Pub Date : 2026-03-26DOI: 10.1021/acs.jpcc.5c08145
Piyush Anil Kumar Sharma, Jaclyn A. Rebstock, Ting-Rong Ko, Emma Pollock, Jeffersson Feutseu, Julia C. Lam, Patrick M. Woodward, L. Robert Baker
CuFeO2 delafossite materials have been researched for their promising photoactivity for CO2 reduction (CO2R) due to their intrinsic p-type conductivity. However, its practical application is limited by its poor stability and low photocurrent densities. In this work, we investigated the mechanistic origin of CuFeO2 degradation under CO2R conditions. Through photoelectrochemical measurements combined with ex situ X-ray photoelectron spectroscopy and in situ surface-enhanced Raman spectroscopy, we show that CO2-saturated sodium bicarbonate electrolytes enhance photoelectrochemical corrosion by facilitating iron leaching from the catalyst. Systematic control experiments reveal that this instability is not governed solely by thermodynamic surface stability but arises from a nonequilibrium interfacial speciation of CO2, bicarbonate, and carbonate. The presence of carbonate species at the catalyst interface facilitates iron(II) complexation and degrades the CuFeO2 surface. These findings establish carbonate-driven photoelectrochemical corrosion as a key degradation pathway for CuFeO2 and underscore the importance of speciation at the interface-electrolyte in dictating the long-term performance of a catalyst for CO2R.
{"title":"Carbonate-Enhanced Photoelectrochemical Corrosion Limits the CO2 Reduction Reactivity on CuFeO2 Delafossite Photocathodes","authors":"Piyush Anil Kumar Sharma, Jaclyn A. Rebstock, Ting-Rong Ko, Emma Pollock, Jeffersson Feutseu, Julia C. Lam, Patrick M. Woodward, L. Robert Baker","doi":"10.1021/acs.jpcc.5c08145","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08145","url":null,"abstract":"CuFeO<sub>2</sub> delafossite materials have been researched for their promising photoactivity for CO<sub>2</sub> reduction (CO<sub>2</sub>R) due to their intrinsic p-type conductivity. However, its practical application is limited by its poor stability and low photocurrent densities. In this work, we investigated the mechanistic origin of CuFeO<sub>2</sub> degradation under CO<sub>2</sub>R conditions. Through photoelectrochemical measurements combined with ex situ X-ray photoelectron spectroscopy and in situ surface-enhanced Raman spectroscopy, we show that CO<sub>2</sub>-saturated sodium bicarbonate electrolytes enhance photoelectrochemical corrosion by facilitating iron leaching from the catalyst. Systematic control experiments reveal that this instability is not governed solely by thermodynamic surface stability but arises from a nonequilibrium interfacial speciation of CO<sub>2</sub>, bicarbonate, and carbonate. The presence of carbonate species at the catalyst interface facilitates iron(II) complexation and degrades the CuFeO<sub>2</sub> surface. These findings establish carbonate-driven photoelectrochemical corrosion as a key degradation pathway for CuFeO<sub>2</sub> and underscore the importance of speciation at the interface-electrolyte in dictating the long-term performance of a catalyst for CO<sub>2</sub>R.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"31 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-26DOI: 10.1021/acs.jpcc.5c08032
Boqiang Chen, Milan S. Wijesinghe, Yu-Shen Hsu, Rongyu Zhang, Charuni M. Gunathunge, Alexis Grimaud, Matthias M Waegele
The solvation properties of aqueous electrolytes have been shown to dramatically impact the outcomes of many electrocatalytic reactions. Understanding the structure and dynamics of interfacial water at the metal electrode/electrolyte contact is therefore of central importance in electrocatalysis. The electrode potential affects the interfacial water structure because it controls the concentration of ions in the electrochemical double layer (EDL), the preferential orientation of solvent dipoles, and the coverage of surface-adsorbed species. Surface-enhanced infrared absorption spectroscopy (SEIRAS) has been widely utilized for probing electrocatalytic interfaces, including potential-dependent solvent structure. However, the electrode/electrolyte interface can undergo time-dependent changes that are irreversible with electrode potential. Such subtle irreversible changes of the interface could lead to imperfect subtraction of infrared signals from the bulk or could otherwise alter interfacial solvation. If unrecognized, this phenomenon could lead to misinterpretations of the SEIRA spectra of water and other solvents at electrode/electrolyte interfaces. Yet, these effects have not been systematically investigated to date. Herein, we probed the O–H stretch band of interfacial water at Cu, Au, and Pt electrodes in the presence of different electrolytes. The SEIRA spectra of water at Cu and Au electrodes can be dominated by irreversible effects, which could inadvertently be misinterpreted as the intrinsic potential dependence of the interfacial water structure. In contrast, the SEIRA spectra of water at Pt electrodes typically exhibit a comparatively higher degree of reversibility with electrode potential. We established robust SEIRAS protocols for isolating changes in interfacial solvation that are reversible with electrode potential, that is, changes that reflect the intrinsic potential dependence of the EDL.
{"title":"Avoiding Pitfalls in Probing Interfacial Solvation Structures Using Surface-Enhanced Infrared Absorption Spectroscopy","authors":"Boqiang Chen, Milan S. Wijesinghe, Yu-Shen Hsu, Rongyu Zhang, Charuni M. Gunathunge, Alexis Grimaud, Matthias M Waegele","doi":"10.1021/acs.jpcc.5c08032","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08032","url":null,"abstract":"The solvation properties of aqueous electrolytes have been shown to dramatically impact the outcomes of many electrocatalytic reactions. Understanding the structure and dynamics of interfacial water at the metal electrode/electrolyte contact is therefore of central importance in electrocatalysis. The electrode potential affects the interfacial water structure because it controls the concentration of ions in the electrochemical double layer (EDL), the preferential orientation of solvent dipoles, and the coverage of surface-adsorbed species. Surface-enhanced infrared absorption spectroscopy (SEIRAS) has been widely utilized for probing electrocatalytic interfaces, including potential-dependent solvent structure. However, the electrode/electrolyte interface can undergo time-dependent changes that are irreversible with electrode potential. Such subtle irreversible changes of the interface could lead to imperfect subtraction of infrared signals from the bulk or could otherwise alter interfacial solvation. If unrecognized, this phenomenon could lead to misinterpretations of the SEIRA spectra of water and other solvents at electrode/electrolyte interfaces. Yet, these effects have not been systematically investigated to date. Herein, we probed the O–H stretch band of interfacial water at Cu, Au, and Pt electrodes in the presence of different electrolytes. The SEIRA spectra of water at Cu and Au electrodes can be dominated by irreversible effects, which could inadvertently be misinterpreted as the intrinsic potential dependence of the interfacial water structure. In contrast, the SEIRA spectra of water at Pt electrodes typically exhibit a comparatively higher degree of reversibility with electrode potential. We established robust SEIRAS protocols for isolating changes in interfacial solvation that are reversible with electrode potential, that is, changes that reflect the intrinsic potential dependence of the EDL.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"38 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-26DOI: 10.1021/acs.jpcc.6c00197
Nadezhda A. Andreeva, Vitaly V. Chaban
Self-healing occurs in metalized-film capacitors after electrical breakdown, thanks to the unique chemical properties of their insulating polymeric films. Polypropylene (PP) is the most successful self-healing polymer because it produces the largest fraction of volatile products, whose electrical conductivity is negligible. Similar to other insulating films, PP exhibits structural defects and voids, which are responsible for local density gradients and foster dielectric breakdowns. Herein, we investigate how specific density impacts the chemical processes constituting the self-healing of PP at high temperatures and pressures. The reactive (ReaxFF) molecular dynamics Hamiltonian was used to propagate atomic movements over time. We report that local density reduction boosts self-healing efficacy. A fraction of gas molecules formed −H2, C2H2, C2H4, and CH4─is inversely proportional to the initial PP density. In turn, the sizes of the soot species (carbon-rich unsaturated aliphatic and aromatic molecules) modestly depend on the pressure and gas densities. While the soot particles merge and thereby increase in mass upon cooling the system after dielectric breakdown, their largest directly observed sizes in no simulation exceeded ∼4% of the system size.
{"title":"Self-Healing Versus Local Specific Density in Metalized-Film Polypropylene Capacitors: A Reactive Molecular Dynamics Investigation","authors":"Nadezhda A. Andreeva, Vitaly V. Chaban","doi":"10.1021/acs.jpcc.6c00197","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00197","url":null,"abstract":"Self-healing occurs in metalized-film capacitors after electrical breakdown, thanks to the unique chemical properties of their insulating polymeric films. Polypropylene (PP) is the most successful self-healing polymer because it produces the largest fraction of volatile products, whose electrical conductivity is negligible. Similar to other insulating films, PP exhibits structural defects and voids, which are responsible for local density gradients and foster dielectric breakdowns. Herein, we investigate how specific density impacts the chemical processes constituting the self-healing of PP at high temperatures and pressures. The reactive (ReaxFF) molecular dynamics Hamiltonian was used to propagate atomic movements over time. We report that local density reduction boosts self-healing efficacy. A fraction of gas molecules formed −H<sub>2</sub>, C<sub>2</sub>H<sub>2</sub>, C<sub>2</sub>H<sub>4</sub>, and CH<sub>4</sub>─is inversely proportional to the initial PP density. In turn, the sizes of the soot species (carbon-rich unsaturated aliphatic and aromatic molecules) modestly depend on the pressure and gas densities. While the soot particles merge and thereby increase in mass upon cooling the system after dielectric breakdown, their largest directly observed sizes in no simulation exceeded ∼4% of the system size.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"20 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507334","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}
In this work, we report the magnetic field-induced enhancement in the photoelectrochemical (PEC) water splitting using a Cs2MnCl6 vacancy-ordered halide double perovskite photoanode. Under applied magnetic fields, enhancement in PEC performance was observed where an approximate 14% enhancement of the photocurrent at 0.62 V vs Ag/AgCl (equivalent to 1.23 V vs RHE) was recorded. Using a combination of temperature-dependent impedance measurements, magnetic measurements, and photoelectric measurements, the role of the magnetic field on the PEC activity was explained. This work establishes Cs2MnCl6 as a magnetic-field-responsive photoabsorber, enabling tunable performance for next-generation solar energy applications.
在这项工作中，我们报道了使用Cs2MnCl6空位有序卤化物双钙钛矿光阳极在光电化学（PEC）水分解中的磁场诱导增强。在施加磁场下，在0.62 V /Ag /AgCl（相当于1.23 V / RHE）下，光电流增强了约14%，可以观察到PEC性能的增强。结合温度相关的阻抗测量、磁测量和光电测量，解释了磁场对PEC活性的作用。这项工作建立了Cs2MnCl6作为磁场响应光吸收剂，为下一代太阳能应用提供可调性能。
{"title":"Magnetic Field-Induced Enhancements in the Photoelectrochemical Performance of Cs2MnCl6 Vacancy-Ordered Halide Double Perovskites","authors":"Jigar Shaileshkumar Halpati, Manasa Manoj, Abhishek Anand, Aravind Kumar Chandiran","doi":"10.1021/acs.jpcc.5c08387","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08387","url":null,"abstract":"In this work, we report the magnetic field-induced enhancement in the photoelectrochemical (PEC) water splitting using a Cs<sub>2</sub>MnCl<sub>6</sub> vacancy-ordered halide double perovskite photoanode. Under applied magnetic fields, enhancement in PEC performance was observed where an approximate 14% enhancement of the photocurrent at 0.62 V vs Ag/AgCl (equivalent to 1.23 V vs RHE) was recorded. Using a combination of temperature-dependent impedance measurements, magnetic measurements, and photoelectric measurements, the role of the magnetic field on the PEC activity was explained. This work establishes Cs<sub>2</sub>MnCl<sub>6</sub> as a magnetic-field-responsive photoabsorber, enabling tunable performance for next-generation solar energy applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"69 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147519092","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 two-dimensional (2D) monolayer honeycomb borophene oxide (h-B<sub>2</sub>O), renowned for its exceptional stability, has attracted considerable attention due to its unique topological features and potential superconducting properties. In this work, we construct a tight-binding (TB) Hamiltonian based on the P<sub><i>y</i></sub> and P<sub><i>z</i></sub> orbitals of boron atoms and, through detailed analysis of the corresponding band structure (BS) and density of states (DOS), demonstrate the metallic nature of monolayer h-B2O. Furthermore, we report for the first time the Pauli spin paramagnetic susceptibility (PSPS) of monolayer h-B<sub>2</sub>O. At room temperature (300 K), the susceptibilities <i></i><math display="inline"><msubsup><mi>χ</mi><mrow><mi mathvariant="normal">P</mi><mi mathvariant="normal">a</mi><mi mathvariant="normal">u</mi><mi mathvariant="normal">l</mi><mi mathvariant="normal">i</mi></mrow><msub><mi mathvariant="normal">P</mi><mi>y</mi></msub></msubsup></math> and <i></i><math display="inline"><msubsup><mi>χ</mi><mrow><mi mathvariant="normal">P</mi><mi mathvariant="normal">a</mi><mi mathvariant="normal">u</mi><mi mathvariant="normal">l</mi><mi mathvariant="normal">i</mi></mrow><msub><mi mathvariant="normal">P</mi><mi>z</mi></msub></msubsup></math> are found to be 5.3 × 10<sup>–9</sup> and 9.5 × 10<sup>–9</sup> (D.L.), respectively, with <i></i><math display="inline"><msubsup><mi>χ</mi><mrow><mi mathvariant="normal">P</mi><mi mathvariant="normal">a</mi><mi mathvariant="normal">u</mi><mi mathvariant="normal">l</mi><mi mathvariant="normal">i</mi></mrow><msub><mi mathvariant="normal">P</mi><mi>z</mi></msub></msubsup><mo>≈</mo><mn>1.8</mn><mo>×</mo><msubsup><mi>χ</mi><mrow><mi mathvariant="normal">P</mi><mi mathvariant="normal">a</mi><mi mathvariant="normal">u</mi><mi mathvariant="normal">l</mi><mi mathvariant="normal">i</mi></mrow><msub><mi mathvariant="normal">P</mi><mi>y</mi></msub></msubsup></math>. The observed orbital anisotropy arises from differences in the DOS of the two orbitals near the Fermi level, which govern the susceptibility. Moreover, our results show that the PSPS exhibits Pauli-type behavior at low temperatures, while at higher temperatures it follows a Curie-like dependence (χ = <i>C</i>/<i>T</i>). Furthermore, we systematically examine the influence of impurity-induced disorder on PSPS in h-B<sub>2</sub>O under both n-type and p-type doping within the T-matrix approximation. In the 0–10% doping range at 300 K, the PSPS exhibits no uniform trend but displays pronounced orbital-dependent variations. For p-type doping, the total χ<sub>Pauli</sub> is strongly modulated by the P<sub><i>z</i></sub> orbital, reaching a maximum at 9% doping (88.8% increase) and a minimum at 10% (25.4% decrease). In contrast, under n-type doping, the total χ<sub>Pauli</sub> closely follows the P<sub><i>y</i></sub> contribution, attaining its peak at 1% doping (14.3% increase) and lowest value at 10% (24.7% decrease). This tunable, do
{"title":"Orbital-Selective Pauli Spin Paramagnetic Susceptibility and Doping-Tunable Magnetic Response in Monolayer Honeycomb Borophene Oxide (h-B2O)","authors":"Farid Mohammadi, Afarin Fatemeh Rezaei, Mahdi Ebrahimi, Kavoos Mirabbaszadeh","doi":"10.1021/acs.jpcc.5c07366","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c07366","url":null,"abstract":"The two-dimensional (2D) monolayer honeycomb borophene oxide (h-B<sub>2</sub>O), renowned for its exceptional stability, has attracted considerable attention due to its unique topological features and potential superconducting properties. In this work, we construct a tight-binding (TB) Hamiltonian based on the P<sub><i>y</i></sub> and P<sub><i>z</i></sub> orbitals of boron atoms and, through detailed analysis of the corresponding band structure (BS) and density of states (DOS), demonstrate the metallic nature of monolayer h-B2O. Furthermore, we report for the first time the Pauli spin paramagnetic susceptibility (PSPS) of monolayer h-B<sub>2</sub>O. At room temperature (300 K), the susceptibilities <i></i><math display=\"inline\"><msubsup><mi>χ</mi><mrow><mi mathvariant=\"normal\">P</mi><mi mathvariant=\"normal\">a</mi><mi mathvariant=\"normal\">u</mi><mi mathvariant=\"normal\">l</mi><mi mathvariant=\"normal\">i</mi></mrow><msub><mi mathvariant=\"normal\">P</mi><mi>y</mi></msub></msubsup></math> and <i></i><math display=\"inline\"><msubsup><mi>χ</mi><mrow><mi mathvariant=\"normal\">P</mi><mi mathvariant=\"normal\">a</mi><mi mathvariant=\"normal\">u</mi><mi mathvariant=\"normal\">l</mi><mi mathvariant=\"normal\">i</mi></mrow><msub><mi mathvariant=\"normal\">P</mi><mi>z</mi></msub></msubsup></math> are found to be 5.3 × 10<sup>–9</sup> and 9.5 × 10<sup>–9</sup> (D.L.), respectively, with <i></i><math display=\"inline\"><msubsup><mi>χ</mi><mrow><mi mathvariant=\"normal\">P</mi><mi mathvariant=\"normal\">a</mi><mi mathvariant=\"normal\">u</mi><mi mathvariant=\"normal\">l</mi><mi mathvariant=\"normal\">i</mi></mrow><msub><mi mathvariant=\"normal\">P</mi><mi>z</mi></msub></msubsup><mo>≈</mo><mn>1.8</mn><mo>×</mo><msubsup><mi>χ</mi><mrow><mi mathvariant=\"normal\">P</mi><mi mathvariant=\"normal\">a</mi><mi mathvariant=\"normal\">u</mi><mi mathvariant=\"normal\">l</mi><mi mathvariant=\"normal\">i</mi></mrow><msub><mi mathvariant=\"normal\">P</mi><mi>y</mi></msub></msubsup></math>. The observed orbital anisotropy arises from differences in the DOS of the two orbitals near the Fermi level, which govern the susceptibility. Moreover, our results show that the PSPS exhibits Pauli-type behavior at low temperatures, while at higher temperatures it follows a Curie-like dependence (χ = <i>C</i>/<i>T</i>). Furthermore, we systematically examine the influence of impurity-induced disorder on PSPS in h-B<sub>2</sub>O under both n-type and p-type doping within the T-matrix approximation. In the 0–10% doping range at 300 K, the PSPS exhibits no uniform trend but displays pronounced orbital-dependent variations. For p-type doping, the total χ<sub>Pauli</sub> is strongly modulated by the P<sub><i>z</i></sub> orbital, reaching a maximum at 9% doping (88.8% increase) and a minimum at 10% (25.4% decrease). In contrast, under n-type doping, the total χ<sub>Pauli</sub> closely follows the P<sub><i>y</i></sub> contribution, attaining its peak at 1% doping (14.3% increase) and lowest value at 10% (24.7% decrease). This tunable, do","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"22 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-26DOI: 10.1021/acs.jpcc.5c07975
Cindy-Ly Tavera-Méndez, Paola Agüero-Gamboa, Ziwen Zhai, György Hantal, Florian M. Wisser, Ana-Sunčana Smith, Thomas M. Koller, Martin Hartmann, Dorothea Wisser
In 129Xe NMR spectroscopy, gaseous xenon is used as a sensitive probe for the structural and textural investigation of porous materials. The chemical shift is responsive to the pore sizes and surface chemistry in a wide range of industrially relevant materials. However, many applications of porous materials necessitate the interaction of a liquid with the pore surface. Little is known about the behavior of xenon in such systems. Supported ionic liquid phase (SILP) catalysts are a promising class of new catalysts, achieved by impregnating a suitable porous solid support with a combination of an ionic liquid (IL) and a catalytically active metal complex. In general, a thin, homogeneous film covering the surface is advantageous for many applications. Using 129Xe as a probe nucleus detected by 129Xe NMR spectroscopy, combined with quantitative xenon physisorption isotherms, different environments can be discerned in the SILP, namely, xenon adsorbed on the bare silica surface and xenon adsorbed on an immobilized IL phase. Moreover, we found that the behavior of xenon and its mobility depend intricately on the nature of the IL and its interactions with the support.
{"title":"129Xe NMR Spectroscopy of Supported Ionic Liquids","authors":"Cindy-Ly Tavera-Méndez, Paola Agüero-Gamboa, Ziwen Zhai, György Hantal, Florian M. Wisser, Ana-Sunčana Smith, Thomas M. Koller, Martin Hartmann, Dorothea Wisser","doi":"10.1021/acs.jpcc.5c07975","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c07975","url":null,"abstract":"In <sup>129</sup>Xe NMR spectroscopy, gaseous xenon is used as a sensitive probe for the structural and textural investigation of porous materials. The chemical shift is responsive to the pore sizes and surface chemistry in a wide range of industrially relevant materials. However, many applications of porous materials necessitate the interaction of a liquid with the pore surface. Little is known about the behavior of xenon in such systems. Supported ionic liquid phase (SILP) catalysts are a promising class of new catalysts, achieved by impregnating a suitable porous solid support with a combination of an ionic liquid (IL) and a catalytically active metal complex. In general, a thin, homogeneous film covering the surface is advantageous for many applications. Using <sup>129</sup>Xe as a probe nucleus detected by <sup>129</sup>Xe NMR spectroscopy, combined with quantitative xenon physisorption isotherms, different environments can be discerned in the SILP, namely, xenon adsorbed on the bare silica surface and xenon adsorbed on an immobilized IL phase. Moreover, we found that the behavior of xenon and its mobility depend intricately on the nature of the IL and its interactions with the support.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"14 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507331","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}
Metal–halide perovskites display diode behavior that systematically deviates from classical Shockley theory, yet the physical origin of their noninteger ideality factors remains debated. Here, we derive a unified analytical framework that links the ideality factor nid to the energetic level and occupancy of defect states, the quasi-Fermi-level splitting at open circuit, and the detrapping kinetics of injected charge. By consistently treating illumination- and bias-dependent measurements, the framework clarifies why trap-assisted recombination in soft, defect-rich semiconductors generally yields 1 < nid < 2 and how nid evolves with trap-level energetics and voltage. The resulting expressions provide a physically transparent reinterpretation of widely used Voc–log(I) and Suns–Voc analyses in perovskite solar cells and offer a general route to quantify trap-controlled recombination in emerging semiconductor absorbers.
金属卤化物钙钛矿显示的二极管行为系统地偏离了经典的肖克利理论，但其非整数理想因子的物理起源仍然存在争议。在这里，我们推导了一个统一的分析框架，将理想因子nid与缺陷态的能级和占有、开路的准费米能级分裂和注入电荷的脱陷动力学联系起来。通过一致地处理依赖于照明和偏倚的测量，该框架阐明了为什么在软的、富含缺陷的半导体中，陷阱辅助重组通常产生1 <； nid < 2，以及nid如何随着陷阱能级的能量和电压而演变。所得表达式为钙钛矿太阳能电池中广泛使用的Voc-log (I)和sun - voc分析提供了物理上透明的重新解释，并为量化新兴半导体吸收剂中陷阱控制的重组提供了一般途径。
{"title":"Trap-Controlled Ideality Factors in Metal–Halide Perovskite Solar Cells: A Unified Analytical Framework","authors":"Jintian Pan, Yanwei Fan, Deli Li, Yue Wang, Qing Song, Yonghua Chen, Wei Huang","doi":"10.1021/acs.jpcc.5c08380","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c08380","url":null,"abstract":"Metal–halide perovskites display diode behavior that systematically deviates from classical Shockley theory, yet the physical origin of their noninteger ideality factors remains debated. Here, we derive a unified analytical framework that links the ideality factor <i>n</i><sub>id</sub> to the energetic level and occupancy of defect states, the quasi-Fermi-level splitting at open circuit, and the detrapping kinetics of injected charge. By consistently treating illumination- and bias-dependent measurements, the framework clarifies why trap-assisted recombination in soft, defect-rich semiconductors generally yields 1 < <i>n</i><sub>id</sub> < 2 and how <i>n</i><sub>id</sub> evolves with trap-level energetics and voltage. The resulting expressions provide a physically transparent reinterpretation of widely used Voc–log(<i>I</i>) and Suns–Voc analyses in perovskite solar cells and offer a general route to quantify trap-controlled recombination in emerging semiconductor absorbers.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"15 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507332","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}
High-entropy perovskite ceramics (HEPC) have attracted significant attention due to their unique structure and applications in energy storage and catalytic properties. The presence of numerous nonequilibrium valence states in HEPC contributes to their advantageous catalytic and energy storage capabilities. In this study, we have studied the structural stability and tunability of La(Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)O3 HEPC from 0 to 51.0 GPa using in situ high-pressure synchrotron radiation X-ray diffraction. We employed scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) to analyze the microstructure morphology and valence state of samples. The results indicate the existence of substable regions in the initial HECP powder and a process of pressure-induced structural reorganization starting at 2.0 GPa. These substable regions in HEPC undergo redistribution and structural reconfiguration, eventually merging into HECP at 16.2 GPa. These findings suggest that the structure of HEPC exhibits remarkable tunability under high pressure, which could enhance the exploration of HEPC for energy storage and catalysis applications under high-pressure conditions.
{"title":"High-Pressure-Induced Structural Reorganization in the High-Entropy Perovskite La(Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)O3","authors":"Baoming Ding, Wenjia Liang, Yingying Zeng, Tianyu Li, Hao Liang","doi":"10.1021/acs.jpcc.6c00428","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00428","url":null,"abstract":"High-entropy perovskite ceramics (HEPC) have attracted significant attention due to their unique structure and applications in energy storage and catalytic properties. The presence of numerous nonequilibrium valence states in HEPC contributes to their advantageous catalytic and energy storage capabilities. In this study, we have studied the structural stability and tunability of La(Co<sub>0.2</sub>Cr<sub>0.2</sub>Fe<sub>0.2</sub>Mn<sub>0.2</sub>Ni<sub>0.2</sub>)O<sub>3</sub> HEPC from 0 to 51.0 GPa using <i>in situ</i> high-pressure synchrotron radiation X-ray diffraction. We employed scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) to analyze the microstructure morphology and valence state of samples. The results indicate the existence of substable regions in the initial HECP powder and a process of pressure-induced structural reorganization starting at 2.0 GPa. These substable regions in HEPC undergo redistribution and structural reconfiguration, eventually merging into HECP at 16.2 GPa. These findings suggest that the structure of HEPC exhibits remarkable tunability under high pressure, which could enhance the exploration of HEPC for energy storage and catalysis applications under high-pressure conditions.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"17 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147507335","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}
Janus MoSeTe, with intrinsic structural asymmetry and strong spin–orbit coupling, is promising for valleytronics and nonlinear optics. While its properties have been widely predicted theoretically, controlled experimental synthesis has remained elusive. Here, we report the successful synthesis of 2H-phase Janus MoSeTe monolayers, bridging theory and experiment. Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning transmission electron microscopy confirm the Janus structure. The extremely weak photoluminescence indicates an indirect bandgap. We further study its second-harmonic generation (SHG) properties, finding that broken out-of-plane mirror symmetry enhances the second-order nonlinear optical response to ∼1.7× that of monolayer MoSe2. When MoSe2 is stacked on Janus MoSeTe with a ∼30° twist, forming a van der Waals heterostructure, SHG is further enhanced to ∼2.7× monolayer MoSe2 and exhibits anisotropy (maximum-to-minimum intensity ratio ∼1.34). These results provide a route for synthesizing novel 2D Janus TMDs and establish Janus MoSeTe-based systems as a platform for tunable second-order nonlinear optics.
{"title":"Synthesis of 2H-Phase Janus MoSeTe Monolayers and Their Second-Harmonic Generation","authors":"Xiaotong Zheng,Xiaoying Wang,Shuilong Chen,Guanglin Yang,Jialong Zhang,Enzi Chen,Hongdie Chen,Chuan Yu,Xi Wan,Ya-qing Bie,Kun Chen","doi":"10.1021/acs.jpcc.6c01235","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c01235","url":null,"abstract":"Janus MoSeTe, with intrinsic structural asymmetry and strong spin–orbit coupling, is promising for valleytronics and nonlinear optics. While its properties have been widely predicted theoretically, controlled experimental synthesis has remained elusive. Here, we report the successful synthesis of 2H-phase Janus MoSeTe monolayers, bridging theory and experiment. Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning transmission electron microscopy confirm the Janus structure. The extremely weak photoluminescence indicates an indirect bandgap. We further study its second-harmonic generation (SHG) properties, finding that broken out-of-plane mirror symmetry enhances the second-order nonlinear optical response to ∼1.7× that of monolayer MoSe2. When MoSe2 is stacked on Janus MoSeTe with a ∼30° twist, forming a van der Waals heterostructure, SHG is further enhanced to ∼2.7× monolayer MoSe2 and exhibits anisotropy (maximum-to-minimum intensity ratio ∼1.34). These results provide a route for synthesizing novel 2D Janus TMDs and establish Janus MoSeTe-based systems as a platform for tunable second-order nonlinear optics.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"35 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147506433","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}
Designing electrocatalysts with high activity, selectivity, and stability for the two-electron water oxidation reaction (2e– WOR) to produce H2O2 remains challenging. Although many single-component electrocatalysts have been investigated, their performance has plateaued. Here, we demonstrate an effective strategy for transforming an inert metal oxide such as rutile TiO2 into an active electrocatalyst by supporting it with a metallic layer that incorporates very mobile charge carriers. Experimentally, we show that a Pt support layer dramatically enhances the performance of TiO2, yielding higher current densities, lower onset potentials, and markedly improved Faradaic efficiency for producing H2O2. Our density functional theory calculations reveal the mechanistic origin of this enhancement, which lies in the presence of free-electron charge carriers on the support required for 2e– WOR. As a result, the Pt support causes the crucial OH* intermediate to bind more tightly to the active site than Pt-free TiO2, leading to improved activity and selectivity of thin TiO2(110) overlayers for producing H2O2. Through a comparative analysis with a nonenhancing Ag support via examination of the density of states, we pinpoint the electronic cause as the hybridization between Ti 3d and Pt 5d orbitals, which creates available 5d-band electrons near the Fermi level. This 5d-band availability and higher work function difference allow for a more favorable charge transfer to the OH* reaction intermediate. Our findings establish the electronic character of the buried support as a key design parameter for creating highly active and selective heterostructure catalysts for H2O2 synthesis.
{"title":"Electronic Role of a Buried Platinum Layer in TiO2 for Selective Two-Electron Water Oxidation to H2O2","authors":"Kiran Srinivasan Hamkins,Pooja Basera,Xiaolin Zheng,Michal Bajdich","doi":"10.1021/acs.jpcc.6c00559","DOIUrl":"https://doi.org/10.1021/acs.jpcc.6c00559","url":null,"abstract":"Designing electrocatalysts with high activity, selectivity, and stability for the two-electron water oxidation reaction (2e– WOR) to produce H2O2 remains challenging. Although many single-component electrocatalysts have been investigated, their performance has plateaued. Here, we demonstrate an effective strategy for transforming an inert metal oxide such as rutile TiO2 into an active electrocatalyst by supporting it with a metallic layer that incorporates very mobile charge carriers. Experimentally, we show that a Pt support layer dramatically enhances the performance of TiO2, yielding higher current densities, lower onset potentials, and markedly improved Faradaic efficiency for producing H2O2. Our density functional theory calculations reveal the mechanistic origin of this enhancement, which lies in the presence of free-electron charge carriers on the support required for 2e– WOR. As a result, the Pt support causes the crucial OH* intermediate to bind more tightly to the active site than Pt-free TiO2, leading to improved activity and selectivity of thin TiO2(110) overlayers for producing H2O2. Through a comparative analysis with a nonenhancing Ag support via examination of the density of states, we pinpoint the electronic cause as the hybridization between Ti 3d and Pt 5d orbitals, which creates available 5d-band electrons near the Fermi level. This 5d-band availability and higher work function difference allow for a more favorable charge transfer to the OH* reaction intermediate. Our findings establish the electronic character of the buried support as a key design parameter for creating highly active and selective heterostructure catalysts for H2O2 synthesis.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"16 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2026-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147506435","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：