We propose a new stable three-dimensional (3D) porous and metallic boron nitride anode material, named h-B10N12, with good ductility for the sodium-ion battery (SIB). Based on first-principles calculations and tight-binding model, we demonstrate that the metallicity originates from the synergistic contribution of the p-orbital of the sp2-hybridized B and N atoms, while the ductility is due to the unique configurations of B-B and N-N dimers in the structure. More importantly, this boron nitride allotrope exhibits high reversible capacity of 582.21 mAhg-1 in gravimetric and 663.72 mAhcm-3 in volumetric density, fast Na-ion transport dynamics with low energy barriers ranging from 0.06 to 0.12 eV, a small volume change of 2.77%, and a long cycle-life. This study not only expands the family of conventional boron nitride materials with new features, but also enriches the family of anode materials for SIBs with high-performance.
{"title":"A new 3D metallic, ductile, and porous boron nitride as a promising anode material for sodium-ion battery","authors":"Wei Sun, Qian Wang, Purusottam Jena","doi":"10.1039/d4cp04297b","DOIUrl":"https://doi.org/10.1039/d4cp04297b","url":null,"abstract":"We propose a new stable three-dimensional (3D) porous and metallic boron nitride anode material, named h-B<small><sub>10</sub></small>N<small><sub>12</sub></small>, with good ductility for the sodium-ion battery (SIB). Based on first-principles calculations and tight-binding model, we demonstrate that the metallicity originates from the synergistic contribution of the <em>p</em>-orbital of the <em>sp</em><small><sup>2</sup></small>-hybridized B and N atoms, while the ductility is due to the unique configurations of B-B and N-N dimers in the structure. More importantly, this boron nitride allotrope exhibits high reversible capacity of 582.21 mAhg<small><sup>-1</sup></small> in gravimetric and 663.72 mAhcm<small><sup>-3</sup></small> in volumetric density, fast Na-ion transport dynamics with low energy barriers ranging from 0.06 to 0.12 eV, a small volume change of 2.77%, and a long cycle-life. This study not only expands the family of conventional boron nitride materials with new features, but also enriches the family of anode materials for SIBs with high-performance.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"115 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912133","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}
Elisa Bassotti, Gaio Paradossi, Ester Chiessi, Mark Telling
The dynamics and functionality of proteins are significantly influenced by their interaction with water. For lyophilised (i.e. h ≤ 0.05 where h = g of H2O per g of protein) and weakly hydrated systems (i.e. h ≤ 0.38) hydration generally enhances protein mobility above the so-called ‘dynamical transition’ temperature (Td > 220 K). However, water-induced mobility hindrance at low temperatures (T < 175 K) has been reported in various proteins of varying secondary structure; namely green fluorescent protein (GFP), pig liver esterase, lysozyme, ribonuclease A (RNAse A) and apoferritin. By focussing on the dynamic behaviour of the apoferritin molecule, this study proposes mechanisms driving these hydration-induced mobility changes, particularly the less understood hindrance at low temperatures. Using atomistic molecular dynamics (MD) simulations of horse spleen apoferritin in the lyophilised (h = 0.05) and weakly hydrated (h = 0.31) states, we report here the impact of water on protein dynamics as a function of temperature. Through residue-specific mean squared displacement (MSD), radial distribution function (RDF), solvent accessible surface area (SASA), local hydration degree and hydrogen bonding analyses, we demonstrate that while water proximity directly correlates with mobility enhancement at high temperatures, the hydration-induced mobility reduction observed at temperatures below 175 K is primarily propagated through the protein backbone.
{"title":"Hydration-induced dynamical changes in lyophilised and weakly hydrated apoferritin: insights from molecular dynamics simulation","authors":"Elisa Bassotti, Gaio Paradossi, Ester Chiessi, Mark Telling","doi":"10.1039/d4cp03481c","DOIUrl":"https://doi.org/10.1039/d4cp03481c","url":null,"abstract":"The dynamics and functionality of proteins are significantly influenced by their interaction with water. For lyophilised (<em>i.e. h</em> ≤ 0.05 where <em>h</em> = g of H<small><sub>2</sub></small>O per g of protein) and weakly hydrated systems (<em>i.e. h</em> ≤ 0.38) hydration generally enhances protein mobility above the so-called ‘dynamical transition’ temperature (<em>T</em><small><sub>d</sub></small> > 220 K). However, water-induced mobility hindrance at low temperatures (<em>T</em> < 175 K) has been reported in various proteins of varying secondary structure; namely green fluorescent protein (GFP), pig liver esterase, lysozyme, ribonuclease A (RNAse A) and apoferritin. By focussing on the dynamic behaviour of the apoferritin molecule, this study proposes mechanisms driving these hydration-induced mobility changes, particularly the less understood hindrance at low temperatures. Using atomistic molecular dynamics (MD) simulations of horse spleen apoferritin in the lyophilised (<em>h</em> = 0.05) and weakly hydrated (<em>h</em> = 0.31) states, we report here the impact of water on protein dynamics as a function of temperature. Through residue-specific mean squared displacement (MSD), radial distribution function (RDF), solvent accessible surface area (SASA), local hydration degree and hydrogen bonding analyses, we demonstrate that while water proximity directly correlates with mobility enhancement at high temperatures, the hydration-induced mobility reduction observed at temperatures below 175 K is primarily propagated through the protein backbone.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"34 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912165","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}
Exploration for new superconducting or superhard transition-metal borides has attracted extensive interest in the past few decades. In this study, we conducted comprehensive theoretical investigations in scandium-boron binary system by employing structural search method based upon first-principles density functional theory. Among the six predicted superconducting scandium-borides, ScB$_{14}$ (Pm-3) has the highest superconducting transition temperature $T_c$ = 12.3 K and Vickers hardness of 12.6 GPa at the ambient pressure. Superconductor ScB$_4$ (C2/m) has $T_c$ = 3.6 K and high Vickers hardness of 25.5 GPa at the ambient pressure. Our discoveries not only enrich the phase diagram of scandium-borides, but also pave the way for future experimental validations and potential applications of superconducting scandium-borides in industry.
{"title":"Superconductivity and high hardness in scandium-borides under pressure","authors":"Xiangru Tao, Aiqin Yang, Yundi Quan, Peng Zhang","doi":"10.1039/d4cp03740e","DOIUrl":"https://doi.org/10.1039/d4cp03740e","url":null,"abstract":"Exploration for new superconducting or superhard transition-metal borides has attracted extensive interest in the past few decades. In this study, we conducted comprehensive theoretical investigations in scandium-boron binary system by employing structural search method based upon first-principles density functional theory. Among the six predicted superconducting scandium-borides, ScB$_{14}$ (Pm-3) has the highest superconducting transition temperature $T_c$ = 12.3 K and Vickers hardness of 12.6 GPa at the ambient pressure. Superconductor ScB$_4$ (C2/m) has $T_c$ = 3.6 K and high Vickers hardness of 25.5 GPa at the ambient pressure. Our discoveries not only enrich the phase diagram of scandium-borides, but also pave the way for future experimental validations and potential applications of superconducting scandium-borides in industry.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"14 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912169","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}
Solid-state batteries (SSBs) have the potential to fulfil the increasing global energy requirement, outperforming their liquid electrolyte counterparts. However, the progress in SSB development is hindered by the conventional approach of screening solid-state electrolytes (SSEs), which relies on human knowledge, introducing biases and requiring a time-consuming, resource-intensive trial-and-error process. As a result, a wide range of promising Li-containing structures remain unexplored. To accelerate the search for optimal SSE materials, it is crucial to understand the chemical and structural factors that govern ion transport within a crystalline lattice. We utilize logistic regression-based machine learning (ML) to identify and quantify key physio-chemical features influencing ion mobility in NASICON compounds. The dopant-related features that influence the ionic conductivity are further used to design doped SSEs for Li-ion batteries. Our innovative design approach results in NASICON electrolytes with significantly improved migration barriers and ionic conductivity, validated through density functional theory-based calculations. Specifically, this approach successfully identifies two doped SSEs with high ionic conductivity: Li$_{2}$Mg$_{0.5}$Ge$_{1.5}$(PO$_4$)$_3$ and Li$_{1.667}$Y$_{0.667}$Ge$_{1.333}$(PO$_4$)$_3$. Li$_{2}$Mg$_{0.5}$Ge$_{1.5}$(PO$_4$)$_3$ has the lowest barrier energy of 0.261 eV, surpassing the previously best-known doped material, Li$_{1.5}$Al$_{0.5}$Ge$_{1.5}$(PO$_4$)$_3$ (LAGP), which has a migration barrier of 0.37 eV. Additionally, Li$_{1.667}$Y$_{0.667}$Ge$_{1.333}$(PO$_4$)$_3$ is identified to have the second-lowest migration barrier height of 0.365 eV. By focusing the training of the machine learning model on a specific class of materials, our approach significantly reduces the time, resources, and size of the dataset required to discover novel materials with targeted properties. This methodology is readily adaptable to the design of materials in various other fields, including catalysis and structural materials.
{"title":"Accelerating Discovery and Design of High-Performance Solid-State Electrolytes: A Machine Learning Approach","authors":"Ram Sewak, Vishnu Sudarsanan, Hemant Kumar","doi":"10.1039/d4cp04043k","DOIUrl":"https://doi.org/10.1039/d4cp04043k","url":null,"abstract":"Solid-state batteries (SSBs) have the potential to fulfil the increasing global energy requirement, outperforming their liquid electrolyte counterparts. However, the progress in SSB development is hindered by the conventional approach of screening solid-state electrolytes (SSEs), which relies on human knowledge, introducing biases and requiring a time-consuming, resource-intensive trial-and-error process. As a result, a wide range of promising Li-containing structures remain unexplored. To accelerate the search for optimal SSE materials, it is crucial to understand the chemical and structural factors that govern ion transport within a crystalline lattice. We utilize logistic regression-based machine learning (ML) to identify and quantify key physio-chemical features influencing ion mobility in NASICON compounds. The dopant-related features that influence the ionic conductivity are further used to design doped SSEs for Li-ion batteries. Our innovative design approach results in NASICON electrolytes with significantly improved migration barriers and ionic conductivity, validated through density functional theory-based calculations. Specifically, this approach successfully identifies two doped SSEs with high ionic conductivity: Li$_{2}$Mg$_{0.5}$Ge$_{1.5}$(PO$_4$)$_3$ and Li$_{1.667}$Y$_{0.667}$Ge$_{1.333}$(PO$_4$)$_3$. Li$_{2}$Mg$_{0.5}$Ge$_{1.5}$(PO$_4$)$_3$ has the lowest barrier energy of 0.261 eV, surpassing the previously best-known doped material, Li$_{1.5}$Al$_{0.5}$Ge$_{1.5}$(PO$_4$)$_3$ (LAGP), which has a migration barrier of 0.37 eV. Additionally, Li$_{1.667}$Y$_{0.667}$Ge$_{1.333}$(PO$_4$)$_3$ is identified to have the second-lowest migration barrier height of 0.365 eV. By focusing the training of the machine learning model on a specific class of materials, our approach significantly reduces the time, resources, and size of the dataset required to discover novel materials with targeted properties. This methodology is readily adaptable to the design of materials in various other fields, including catalysis and structural materials.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"70 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912161","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}
Ternary solar cells have been rapidly developed in the realm of organic solar cells (OSCs). The incorporation of a third component into a cell results in a complicated active layer morphology, and the relation of this morphology to power conversion efficiency remains elusive. In this work, two ternary active layers, B1:Y7 (10 wt%):BO-4Cl and B1:Y7 (50 wt%):BO-4Cl are constructed, and the reasons for the differences in PCE caused by varying the Y7 content are investigated using theoretical calculations. Firstly, four groups of binary complexes (B1:BO-4Cl-10 wt%, B1:BO-4Cl-50 wt%, B1:Y7-10 wt%, B1:Y7-50 wt%) were examined using molecular dynamics simulation and the stacking patterns of the complexes could mainly be categorized into three groups (IC-T, IC-BDT, IC-RHD). The results showed that with an increase of the Y7 content, the proportion of IC-T stacking decreased while IC-BDT stacking increased. Moreover, the properties of each stacking pattern were calculated and IC-T stacking was found to have a greater charge separation coupling and rate, and a smaller interaction energy. With more IC-T stacking, the number of charge transfer (CT) states and CT mechanisms in B1:BO-4Cl-10 wt% and B1:Y7-10 wt% improves the PCE of B1:Y7 (10 wt%):BO-4Cl. For the trimers, a greater number of CT states and CT pathways can also facilitate efficient charge separation in B1:Y7 (10 wt%):BO-4Cl. Additionally, this work provides basic knowledge of the influence that the third component content on cell performance, providing theoretical instruction for experimental work based on Y-series non-fullerene acceptor materials.
{"title":"A theoretical comparison of different third component content in ternary organic solar cells","authors":"Ying Sun, Li-Li Wang, Jin-Hong Han, Hai-Ping Zhou, Qing-Qing Pan, Zhi-Wen Zhao, Xing-Man Liu, Zhong-Min Su","doi":"10.1039/d4cp02120g","DOIUrl":"https://doi.org/10.1039/d4cp02120g","url":null,"abstract":"Ternary solar cells have been rapidly developed in the realm of organic solar cells (OSCs). The incorporation of a third component into a cell results in a complicated active layer morphology, and the relation of this morphology to power conversion efficiency remains elusive. In this work, two ternary active layers, <strong>B1:Y7 (10 wt%):BO-4Cl</strong> and <strong>B1:Y7 (50 wt%):BO-4Cl</strong> are constructed, and the reasons for the differences in PCE caused by varying the <strong>Y7</strong> content are investigated using theoretical calculations. Firstly, four groups of binary complexes (<strong>B1:BO-4Cl-10 wt%</strong>, <strong>B1:BO-4Cl-50 wt%</strong>, <strong>B1:Y7-10 wt%</strong>, <strong>B1:Y7-50 wt%</strong>) were examined using molecular dynamics simulation and the stacking patterns of the complexes could mainly be categorized into three groups (IC-T, IC-BDT, IC-RHD). The results showed that with an increase of the <strong>Y7</strong> content, the proportion of IC-T stacking decreased while IC-BDT stacking increased. Moreover, the properties of each stacking pattern were calculated and IC-T stacking was found to have a greater charge separation coupling and rate, and a smaller interaction energy. With more IC-T stacking, the number of charge transfer (CT) states and CT mechanisms in <strong>B1:BO-4Cl-10 wt%</strong> and <strong>B1:Y7-10 wt%</strong> improves the PCE of <strong>B1:Y7 (10 wt%):BO-4Cl</strong>. For the trimers, a greater number of CT states and CT pathways can also facilitate efficient charge separation in <strong>B1:Y7 (10 wt%):BO-4Cl</strong>. Additionally, this work provides basic knowledge of the influence that the third component content on cell performance, providing theoretical instruction for experimental work based on Y-series non-fullerene acceptor materials.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"36 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912162","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}
Density functional theory has been employed to study Indolo[3,2,1-jk]carbazole donor-based dyes, incorporating one and two units of 2,4-Dimethoxybenzene auxiliary donors. Electrostatic potential analysis highlights the dye with one auxiliary donor (D2) as having highest charge-donating capability. Structural analysis shows auxiliary donors enhance planarity, reduce steric hindrance, and improve π-conjugation. Highest occupied molecular orbital (-6.025 − -5.660 eV) and lowest unoccupied molecular orbital (-2.927 − -2.844 eV) of all dyes support efficient electron injection into the semiconductor and dye regeneration process. Auxiliary donors enhance chemical reactivity parameters, improving suitability of these dyes for dye-sensitized solar cells (DSSCs). Inclusion of extra donors reduces excitonic binding energy, minimizing recombination losses, and increases polarization, enhancing charge injection efficiency. Additional analyses explored properties such as charge separation, charge transfer length, transition density matrix and non-covalent interactions. All dyes exhibit strong absorption (410 − 440 nm) in visible region, confirming their applicability to DSSCs, while emission spectra provide insights into their fluorescence lifetimes. D2 demonstrates improved performance in specific properties. However, D3, with two auxiliary donors, achieves the best overall balance across other computed parameters. Indeed, the inclusion of auxiliary donors induces significant changes and may be considered as a valuable strategy for designing efficient DSSCs.
{"title":"A study on indolo[3,2,1-jk]carbazole donor-based dye-sensitized solar cells and effects from addition of auxiliary donors","authors":"Harkishan Dua, Debolina Paul, Utpal Sarkar","doi":"10.1039/d4cp04701j","DOIUrl":"https://doi.org/10.1039/d4cp04701j","url":null,"abstract":"Density functional theory has been employed to study Indolo[3,2,1-jk]carbazole donor-based dyes, incorporating one and two units of 2,4-Dimethoxybenzene auxiliary donors. Electrostatic potential analysis highlights the dye with one auxiliary donor (D2) as having highest charge-donating capability. Structural analysis shows auxiliary donors enhance planarity, reduce steric hindrance, and improve π-conjugation. Highest occupied molecular orbital (-6.025 − -5.660 eV) and lowest unoccupied molecular orbital (-2.927 − -2.844 eV) of all dyes support efficient electron injection into the semiconductor and dye regeneration process. Auxiliary donors enhance chemical reactivity parameters, improving suitability of these dyes for dye-sensitized solar cells (DSSCs). Inclusion of extra donors reduces excitonic binding energy, minimizing recombination losses, and increases polarization, enhancing charge injection efficiency. Additional analyses explored properties such as charge separation, charge transfer length, transition density matrix and non-covalent interactions. All dyes exhibit strong absorption (410 − 440 nm) in visible region, confirming their applicability to DSSCs, while emission spectra provide insights into their fluorescence lifetimes. D2 demonstrates improved performance in specific properties. However, D3, with two auxiliary donors, achieves the best overall balance across other computed parameters. Indeed, the inclusion of auxiliary donors induces significant changes and may be considered as a valuable strategy for designing efficient DSSCs.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"4 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912170","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}
To realize the optical transfer of electron spin information, developing a semiconductor layer for efficient transport of spin-polarized electrons to the active layers is necessary. In this study, electron spin transport from a GaAs/Al0.3Ga0.7As superlattice (SL) barrier to In0.5Ga0.5As quantum dots (QDs) is investigated at room temperature through a combination of time-resolved photoluminescence and rate equation analysis, separating the two transport processes from the GaAs layer around the QDs and SL barrier. The electron transport time in the SL increases for a thicker quantum well (QW) of SL due to the weaker wavefunction overlap between adjacent QWs. Additionally, the degree of conservation of spin polarization during transport varies with QW thickness. Rate equation analysis demonstrates an electron transport from SL to QDs while maintaining a high spin polarization for thick QWs. The achieved spin-conserved electron transport can be attributed to the combination of electron transport being sufficiently faster than the spin relaxation in SL and the suppressed spin relaxation in the p-doped GaAs layer capping the QDs. The findings indicate that SL is a promising candidate as an electron spin transport layer for optical spin devices.
{"title":"Room-temperature spin-conserved electron transport to semiconductor quantum dots using a superlattice barrier","authors":"Satoshi Hiura, Saeko Hatakeyama, Mattias Jansson, Junichi Takayama, Irina Buyanova, Weimin Chen, Akihiro Murayama","doi":"10.1039/d4cp03973d","DOIUrl":"https://doi.org/10.1039/d4cp03973d","url":null,"abstract":"To realize the optical transfer of electron spin information, developing a semiconductor layer for efficient transport of spin-polarized electrons to the active layers is necessary. In this study, electron spin transport from a GaAs/Al<small><sub>0.3</sub></small>Ga<small><sub>0.7</sub></small>As superlattice (SL) barrier to In<small><sub>0.5</sub></small>Ga<small><sub>0.5</sub></small>As quantum dots (QDs) is investigated at room temperature through a combination of time-resolved photoluminescence and rate equation analysis, separating the two transport processes from the GaAs layer around the QDs and SL barrier. The electron transport time in the SL increases for a thicker quantum well (QW) of SL due to the weaker wavefunction overlap between adjacent QWs. Additionally, the degree of conservation of spin polarization during transport varies with QW thickness. Rate equation analysis demonstrates an electron transport from SL to QDs while maintaining a high spin polarization for thick QWs. The achieved spin-conserved electron transport can be attributed to the combination of electron transport being sufficiently faster than the spin relaxation in SL and the suppressed spin relaxation in the <em>p</em>-doped GaAs layer capping the QDs. The findings indicate that SL is a promising candidate as an electron spin transport layer for optical spin devices.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"36 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912268","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}
An ab initio modelling workflow is used to predict the thermoelectric properties and figure of merit ZT of the lanthanide cobalates LaCoO3, PrCoO3 and NdCoO3 in the orthorhombic Pnma phase with the low-spin magnetic configuration. The LnCoO3 show significantly lower “particle-like” lattice thermal conductivity than the widely-studied SrTiO3, due to lower phonon velocities, and substantial heat transport through glass-like intraband tunnelling. Comparison of the calculations to experimental measurements suggests the p-type electrical properties are significantly degraded by the thermal spin crossover, and materials-engineering strategies to suppress this could yield improved ZT. We also predict that n-doped LnCoO3 could show larger Seebeck coefficients, superior power factors, lower thermal conductivity, and higher ZT than SrTiO3. Our results highlight the exploration of a wider range of perovskite chemistries as a facile route to high-performing oxide thermoelectrics, and identify descriptors that could be used as part of a modelling-based screening approach.
{"title":"Thermoelectric properties of the low-spin lanthanide cobalate perovskites LaCoO3, PrCoO3, and NdCoO3 from first-principles calculations","authors":"Alveena Khan, Joseph Flitcroft, Jonathan Skelton","doi":"10.1039/d4cp04303k","DOIUrl":"https://doi.org/10.1039/d4cp04303k","url":null,"abstract":"An ab initio modelling workflow is used to predict the thermoelectric properties and figure of merit ZT of the lanthanide cobalates LaCoO3, PrCoO3 and NdCoO3 in the orthorhombic Pnma phase with the low-spin magnetic configuration. The LnCoO3 show significantly lower “particle-like” lattice thermal conductivity than the widely-studied SrTiO3, due to lower phonon velocities, and substantial heat transport through glass-like intraband tunnelling. Comparison of the calculations to experimental measurements suggests the p-type electrical properties are significantly degraded by the thermal spin crossover, and materials-engineering strategies to suppress this could yield improved ZT. We also predict that n-doped LnCoO3 could show larger Seebeck coefficients, superior power factors, lower thermal conductivity, and higher ZT than SrTiO3. Our results highlight the exploration of a wider range of perovskite chemistries as a facile route to high-performing oxide thermoelectrics, and identify descriptors that could be used as part of a modelling-based screening approach.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"55 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912134","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}
Molecular dynamics simulations demonstrate that regular conical helices of poly(para-phenylene) (PPP) chains can be constructed inside the confined space of single-walled carbon nanocones (CNCs). The translocation displacement of PPP chain combined with the change of system total potential energy including each energy component and structural parameters of formed conical helix are discussed to deeper explore the microstructure evolution, driving forces and dynamic mechanism. In addition, the influence of chain length, cone angle, temperature, chain number and linked position of benzene rings on the helical encapsulation is further studied. The proposed method may provide a new way for constructing regular conical helices from polymer chains and ultimately applied to electronic nanodevices.
{"title":"Constructing conical helices inside carbon nanocones","authors":"Yuliang Yin, Qinzheng Yu, Hongjin Fu, Yunfang Li","doi":"10.1039/d4cp03149k","DOIUrl":"https://doi.org/10.1039/d4cp03149k","url":null,"abstract":"Molecular dynamics simulations demonstrate that regular conical helices of poly(para-phenylene) (PPP) chains can be constructed inside the confined space of single-walled carbon nanocones (CNCs). The translocation displacement of PPP chain combined with the change of system total potential energy including each energy component and structural parameters of formed conical helix are discussed to deeper explore the microstructure evolution, driving forces and dynamic mechanism. In addition, the influence of chain length, cone angle, temperature, chain number and linked position of benzene rings on the helical encapsulation is further studied. The proposed method may provide a new way for constructing regular conical helices from polymer chains and ultimately applied to electronic nanodevices.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"66 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912138","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}
Monolayer MoS2, a compound in two-dimensional TMDs, exhibits excellent physical and chemical properties due to its sandwich structure, making it widely used in the design of nanodevices. We investigated the impact of GaN substrates on the thermal and electronic properties of monolayer MoS2. The results reveal that the polarity of the GaN substrate significantly affects the thermal conductivity of monolayer MoS2. The surface layer of the GaN substrate can be a Ga layer or an N layer, and in this paper, we investigated the effect of the surface layer type of the GaN substrate on the thermal conductivity of GaN supported monolayer MoS2, and denoted the GaN substrate with a Ga surface layer as Ga-GaN and the GaN substrate with an N surface layer as N-GaN. This reduction is primarily attributed to the enhanced Mo–S antibonding with the Ga-GaN substrate, leading to increased phonon anharmonicity. Notably, while the Ga-GaN substrate has a minimal effect on the electronic properties of MoS2, its impact on reducing thermal conductivity is more pronounced, thereby substantially enhancing the thermoelectric performance of the overlying material. This study provides valuable insights for the application of monolayer MoS2 in thermal management.
{"title":"Effects of GaN substrates of different polarity on the thermal and electronic properties of monolayer MoS2","authors":"Qiaoxi Yu, Feng Tao, Xiaoliang Zhang, Yufei Gao, Dawei Tang","doi":"10.1039/d4cp03803g","DOIUrl":"https://doi.org/10.1039/d4cp03803g","url":null,"abstract":"Monolayer MoS<small><sub>2</sub></small>, a compound in two-dimensional TMDs, exhibits excellent physical and chemical properties due to its sandwich structure, making it widely used in the design of nanodevices. We investigated the impact of GaN substrates on the thermal and electronic properties of monolayer MoS<small><sub>2</sub></small>. The results reveal that the polarity of the GaN substrate significantly affects the thermal conductivity of monolayer MoS<small><sub>2</sub></small>. The surface layer of the GaN substrate can be a Ga layer or an N layer, and in this paper, we investigated the effect of the surface layer type of the GaN substrate on the thermal conductivity of GaN supported monolayer MoS<small><sub>2</sub></small>, and denoted the GaN substrate with a Ga surface layer as Ga-GaN and the GaN substrate with an N surface layer as N-GaN. This reduction is primarily attributed to the enhanced Mo–S antibonding with the Ga-GaN substrate, leading to increased phonon anharmonicity. Notably, while the Ga-GaN substrate has a minimal effect on the electronic properties of MoS<small><sub>2</sub></small>, its impact on reducing thermal conductivity is more pronounced, thereby substantially enhancing the thermoelectric performance of the overlying material. This study provides valuable insights for the application of monolayer MoS<small><sub>2</sub></small> in thermal management.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"81 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912164","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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