub>6</sub> (X = I, F) using Density Functional Theory (DFT). The investigations employ the ultrasoft pseudopotential plane wave (PW) method combined with the Perdew Burke Ernzerhof (PBE) exchange correlation functional within the Generalized Gradient Approximation (GGA) context. CASTEP code is utilized to analyze the structural, mechanical, electrical, and optical properties of these materials. The structural analysis exposes that these compounds crystallize in a cubic structure with a space group of 225 (Fm<span><math><mover><mn>3</mn><mo>¯</mo></mover></math></span>m). The formation energies of Na<sub>2</sub>ScCuF<sub>6</sub>, and Na<sub>2</sub>ScCuI<sub>6</sub> are calculated to be −2.80 eV, and − 2.17 eV, respectively, while phonon dispersion calculations confirm their thermodynamic stability. The electronic band structure analysis indicates that both compounds exhibit indirect bandgaps, with values of 0.055 eV for Na<sub>2</sub>ScCuF<sub>6</sub>, and 1.528 eV for Na<sub>2</sub>ScCuI<sub>6</sub>, which means they behave like semiconductors. Mechanical properties, including Pugh's ratio (5.05, 3.47), Poisson's ratio (0.40, 0.37), and anisotropy factors (0.74, 1.74), further confirm the ductile nature of these perovskites. The thermodynamic features, including enthalpy, free energy, entropy, and heat capacity, were evaluated through phonon mode analysis. Based on their optical and thermodynamic performance, pure Na<sub>2</sub>ScCuF<sub>6</sub> and Na<sub>2</sub>ScCuI<sub>6</sub> compounds exhibit promising potential for use in optoelectronic and photovoltaic applications.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113070"},"PeriodicalIF":2.4,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836592","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}
Herein, MoO2/C nanocomposites was synthesized in a single-step reduction process using waste plastic polyethene (C₂H₄)ₙ as a carbon source. The effect of supporting carbon content on the oxygen evolution reaction (OER) activity of MoO2 nanoparticles is investigated. The hydrocarbons present in the polyethene acts as reducing agents during synthesis. The synthesized samples are characterized using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The highly conductive supporting carbon acts like a highway for the charge carries between MoO2 nanoparticles. The amount of carbon is optimized to get highest possible activity from the MoO2 nanoparticles. Furthermore, the sample MoO2/C (C3) shows optimal OER performance with a low overpotential of 1.58 V vs RHE at current density of 10 mA cm−2. Chronoamperometry Stability of 18 h shows that all the samples possess good stability under alkaline medium. The amount of supporting carbon plays a crucial role to achieve optimal OER performance from MoO2 nanoparticles.
本文以废塑料聚乙烯（C₂H₄）为碳源，采用一步还原法合成了MoO2/C纳米复合材料。研究了负载碳含量对MoO2纳米颗粒析氧反应活性的影响。聚乙烯中的碳氢化合物在合成过程中起还原剂的作用。利用x射线衍射（XRD）、拉曼光谱（Raman spectroscopy）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和x射线光电子能谱（XPS）对合成的样品进行了表征。高导电性的支撑碳就像MoO2纳米颗粒之间的电荷携带的高速公路。优化了碳的用量，使MoO2纳米颗粒的活性尽可能高。此外，样品MoO2/C （C3）在电流密度为10 mA cm−2时表现出最佳的OER性能，过电位低至1.58 V vs RHE。18h的计时安培稳定性表明，样品在碱性介质中具有良好的稳定性。负载碳的数量对MoO2纳米颗粒获得最佳OER性能起着至关重要的作用。
{"title":"Waste plastic upcycling: MoO₂/C nanocomposites supported on Ni foam for efficient oxygen evolution reaction","authors":"Soubhagya Ranjan Panda , Sanjay Upadhyay , Ruby Priya , Abhishek Chandel , O.P. Pandey","doi":"10.1016/j.chemphys.2025.113071","DOIUrl":"10.1016/j.chemphys.2025.113071","url":null,"abstract":"<div><div>Herein, MoO<sub>2</sub>/C nanocomposites was synthesized in a single-step reduction process using waste plastic polyethene (C₂H₄)<strong>ₙ</strong> as a carbon source. The effect of supporting carbon content on the oxygen evolution reaction (OER) activity of MoO<sub>2</sub> nanoparticles is investigated. The hydrocarbons present in the polyethene acts as reducing agents during synthesis. The synthesized samples are characterized using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The highly conductive supporting carbon acts like a highway for the charge carries between MoO<sub>2</sub> nanoparticles. The amount of carbon is optimized to get highest possible activity from the MoO<sub>2</sub> nanoparticles. Furthermore, the sample MoO<sub>2</sub>/C (C3) shows optimal OER performance with a low overpotential of 1.58 V vs RHE at current density of 10 mA cm<sup>−2</sup>. Chronoamperometry Stability of 18 h shows that all the samples possess good stability under alkaline medium. The amount of supporting carbon plays a crucial role to achieve optimal OER performance from MoO<sub>2</sub> nanoparticles.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113071"},"PeriodicalIF":2.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836596","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 : 2025-12-17DOI: 10.1016/j.chemphys.2025.113064
Ameneh Zarei, Alireza Fattahi
Ionic liquids (ILs) have become a significant area of interest across numerous industrial applications in contemporary settings. Ionic liquids possess distinctive features, including low melting points, low volatility, high electrical conductivity, remarkable chemical stability, and, importantly, low toxicity. These attributes render them particularly advantageous as solvents in green chemistry applications. This study focuses on designing and investigating ionic liquids comprising a cytosine-based cation paired with a range of carboxylate anions, known for their environmentally friendly properties. In developing these ionic liquids, various factors were assessed using quantum calculations, including the energy of the ion-pair arrangement, thermodynamic stability, and other electronic structure characteristics.
Furthermore, the analysis of bulk properties via molecular dynamics simulations addressed hydrogen bonds and the contributions of different interaction energies to the arrangement of ion pairs. Quantum calculations (thermochemical) indicate that all resulting ion pairs are energetically favorable, and hydrogen bonding plays a significant role in their arrangement. The binding energy for the most stable ion pairs (IPs) calculated using the quantum method is −91.41 kcal/mol, whereas the PBSA method, derived from molecular dynamics calculations, yields −82.02 kcal/mol, resulting in a 9.39 % difference. Additionally, the molecular dynamics approach identifies electrostatic interactions as the primary driver of ion-pair arrangement in the designed ILs.
{"title":"Design and computational analysis of cytosine-based ionic liquids for green chemistry applications","authors":"Ameneh Zarei, Alireza Fattahi","doi":"10.1016/j.chemphys.2025.113064","DOIUrl":"10.1016/j.chemphys.2025.113064","url":null,"abstract":"<div><div>Ionic liquids (ILs) have become a significant area of interest across numerous industrial applications in contemporary settings. Ionic liquids possess distinctive features, including low melting points, low volatility, high electrical conductivity, remarkable chemical stability, and, importantly, low toxicity. These attributes render them particularly advantageous as solvents in green chemistry applications. This study focuses on designing and investigating ionic liquids comprising a cytosine-based cation paired with a range of carboxylate anions, known for their environmentally friendly properties. In developing these ionic liquids, various factors were assessed using quantum calculations, including the energy of the ion-pair arrangement, thermodynamic stability, and other electronic structure characteristics.</div><div>Furthermore, the analysis of bulk properties via molecular dynamics simulations addressed hydrogen bonds and the contributions of different interaction energies to the arrangement of ion pairs. Quantum calculations (thermochemical) indicate that all resulting ion pairs are energetically favorable, and hydrogen bonding plays a significant role in their arrangement. The binding energy for the most stable ion pairs (IPs) calculated using the quantum method is −91.41 kcal/mol, whereas the PBSA method, derived from molecular dynamics calculations, yields −82.02 kcal/mol, resulting in a 9.39 % difference. Additionally, the molecular dynamics approach identifies electrostatic interactions as the primary driver of ion-pair arrangement in the designed ILs.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113064"},"PeriodicalIF":2.4,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786515","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 : 2025-12-17DOI: 10.1016/j.chemphys.2025.113069
Anmei Wang , Xiaoyun Wang , Litian Wang
The decomposition mechanism of •OH/O3 with pentabromotoluene (PBT) and pentabromoethylbenzene (PBEB) is investigated using the density functional theory method. The reaction involves the •OH-addition, •OH-abstraction, O3-addition. The optimal initial pathways of PBT and PBEB initiated by •OH are PBT + •OH → IM1–5 + H2O and PBEB + •OH → IM2–7, respectively, with corresponding reaction energy barriers of 45.7 and 40.9 kJ/mol. The optimal initial pathways of PBT and PBEB initiated by O3 are PBT + O3 → TS1–6 (99.6 kJ/mol) → IM1–5 + H2O and PBEB + O3 → TS2–8 (97.6 kJ/mol) → IM2–8, respectively. The total kinetic rate constants for the reactions of •OH/O3 with PBT and PBEB at 298 K are 5.51 × 10−15, 6.63 × 10−14, 1.12 × 10−24, and 2.45 × 10−24 cm3 molecule−1 s−1, respectively. PBT and PBEB can degrade to small molecular products without acute and chronic toxicity during the degradation process.
{"title":"Oxidative degradation of pentabromotoluene and pentabromoethylbenzene in aqueous phase initiated by •OH/O3","authors":"Anmei Wang , Xiaoyun Wang , Litian Wang","doi":"10.1016/j.chemphys.2025.113069","DOIUrl":"10.1016/j.chemphys.2025.113069","url":null,"abstract":"<div><div>The decomposition mechanism of •OH/O<sub>3</sub> with pentabromotoluene (PBT) and pentabromoethylbenzene (PBEB) is investigated using the density functional theory method. The reaction involves the •OH-addition, •OH-abstraction, O<sub>3</sub>-addition. The optimal initial pathways of PBT and PBEB initiated by •OH are PBT + •OH → IM1–5 + H<sub>2</sub>O and PBEB + •OH → IM2–7, respectively, with corresponding reaction energy barriers of 45.7 and 40.9 kJ/mol. The optimal initial pathways of PBT and PBEB initiated by O<sub>3</sub> are PBT + O<sub>3</sub> → TS1–6 (99.6 kJ/mol) → IM1–5 + H<sub>2</sub>O and PBEB + O<sub>3</sub> → TS2–8 (97.6 kJ/mol) → IM2–8, respectively. The total kinetic rate constants for the reactions of •OH/O<sub>3</sub> with PBT and PBEB at 298 K are 5.51 × 10<sup>−15</sup>, 6.63 × 10<sup>−14</sup>, 1.12 × 10<sup>−24</sup>, and 2.45 × 10<sup>−24</sup> cm<sup>3</sup> molecule<sup>−1</sup> s<sup>−1</sup>, respectively. PBT and PBEB can degrade to small molecular products without acute and chronic toxicity during the degradation process.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113069"},"PeriodicalIF":2.4,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836597","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 : 2025-12-16DOI: 10.1016/j.chemphys.2025.113058
Monika Srivastava, Anurag Srivastava
The copper-functionalized boron/nitrogen-substituted graphene (Cu-decorated BG/NG) has been theoretically modeled and analyzed as a nanosensor for green-house gas-CO2 detection via density functional theory (DFT). The calculated structural parameters, adsorption energy, and binding distance elucidate the structural evolution of the modeled sheets in the presence of CO2. The observations confirm that the CO2 is chemisorbed on the cu-decorated NG nanosheets, as evidenced by the plotted electron difference density plots. Further, electronic properties, including Bader charge transfer, band gap, density of states (DOS), and projected density of states (PDOS), were examined to assess the impact of CO2 adsorption, reveals variation in the electronic properties which reflect corresponding change in the conductance of the nanosheets. Finally, the key sensing parameters such as the response of the device and desorption time have been intended, concludes that the Cu-decorated NG sheet exhibits 23% higher sensitivity and a faster desorption time ∼25.8 ms compared to Cu-decorated BG sheet at room temperature.
{"title":"DFT investigations of CO2 adsorbed Cu decorated boron and nitrogen doped graphene","authors":"Monika Srivastava, Anurag Srivastava","doi":"10.1016/j.chemphys.2025.113058","DOIUrl":"10.1016/j.chemphys.2025.113058","url":null,"abstract":"<div><div>The copper-functionalized boron/nitrogen-substituted graphene (Cu-decorated BG/NG) has been theoretically modeled and analyzed as a nanosensor for green-house gas-CO<sub>2</sub> detection via density functional theory (DFT). The calculated structural parameters, adsorption energy, and binding distance elucidate the structural evolution of the modeled sheets in the presence of CO<sub>2</sub>. The observations confirm that the CO<sub>2</sub> is chemisorbed on the cu-decorated NG nanosheets, as evidenced by the plotted electron difference density plots. Further, electronic properties, including Bader charge transfer, band gap, density of states (DOS), and projected density of states (PDOS), were examined to assess the impact of CO<sub>2</sub> adsorption, reveals variation in the electronic properties which reflect corresponding change in the conductance of the nanosheets. Finally, the key sensing parameters such as the response of the device and desorption time have been intended, concludes that the Cu-decorated NG sheet exhibits 23% higher sensitivity and a faster desorption time ∼25.8 ms compared to Cu-decorated BG sheet at room temperature.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113058"},"PeriodicalIF":2.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786462","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 : 2025-12-16DOI: 10.1016/j.chemphys.2025.113065
Yu Zhang, Zheng-Hua He, Guang-Fu Ji
The dynamic evolution process of carbon products critically influences the reaction behaviors of energetic materials, but is not well understood yet. Here, we employ long-timescale reactive molecular dynamics simulations to investigate the carbon clusters involved in thermal decomposition of β-HMX. The microscopic structure evolution of carbon products and the concurrent heteroatom releases are systematically investigated under varying conditions. Elevated temperature promotes the generation of N2, H2O, and CO2 (at 1 GPa), while high pressure suppresses CO2 formation and facilitates carbon aggregation. The oxygen migration is identified as the principal driver for carbon cluster evolution, promoting the formation of sp2-hybridized hexagonal frameworks at high temperatures and pressures, ultimately yielding graphene-like or partially amorphous carbon phases. The five-membered rings play an important role on carbon structure evolution, by coupling with seven- or eight-membered rings and promoting their conversion into more stable six-membered rings.
{"title":"Temporal evolution characteristics of carbon product in β-HMX thermal decomposition: A theoretical study based on ReaxFF-MD simulations","authors":"Yu Zhang, Zheng-Hua He, Guang-Fu Ji","doi":"10.1016/j.chemphys.2025.113065","DOIUrl":"10.1016/j.chemphys.2025.113065","url":null,"abstract":"<div><div>The dynamic evolution process of carbon products critically influences the reaction behaviors of energetic materials, but is not well understood yet. Here, we employ long-timescale reactive molecular dynamics simulations to investigate the carbon clusters involved in thermal decomposition of β-HMX. The microscopic structure evolution of carbon products and the concurrent heteroatom releases are systematically investigated under varying conditions. Elevated temperature promotes the generation of N<sub>2</sub>, H<sub>2</sub>O, and CO<sub>2</sub> (at 1 GPa), while high pressure suppresses CO<sub>2</sub> formation and facilitates carbon aggregation. The oxygen migration is identified as the principal driver for carbon cluster evolution, promoting the formation of sp<sup>2</sup>-hybridized hexagonal frameworks at high temperatures and pressures, ultimately yielding graphene-like or partially amorphous carbon phases. The five-membered rings play an important role on carbon structure evolution, by coupling with seven- or eight-membered rings and promoting their conversion into more stable six-membered rings.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113065"},"PeriodicalIF":2.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786512","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 : 2025-12-16DOI: 10.1016/j.chemphys.2025.113067
Vladimir P. Zhdanov
Herein, the kinetics of Ostwald ripening of supported metal nanoparticles (MNPs) made of two miscible metals is scrutinized theoretically. The whole process is treated as the interplay of two channels including rapid support-mediated redistribution of atoms with smaller sublimation energy and slow redistribution of atoms with larger sublimation energy, so that the growth of the average MNP size is related primarily to the latter channel. The equation derived for this size is similar to that for MNPs made of pure metals and can be easily integrated and employed in applications. The corresponding activation energies and specific surface free energies depend on the alloy composition, and the analysis proposed allows one to describe this effect. In illustrations, it has been done for MNPs made of typical metals used in heterogeneous catalysis by employing the parameters obtained on the basis of the density functional theory.
{"title":"Basics of Ostwald ripening of supported metallic alloy nanoparticles","authors":"Vladimir P. Zhdanov","doi":"10.1016/j.chemphys.2025.113067","DOIUrl":"10.1016/j.chemphys.2025.113067","url":null,"abstract":"<div><div>Herein, the kinetics of Ostwald ripening of supported metal nanoparticles (MNPs) made of two miscible metals is scrutinized theoretically. The whole process is treated as the interplay of two channels including rapid support-mediated redistribution of atoms with smaller sublimation energy and slow redistribution of atoms with larger sublimation energy, so that the growth of the average MNP size is related primarily to the latter channel. The equation derived for this size is similar to that for MNPs made of pure metals and can be easily integrated and employed in applications. The corresponding activation energies and specific surface free energies depend on the alloy composition, and the analysis proposed allows one to describe this effect. In illustrations, it has been done for MNPs made of typical metals used in heterogeneous catalysis by employing the parameters obtained on the basis of the density functional theory.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113067"},"PeriodicalIF":2.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786521","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 : 2025-12-16DOI: 10.1016/j.chemphys.2025.113066
Kai Zhang , Guanglu He , Yiquan Wang , Guoliang Chen , Jianjun Fang , Chuan-Kui Wang , Jing Li
Orange-red thermally activated delayed fluorescence (TADF) molecules show great potential for OLEDs. Based on density functional theory (DFT) and the thermal vibration correlation function (TVCF) method, the luminescence mechanisms of the bridged open-ring structure T-DMAC-PPyM and the bridged closed-ring structure P-DMAC-BPyM are investigated in both toluene and the solid state. The fluorescence efficiency (ΦF) of the T-DMAC-PPyM in toluene is slightly higher than that of P-DMAC-BPyM, which is due to the larger radiation rate (kr) and smaller non-radiative decay rate (knr). In contrast, the sharply increased kr of P-DMAC-BPyM in the solid state leads to a much higher ΦF than that of T-DMAC-PPyM. In addition, P-DMAC-BPyM reduces ΔEST in the solid state and increases the spin-orbit coupling (SOC) constant, which is beneficial to improve the reverse intersystem crossing rate (RISC). Studies have shown that T-DMAC-PPyM has better intrinsic fluorescence properties, while P-DMAC-BPyM has better TADF properties in the solid state.
{"title":"Effect of molecular bridging group flexibility on the luminescent properties of Orange-red TADF molecules: A QM/MM study","authors":"Kai Zhang , Guanglu He , Yiquan Wang , Guoliang Chen , Jianjun Fang , Chuan-Kui Wang , Jing Li","doi":"10.1016/j.chemphys.2025.113066","DOIUrl":"10.1016/j.chemphys.2025.113066","url":null,"abstract":"<div><div>Orange-red thermally activated delayed fluorescence (TADF) molecules show great potential for OLEDs. Based on density functional theory (DFT) and the thermal vibration correlation function (TVCF) method, the luminescence mechanisms of the bridged open-ring structure T-DMAC-PPyM and the bridged closed-ring structure P-DMAC-BPyM are investigated in both toluene and the solid state. The fluorescence efficiency (Φ<sub>F</sub>) of the T-DMAC-PPyM in toluene is slightly higher than that of P-DMAC-BPyM, which is due to the larger radiation rate (k<sub>r</sub>) and smaller non-radiative decay rate (k<sub>nr</sub>). In contrast, the sharply increased k<sub>r</sub> of P-DMAC-BPyM in the solid state leads to a much higher Φ<sub>F</sub> than that of T-DMAC-PPyM. In addition, P-DMAC-BPyM reduces ΔE<sub>ST</sub> in the solid state and increases the spin-orbit coupling (SOC) constant, which is beneficial to improve the reverse intersystem crossing rate (RISC). Studies have shown that T-DMAC-PPyM has better intrinsic fluorescence properties, while P-DMAC-BPyM has better TADF properties in the solid state.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113066"},"PeriodicalIF":2.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786513","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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