Pub Date : 2025-12-16DOI: 10.1016/j.chemphys.2025.113066
Kai Zhang , Guanglu He , Yiquan Wang , Guoliang Chen , Jianjun Fang , Chuan-Kui Wang , Jing Li
Orange-red thermally activated delayed fluorescence (TADF) molecules show great potential for OLEDs. Based on density functional theory (DFT) and the thermal vibration correlation function (TVCF) method, the luminescence mechanisms of the bridged open-ring structure T-DMAC-PPyM and the bridged closed-ring structure P-DMAC-BPyM are investigated in both toluene and the solid state. The fluorescence efficiency (ΦF) of the T-DMAC-PPyM in toluene is slightly higher than that of P-DMAC-BPyM, which is due to the larger radiation rate (kr) and smaller non-radiative decay rate (knr). In contrast, the sharply increased kr of P-DMAC-BPyM in the solid state leads to a much higher ΦF than that of T-DMAC-PPyM. In addition, P-DMAC-BPyM reduces ΔEST in the solid state and increases the spin-orbit coupling (SOC) constant, which is beneficial to improve the reverse intersystem crossing rate (RISC). Studies have shown that T-DMAC-PPyM has better intrinsic fluorescence properties, while P-DMAC-BPyM has better TADF properties in the solid state.
{"title":"Effect of molecular bridging group flexibility on the luminescent properties of Orange-red TADF molecules: A QM/MM study","authors":"Kai Zhang , Guanglu He , Yiquan Wang , Guoliang Chen , Jianjun Fang , Chuan-Kui Wang , Jing Li","doi":"10.1016/j.chemphys.2025.113066","DOIUrl":"10.1016/j.chemphys.2025.113066","url":null,"abstract":"<div><div>Orange-red thermally activated delayed fluorescence (TADF) molecules show great potential for OLEDs. Based on density functional theory (DFT) and the thermal vibration correlation function (TVCF) method, the luminescence mechanisms of the bridged open-ring structure T-DMAC-PPyM and the bridged closed-ring structure P-DMAC-BPyM are investigated in both toluene and the solid state. The fluorescence efficiency (Φ<sub>F</sub>) of the T-DMAC-PPyM in toluene is slightly higher than that of P-DMAC-BPyM, which is due to the larger radiation rate (k<sub>r</sub>) and smaller non-radiative decay rate (k<sub>nr</sub>). In contrast, the sharply increased k<sub>r</sub> of P-DMAC-BPyM in the solid state leads to a much higher Φ<sub>F</sub> than that of T-DMAC-PPyM. In addition, P-DMAC-BPyM reduces ΔE<sub>ST</sub> in the solid state and increases the spin-orbit coupling (SOC) constant, which is beneficial to improve the reverse intersystem crossing rate (RISC). Studies have shown that T-DMAC-PPyM has better intrinsic fluorescence properties, while P-DMAC-BPyM has better TADF properties in the solid state.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113066"},"PeriodicalIF":2.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-14DOI: 10.1016/j.chemphys.2025.113061
Hamza Kellou , Salem Boudinar , Nassima Benbrahim , Eric Chainet
Chromium three oxide (Cr2O3) nanopowder (NPW) was synthesized by chemical method, using (NaBH4) as a reducing agent from chromium six oxide (CrO3) dissolved in water.
The obtained Cr2O3 NPWs were characterized by several techniques such as scanning electron microscopy (SEM) coupled energy dispersive spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–Visible spectrophotometer and Brunauer–Emmett–Teller (BET) analysis. The SEM observation of NPW, shows the formation of particles with nano-meter sizes about 25–175 nm. The FTIR shows two large band attributed to the CrO and CrO vibrations. The mesoporous Cr2O3 powder exhibited a specific surface area of 130 m2 g−1, as determined by BET analysis. UV–Vis spectrum of Cr2O3 NPs revels two strong bands (in solution) at 270 and 370 nm. For the solid UV–Vis, there are three peaks localized at 268, 397 and 603 nm which confirms the formation of Cr (III).
The electrochemical and photoelectrochemical performance of the synthesized NPW was evaluated by electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV), respectively. The powder presents a pseudo super-capacitor behavior. The stability, the electrochemical impedance, energy storage and semiconductor (SC) behavior of the NPW were also tested. Electrochemical impedance spectroscopy (EIS) analysis revealed a charge transfer resistance Rct of 7100, 4225 and 2970 Ω in the dark, under visible light and under UV irradiation, respectively, as shown in the Nyquist plot. The specific capacitance, calculated from cyclic voltammetry (CV) at a scan rate of 100 mV s−1, exhibited high stability, with a variation of only ∼83 nF after 1000 cycles. The highest areal specific capacitance equal 332 mF g−1 during the charging process and 388 mF g−1 during discharge at a current density of 160 mA g−1. The n-type semiconductor (SC) shows a good potential for energy storage and PEC applications.
The photocatalytic activity of Cr2O3 NPs was evaluated by degradation of methylene blue (MB) under UV and visible light irradiation, which lead to 98 and 93 % of BM degradation, respectively.
{"title":"Chromium three oxide nanoparticle electrodes for supercapacitor and photocatalytic applications","authors":"Hamza Kellou , Salem Boudinar , Nassima Benbrahim , Eric Chainet","doi":"10.1016/j.chemphys.2025.113061","DOIUrl":"10.1016/j.chemphys.2025.113061","url":null,"abstract":"<div><div>Chromium three oxide (Cr<sub>2</sub>O<sub>3</sub>) nanopowder (NPW) was synthesized by chemical method, using (NaBH<sub>4</sub>) as a reducing agent from chromium six oxide (CrO<sub>3</sub>) dissolved in water.</div><div>The obtained Cr<sub>2</sub>O<sub>3</sub> NPWs were characterized by several techniques such as scanning electron microscopy (SEM) coupled energy dispersive spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–Visible spectrophotometer and Brunauer–Emmett–Teller (BET) analysis. The SEM observation of NPW, shows the formation of particles with nano-meter sizes about 25–175 nm. The FTIR shows two large band attributed to the Cr<img>O and Cr<img>O vibrations. The mesoporous Cr<sub>2</sub>O<sub>3</sub> powder exhibited a specific surface area of 130 m<sup>2</sup> g<sup>−1</sup>, as determined by BET analysis. UV–Vis spectrum of Cr<sub>2</sub>O<sub>3</sub> NPs revels two strong bands (in solution) at 270 and 370 nm. For the solid UV–Vis, there are three peaks localized at 268, 397 and 603 nm which confirms the formation of Cr (III).</div><div>The electrochemical and photoelectrochemical performance of the synthesized NPW was evaluated by electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV), respectively. The powder presents a pseudo super-capacitor behavior. The stability, the electrochemical impedance, energy storage and semiconductor (SC) behavior of the NPW were also tested. Electrochemical impedance spectroscopy (EIS) analysis revealed a charge transfer resistance R<sub>ct</sub> of 7100, 4225 and 2970 Ω in the dark, under visible light and under UV irradiation, respectively, as shown in the Nyquist plot. The specific capacitance, calculated from cyclic voltammetry (CV) at a scan rate of 100 mV s<sup>−1</sup>, exhibited high stability, with a variation of only ∼83 nF after 1000 cycles. The highest areal specific capacitance equal 332 mF g<sup>−1</sup> during the charging process and 388 mF g<sup>−1</sup> during discharge at a current density of 160 mA g<sup>−1</sup>. The n-type semiconductor (SC) shows a good potential for energy storage and PEC applications.</div><div>The photocatalytic activity of Cr<sub>2</sub>O<sub>3</sub> NPs was evaluated by degradation of methylene blue (MB) under UV and visible light irradiation, which lead to 98 and 93 % of BM degradation, respectively.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113061"},"PeriodicalIF":2.4,"publicationDate":"2025-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-13DOI: 10.1016/j.chemphys.2025.113062
Youssef Jouad , Younes Ziat , Abdellah Bouzaid , Mohammed Miri , Hamza Belkhanchi , Zakaryaa Zarhri
This study uses density functional theory (DFT) to examine the impact of hydrostatic pressure (0–2 GPa) on the structural, mechanical, electrical, and optical characteristics of the halide perovskites AlSnBr₃ and AlSnI₃. The computed negative formation energies affirm the thermodynamic stability of the compounds, while the Born criteria, derived from the assessment of the three principal elastic coefficients (C11, C22, and C44) typical of cubic structures, further substantiate their mechanical stability. The examination of the elastic constants shows that both materials are mechanically stable and relatively soft, and that their values change gradually when pressure is applied. Complementary measures, such as the Pugh ratio (K/G) and Poisson's ratio (v), substantiate that both compounds exhibit enhanced ductility with increasing pressure. At ambient pressure, AlSnX3 (X = Br, I) demonstrates band gaps of 0.564 eV (indirect) and 0.533 eV (direct) using the mBJ potential, which increases to 0.84 eV and 0.83 eV using the HSE06 approach. As pressure intensifies, the band gap steadily diminishes, modifying electronic transitions and ultimately shutting at around 2 GPa. This closure signifies a semiconductor-to-metal transition, primarily influenced by the substantial addition of aluminum states to the conduction band, hence augmenting electron density and electrical conductivity. The optical characteristics develop along with these electronic alterations. Increased absorption intensity and alterations in the dielectric function, particularly in the visible and ultraviolet areas, reveal better light–matter interaction. These improvements result in enhanced light-harvesting capacity and increased photon-to-carrier conversion efficiency. Our results collectively show that AlSnBr₃ and AlSnI₃ constitute promising candidates for optoelectronic applications that can be changed by pressure.
{"title":"Exploring the influence of hydrostatic pressure on the structural, mechanical, and optoelectronic behavior of AlSnBr3 and AlSnI3 halide perovskites via DFT","authors":"Youssef Jouad , Younes Ziat , Abdellah Bouzaid , Mohammed Miri , Hamza Belkhanchi , Zakaryaa Zarhri","doi":"10.1016/j.chemphys.2025.113062","DOIUrl":"10.1016/j.chemphys.2025.113062","url":null,"abstract":"<div><div>This study uses density functional theory (DFT) to examine the impact of hydrostatic pressure (0–2 GPa) on the structural, mechanical, electrical, and optical characteristics of the halide perovskites AlSnBr₃ and AlSnI₃. The computed negative formation energies affirm the thermodynamic stability of the compounds, while the Born criteria, derived from the assessment of the three principal elastic coefficients (C<sub>11</sub>, C<sub>22</sub>, and C<sub>44</sub>) typical of cubic structures, further substantiate their mechanical stability. The examination of the elastic constants shows that both materials are mechanically stable and relatively soft, and that their values change gradually when pressure is applied. Complementary measures, such as the Pugh ratio (K/G) and Poisson's ratio (v), substantiate that both compounds exhibit enhanced ductility with increasing pressure. At ambient pressure, AlSnX<sub>3</sub> (X = Br, I) demonstrates band gaps of 0.564 eV (indirect) and 0.533 eV (direct) using the mBJ potential, which increases to 0.84 eV and 0.83 eV using the HSE06 approach. As pressure intensifies, the band gap steadily diminishes, modifying electronic transitions and ultimately shutting at around 2 GPa. This closure signifies a semiconductor-to-metal transition, primarily influenced by the substantial addition of aluminum states to the conduction band, hence augmenting electron density and electrical conductivity. The optical characteristics develop along with these electronic alterations. Increased absorption intensity and alterations in the dielectric function, particularly in the visible and ultraviolet areas, reveal better light–matter interaction. These improvements result in enhanced light-harvesting capacity and increased photon-to-carrier conversion efficiency. Our results collectively show that AlSnBr₃ and AlSnI₃ constitute promising candidates for optoelectronic applications that can be changed by pressure.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113062"},"PeriodicalIF":2.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-13DOI: 10.1016/j.chemphys.2025.113052
Waqar Ahmad , Atta Ur Rahman , Iftikhar Ahmad , Imad Khan
The majority of reported two-dimensional (2D) Ruddlesden-Popper (RP) lead halide perovskites, follow the general formula An+1BnX3n+1 (where n = 1, 2, …), featuring layered perovskite structures interleaved with A-site-substituted organic or inorganic spacer cations. However, X-site-substituted RP halide perovskites (pseudo-halide) remain relatively underexplored. In this work, we performed first-principles investigations of an all-inorganic pseudo-halide 2D perovskite, Cs2Pb(SCN)2Br2, using density functional theory (DFT). The 3D lattice is composed of 2D perovskite layers that function as quantum wells for charge carriers and the spacer layers serve as potential barriers. The calculations for the electronic structures have confirmed that Cs2Pb(SCN)2Br2 holds a direct band gap of 2.69 eV, a low binding energy of 166 meV and a small interlayer distance of 1.69 Å with effective light absorption in the visible spectra. The results from optical characterization signify its promising features for the optoelectronic applications, such as solar cells and light emitting diodes (LEDs). For the evaluation of photovoltaic performance, FTO/SnO2/Cs2Pb(SCN)2Br2/Cu2O/Au device structure was simulated, in which SnO2 serves as electron transport layer (ETL) and Cu2O as the hole transport layer (HTL). The device in optimized state showed fill factor (FF) of 82.2 %, open-circuit voltage (Voc) of 1.73 V, power conversion efficiency (PCE) of 19.03 %, and short-circuit density (Jsc) of 13.2 mA cm−2. The results of this study provides a strong basis for future research focusing on inorganic pseudo-halide perovskites, thus enabling for the development of enhanced photovoltaic performance via experimental and theoretical advancements.
{"title":"Optoelectronic properties of all-inorganic pseudo-halide perovskite Cs2Pb(SCN)2Br2: a first-principles study","authors":"Waqar Ahmad , Atta Ur Rahman , Iftikhar Ahmad , Imad Khan","doi":"10.1016/j.chemphys.2025.113052","DOIUrl":"10.1016/j.chemphys.2025.113052","url":null,"abstract":"<div><div>The majority of reported two-dimensional (2D) Ruddlesden-Popper (RP) lead halide perovskites, follow the general formula A<sub>n+1</sub>B<sub>n</sub>X<sub>3n+1</sub> (where <em>n</em> = 1, 2, …), featuring layered perovskite structures interleaved with A-site-substituted organic or inorganic spacer cations. However, X-site-substituted RP halide perovskites (pseudo-halide) remain relatively underexplored. In this work, we performed first-principles investigations of an all-inorganic pseudo-halide 2D perovskite, Cs<sub>2</sub>Pb(SCN)<sub>2</sub>Br<sub>2</sub>, using density functional theory (DFT). The 3D lattice is composed of 2D perovskite layers that function as quantum wells for charge carriers and the spacer layers serve as potential barriers. The calculations for the electronic structures have confirmed that Cs<sub>2</sub>Pb(SCN)<sub>2</sub>Br<sub>2</sub> holds a direct band gap of 2.69 eV, a low binding energy of 166 meV and a small interlayer distance of 1.69 Å with effective light absorption in the visible spectra. The results from optical characterization signify its promising features for the optoelectronic applications, such as solar cells and light emitting diodes (LEDs). For the evaluation of photovoltaic performance, FTO/SnO<sub>2</sub>/Cs<sub>2</sub>Pb(SCN)<sub>2</sub>Br<sub>2</sub>/Cu<sub>2</sub>O/Au device structure was simulated, in which SnO<sub>2</sub> serves as electron transport layer (ETL) and Cu<sub>2</sub>O as the hole transport layer (HTL). The device in optimized state showed fill factor (FF) of 82.2 %, open-circuit voltage (V<sub>oc</sub>) of 1.73 V, power conversion efficiency (PCE) of 19.03 %, and short-circuit density (J<sub>sc</sub>) of 13.2 mA cm<sup>−2</sup>. The results of this study provides a strong basis for future research focusing on inorganic pseudo-halide perovskites, thus enabling for the development of enhanced photovoltaic performance via experimental and theoretical advancements.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113052"},"PeriodicalIF":2.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-13DOI: 10.1016/j.chemphys.2025.113060
Khurshid Ahmad , Faiz Mahmood , Dibakar Roy , Alamgir Khan , Munir Ahmad , Subhashree Ray , Naveen Chandra Talniya , Gunjan Garg , Islom Khudayberganov , Egambergan Madrahimovich Xudaynazarov , Iqra Sarwar
In this study, a simple and low-cost hydrothermal method was used to create Cu-doped NiO with tunable shape. The inclusion of copper enhanced the material's electrical transport and electrochemical activity, leading to a higher charge-storage capacity and better rate performance. XRD and electron microscopy effectively confirmed Cu2+ substitution in the NiO lattice, leading to improved surface texturing, reduced crystallite size, and internal strain. At 5 % Cu doping, lattice distortions produced a unique hierarchical flower-like structure composed of thin, uneven Nano sheets. These structural modifications facilitate enhanced ionic transport pathways and more efficient electron transfer, ultimately elevating the material's electrochemical functionality. Optical characterization via UV–visible spectroscopy demonstrated a reduction in the energy band gap, decreasing from 3.14 eV in pure NiO to 2.50 eV in the 5 % Cu-doped variant, suggesting enhanced photoresponse characteristics. Electrochemical evaluation revealed substantial enhancement in pseudocapacitive behavior: specific capacitance values increased from 212 F g−1 for the undoped material to 377 F g−1 for the 5 % Cu-NiO sample when measured at a scan rate of 10 mV/s. Constant current charge-discharge measurements yielded an even higher capacitance of 394 F g−1 at a current density of 1 A g−1.The optimized electrode configuration achieved an energy density of 45 Wh/kg coupled with a power density of 788 W/kg when operated at 3 A g−1. Long-term cycling stability tests demonstrated that the 5 % Cu-NiO electrode maintained 90 % of its initial capacitance alongside 85 % coulombic efficiency even after 10,000 consecutive charge-discharge cycles, confirming remarkable operational stability. These findings validate that strategic copper incorporation substantially improves the electrochemical characteristics of nickel oxide, establishing its potential for advanced energy storage applications with efficient charge storage mechanisms, minimal capacity fade, and robust long-term performance.
本研究采用简单、低成本的水热法制备了形状可调的cu掺杂NiO。铜的加入增强了材料的电传输和电化学活性，导致更高的电荷存储容量和更好的倍率性能。XRD和电镜有效地证实了NiO晶格中的Cu2+取代，从而改善了表面织构，减小了晶粒尺寸，降低了内部应变。在5%的Cu掺杂下，晶格扭曲产生了一种独特的分层花状结构，由薄而不均匀的纳米片组成。这些结构修饰有助于增强离子传递途径和更有效的电子传递，最终提高材料的电化学功能。通过紫外可见光谱进行的光学表征表明，能带隙减小，从纯NiO的3.14 eV减小到5% cu掺杂的2.50 eV，表明光响应特性增强。电化学评价表明，在扫描速率为10 mV/s时，未掺杂材料的比电容值从212 F g−1增加到5% Cu-NiO样品的377 F g−1。恒流充放电测量在电流密度为1 a g−1时产生了更高的394 F g−1电容。优化后的电极结构在3 a g−1下的能量密度为45 Wh/kg，功率密度为788 W/kg。长期循环稳定性测试表明，即使在连续10,000次充放电循环后，5% Cu-NiO电极仍保持90%的初始电容和85%的库仑效率，证实了卓越的运行稳定性。这些研究结果证实，战略性铜掺入大大改善了氧化镍的电化学特性，并以高效的电荷存储机制、最小的容量衰减和稳定的长期性能，确立了其在先进储能应用中的潜力。
{"title":"Enhanced supercapacitor performance of copper-doped NiO nanostructures synthesized via hydrothermal method","authors":"Khurshid Ahmad , Faiz Mahmood , Dibakar Roy , Alamgir Khan , Munir Ahmad , Subhashree Ray , Naveen Chandra Talniya , Gunjan Garg , Islom Khudayberganov , Egambergan Madrahimovich Xudaynazarov , Iqra Sarwar","doi":"10.1016/j.chemphys.2025.113060","DOIUrl":"10.1016/j.chemphys.2025.113060","url":null,"abstract":"<div><div>In this study, a simple and low-cost hydrothermal method was used to create Cu-doped NiO with tunable shape. The inclusion of copper enhanced the material's electrical transport and electrochemical activity, leading to a higher charge-storage capacity and better rate performance. XRD and electron microscopy effectively confirmed Cu<sup>2+</sup> substitution in the NiO lattice, leading to improved surface texturing, reduced crystallite size, and internal strain. At 5 % Cu doping, lattice distortions produced a unique hierarchical flower-like structure composed of thin, uneven Nano sheets. These structural modifications facilitate enhanced ionic transport pathways and more efficient electron transfer, ultimately elevating the material's electrochemical functionality. Optical characterization via UV–visible spectroscopy demonstrated a reduction in the energy band gap, decreasing from 3.14 eV in pure NiO to 2.50 eV in the 5 % Cu-doped variant, suggesting enhanced photoresponse characteristics. Electrochemical evaluation revealed substantial enhancement in pseudocapacitive behavior: specific capacitance values increased from 212 F g<sup>−1</sup> for the undoped material to 377 F g<sup>−1</sup> for the 5 % Cu-NiO sample when measured at a scan rate of 10 mV/s. Constant current charge-discharge measurements yielded an even higher capacitance of 394 F g<sup>−1</sup> at a current density of 1 A g<sup>−1</sup>.The optimized electrode configuration achieved an energy density of 45 Wh/kg coupled with a power density of 788 W/kg when operated at 3 A g<sup>−1</sup>. Long-term cycling stability tests demonstrated that the 5 % Cu-NiO electrode maintained 90 % of its initial capacitance alongside 85 % coulombic efficiency even after 10,000 consecutive charge-discharge cycles, confirming remarkable operational stability. These findings validate that strategic copper incorporation substantially improves the electrochemical characteristics of nickel oxide, establishing its potential for advanced energy storage applications with efficient charge storage mechanisms, minimal capacity fade, and robust long-term performance.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113060"},"PeriodicalIF":2.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-13DOI: 10.1016/j.chemphys.2025.113063
Sajid Ali , Basit Ali , Sani Abdulkarim , Mengtao Sun
The optoelectronic and photocatalytic characteristics of MoS₂, WS₂, and SiS₂ monolayers, as well as MoS₂/SiS₂ and WS₂/SiS₂ van der Waals (vdW) heterostructures, are investigated using first-principles density functional theory (DFT) calculations. Initially, it is verified that, in energy, all monolayers and their vdW heterostructures are structurally stable. SiS₂ has a direct band gap of 2.02 eV, monolayer MoS₂ exhibits a direct band gap of approximately 1.82 eV, while monolayer WS₂ shows a direct band gap of around 1.97 eV. These values differ from their bulk counterparts, which possess indirect band gaps due to interlayer interactions. When applied in photovoltaic and energy-harvesting devices, type-II band alignment has been observed in the MoS₂/SiS₂ and WS₂/SiS₂ vdW heterostructures. Moreover, charge transfer at the interface of these heterostructures provides an intrinsic electric field, which drives electrons and holes in opposite directions, thereby reducing the recombination rate of photogenerated electron–hole pairs. The main prerequisite for optoelectronic and photocatalytic applications in materials is efficient charge-carrier separation within them. Improved optical characteristics of the vdW heterostructures reveal their enhanced absorption in the visible-light region, which offers promise for the development of high-performance photocatalysts and optoelectronic devices.
利用第一性原理密度泛函理论（DFT）计算研究了MoS 2、WS 2和SiS 2单层以及MoS 2 /SiS 2和WS 2 /SiS 2 van der Waals （vdW）异质结构的光电和光催化特性。初步验证了在能量上，所有单层及其vdW异质结构都是结构稳定的。SiS₂的直接带隙为2.02 eV，单层MoS₂的直接带隙约为1.82 eV，单层WS₂的直接带隙约为1.97 eV。这些值不同于它们的体对应值，后者由于层间相互作用而具有间接带隙。当应用于光伏和能量收集器件时，在MoS₂/SiS₂和WS₂/SiS₂vdW异质结构中观察到ii型波段对准。此外，这些异质结构界面处的电荷转移提供了一个本征电场，该电场驱动电子和空穴向相反方向运动，从而降低了光生电子-空穴对的复合速率。光电子和光催化在材料中应用的主要前提是材料内部有效的载流子分离。改进的vdW异质结构的光学特性揭示了其在可见光区的吸收增强，这为高性能光催化剂和光电子器件的发展提供了希望。
{"title":"Structural and optoelectronic properties of XS₂ (X = Mo, W)/SiS₂ van der Waals Heterostructures for advanced energy applications","authors":"Sajid Ali , Basit Ali , Sani Abdulkarim , Mengtao Sun","doi":"10.1016/j.chemphys.2025.113063","DOIUrl":"10.1016/j.chemphys.2025.113063","url":null,"abstract":"<div><div>The optoelectronic and photocatalytic characteristics of MoS₂, WS₂, and SiS₂ monolayers, as well as MoS₂/SiS₂ and WS₂/SiS₂ van der Waals (vdW) heterostructures, are investigated using first-principles density functional theory (DFT) calculations. Initially, it is verified that, in energy, all monolayers and their vdW heterostructures are structurally stable<strong>.</strong> SiS₂ has a direct band gap of 2.02 eV<strong>,</strong> monolayer MoS₂ exhibits a direct band gap of approximately 1.82 eV<strong>,</strong> while monolayer WS₂ shows a direct band gap of around 1.97 eV<strong>.</strong> These values differ from their bulk counterparts, which possess <strong>i</strong>ndirect band gaps due to interlayer interactions. When applied in photovoltaic and energy-harvesting devices, type-II band alignment has been observed in the MoS₂/SiS₂ and WS₂/SiS₂ vdW heterostructures. Moreover, charge transfer at the interface of these heterostructures provides an intrinsic electric field, which drives electrons and holes in opposite directions, thereby reducing the recombination rate of photogenerated electron–hole pairs. The main prerequisite for optoelectronic and photocatalytic applications in materials is efficient charge-carrier separation within them. Improved optical characteristics of the vdW heterostructures reveal their enhanced absorption in the visible-light region, which offers promise for the development of high-performance photocatalysts and optoelectronic devices.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113063"},"PeriodicalIF":2.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.chemphys.2025.113059
Cesar A. de Mello
Palladium’s Madelung anomaly arises from a spectral phase transition that extinguishes the 5s channel, yielding the [Kr] 4d105s ground state. The transition is set by the sign of an asymptotic operator level, enforcing spectral locking of the s amplitude and giving a sub-Ångström evanescent length (99.9% suppression at sub-Å radii). This extinction/survival mechanism organizes Group-10 trends: Ni near the boundary, Pd deep in the extinct phase, and Pt partially reactivated by relativistic softening. Chemically, s-extinction narrows the d manifold, shifts the d-band center toward , suppresses isotropic mixing, and rationalizes square-planar preference, d-dominated XPS/EELS screening, and near-vanishing Fermi-contact/Knight terms. Angle-integrated XPS shows null s-weight near threshold, as predicted. The asymptotic level maps alloying, strain, coverage, and support/ligand fields to phase control, enabling testable diagnostics and engineering of orbital extinction/reactivation across Group-10 metals.
{"title":"Spectral–topological predictors of surface reactivity in palladium and Group-10 metals","authors":"Cesar A. de Mello","doi":"10.1016/j.chemphys.2025.113059","DOIUrl":"10.1016/j.chemphys.2025.113059","url":null,"abstract":"<div><div>Palladium’s Madelung anomaly arises from a spectral phase transition that extinguishes the 5s channel, yielding the [Kr]<!--> <!-->4d<sup>10</sup>5s<span><math><msup><mrow></mrow><mrow><mn>0</mn></mrow></msup></math></span> ground state. The transition is set by the sign of an asymptotic operator level, enforcing spectral locking of the s amplitude and giving a sub-Ångström evanescent length (<span><math><mo>></mo></math></span>99.9% suppression at sub-Å radii). This <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> extinction/survival mechanism organizes Group-10 trends: Ni near the boundary, Pd deep in the extinct phase, and Pt partially reactivated by relativistic softening. Chemically, s-extinction narrows the d manifold, shifts the d-band center toward <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>F</mi></mrow></msub></math></span>, suppresses isotropic mixing, and rationalizes square-planar preference, d-dominated XPS/EELS screening, and near-vanishing Fermi-contact/Knight terms. Angle-integrated XPS shows null s-weight near threshold, as predicted. The asymptotic level maps alloying, strain, coverage, and support/ligand fields to phase control, enabling testable diagnostics and engineering of orbital extinction/reactivation across Group-10 metals.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113059"},"PeriodicalIF":2.4,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-07DOI: 10.1016/j.chemphys.2025.113057
Ahmad Ali , Shayan Ahmad , Muhammad Hashir , Mohamed Karouchi , Asif Nawaz Khan , Imran Shakir
In this article, the structural, optoelectronic, and thermoelectric properties of novel Sc2BaX₄ (X = S, Se) chalcogenides have been elaborated, utilizing ab initio investigations. The FP-LAPW method incorporated in the WIEN2k code is used to investigate the structural, optoelectronic, and thermoelectric properties of these chalcogenides. The phonon dispersion and mechanical study confirm the dynamical and mechanical stability of the materials. The TB-mBj potential is utilized to achieve accurate electronic band gaps of the materials. The study of the electronic structure reveals that the materials are indirect band semiconductors, with energy band gaps of 1.8 and 1.7 eV for Sc2BaS4 and Sc2BaSe4, respectively. The optical study predicts that the energy absorption is maximum in the visible range of optical spectra. The energy band gaps and optical absorption in the visible range make these materials promising for sustainable energy applications. The Seebeck coefficient of the materials suggests that the Sc2BaS4 is n-type, while Sc2BaSe4 is to be p-type semiconductor at high temperatures.
{"title":"First-principles study of the dynamical, mechanical, optoelectronic, and thermoelectric properties of Sc2BaX4 (X = S, Se) chalcogenides for sustainable energy applications","authors":"Ahmad Ali , Shayan Ahmad , Muhammad Hashir , Mohamed Karouchi , Asif Nawaz Khan , Imran Shakir","doi":"10.1016/j.chemphys.2025.113057","DOIUrl":"10.1016/j.chemphys.2025.113057","url":null,"abstract":"<div><div>In this article, the structural, optoelectronic, and thermoelectric properties of novel Sc<sub>2</sub>BaX₄ (X = S, Se) chalcogenides have been elaborated, utilizing ab initio investigations. The FP-LAPW method incorporated in the WIEN2k code is used to investigate the structural, optoelectronic, and thermoelectric properties of these chalcogenides. The phonon dispersion and mechanical study confirm the dynamical and mechanical stability of the materials. The TB-mBj potential is utilized to achieve accurate electronic band gaps of the materials. The study of the electronic structure reveals that the materials are indirect band semiconductors, with energy band gaps of 1.8 and 1.7 eV for Sc<sub>2</sub>BaS<sub>4</sub> and Sc<sub>2</sub>BaSe<sub>4</sub>, respectively. The optical study predicts that the energy absorption is maximum in the visible range of optical spectra. The energy band gaps and optical absorption in the visible range make these materials promising for sustainable energy applications. The Seebeck coefficient of the materials suggests that the Sc<sub>2</sub>BaS<sub>4 is</sub> n-type, while Sc<sub>2</sub>BaSe<sub>4</sub> is to be p-type semiconductor at high temperatures.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113057"},"PeriodicalIF":2.4,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1016/j.chemphys.2025.113055
Roberto Luiz Andrade Haiduke
The molecular method is used to determine the nuclear quadrupole moments (NQMs) of two barium isotopes, 135Ba and 137Ba. Hence, accurate relativistic electric field gradient (EFG) calculations based on the four-component formalism done at the barium nucleus in two diatomic systems, BaO and BaF, are combined with experimental data of nuclear quadrupole coupling constants. The best EFGs are provided by accounting for electron correlation effects from Dirac-Coulomb Coupled Cluster calculations with iterative single and double excitations plus perturbative triples, with additive Gaunt, vibrational, and extra basis set corrections. Therefore, the recommended NQMs for 135Ba and 137Ba are 155(5) and 239(7) mbarn, respectively.
{"title":"The nuclear quadrupole moment of barium from the molecular method","authors":"Roberto Luiz Andrade Haiduke","doi":"10.1016/j.chemphys.2025.113055","DOIUrl":"10.1016/j.chemphys.2025.113055","url":null,"abstract":"<div><div>The molecular method is used to determine the nuclear quadrupole moments (NQMs) of two barium isotopes, <sup>135</sup>Ba and <sup>137</sup>Ba. Hence, accurate relativistic electric field gradient (EFG) calculations based on the four-component formalism done at the barium nucleus in two diatomic systems, BaO and BaF, are combined with experimental data of nuclear quadrupole coupling constants. The best EFGs are provided by accounting for electron correlation effects from Dirac-Coulomb Coupled Cluster calculations with iterative single and double excitations plus perturbative triples, with additive Gaunt, vibrational, and extra basis set corrections. Therefore, the recommended NQMs for <sup>135</sup>Ba and <sup>137</sup>Ba are 155(5) and 239(7) mbarn, respectively.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113055"},"PeriodicalIF":2.4,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1016/j.chemphys.2025.113056
Feng Gu, Jijun Xiao
Organic-inorganic energetic perovskite materials have become a major attraction in the field of energetic materials. Silver-based energetic perovskite (H2pz)[Ag(ClO4)3] (PAP-5) has garnered significant interest due to its unique detonation properties, mechanical, electrical, and structural characteristics. Since strain engineering serves as a powerful tool for modifying the physical properties and crystal structure of perovskite materials, this study employs density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations to investigate the microstructural characteristics of PAP-5 under mechanical loading. The focus includes its structural evolution, band gap, electron charge density, mechanical stability, and interatomic/molecular interactions within the material. It is found that the compressive strength of PAP-5 is greater than the tensile strength, and the stress in different directions is anisotropic. The analysis of bond length and bond angle show that tensile strain has a greater influence on the structure of PAP-5. The band gap will shrink under tensile strain and fluctuate under compressive strain, which is explained from the total density of states. PAP-5 exhibits elastic anisotropy after strain is applied, showing brittleness and ductility during tension and compression respectively. The results of Hirshfeld surface analysis show that the structure of BX3 is more responsive to the applied strain than that of A-site cation.
{"title":"Theoretical study on the effect of strain engineering on the structure and properties of energetic silver-based perovskite","authors":"Feng Gu, Jijun Xiao","doi":"10.1016/j.chemphys.2025.113056","DOIUrl":"10.1016/j.chemphys.2025.113056","url":null,"abstract":"<div><div>Organic-inorganic energetic perovskite materials have become a major attraction in the field of energetic materials. Silver-based energetic perovskite (H<sub>2</sub>pz)[Ag(ClO<sub>4</sub>)<sub>3</sub>] (PAP-5) has garnered significant interest due to its unique detonation properties, mechanical, electrical, and structural characteristics. Since strain engineering serves as a powerful tool for modifying the physical properties and crystal structure of perovskite materials, this study employs density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations to investigate the microstructural characteristics of PAP-5 under mechanical loading. The focus includes its structural evolution, band gap, electron charge density, mechanical stability, and interatomic/molecular interactions within the material. It is found that the compressive strength of PAP-5 is greater than the tensile strength, and the stress in different directions is anisotropic. The analysis of bond length and bond angle show that tensile strain has a greater influence on the structure of PAP-5. The band gap will shrink under tensile strain and fluctuate under compressive strain, which is explained from the total density of states. PAP-5 exhibits elastic anisotropy after strain is applied, showing brittleness and ductility during tension and compression respectively. The results of Hirshfeld surface analysis show that the structure of BX<sub>3</sub> is more responsive to the applied strain than that of A-site cation.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"603 ","pages":"Article 113056"},"PeriodicalIF":2.4,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733042","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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