Electrocatalytic reduction of nitrogen monoxide (NO) to ammonia (NH3) offers a win–win solution for environmental remediation and chemical production. The key to realizing this technology lies in designing catalysts with superior performance. This study employs a combined density functional theory (DFT) and machine learning (ML) approach to systematically screen the nitric oxide reduction reaction (NORR) performance of 26 single-atom catalysts (TM@NiN2, where TM = 3d, 4d, 5d). Through a multi-step screening protocol evaluating stability, NO adsorption, activity, and selectivity, Zn@NiN2 is identified as the most promising candidate, exhibiting an ultra-low limiting potential (UL) of 0 V. ML results reveal that high Qs values and appropriate εd positions jointly determine NORR activity. Electronic structure analysis further reveals hybridization between Zn-3d orbitals and NO-2p orbitals, facilitating donor–acceptor interactions for NO activation. Concurrently, Bader analysis indicates the Zn site acts as an electron transfer mediator, directing electrons from the NiN2 substrate to the reaction intermediate, thereby promoting NORR. To more accurately evaluate the activity of Zn@NiN2, we explicitly consider the effects of solvent, pH, and electrode potential. Under these conditions, it achieves a record-low UL of 0 V (vs. RHE). This work not only identifies an exceptional NORR catalyst but also provides guidelines for the rational development of electrocatalysts for NORR and related electrochemical reactions.
{"title":"Electrochemical NO-to-NH3 conversion on TM@NiN2 single-atom catalysts: a DFT and machine learning investigation","authors":"Fuwei Chen, Yanlong Liu, Nan Xia, Yan Gao","doi":"10.1039/d5cp04918k","DOIUrl":"https://doi.org/10.1039/d5cp04918k","url":null,"abstract":"Electrocatalytic reduction of nitrogen monoxide (NO) to ammonia (NH<small><sub>3</sub></small>) offers a win–win solution for environmental remediation and chemical production. The key to realizing this technology lies in designing catalysts with superior performance. This study employs a combined density functional theory (DFT) and machine learning (ML) approach to systematically screen the nitric oxide reduction reaction (NORR) performance of 26 single-atom catalysts (TM@NiN<small><sub>2</sub></small>, where TM = 3d, 4d, 5d). Through a multi-step screening protocol evaluating stability, NO adsorption, activity, and selectivity, Zn@NiN<small><sub>2</sub></small> is identified as the most promising candidate, exhibiting an ultra-low limiting potential (<em>U</em><small><sub>L</sub></small>) of 0 V. ML results reveal that high <em>Q</em><small><sub>s</sub></small> values and appropriate <em>ε</em><small><sub>d</sub></small> positions jointly determine NORR activity. Electronic structure analysis further reveals hybridization between Zn-3d orbitals and NO-2p orbitals, facilitating donor–acceptor interactions for NO activation. Concurrently, Bader analysis indicates the Zn site acts as an electron transfer mediator, directing electrons from the NiN<small><sub>2</sub></small> substrate to the reaction intermediate, thereby promoting NORR. To more accurately evaluate the activity of Zn@NiN<small><sub>2</sub></small>, we explicitly consider the effects of solvent, pH, and electrode potential. Under these conditions, it achieves a record-low <em>U</em><small><sub>L</sub></small> of 0 V (<em>vs.</em> RHE). This work not only identifies an exceptional NORR catalyst but also provides guidelines for the rational development of electrocatalysts for NORR and related electrochemical reactions.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"11 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098373","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}
Pentalene derivatives were earlier hypothesised to have potential as singlet fission (SF) chromophores, but their function is hampered by both the symmetry-forbidden transition to the first singlet excited state (S1) and the thermal instability due to antiaromatic character in their ground state (S0). A possible benefit is a Baird-aromatic character in the lowest ππ* excited states which may provide for higher photochemical stability than present SF chromophores. In this computational work, we explored different heteroatomic replacements on the pentalene skeleton as well as heteroareno fusions with the aim to identify derivatives with (i) allowed transitions to S1, (ii) reduced antiaromatic character in S0, (iii) highly Baird-aromatic pentalene cores in T1 and S1, and (iv) the SF energy criteria (2 ≤ E(S1)/E(T1) and E(S1) < E(T2)) fulfilled. The results show that the symmetry-forbidden nature of the transition to S1 can be lifted, whilst maintaining excited state Baird-aromatic character providing for photostability. However, there are other drawbacks that impede usage of pentalenes as SF chromophores: (i) the E(S1)/E(T1) ratios when adiabatic S1 states are considered are in nearly all cases well below 2 as the pentalene cores exhibit large relaxation energies in this state (thus, both adiabatic E(S1) and E(T1) must be used for Baird-aromatic SF chromophore candidates), and (ii) competing decay pathways exist due to accessible S1/S0 conical intersections. Hence, the design of pentalene derivatives that are suitable as SF chromophores will be challenging. Still, our findings may pave the way to other related species for which all drawbacks can be avoided.
{"title":"Can Heteroatoms and Heteroareno Annelations Make Pentalenes Suitable as Singlet Fission Chromophores?","authors":"Emil Säbb, Péter József Mayer, Henrik Ottosson","doi":"10.1039/d5cp04492h","DOIUrl":"https://doi.org/10.1039/d5cp04492h","url":null,"abstract":"Pentalene derivatives were earlier hypothesised to have potential as singlet fission (SF) chromophores, but their function is hampered by both the symmetry-forbidden transition to the first singlet excited state (S<small><sub>1</sub></small>) and the thermal instability due to antiaromatic character in their ground state (S<small><sub>0</sub></small>). A possible benefit is a Baird-aromatic character in the lowest ππ* excited states which may provide for higher photochemical stability than present SF chromophores. In this computational work, we explored different heteroatomic replacements on the pentalene skeleton as well as heteroareno fusions with the aim to identify derivatives with (i) allowed transitions to S<small><sub>1</sub></small>, (ii) reduced antiaromatic character in S<small><sub>0</sub></small>, (iii) highly Baird-aromatic pentalene cores in T<small><sub>1</sub></small> and S<small><sub>1</sub></small>, and (iv) the SF energy criteria (2 ≤ E(S<small><sub>1</sub></small>)/E(T<small><sub>1</sub></small>) and E(S<small><sub>1</sub></small>) < E(T<small><sub>2</sub></small>)) fulfilled. The results show that the symmetry-forbidden nature of the transition to S<small><sub>1</sub></small> can be lifted, whilst maintaining excited state Baird-aromatic character providing for photostability. However, there are other drawbacks that impede usage of pentalenes as SF chromophores: (i) the E(S<small><sub>1</sub></small>)/E(T<small><sub>1</sub></small>) ratios when adiabatic S<small><sub>1</sub></small> states are considered are in nearly all cases well below 2 as the pentalene cores exhibit large relaxation energies in this state (thus, both adiabatic E(S<small><sub>1</sub></small>) and E(T<small><sub>1</sub></small>) must be used for Baird-aromatic SF chromophore candidates), and (ii) competing decay pathways exist due to accessible S<small><sub>1</sub></small>/S<small><sub>0</sub></small> conical intersections. Hence, the design of pentalene derivatives that are suitable as SF chromophores will be challenging. Still, our findings may pave the way to other related species for which all drawbacks can be avoided.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"90 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098379","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}
Fluids under nanoscale confinement differ -and often dramatically -from their bulk counterparts. A notorious feature of nanoconfined fluids is their inhomogeneous density profile along the confining dimension, which plays a key role in many fluid structural and transport phenomena in nanopores. Nearly five decades of theoretical efforts on predicting this phenomenon (fluid layering) have shown that its complexity resists purely analytical treatments; as a consequence, nearly all current approaches make extensive use of molecular simulations, and tend not to have generalizable predictive capabilities. In this work, we demonstrate that machine-learning-based models (in particular, a random forest model), trained upon large molecular simulation data sets, can serve as reliable surrogates in lieu of further molecular simulation. We show that this random forest model has excellent interpolative capabilities over a wide range of temperatures and confining lengthscales, and even has modest extrapolative ability. These results provide a promising pathway forward for developing models of nanoconfined fluid properties that are generalizable, lower cost than "pure" molecular simulation, and sufficiently predictive for fluids-in-nanopores practitioners.
{"title":"Fluid Density Regulation under Nanoconfinement Revealed by Machine Learning","authors":"Yuanhao Li","doi":"10.1039/d5cp03804a","DOIUrl":"https://doi.org/10.1039/d5cp03804a","url":null,"abstract":"Fluids under nanoscale confinement differ -and often dramatically -from their bulk counterparts. A notorious feature of nanoconfined fluids is their inhomogeneous density profile along the confining dimension, which plays a key role in many fluid structural and transport phenomena in nanopores. Nearly five decades of theoretical efforts on predicting this phenomenon (fluid layering) have shown that its complexity resists purely analytical treatments; as a consequence, nearly all current approaches make extensive use of molecular simulations, and tend not to have generalizable predictive capabilities. In this work, we demonstrate that machine-learning-based models (in particular, a random forest model), trained upon large molecular simulation data sets, can serve as reliable surrogates in lieu of further molecular simulation. We show that this random forest model has excellent interpolative capabilities over a wide range of temperatures and confining lengthscales, and even has modest extrapolative ability. These results provide a promising pathway forward for developing models of nanoconfined fluid properties that are generalizable, lower cost than \"pure\" molecular simulation, and sufficiently predictive for fluids-in-nanopores practitioners.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"94 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098380","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}
Rovibrational spectrum of CO-SO2 complex has been measured in the CO fundamental region by direct absorption in a supersonic slit jet expansion. Two new vibrational bands were assigned for CO-SO2 and the observed transitions were analyzed using the standard Watson's S-reduced asymmetric-top Hamiltonian. The band origin is 2150.95502(18) cm -1 for band I and 2148.24081(39) cm -1 for band II, which shows a blue-shift from that of the CO monomer by about +7.684 cm -1 and +4.753 cm -1 , respectively. Band I is an ordinary a/c hybrid vibrational band, while only a-type transitions with even-K a levels were observed in Band II. A restricted 2-dimensional intermolecular potential energy surface (2D-IPES) was constructed at the MP2/aug-cc-PVTZ level of theory. Full geometry optimizations and harmonic frequencies calculations were performed for stationary points on the 2D-IPES. Band I is attributed to the most stable C-bonded isomer of CO-SO2 . Band II is attributed to a higher-energy O-bonded isomer with a vibrationally averaged planar structure of C2v symmetry.
用超音速狭缝射流膨胀直接吸收法在CO基区测量了CO- so2配合物的振动谱。为CO-SO2分配了两个新的振动带，并使用标准沃森s -还原不对称顶部哈密顿量分析了观察到的跃迁。带原点为2150.95502(18)cm -1，带原点为2148.24081(39)cm -1，与CO单体的蓝移分别为+7.684 cm -1和+4.753 cm -1。波段I是普通的a/c混合振动带，而波段II只观察到偶k a能级的a型跃迁。在MP2/aug-cc-PVTZ的理论水平上构建了受限的二维分子间势能面（2D-IPES）。对2D-IPES的静止点进行了全几何优化和谐波频率计算。波段I属于CO-SO2最稳定的c键异构体。带II属于具有C2v对称振动平均平面结构的高能量o键异构体。
{"title":"Infrared spectrum and theoretical calculations of a higher energy isomer of CO-SO2 complex","authors":"Yun Liu, Zening Huang, Cheng Chen, Chuanxi Duan","doi":"10.1039/d5cp04772b","DOIUrl":"https://doi.org/10.1039/d5cp04772b","url":null,"abstract":"Rovibrational spectrum of CO-SO2 complex has been measured in the CO fundamental region by direct absorption in a supersonic slit jet expansion. Two new vibrational bands were assigned for CO-SO2 and the observed transitions were analyzed using the standard Watson's S-reduced asymmetric-top Hamiltonian. The band origin is 2150.95502(18) cm -1 for band I and 2148.24081(39) cm -1 for band II, which shows a blue-shift from that of the CO monomer by about +7.684 cm -1 and +4.753 cm -1 , respectively. Band I is an ordinary a/c hybrid vibrational band, while only a-type transitions with even-K a levels were observed in Band II. A restricted 2-dimensional intermolecular potential energy surface (2D-IPES) was constructed at the MP2/aug-cc-PVTZ level of theory. Full geometry optimizations and harmonic frequencies calculations were performed for stationary points on the 2D-IPES. Band I is attributed to the most stable C-bonded isomer of CO-SO2 . Band II is attributed to a higher-energy O-bonded isomer with a vibrationally averaged planar structure of C2v symmetry.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"289 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102036","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 is used to investigate the quantum capacitance (CQ) and surface charge storage (Q) of bare (Al12N12 (AN), Al12Pl12 (AP), B12N12 (BN), and B12P12 (BP)) and 3d transition metal (TM) (Sc–Zn)-doped nanocages. Ground-state spin configurations are confirmed for all metal-doped systems. Cohesive energy values indicate the following stability trend: BN (−6.69) > BP (−5.09) ≈ AN (−5.12) > AP (−4.46 eV per atom). Metal doping is energetically favorable, with strong binding energies for AN/Cr (−3.86 eV), AP/Ni (−4.32 eV), BN/Cr (−2.89 eV) and BP/Mn (−3.69 eV). Electronic structures are analyzed using both the PBE0 and HSE06 functionals, allowing reliable comparison of exchange–correlation effects on CQ and Q. Projected density of states reveals that TM 3d states hybridize with N/P 2p/3p orbitals, increasing delocalized states near the Fermi level and enhancing charge accommodation. Among bare cages, the order of maximum CQ is as follows: AN (543) < AP (579) < BP (670) < BN (688 µF cm−2) via the HSE06 method. BN/Zn achieves a peak CQ of 678 µF cm−2 at −1.5 V and the AN/Zn system exhibits the highest Q of −384 µC cm−2. Overall, TM doping converts the reduction-dominated charge storage of the bare nanocages into a more balanced, bidirectional response, with AN and BN cages exhibiting the most pronounced and controllable enhancement in both CQ and Q due to strong metal–nitrogen hybridization, identifying them as promising non-carbon electrodes for electrochemical double-layer supercapacitors.
利用密度泛函理论研究了裸掺杂（Al12N12 （AN）、Al12Pl12 （AP）、B12N12 （BN）和B12P12 (BP)）和3d掺杂过渡金属（TM） （Sc-Zn）纳米笼的量子电容（CQ）和表面电荷存储(Q)。确定了所有金属掺杂体系的基态自旋构型。黏结能值表明：BN(−6.69)>； BP(−5.09)≈AN(−5.12)>； AP（−4.46 eV /原子）。金属掺杂对AN/Cr（−3.86 eV）、AP/Ni（−4.32 eV）、BN/Cr（−2.89 eV）和BP/Mn（−3.69 eV）具有较强的结合能。利用PBE0和HSE06两种官能团分析了电子结构，可以可靠地比较交换相关效应对CQ和q的影响。态的投影密度表明，TM三维态与N/P 2p/3p轨道杂化，增加了费米能级附近的离域态，增强了电荷调节。在裸网箱中，HSE06法测得最大CQ的顺序为：AN (543) < AP (579) < BP (670) <； BN（688µF cm−2）。在−1.5 V时，BN/Zn体系的峰值CQ为678µF cm−2，AN/Zn体系的最高Q为−384µC cm−2。总体而言，TM掺杂将裸纳米笼的还原主导电荷存储转变为更平衡的双向响应，由于强金属氮杂化，AN和BN笼在CQ和Q上都表现出最明显和可控的增强，这表明它们是电化学双层超级电容器的有前途的非碳电极。
{"title":"Unveiling the influence of 3d transition metal (Sc–Zn) doping on quantum capacitance and surface charge storage in bare nano cages (Al12N12, Al12P12, B12N12, and B12P12) – a first principles simulation study","authors":"Divyakaaviri Subramani, Deepak Arumugam, Akilesh Muralidharan, Shamini Pazhani Beena, Shankar Ramasamy","doi":"10.1039/d5cp04898b","DOIUrl":"https://doi.org/10.1039/d5cp04898b","url":null,"abstract":"Density functional theory is used to investigate the quantum capacitance (<em>C</em><small><sub>Q</sub></small>) and surface charge storage (<em>Q</em>) of bare (Al<small><sub>12</sub></small>N<small><sub>12</sub></small> (AN), Al<small><sub>12</sub></small>Pl<small><sub>12</sub></small> (AP), B<small><sub>12</sub></small>N<small><sub>12</sub></small> (BN), and B<small><sub>12</sub></small>P<small><sub>12</sub></small> (BP)) and 3d transition metal (TM) (Sc–Zn)-doped nanocages. Ground-state spin configurations are confirmed for all metal-doped systems. Cohesive energy values indicate the following stability trend: BN (−6.69) > BP (−5.09) ≈ AN (−5.12) > AP (−4.46 eV per atom). Metal doping is energetically favorable, with strong binding energies for AN/Cr (−3.86 eV), AP/Ni (−4.32 eV), BN/Cr (−2.89 eV) and BP/Mn (−3.69 eV). Electronic structures are analyzed using both the PBE0 and HSE06 functionals, allowing reliable comparison of exchange–correlation effects on <em>C</em><small><sub>Q</sub></small> and <em>Q</em>. Projected density of states reveals that TM 3d states hybridize with N/P 2p/3p orbitals, increasing delocalized states near the Fermi level and enhancing charge accommodation. Among bare cages, the order of maximum <em>C</em><small><sub>Q</sub></small> is as follows: AN (543) < AP (579) < BP (670) < BN (688 µF cm<small><sup>−2</sup></small>) <em>via</em> the HSE06 method. BN/Zn achieves a peak <em>C</em><small><sub>Q</sub></small> of 678 µF cm<small><sup>−2</sup></small> at −1.5 V and the AN/Zn system exhibits the highest <em>Q</em> of −384 µC cm<small><sup>−2</sup></small>. Overall, TM doping converts the reduction-dominated charge storage of the bare nanocages into a more balanced, bidirectional response, with AN and BN cages exhibiting the most pronounced and controllable enhancement in both <em>C</em><small><sub>Q</sub></small> and <em>Q</em> due to strong metal–nitrogen hybridization, identifying them as promising non-carbon electrodes for electrochemical double-layer supercapacitors.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"275 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098378","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}
Efficient CO₂ capture is essential to industrial decarbonization. Ionic liquids (ILs) are promising solvents for this purpose due to their tuneable structures and selective interactions with CO₂. In this work, classical molecular dynamics simulations of two ILs, [BMIM][BF4] and [BMIM][NTF2], reveal an interesting trade-off between interfacial adsorption and bulk solubility. [BMIM][BF4] exhibits pronounced CO₂ surface enrichment, while [BMIM][NTF2] shows weaker interfacial adsorption but greater bulk uptake. The difference originates from distinct thermodynamic driving forces at the interface versus in the bulk. Interfacial adsorption is primarily enthalpically driven, with CO₂ experiencing stronger interactions at the [BMIM][BF4] surface (-17.7 kJ/mol) compared to [BMIM][NTF2] (-12.4 kJ/mol). In contrast, bulk solubility is governed by the balance between enthalpic stabilization and entropic penalty. [BMIM][NTF2] shows a reduced entropic penalty (-0.035 kJ/mol•K vs. -0.052 kJ/mol•K for [BMIM][ BF4]), resulting in slightly more favourable solvation free energy (-2.1 kJ/mol vs. -2.0 kJ/mol) and higher overall CO₂ capacity. Free volume analysis supports the greater structural adaptability of [BMIM][NTF2], with the flexible NTF2 anion enabling better structural relaxation for CO₂ accommodation. These results demonstrate that anion structure profoundly influences CO 2 absorption characteristics: compact anions (e.g., [BMIM][BF4]) promote enthalpy-driven surface capture, whereas bulky, charge-delocalized anions (e.g., [BMIM][NTF2]) favour entropy-relieved bulk absorption with lower energy costs. Interfacial adsorption may offer advantages over bulk dissolution by circumventing viscosity-related mass transfer limitations and reducing energy requirements for solvent regeneration.
{"title":"Thermodynamic Origins of the Interfacial-Bulk Solubility Trade-off for CO₂ in Ionic Liquids: A Molecular Dynamics Simulation Study","authors":"Sanchari Bhattacharjee, Shiang-Tai Lin","doi":"10.1039/d5cp04570c","DOIUrl":"https://doi.org/10.1039/d5cp04570c","url":null,"abstract":"Efficient CO₂ capture is essential to industrial decarbonization. Ionic liquids (ILs) are promising solvents for this purpose due to their tuneable structures and selective interactions with CO₂. In this work, classical molecular dynamics simulations of two ILs, [BMIM][BF4] and [BMIM][NTF2], reveal an interesting trade-off between interfacial adsorption and bulk solubility. [BMIM][BF4] exhibits pronounced CO₂ surface enrichment, while [BMIM][NTF2] shows weaker interfacial adsorption but greater bulk uptake. The difference originates from distinct thermodynamic driving forces at the interface versus in the bulk. Interfacial adsorption is primarily enthalpically driven, with CO₂ experiencing stronger interactions at the [BMIM][BF4] surface (-17.7 kJ/mol) compared to [BMIM][NTF2] (-12.4 kJ/mol). In contrast, bulk solubility is governed by the balance between enthalpic stabilization and entropic penalty. [BMIM][NTF2] shows a reduced entropic penalty (-0.035 kJ/mol•K vs. -0.052 kJ/mol•K for [BMIM][ BF4]), resulting in slightly more favourable solvation free energy (-2.1 kJ/mol vs. -2.0 kJ/mol) and higher overall CO₂ capacity. Free volume analysis supports the greater structural adaptability of [BMIM][NTF2], with the flexible NTF2 anion enabling better structural relaxation for CO₂ accommodation. These results demonstrate that anion structure profoundly influences CO 2 absorption characteristics: compact anions (e.g., [BMIM][BF4]) promote enthalpy-driven surface capture, whereas bulky, charge-delocalized anions (e.g., [BMIM][NTF2]) favour entropy-relieved bulk absorption with lower energy costs. Interfacial adsorption may offer advantages over bulk dissolution by circumventing viscosity-related mass transfer limitations and reducing energy requirements for solvent regeneration.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"50 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089626","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}
Stanislav Pshenichnyuk, Mars Muftakhov, Nail L. Asfandiarov, Rustam G Rakhmeyev, Viktor A. Timoshnikov, Nikolay Polyakov, Alexei Komolov
Low-energy (0-14 eV) resonance electron interaction with gas-phase ellagic acid (EA) molecules is studied using dissociative electron attachment (DEA) spectroscopy. Photoinduced electron transfer reactions with solvated EA are studied using chemically induced dynamic nuclear polarization (CIDNP) technique. Molecular negative ions EA• -, the most abundant species generated by thermal electron attachment to EA, autodetach extra electron in 200 µs that allows to estimate adiabatic electron affinity of EA as 1.3 eV, the value being in excellent agreement with that predicted on B3LYP/6-31+G(d) level. Intriguing observation, slow (microsecond timescale) cleavage of a single O-H bond, to form the [EA -H] -fragments can tentatively be explained by the H-atom roaming across the molecular frame or statistical accumulation of the energy required to overcome the potential barrier on the reaction coordinate. Oppositely to a variety of polyphenolic molecules, formation of [EA -2H]• -is not observed at thermal electron energy despite this decay is energetically favorable, that is likely due to competition with a single H-atom abstraction. Fully deprotonated EA form (it exists in solution at pH > 10) can attach solvated electrons to produce the [EA -4H + ] •5-radicals in consistent with high electron-accepting ability of isolated EA. However, the deprotonated EA can also donate electron to a model electron acceptor 2,2ʹ-dipyridyl producing the [EA -4H + ] •3- radicals, no further decomposition being registered in the present CIDNP experiments in agreement with only few fragment species generated by gas-phase DEA to intact EA. The present findings can be of importance to understand biological effects produced by EA, namely, its synergism in combination with radiotherapy and its antibacterial activity, the both being likely associated with the electron-driven processes.
{"title":"Electron-induced processes in the ellagic acid molecule via gas-phase resonance electron attachment and electron transfer following photoexcitation in solution","authors":"Stanislav Pshenichnyuk, Mars Muftakhov, Nail L. Asfandiarov, Rustam G Rakhmeyev, Viktor A. Timoshnikov, Nikolay Polyakov, Alexei Komolov","doi":"10.1039/d5cp04866d","DOIUrl":"https://doi.org/10.1039/d5cp04866d","url":null,"abstract":"Low-energy (0-14 eV) resonance electron interaction with gas-phase ellagic acid (EA) molecules is studied using dissociative electron attachment (DEA) spectroscopy. Photoinduced electron transfer reactions with solvated EA are studied using chemically induced dynamic nuclear polarization (CIDNP) technique. Molecular negative ions EA• -, the most abundant species generated by thermal electron attachment to EA, autodetach extra electron in 200 µs that allows to estimate adiabatic electron affinity of EA as 1.3 eV, the value being in excellent agreement with that predicted on B3LYP/6-31+G(d) level. Intriguing observation, slow (microsecond timescale) cleavage of a single O-H bond, to form the [EA -H] -fragments can tentatively be explained by the H-atom roaming across the molecular frame or statistical accumulation of the energy required to overcome the potential barrier on the reaction coordinate. Oppositely to a variety of polyphenolic molecules, formation of [EA -2H]• -is not observed at thermal electron energy despite this decay is energetically favorable, that is likely due to competition with a single H-atom abstraction. Fully deprotonated EA form (it exists in solution at pH > 10) can attach solvated electrons to produce the [EA -4H + ] •5-radicals in consistent with high electron-accepting ability of isolated EA. However, the deprotonated EA can also donate electron to a model electron acceptor 2,2ʹ-dipyridyl producing the [EA -4H + ] •3- radicals, no further decomposition being registered in the present CIDNP experiments in agreement with only few fragment species generated by gas-phase DEA to intact EA. The present findings can be of importance to understand biological effects produced by EA, namely, its synergism in combination with radiotherapy and its antibacterial activity, the both being likely associated with the electron-driven processes.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"7 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089634","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}
Two-dimensional (2D) topological materials are at the forefront of quantum materials research due to their potential in next-generation spintronic devices. In this study, we investigate the structural, mechanical, and electronic properties of Janus MoWCO2 MXene using first-principles density functional theory (DFT) calculations, both with and without spin-orbit coupling (SOC). The energetically preferred structure features O atoms are systematically explored, with the 2H phase exhibiting greater thermodynamic, mechanical, and dynamic stability than the 1T phase. Without SOC, both phases behave like metals; however, the inclusion of SOC and HSE06 hybrid functional calculations opens significant band gaps (∼ 0.84 eV in the 2H phase and ∼ 0.50 eV in the 1T phase), revealing a transition to semiconducting behavior. Notably, band inversion and Rashba splitting are observed at the Γ point, and Z2 topological invariants confirm 2H-MoWCO2 as a strong topological insulator, while 1T-MoWCO2 is identified as a topological semimetal. These findings position MoWCO2 as a promising 2D material platform for realizing robust topological phases and quantum spintronic device applications.
{"title":"Structural Stabilities, Elastic Property, and Robust Topological Phases in Janus MoWCO2 MXene from First-Principles Investigation","authors":"Sirinee Thasitha, Prutthipong Tsuppayakorn-aek, Thanayut Kaewmaraya, Tanveer Hussain, Thiti Bovornratanaraks, Komsilp Kotmool","doi":"10.1039/d5cp03820k","DOIUrl":"https://doi.org/10.1039/d5cp03820k","url":null,"abstract":"Two-dimensional (2D) topological materials are at the forefront of quantum materials research due to their potential in next-generation spintronic devices. In this study, we investigate the structural, mechanical, and electronic properties of Janus MoWCO<small><sub>2</sub></small> MXene using first-principles density functional theory (DFT) calculations, both with and without spin-orbit coupling (SOC). The energetically preferred structure features O atoms are systematically explored, with the 2H phase exhibiting greater thermodynamic, mechanical, and dynamic stability than the 1T phase. Without SOC, both phases behave like metals; however, the inclusion of SOC and HSE06 hybrid functional calculations opens significant band gaps (∼ 0.84 eV in the 2H phase and ∼ 0.50 eV in the 1T phase), revealing a transition to semiconducting behavior. Notably, band inversion and Rashba splitting are observed at the Γ point, and Z<small><sub>2</sub></small> topological invariants confirm 2H-MoWCO<small><sub>2</sub></small> as a strong topological insulator, while 1T-MoWCO<small><sub>2</sub></small> is identified as a topological semimetal. These findings position MoWCO<small><sub>2</sub></small> as a promising 2D material platform for realizing robust topological phases and quantum spintronic device applications.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"24 1-2 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The hydrogen evolution reaction (HER) is pivotal for sustainable hydrogen production through water electrolysis, yet the scarcity and high cost of efficient catalysts remain primary obstacles to its widespread application. Two-dimensional MXenes, particularly O-terminated Ti 3 C 2 , have emerged as promising candidate materials. In this study, we systematically designed and investigated a series of dual non-metal doped configurations (Si-P, Si-As, etc.) on the Ti 3 C 2 O 2 using density functional theory (DFT) calculations. Our results confirm the structural stability of these doped systems without clustering of non-metal atoms. Among them, the Si-P and Si-As co-doped Ti 3 C 2 O 2 exhibit outstanding HER performance, with hydrogen adsorption Gibbs free energies (ΔG H *) of -0.228 eV and -0.226 eV, respectively. These values are significantly superior to those of pristine Ti 3 C 2 O 2 and surpass the performance of inplane transition metal-modified configurations (Hf-doped Ti 3 C 2 O 2 ). Bader charge analysis further reveals that the dual non-metal dopants synergistically modulate the local electronic structure, optimizing the charge distribution at the active sites and thereby enhancing their adsorption behavior for hydrogen intermediates (H*). This work not only elucidates the mechanistic role of non-metal co-doping in enhancing HER activity but also provides a theoretical basis for the rational design of highperformance MXene-based electrocatalysts.
析氢反应（HER）是水电解可持续制氢的关键，但高效催化剂的稀缺和高成本仍然是其广泛应用的主要障碍。二维MXenes，特别是o端Ti 3c2，已经成为有前途的候选材料。在本研究中，我们利用密度泛函理论（DFT）计算系统地设计和研究了Ti 3c2o2上的一系列双非金属掺杂构型（Si-P， Si-As等）。我们的结果证实了这些掺杂体系在没有非金属原子聚集的情况下的结构稳定性。其中，Si-P和Si-As共掺杂的Ti 3c2o2表现出优异的HER性能，氢吸附吉布斯自由能（ΔG H *）分别为-0.228 eV和-0.226 eV。这些值明显优于原始ti3c2o2，并且超过了平面内过渡金属修饰构型（hf掺杂ti3c2o2）的性能。Bader电荷分析进一步表明，双非金属掺杂剂协同调节了局部电子结构，优化了活性位点的电荷分布，从而增强了它们对氢中间体（H*）的吸附行为。本研究不仅阐明了非金属共掺杂提高HER活性的机理作用，也为合理设计高性能mxene基电催化剂提供了理论依据。
{"title":"Enhancing hydrogen evolution reaction on Oterminated Ti 3 C 2 MXene via dual non-metal doping: a first-principles study","authors":"Hui Li, Jianhua Hou, Qian Duan","doi":"10.1039/d5cp04571a","DOIUrl":"https://doi.org/10.1039/d5cp04571a","url":null,"abstract":"The hydrogen evolution reaction (HER) is pivotal for sustainable hydrogen production through water electrolysis, yet the scarcity and high cost of efficient catalysts remain primary obstacles to its widespread application. Two-dimensional MXenes, particularly O-terminated Ti 3 C 2 , have emerged as promising candidate materials. In this study, we systematically designed and investigated a series of dual non-metal doped configurations (Si-P, Si-As, etc.) on the Ti 3 C 2 O 2 using density functional theory (DFT) calculations. Our results confirm the structural stability of these doped systems without clustering of non-metal atoms. Among them, the Si-P and Si-As co-doped Ti 3 C 2 O 2 exhibit outstanding HER performance, with hydrogen adsorption Gibbs free energies (ΔG H *) of -0.228 eV and -0.226 eV, respectively. These values are significantly superior to those of pristine Ti 3 C 2 O 2 and surpass the performance of inplane transition metal-modified configurations (Hf-doped Ti 3 C 2 O 2 ). Bader charge analysis further reveals that the dual non-metal dopants synergistically modulate the local electronic structure, optimizing the charge distribution at the active sites and thereby enhancing their adsorption behavior for hydrogen intermediates (H*). This work not only elucidates the mechanistic role of non-metal co-doping in enhancing HER activity but also provides a theoretical basis for the rational design of highperformance MXene-based electrocatalysts.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"284 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089628","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}
Overcoming the intrinsic phonon mismatch at heterogeneous interfaces is a central challenge in nanoscale thermal management. In this work, we use non-equilibrium molecular dynamics (NEMD) to investigate the Si/SiC interface, uncovering a mechanism whereby strategically placed vacancy defects within the SiC bulk significantly enhance interfacial thermal conductance (ITC) by up to 87%. Our analysis of the phonon density of states (PDOS) demonstrates that this enhancement arises from inelastic phonon scattering in the defective region. High-frequency SiC phonons are effectively downconverted into lower-frequency modes, dramatically increasing the vibrational spectral overlap with Si and opening new, efficient channels for energy transport across the phononic barrier. Therefore, engineering remote defects offers a viable strategy to enhance thermal transport across dissimilar material interfaces without compromising the interface's structural quality, providing clear design guidelines for advanced thermal management solutions.
{"title":"Vacancy-Mediated Enhancement of Interfacial Thermal Transport in Si/SiC Heterojunctions: A Molecular Dynamics Study","authors":"yang zhang, Zhenping Wu, Huiping Zhu","doi":"10.1039/d5cp03938j","DOIUrl":"https://doi.org/10.1039/d5cp03938j","url":null,"abstract":"Overcoming the intrinsic phonon mismatch at heterogeneous interfaces is a central challenge in nanoscale thermal management. In this work, we use non-equilibrium molecular dynamics (NEMD) to investigate the Si/SiC interface, uncovering a mechanism whereby strategically placed vacancy defects within the SiC bulk significantly enhance interfacial thermal conductance (ITC) by up to 87%. Our analysis of the phonon density of states (PDOS) demonstrates that this enhancement arises from inelastic phonon scattering in the defective region. High-frequency SiC phonons are effectively downconverted into lower-frequency modes, dramatically increasing the vibrational spectral overlap with Si and opening new, efficient channels for energy transport across the phononic barrier. Therefore, engineering remote defects offers a viable strategy to enhance thermal transport across dissimilar material interfaces without compromising the interface's structural quality, providing clear design guidelines for advanced thermal management solutions.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"115 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146097803","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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