Developing superionic conductor (SIC) materials offers a promising pathway to achieving high ionic conductivity in solid-state electrolytes (SSEs). The Li10GeP2S12 (LGPS) family has received significant attention due to its remarkable ionic conductivity among various SIC materials. Ab initio molecular dynamics (AIMD) simulations have been extensively used to explore the diffusion behavior of Li⁺ ions in Li10GeP2S12. These simulations indicate that Li⁺ ions diffuse rapidly along a one-dimensional (1D) chain direction, specifically along the c-axis, a process known as in-channel diffusion. In addition, these computational studies have identified additional diffusion pathways within the ab planes, referred to as in-plane diffusion. However, there are still notable limitations in the time scale associated with AIMD simulation techniques for studying the dynamic behavior of Li10GeP2S12 at room temperature. In this study, we trained a deep potential (DP) model for the LGPS system and performed a 300-nanosecond DeePMD simulation to investigate the diffusion behavior of Li10GeP2S12 at room temperature. The neural network (NN) assistedsimulation showed that the framework structure of LGPS remained remarkably stable over the entire 300-nanosecond period. Following this, our investigation focused on the 2D diffusion pathways within the ab plane (in-plane diffusion mechanism) and the 1D diffusion channel along the c-axis (in-channel diffusion mechanism). Upon analyzing the DeePMD simulation results, we identified two distinct pathways for in-plane Li⁺ diffusion within the ab plane: the Li-2 and Li-4 pathways. We determined the energy barriers for the two diffusion pathways to be 0.23 eV and 0.34 eV, respectively, in qualitative agreement with recent experimental and theoretical results. For the in-channel diffusion along the c-axis, our calculated energy barrier was approximately 0.083 eV, closely matching the previous one-particle potential (OPP) analysis. Our results confirm experimental and theoretical studies, indicating that lithium ions experience significantly less resistance when diffusing through the in-channel pathway compared to the in-plane migration mechanism. However, our findings suggest that despite having a higher energy barrier than the Li-4 pathway, the Li-2 pathway remains a viable option for in-plane lithium-ion migration.
{"title":"Revisiting the in-plane and in-channel diffusion of lithium ions in a solid-state electrolyte at room temperature through neural network-assisted molecular dynamics simulations","authors":"Yao Huang, Dan Zhao, Mingsen Deng, Hujun Shen","doi":"10.1039/d4cp04472j","DOIUrl":"https://doi.org/10.1039/d4cp04472j","url":null,"abstract":"Developing superionic conductor (SIC) materials offers a promising pathway to achieving high ionic conductivity in solid-state electrolytes (SSEs). The Li10GeP2S12 (LGPS) family has received significant attention due to its remarkable ionic conductivity among various SIC materials. Ab initio molecular dynamics (AIMD) simulations have been extensively used to explore the diffusion behavior of Li⁺ ions in Li10GeP2S12. These simulations indicate that Li⁺ ions diffuse rapidly along a one-dimensional (1D) chain direction, specifically along the c-axis, a process known as in-channel diffusion. In addition, these computational studies have identified additional diffusion pathways within the ab planes, referred to as in-plane diffusion. However, there are still notable limitations in the time scale associated with AIMD simulation techniques for studying the dynamic behavior of Li10GeP2S12 at room temperature. In this study, we trained a deep potential (DP) model for the LGPS system and performed a 300-nanosecond DeePMD simulation to investigate the diffusion behavior of Li10GeP2S12 at room temperature. The neural network (NN) assistedsimulation showed that the framework structure of LGPS remained remarkably stable over the entire 300-nanosecond period. Following this, our investigation focused on the 2D diffusion pathways within the ab plane (in-plane diffusion mechanism) and the 1D diffusion channel along the c-axis (in-channel diffusion mechanism). Upon analyzing the DeePMD simulation results, we identified two distinct pathways for in-plane Li⁺ diffusion within the ab plane: the Li-2 and Li-4 pathways. We determined the energy barriers for the two diffusion pathways to be 0.23 eV and 0.34 eV, respectively, in qualitative agreement with recent experimental and theoretical results. For the in-channel diffusion along the c-axis, our calculated energy barrier was approximately 0.083 eV, closely matching the previous one-particle potential (OPP) analysis. Our results confirm experimental and theoretical studies, indicating that lithium ions experience significantly less resistance when diffusing through the in-channel pathway compared to the in-plane migration mechanism. However, our findings suggest that despite having a higher energy barrier than the Li-4 pathway, the Li-2 pathway remains a viable option for in-plane lithium-ion migration.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"30 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987407","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}
Sebastián Miranda-Rojas, Néstor Gutiérrez-Sánchez, Carlos Orellana, Kevin Blanco-Esperguez, Sasha Gazzari-Jara, Paulina Sierra-Rosales, Fernando Mendizábal
In this study, we focused on the mechanism of the electrocatalytic oxidation of thiocyanate, which in traditional electrodes typically requires high overpotentials. As models for reducing these overpotentials and catalyzing the reaction, we used a set of modified cobalt phthalocyanines (CoPc), known as electrocatalysts. Using DFT calculations, we explored how modifications to CoPc by adding electron-donating and withdrawing groups and the coordination of 4-amino thiophenol impact the oxidation process. The reaction mechanism for the electrooxidation of thiocyanate has remained elusive, where only the reaction products have been properly identified, including hydrogen cyanide and sulfate ions at pH 4. The approach for understanding the reaction was considering the formation of an (SCN)2 dimer as an intermediate that is a suitable precursor of the products of the reaction. Our findings showed that electron-donating groups and 4-amino thiophenol coordination lowered oxidation potentials, enhancing electrocatalytic efficiency and promoting thiocyanate radical formation and release before dimerization occurs. In contrast, electron-withdrawing groups facilitated dimerization while attached to cobalt, albeit with lower electrocatalytic proficiency. This study highlights the crucial role of CoPc modifications in thiocyanate oxidation, demonstrating the potential for improved electrocatalytic processes through tailored catalyst design.
{"title":"Computational exploration of the electrochemical oxidation mechanism of thiocyanate catalyzed by cobalt-phthalocyanines","authors":"Sebastián Miranda-Rojas, Néstor Gutiérrez-Sánchez, Carlos Orellana, Kevin Blanco-Esperguez, Sasha Gazzari-Jara, Paulina Sierra-Rosales, Fernando Mendizábal","doi":"10.1039/d4cp04256e","DOIUrl":"https://doi.org/10.1039/d4cp04256e","url":null,"abstract":"In this study, we focused on the mechanism of the electrocatalytic oxidation of thiocyanate, which in traditional electrodes typically requires high overpotentials. As models for reducing these overpotentials and catalyzing the reaction, we used a set of modified cobalt phthalocyanines (CoPc), known as electrocatalysts. Using DFT calculations, we explored how modifications to CoPc by adding electron-donating and withdrawing groups and the coordination of 4-amino thiophenol impact the oxidation process. The reaction mechanism for the electrooxidation of thiocyanate has remained elusive, where only the reaction products have been properly identified, including hydrogen cyanide and sulfate ions at pH 4. The approach for understanding the reaction was considering the formation of an (SCN)<small><sub>2</sub></small> dimer as an intermediate that is a suitable precursor of the products of the reaction. Our findings showed that electron-donating groups and 4-amino thiophenol coordination lowered oxidation potentials, enhancing electrocatalytic efficiency and promoting thiocyanate radical formation and release before dimerization occurs. In contrast, electron-withdrawing groups facilitated dimerization while attached to cobalt, albeit with lower electrocatalytic proficiency. This study highlights the crucial role of CoPc modifications in thiocyanate oxidation, demonstrating the potential for improved electrocatalytic processes through tailored catalyst design.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"31 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986251","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}
Huan Zhang, Meijun Yin, Shuangli Du, Yitao Li, Jialiang Bai, Haonan Chai, Jun Ren, Mingji Ding
Photocatalytic reduction of CO2 will play a major role in future energy and environmental crisis. To investigate the adsorption mechanisms of CO2 and H2O molecules involved in the catalytic process on the surface of anatase titanium dioxide 101 (TiO2(101)) and the influence of Au atom doping on their adsorption, first-principles density functional theory calculations were used. The results show that 1. Au atom doping stabilizes the structure of the catalyst system and reduces the band gap, facilitating the reaction of CO2 and H2O molecules. 2. The O site is the most stable adsorption site for the CO2 molecule on the surface, and chemical adsorption occurs, leading to structural deformation during the adsorption process. The adsorption energy is the highest when the H2O molecule is adsorbed parallel to the surface, and there is a bonding trend between H2O and the surface. 3. The adsorption performances of CO2 and H2O molecules improve after Au atom doping. 4. Au atom doping creates stronger adsorption sites on the catalyst surface, with the two-coordinated O atoms near the Au atom becoming the preferred adsorption sites for both molecules. The revealed microscopic mechanism provides theoretical support for the design and manufacture of photocatalytic CO2 reduction catalysts.
{"title":"First-principles study of CO2 and H2O adsorption on the anatase TiO2(101) surface: effect of Au doping","authors":"Huan Zhang, Meijun Yin, Shuangli Du, Yitao Li, Jialiang Bai, Haonan Chai, Jun Ren, Mingji Ding","doi":"10.1039/d4cp03511a","DOIUrl":"https://doi.org/10.1039/d4cp03511a","url":null,"abstract":"Photocatalytic reduction of CO<small><sub>2</sub></small> will play a major role in future energy and environmental crisis. To investigate the adsorption mechanisms of CO<small><sub>2</sub></small> and H<small><sub>2</sub></small>O molecules involved in the catalytic process on the surface of anatase titanium dioxide 101 (TiO<small><sub>2</sub></small>(101)) and the influence of Au atom doping on their adsorption, first-principles density functional theory calculations were used. The results show that 1. Au atom doping stabilizes the structure of the catalyst system and reduces the band gap, facilitating the reaction of CO<small><sub>2</sub></small> and H<small><sub>2</sub></small>O molecules. 2. The O site is the most stable adsorption site for the CO<small><sub>2</sub></small> molecule on the surface, and chemical adsorption occurs, leading to structural deformation during the adsorption process. The adsorption energy is the highest when the H<small><sub>2</sub></small>O molecule is adsorbed parallel to the surface, and there is a bonding trend between H<small><sub>2</sub></small>O and the surface. 3. The adsorption performances of CO<small><sub>2</sub></small> and H<small><sub>2</sub></small>O molecules improve after Au atom doping. 4. Au atom doping creates stronger adsorption sites on the catalyst surface, with the two-coordinated O atoms near the Au atom becoming the preferred adsorption sites for both molecules. The revealed microscopic mechanism provides theoretical support for the design and manufacture of photocatalytic CO<small><sub>2</sub></small> reduction catalysts.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"68 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986252","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}
Meng Tang, Wenyuan Zhang, Guochun Yang, Huiqiu Deng
Two-dimensional (2D) Janus structures with the breaking of out-of-plane mirror symmetry can induce many interesting physical phenomena, and have attracted widespread attention. Herein, we propose a Mo2PS monolayer with mirror asymmetry, identified by first-principles structural search calculations, which demonstrates high thermodynamic and dynamic stability. Our findings reveal that Mo 4d-orbitals dominate the metallicity, significantly enhancing the density of states near the Fermi level due to Van Hove singularities (VHSs), leading to the existence of phonon-mediated superconductivity. Notably, tensile strain elevates the critical temperature (Tc) nearly tenfold, driven by strong coupling between softened acoustic modes of Mo vibrations and a new saddle point VHS at point X. These results highlight that the Janus Mo2PS monolayer serves as a promising candidate for 2D straintronic applications with desirable physical properties.
{"title":"Emergent superconductivity driven by Van Hove singularity in a Janus Mo2PS monolayer","authors":"Meng Tang, Wenyuan Zhang, Guochun Yang, Huiqiu Deng","doi":"10.1039/d4cp04053h","DOIUrl":"https://doi.org/10.1039/d4cp04053h","url":null,"abstract":"Two-dimensional (2D) Janus structures with the breaking of out-of-plane mirror symmetry can induce many interesting physical phenomena, and have attracted widespread attention. Herein, we propose a Mo<small><sub>2</sub></small>PS monolayer with mirror asymmetry, identified by first-principles structural search calculations, which demonstrates high thermodynamic and dynamic stability. Our findings reveal that Mo 4d-orbitals dominate the metallicity, significantly enhancing the density of states near the Fermi level due to Van Hove singularities (VHSs), leading to the existence of phonon-mediated superconductivity. Notably, tensile strain elevates the critical temperature (<em>T</em><small><sub>c</sub></small>) nearly tenfold, driven by strong coupling between softened acoustic modes of Mo vibrations and a new saddle point VHS at point <em>X</em>. These results highlight that the Janus Mo<small><sub>2</sub></small>PS monolayer serves as a promising candidate for 2D straintronic applications with desirable physical properties.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"41 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986253","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}
Huai-Jin Zhang, Yuping Tian, Cui Jiang, Xiangru Kong, Wei-Jiang Gong
In this work, using first-principles calculations,we predict a promising class of two-dimensional ferromagnetic semiconductors, namely Janus PrXY(X≠Y=Cl,Br,I) monolayers. Through first-principles calculations, we found that PrXY monolayers have excellent dynamic and thermal stability, and their band structures, influenced by magnetic exchange and spin-orbital coupling, exhibit significant valley polarization. Between K and −K valleys, the Berry curvature values are opposite to each other, resulting in the anomalous valley Hall effect. In addition, applying moderate biaxial strain can further enhance their magnetic anisotropy energy and valley polarization. These findings do not only emphasize the importance of strain in regulating spin and valley characteristics, but also provide new possibilities for the application of ferromagnetic semiconducting materials in spintronics and valleytronics devices.
{"title":"First-Principles Prediction of Intrinsic Ferrovalley Properties in Janus Rare-Earth PrXY (X≠Y=Cl, Br, I) Monolayers","authors":"Huai-Jin Zhang, Yuping Tian, Cui Jiang, Xiangru Kong, Wei-Jiang Gong","doi":"10.1039/d4cp03519d","DOIUrl":"https://doi.org/10.1039/d4cp03519d","url":null,"abstract":"In this work, using first-principles calculations,we predict a promising class of two-dimensional ferromagnetic semiconductors, namely Janus PrXY(X≠Y=Cl,Br,I) monolayers. Through first-principles calculations, we found that PrXY monolayers have excellent dynamic and thermal stability, and their band structures, influenced by magnetic exchange and spin-orbital coupling, exhibit significant valley polarization. Between K and −K valleys, the Berry curvature values are opposite to each other, resulting in the anomalous valley Hall effect. In addition, applying moderate biaxial strain can further enhance their magnetic anisotropy energy and valley polarization. These findings do not only emphasize the importance of strain in regulating spin and valley characteristics, but also provide new possibilities for the application of ferromagnetic semiconducting materials in spintronics and valleytronics devices.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"77 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986288","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}
Astrid Marthinsen, Bartłomiej A. Gaweł, Anna Górska-Ratusznik, Kamila Gaweł, Gabriela Warden, Marisa Di Sabatino, Benny Hallam
High Purity Quartz glass is an important material in high-tech industry like semiconductors and photovoltaics due to, among other properties, its good mechanical performance at high temperatures. Small amounts of Al in silica glass (in the rage between 20 ppm and 100 ppm) have previously been shown to increase the viscosity of the SiO2 glass. The underlying mechanism for this increase is, however, not well understood. In this paper we report on the local structural and electronic effects of the presence of Al in the SiO2 structure by density functional theory (DFT). Comparing the quartz and cristobalite polymorphs, we find that the driving force for Al substitution is larger in the denser quartz structure compared to cristobalite, and that oxygen vacancy (Vo) formation is most stabilized in a nearest neighbour position relative to Al in both polymorphs. Al is not found to inherently strengthen the SiO2 network in the two crystalline polymorphs considered. However, our results suggest that Al preferentially substitutes Si in denser ring configurations, which combined with local Vo formation could lead to local favourable SiO2 network reconstructions in SiO2 glasses (likely towards 6-membered rings), which could propagate causing an increase in the viscosity. Furthermore, we show that the presence of Al can lower the stability of OH groups due to increased electrostatic interactions between the substitutional Al and H2O which may also be a contributing factor in increased viscosity of Al doped SiO2 glass. The modelling results are in line with the experimental fluorescence and FT-IR spectroscopy data confirming that the presence of Al in the glass causes formation of oxygen vacancies and correlates with lower fictive temperature which typically corresponds to larger average Si-O-Si angle in the glass structure. Our results suggest that Al contribution to high glass viscosity is not solely due to the substitution of Si atoms by Al atom in the glass structure but rather due to structural changes of silica network the substitution causes.
{"title":"Al doped silica glass: investigation of structural response and defects interactions based on crystalline models","authors":"Astrid Marthinsen, Bartłomiej A. Gaweł, Anna Górska-Ratusznik, Kamila Gaweł, Gabriela Warden, Marisa Di Sabatino, Benny Hallam","doi":"10.1039/d4cp04581e","DOIUrl":"https://doi.org/10.1039/d4cp04581e","url":null,"abstract":"High Purity Quartz glass is an important material in high-tech industry like semiconductors and photovoltaics due to, among other properties, its good mechanical performance at high temperatures. Small amounts of Al in silica glass (in the rage between 20 ppm and 100 ppm) have previously been shown to increase the viscosity of the SiO2 glass. The underlying mechanism for this increase is, however, not well understood. In this paper we report on the local structural and electronic effects of the presence of Al in the SiO2 structure by density functional theory (DFT). Comparing the quartz and cristobalite polymorphs, we find that the driving force for Al substitution is larger in the denser quartz structure compared to cristobalite, and that oxygen vacancy (Vo) formation is most stabilized in a nearest neighbour position relative to Al in both polymorphs. Al is not found to inherently strengthen the SiO2 network in the two crystalline polymorphs considered. However, our results suggest that Al preferentially substitutes Si in denser ring configurations, which combined with local Vo formation could lead to local favourable SiO2 network reconstructions in SiO2 glasses (likely towards 6-membered rings), which could propagate causing an increase in the viscosity. Furthermore, we show that the presence of Al can lower the stability of OH groups due to increased electrostatic interactions between the substitutional Al and H2O which may also be a contributing factor in increased viscosity of Al doped SiO2 glass. The modelling results are in line with the experimental fluorescence and FT-IR spectroscopy data confirming that the presence of Al in the glass causes formation of oxygen vacancies and correlates with lower fictive temperature which typically corresponds to larger average Si-O-Si angle in the glass structure. Our results suggest that Al contribution to high glass viscosity is not solely due to the substitution of Si atoms by Al atom in the glass structure but rather due to structural changes of silica network the substitution causes.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"1 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986287","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}
Vincent Peters, Janou Aranka Koskamp, Devis Di Tommaso, Mariette Wolthers
The significance of iron sulphide (FeS) formation extends to "origin of life" theories, industrial applications, and unwanted scale formation. However, the initial stages of FeS nucleation, particularly the impact of solution composition, remain unclear. Often, the iron and sulphide components' stoichiometry in solution differs from that in formed particles. This study uses ab initio methods to computationally examine aqueous FeS prenucleation clusters with excess Fe(II) or S(-II). The results suggest that clusters with additional S(-II) are more likely to form, implying faster nucleation of FeS particles in S(-II)-rich environments compared to Fe(II)-rich ones.
{"title":"Influence of Solution Stoichiometry on the Thermodynamic Stability of Prenucleation FeS Clusters","authors":"Vincent Peters, Janou Aranka Koskamp, Devis Di Tommaso, Mariette Wolthers","doi":"10.1039/d4cp03758h","DOIUrl":"https://doi.org/10.1039/d4cp03758h","url":null,"abstract":"The significance of iron sulphide (FeS) formation extends to \"origin of life\" theories, industrial applications, and unwanted scale formation. However, the initial stages of FeS nucleation, particularly the impact of solution composition, remain unclear. Often, the iron and sulphide components' stoichiometry in solution differs from that in formed particles. This study uses ab initio methods to computationally examine aqueous FeS prenucleation clusters with excess Fe(II) or S(-II). The results suggest that clusters with additional S(-II) are more likely to form, implying faster nucleation of FeS particles in S(-II)-rich environments compared to Fe(II)-rich ones.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"28 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981167","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}
Jia-Ying Li, Rui-Tian Ma, Shi-Qi Zheng, Tian Xia, Hai-Bo Yi
Herein, the interfacial effects on calcium carbonate clustering within two-dimensional (2D) graphene nanochannels were systematically investigated using molecular dynamics simulations. The distribution characteristics of the ions at the interface can be attributed to the ordered water layers within the 2D nanochannels. The orientation of CO32− being approximately perpendicular to the interface can be attributed to hydrogen bonding and its association with Ca2+ at the interface region. Results show that characteristics of CaCO3 clusters can be affected by ion dynamics at the interface and nanoconfinement, although they prefer to locate in the bulk-like region. Due to nanoconfinement, ion dynamics are slowed down, especially in the direction perpendicular to the graphene surface. Due to the distribution and orientation characteristics of CO32− in the interface region, particularly considering the hydration dynamics of Ca2+ and CO32−, the association between Ca2+ and CO32− ions in CaCO3 clusters at the interface can be promoted as Ca2+ move from the interface region to the bulk-like region. The ion dynamics and coordination characteristics of CaCO3 near the interface region within 2D nanochannels facilitate the formation of CaCO3 clusters with highly coordinated Ca2+–CO32− structures, which might favor the nucleation of aragonite. The results provide insight into the effects of nanoconfinement and interfacial water layers on biomineral nucleation and offer theoretical insights into the new preparation methods of novel inorganic functional materials.
{"title":"Microscopic insights into the effects of interfacial dynamics and nanoconfinement on characteristics of calcium carbonate clusters within two-dimensional nanochannels","authors":"Jia-Ying Li, Rui-Tian Ma, Shi-Qi Zheng, Tian Xia, Hai-Bo Yi","doi":"10.1039/d4cp03924f","DOIUrl":"https://doi.org/10.1039/d4cp03924f","url":null,"abstract":"Herein, the interfacial effects on calcium carbonate clustering within two-dimensional (2D) graphene nanochannels were systematically investigated using molecular dynamics simulations. The distribution characteristics of the ions at the interface can be attributed to the ordered water layers within the 2D nanochannels. The orientation of CO32− being approximately perpendicular to the interface can be attributed to hydrogen bonding and its association with Ca2+ at the interface region. Results show that characteristics of CaCO3 clusters can be affected by ion dynamics at the interface and nanoconfinement, although they prefer to locate in the bulk-like region. Due to nanoconfinement, ion dynamics are slowed down, especially in the direction perpendicular to the graphene surface. Due to the distribution and orientation characteristics of CO32− in the interface region, particularly considering the hydration dynamics of Ca2+ and CO32−, the association between Ca2+ and CO32− ions in CaCO3 clusters at the interface can be promoted as Ca2+ move from the interface region to the bulk-like region. The ion dynamics and coordination characteristics of CaCO3 near the interface region within 2D nanochannels facilitate the formation of CaCO3 clusters with highly coordinated Ca2+–CO32− structures, which might favor the nucleation of aragonite. The results provide insight into the effects of nanoconfinement and interfacial water layers on biomineral nucleation and offer theoretical insights into the new preparation methods of novel inorganic functional materials.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"28 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981265","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}
David Santamaria, Raquel Chulia-Jordan, Benedito Donizeti Botan-Neto, Ganesh Bera, Julio Julio Pellicer-Porres, Lkhamsuren Bayarjargal, Alberto Otero-de-la-Roza, Catalin Popescu
Magnesium and calcium carbonate minerals are significant reservoirs of Earth’s carbon and the understanding their behavior under different conditions is crucial for elucidating the mechanisms of deep carbon storage. Huntite, Mg3Ca(CO3)4, is one of the two stable calcium magnesium carbonate phases, together with dolomite. The distinctive cation coordination environment of Ca atoms compared to calcite-type and dolomite structures makes huntite a comparatively less dense phase. Here we examine the behavior of a polycrystalline natural huntite sample under room-temperature compression up to 38 GPa. Synchrotron X-ray diffraction and Raman spectroscopy experiments were carried out in a diamond-anvil cell using He as a highly hydrostatic pressure transmitting medium. XRD results suggest that the initial R32 huntite structure persists up to 21 GPa. The Raman experiment agrees with this result but also suggests the appearance of structural defects from 10 GPa on. Birch-Murnaghan equation of state parameters were fit to the pressure-volume huntite data resulting in zero-pressure volume V0 of 611.7(2) Å3, a bulk modulus B0 of 99.5(11) GPa and a pressure derivative of the bulk modulus of B0′ = 3.51(11). At 21 GPa, huntite transforms to another trigonal phase (R3), designated here as huntite II (Hun-II). This phase persists up to at least 38 GPa, the maximum pressure reached in this study. The major structural differences between huntite and the Hun-II phase involve the tilting of the [CO3] units with respect to the basal plane and a progressive change in the coordination number of the Ca atoms, from 6 to 9. Our experimental study extends the pressure range over which huntite has been examined by a factor of three, providing new insights into the structural response to high-pressure conditions of this magnesium-calcium double carbonate mineral.
{"title":"Pressure-driven phase transformations on Mg3Ca(CO3)4 huntite carbonate","authors":"David Santamaria, Raquel Chulia-Jordan, Benedito Donizeti Botan-Neto, Ganesh Bera, Julio Julio Pellicer-Porres, Lkhamsuren Bayarjargal, Alberto Otero-de-la-Roza, Catalin Popescu","doi":"10.1039/d4cp04200j","DOIUrl":"https://doi.org/10.1039/d4cp04200j","url":null,"abstract":"Magnesium and calcium carbonate minerals are significant reservoirs of Earth’s carbon and the understanding their behavior under different conditions is crucial for elucidating the mechanisms of deep carbon storage. Huntite, Mg<small><sub>3</sub></small>Ca(CO<small><sub>3</sub></small>)<small><sub><small><sub>4</sub></small></sub></small>, is one of the two stable calcium magnesium carbonate phases, together with dolomite. The distinctive cation coordination environment of Ca atoms compared to calcite-type and dolomite structures makes huntite a comparatively less dense phase. Here we examine the behavior of a polycrystalline natural huntite sample under room-temperature compression up to 38 GPa. Synchrotron X-ray diffraction and Raman spectroscopy experiments were carried out in a diamond-anvil cell using He as a highly hydrostatic pressure transmitting medium. XRD results suggest that the initial <em>R</em>32 huntite structure persists up to 21 GPa. The Raman experiment agrees with this result but also suggests the appearance of structural defects from 10 GPa on. Birch-Murnaghan equation of state parameters were fit to the pressure-volume huntite data resulting in zero-pressure volume V<small><sub>0</sub></small> of 611.7(2) Å<small><sup>3</sup></small>, a bulk modulus B<small><sub>0</sub></small> of 99.5(11) GPa and a pressure derivative of the bulk modulus of B<small><sub>0</sub></small>′ = 3.51(11). At 21 GPa, huntite transforms to another trigonal phase (<em><em>R</em></em>3), designated here as huntite II (Hun-II). This phase persists up to at least 38 GPa, the maximum pressure reached in this study. The major structural differences between huntite and the Hun-II phase involve the tilting of the [CO<small><sub>3</sub></small>] units with respect to the basal plane and a progressive change in the coordination number of the Ca atoms, from 6 to 9. Our experimental study extends the pressure range over which huntite has been examined by a factor of three, providing new insights into the structural response to high-pressure conditions of this magnesium-calcium double carbonate mineral.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"7 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981216","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}
Defect engineering is an important means to control material properties. In this paper, large-scale sampling density functional theory (DFT) was used to investigate the adsorption and sensing behavior of NH3 and NO2 on WSe2 monolayer, with focus on the effect of selenium vacancy concentration. Results show that selectivity is inhibited on perfect monolayer due to close adsorption energy of the two gases of NH3 and NO2. While selectivity can be obtained for both of them under different selenium vacancy concentration ( NH3 about 2~5.6%, NO2 about > 8.3%). It is believed that the good match between the unique surface structure of double color (double charged) wave wheel disk like structure of WSe2 monolayer and molecule structure of both the two representative molecules of NH3 and NO2 contributes dominantly to the unusual performance. Results expresses that one material of WSe2 monolayer can perform selective sensing respectively to both NH3 and NO2 just via defects adjusting. And especially, it is precious of the selectivity to NH3 in the mixture of NO2 and NH3. It also provides chances for materials understanding and patterned catalyst design.
{"title":"Selective Sensing of NH3 and NO2 on WSe2 Monolayer based on Defect Concentration Regulation","authors":"Jinghao Zhang, Yunfan Zhang, FengHui Tian, Luxiao Sun, Xiaodong Zhang, Aiping Fu, Mingwei Tian","doi":"10.1039/d4cp04241g","DOIUrl":"https://doi.org/10.1039/d4cp04241g","url":null,"abstract":"Defect engineering is an important means to control material properties. In this paper, large-scale sampling density functional theory (DFT) was used to investigate the adsorption and sensing behavior of NH3 and NO2 on WSe2 monolayer, with focus on the effect of selenium vacancy concentration. Results show that selectivity is inhibited on perfect monolayer due to close adsorption energy of the two gases of NH3 and NO2. While selectivity can be obtained for both of them under different selenium vacancy concentration ( NH3 about 2~5.6%, NO2 about > 8.3%). It is believed that the good match between the unique surface structure of double color (double charged) wave wheel disk like structure of WSe2 monolayer and molecule structure of both the two representative molecules of NH3 and NO2 contributes dominantly to the unusual performance. Results expresses that one material of WSe2 monolayer can perform selective sensing respectively to both NH3 and NO2 just via defects adjusting. And especially, it is precious of the selectivity to NH3 in the mixture of NO2 and NH3. It also provides chances for materials understanding and patterned catalyst design.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"74 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142981268","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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