Pub Date : 2024-11-19DOI: 10.1016/j.chemphys.2024.112523
Zhi-Ang Jiang, Hai-Bo Li, Hao-Qing Zhu, Yong Ma, Xiu-Neng Song
C70 fullerene and its five mono-nitrogen-doped C69N derivatives were identified by calculated x-ray photoelectron spectroscopy (XPS) and near-edge x-ray absorption fine structure (NEXAFS) spectra on density functional theory (DFT) level. The results show that the NEXAFS spectra are more ideal to identify C69N isomers accurately. Furthermore, the relationship between the spectra and local structures is discussed as well. The analysis of XPS and NEXAFS spectra for C69N isomers can help in understanding the preparation and modification of these materials and providing a theoretical foundation for the development of nitrogen-doped fullerenes.
通过在密度泛函理论（DFT）水平上计算 X 射线光电子能谱（XPS）和近边 X 射线吸收精细结构（NEXAFS）光谱，鉴定了 C70 富勒烯及其五种单氮掺杂的 C69N 衍生物。结果表明，近边 X 射线吸收精细结构光谱更适合准确识别 C69N 异构体。此外，还讨论了光谱与局部结构之间的关系。对 C69N 异构体的 XPS 和 NEXAFS 光谱分析有助于理解这些材料的制备和改性，并为掺氮富勒烯的开发提供理论基础。
{"title":"Structural and spectral characterizations of mono-nitrogen doped C70 fullerene by soft X-ray spectroscopy","authors":"Zhi-Ang Jiang, Hai-Bo Li, Hao-Qing Zhu, Yong Ma, Xiu-Neng Song","doi":"10.1016/j.chemphys.2024.112523","DOIUrl":"10.1016/j.chemphys.2024.112523","url":null,"abstract":"<div><div>C70 fullerene and its five mono-nitrogen-doped C69N derivatives were identified by calculated x-ray photoelectron spectroscopy (XPS) and near-edge x-ray absorption fine structure (NEXAFS) spectra on density functional theory (DFT) level. The results show that the NEXAFS spectra are more ideal to identify C69N isomers accurately. Furthermore, the relationship between the spectra and local structures is discussed as well. The analysis of XPS and NEXAFS spectra for C69N isomers can help in understanding the preparation and modification of these materials and providing a theoretical foundation for the development of nitrogen-doped fullerenes.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112523"},"PeriodicalIF":2.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701713","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 : 2024-11-17DOI: 10.1016/j.chemphys.2024.112517
Matamba Musungayi Georges , Kai Wang , Jiafang Xu , Mbombo Musau Christelle , Wetshondo Osomba Dominique , Camara Moussa
Polyacrylamide (PAM) molecular structures are not stable at higher temperatures, limiting their effectiveness in water-based drilling fluid (WBDF) applications. This study focuses on identifying functional groups that can enhance the thermal stability of PAM structure. It presents a comprehensive and comparative analysis of the swelling inhibition capacity of both low and high molecular weight (MW) PAM-based polymers at high temperature and high pressure (HT/HP). The mechanism by which modified PAM interacts with and adsorbs to the clay (Na-MMT) surface is examined, along with an analysis of the surface properties of the clay minerals. Therefore, molecular dynamic (MD) simulation results revealed that the Novel PAM polymers with high MW containing ethyl and benzyl groups demonstrate greater stability and more controlled deformation behavior compared to conventional PAM at HT conditions. Surface modification and hydrophobic effects were observed in the interactions between polymers and Na-MMT. Low MW PAM-based polymers showed larger fluctuations in d-spacing, indicating various or more disruptive interactions. In contrast, the insertion of high MW PAM-based polymer resulted in significantly narrower and lower d-spacing fluctuation ranges. The Novel PAM exhibited superior performance, providing lower d-spacing fluctuations compared to both low MW PAM-based polymers and standard PAM. Across a temperature range from 300 to 600°K, the Novel PAM consistently improved polymer adsorption on the Na-MMT surface compared to standard PAM. Indicating that the modifications effectively reduce the interaction between Na-MMT particles and water molecules while enhancing the interaction between the polymer and Na-MMT, potentially leading to more stable structures in HT/HP environments. The enhanced stability suggests that Novel PAM is more suitable for WBDF applications, as it is less prone to structural changes and can maintain its integrity under harsh conditions. The modifications provide the polymer with better resilience, potentially leading to improved performance in practical applications.
{"title":"Investigation on the development of Novel PAM structure as high-performance clay inhibitor in HT/HP conditions by using functional groups","authors":"Matamba Musungayi Georges , Kai Wang , Jiafang Xu , Mbombo Musau Christelle , Wetshondo Osomba Dominique , Camara Moussa","doi":"10.1016/j.chemphys.2024.112517","DOIUrl":"10.1016/j.chemphys.2024.112517","url":null,"abstract":"<div><div>Polyacrylamide (PAM) molecular structures are not stable at higher temperatures, limiting their effectiveness in water-based drilling fluid (WBDF) applications. This study focuses on identifying functional groups that can enhance the thermal stability of PAM structure. It presents a comprehensive and comparative analysis of the swelling inhibition capacity of both low and high molecular weight (MW) PAM-based polymers at high temperature and high pressure (HT/HP). The mechanism by which modified PAM interacts with and adsorbs to the clay (Na-MMT) surface is examined, along with an analysis of the surface properties of the clay minerals. Therefore, molecular dynamic (MD) simulation results revealed that the Novel PAM polymers with high MW containing ethyl and benzyl groups demonstrate greater stability and more controlled deformation behavior compared to conventional PAM at HT conditions. Surface modification and hydrophobic effects were observed in the interactions between polymers and Na-MMT. Low MW PAM-based polymers showed larger fluctuations in d-spacing, indicating various or more disruptive interactions. In contrast, the insertion of high MW PAM-based polymer resulted in significantly narrower and lower d-spacing fluctuation ranges. The Novel PAM exhibited superior performance, providing lower d-spacing fluctuations compared to both low MW PAM-based polymers and standard PAM. Across a temperature range from 300 to 600°K, the Novel PAM consistently improved polymer adsorption on the Na-MMT surface compared to standard PAM. Indicating that the modifications effectively reduce the interaction between Na-MMT particles and water molecules while enhancing the interaction between the polymer and Na-MMT, potentially leading to more stable structures in HT/HP environments. The enhanced stability suggests that Novel PAM is more suitable for WBDF applications, as it is less prone to structural changes and can maintain its integrity under harsh conditions. The modifications provide the polymer with better resilience, potentially leading to improved performance in practical applications.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112517"},"PeriodicalIF":2.0,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701714","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 electronic and optical properties of borophene nanoribbons, influenced by the adsorption of copper (Cu) and oxygen (O) atoms in various configurations, were studied using first-principles calculations. The findings indicated that the most stable configuration, with the minimum adsorption energy of −9.09 eV, was achieved with double-upper center adsorbed double O atoms. By varying the adsorption positions and the number of Cu and O atoms, borophene nanoribbons were successfully tuned to transform into direct and indirect band-gap semiconductors. In particular, borophene nanoribbons with single and double-upper center adsorbed Cu atoms exhibited direct band gaps of 0.083 eV and 0.185 eV, respectively. In contrast, the double-upper center adsorbed double O atoms configuration resulted in an indirect band gap of 0.039 eV. The results further demonstrated that the Fermi levels crossed into the valence band, displaying p-type degenerate semiconductor characteristics for configurations with single and double-upper center adsorbed Cu atoms as well as double-upper center adsorbed double O atoms.
通过第一原理计算，研究了硼吩纳米带的电子和光学特性受铜（Cu）和氧（O）原子以不同构型吸附的影响。结果表明，双上中心吸附双 O 原子的构型最稳定，吸附能最小，为 -9.09 eV。通过改变 Cu 原子和 O 原子的吸附位置和数量，成功地将硼吩纳米带调整为直接和间接带隙半导体。其中，单中心和双上中心吸附 Cu 原子的硼吩纳米带的直接带隙分别为 0.083 eV 和 0.185 eV。相比之下，双上中心吸附双 O 原子构型的间接带隙为 0.039 eV。结果进一步表明，费米级跨入价带，在单中心和双上中心吸附铜原子以及双上中心吸附双 O 原子的配置中显示出 p 型退化半导体特性。
{"title":"Modulated electronic properties of borophene nanoribbons using copper and oxygen atoms","authors":"Weihua Wang, Junchi Ma, Yuxuan Wang, Fushi Jiang, Kunpeng Zhou, Peifang Li","doi":"10.1016/j.chemphys.2024.112520","DOIUrl":"10.1016/j.chemphys.2024.112520","url":null,"abstract":"<div><div>The electronic and optical properties of borophene nanoribbons, influenced by the adsorption of copper (Cu) and oxygen (O) atoms in various configurations, were studied using first-principles calculations. The findings indicated that the most stable configuration, with the minimum adsorption energy of −9.09 eV, was achieved with double-upper center adsorbed double O atoms. By varying the adsorption positions and the number of Cu and O atoms, borophene nanoribbons were successfully tuned to transform into direct and indirect band-gap semiconductors. In particular, borophene nanoribbons with single and double-upper center adsorbed Cu atoms exhibited direct band gaps of 0.083 eV and 0.185 eV, respectively. In contrast, the double-upper center adsorbed double O atoms configuration resulted in an indirect band gap of 0.039 eV. The results further demonstrated that the Fermi levels crossed into the valence band, displaying p-type degenerate semiconductor characteristics for configurations with single and double-upper center adsorbed Cu atoms as well as double-upper center adsorbed double O atoms.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112520"},"PeriodicalIF":2.0,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701812","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 : 2024-11-17DOI: 10.1016/j.chemphys.2024.112531
Yulin Mo , Shirong Dong , Haibin Lin
Most fluorescent compounds have only one fluorescence emission peak, it is difficult to directly construct double-output or triple-output molecular logic devices using a single fluorescent compound. Therefore, this paper proposes using bovine serum albumin (BSA) as a carrier to load 5-sulfosalicylic acid and fluorescein isothiocyanate at different sites of BSA to synthesize the L1/L2@BSA complex, and based on fluorescence resonance and electron exchange energy transfer (or hybrid FRET-DET) to construct a dual-output molecular logic circuit. This construction of double-output molecular logic devices based on the combination of two fluorescent compounds using BSA as a carrier can not only perform controllable screening and combination according to the requirements of excitation wavelength or emission wavelength, but perhaps also build an ideal research model for exploring the energy transfer mechanism of multi-molecular coupled exciton fields.
{"title":"Construction of dual-output molecular logic circuit based on bovine serum albumin loaded with two fluorescent compounds","authors":"Yulin Mo , Shirong Dong , Haibin Lin","doi":"10.1016/j.chemphys.2024.112531","DOIUrl":"10.1016/j.chemphys.2024.112531","url":null,"abstract":"<div><div>Most fluorescent compounds have only one fluorescence emission peak, it is difficult to directly construct double-output or triple-output molecular logic devices using a single fluorescent compound. Therefore, this paper proposes using bovine serum albumin (BSA) as a carrier to load 5-sulfosalicylic acid and fluorescein isothiocyanate at different sites of BSA to synthesize the L<sub>1</sub>/L<sub>2</sub>@BSA complex, and based on fluorescence resonance and electron exchange energy transfer (or hybrid FRET-DET) to construct a dual-output molecular logic circuit. This construction of double-output molecular logic devices based on the combination of two fluorescent compounds using BSA as a carrier can not only perform controllable screening and combination according to the requirements of excitation wavelength or emission wavelength, but perhaps also build an ideal research model for exploring the energy transfer mechanism of multi-molecular coupled exciton fields.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112531"},"PeriodicalIF":2.0,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701712","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 : 2024-11-16DOI: 10.1016/j.chemphys.2024.112529
Raihan Alfaridzi , Herbert M. Urbassek , Yudi Rosandi
Using molecular dynamics simulation, we analyze the collision between a water-ice grain and a silica surface. Both a flat and porous surfaces are studied. We find that the presence of pores in the silica sample and the induced roughness of the silica surface significantly influence the collision outcome. The presence of pores on the surface increases the contact area of the colliding grain with the silica sample, and consequently also the number of reaction products, i.e., water dissociation products and silanol groups formed at the silica surface. The effect is maximum if the pore size is of the order of the grain radius. In addition, the presence of pores on the surface allows for the penetration of water molecules under the surface, molecule ejection from the colliding ice grain is enhanced, and dissipation of the collision energy into the sample is hindered.
{"title":"Ice-grain impact on a rough amorphous silica surface","authors":"Raihan Alfaridzi , Herbert M. Urbassek , Yudi Rosandi","doi":"10.1016/j.chemphys.2024.112529","DOIUrl":"10.1016/j.chemphys.2024.112529","url":null,"abstract":"<div><div>Using molecular dynamics simulation, we analyze the collision between a water-ice grain and a silica surface. Both a flat and porous surfaces are studied. We find that the presence of pores in the silica sample and the induced roughness of the silica surface significantly influence the collision outcome. The presence of pores on the surface increases the contact area of the colliding grain with the silica sample, and consequently also the number of reaction products, i.e., water dissociation products and silanol groups formed at the silica surface. The effect is maximum if the pore size is of the order of the grain radius. In addition, the presence of pores on the surface allows for the penetration of water molecules under the surface, molecule ejection from the colliding ice grain is enhanced, and dissipation of the collision energy into the sample is hindered.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112529"},"PeriodicalIF":2.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.chemphys.2024.112516
V. Chellasamy , P. Thangadurai
The methanol oxidation reaction of a PtSn nanoparticle decorated NiTiO3 nanostructured material system is reported in this paper. NiTiO3 and PtSn nanoparticles were formed in rhombohedral and cubic phases, respectively. The crystallite size of the PtSn nanoparticles was calculated to be 2.8 nm from the XRD peak parameters and TEM studies. The surface plasmon resonance peak observed at 308 nm indicates the decoration of PtSn-NiTiO3 nanostructures with Pt nanoparticles on the surface. The chemical oxidation states investigated by XPS showed a metallic state of Pt and Sn with a small amount of surface oxidization. From the electrochemical analysis, the Pt0.5Sn0.5-NiTiO3 nanostructures showed superior electrocatalytic performance with higher electrochemical surface area (252 m2/g), high current density (196 mA/cm2), lower Tafel value (161.31 mV/dec) and small charge transfer resistance. This work demonstrated that the Pt0.5Sn0.5 −NiTiO3 nanostructure would be a suitable electrocatalyst for oxidation for methanol in DMFC.
{"title":"Fabrication and electrochemical investigations of nanostructured PtSn-NiTiO3 heterostructured electrocatalysts for direct methanol oxidation","authors":"V. Chellasamy , P. Thangadurai","doi":"10.1016/j.chemphys.2024.112516","DOIUrl":"10.1016/j.chemphys.2024.112516","url":null,"abstract":"<div><div>The methanol oxidation reaction of a PtSn nanoparticle decorated NiTiO<sub>3</sub> nanostructured material system is reported in this paper. NiTiO<sub>3</sub> and PtSn nanoparticles were formed in rhombohedral and cubic phases, respectively. The crystallite size of the PtSn nanoparticles was calculated to be 2.8 nm from the XRD peak parameters and TEM studies. The surface plasmon resonance peak observed at 308 nm indicates the decoration of PtSn-NiTiO<sub>3</sub> nanostructures with Pt nanoparticles on the surface. The chemical oxidation states investigated by XPS showed a metallic state of Pt and Sn with a small amount of surface oxidization. From the electrochemical analysis, the Pt<sub>0.5</sub>Sn<sub>0.5</sub>-NiTiO<sub>3</sub> nanostructures showed superior electrocatalytic performance with higher electrochemical surface area (252 m<sup>2</sup>/g), high current density (196 mA/cm<sup>2</sup>), lower Tafel value (161.31 mV/dec) and small charge transfer resistance. This work demonstrated that the Pt<sub>0.5</sub>Sn<sub>0.5</sub> −NiTiO<sub>3</sub> nanostructure would be a suitable electrocatalyst for oxidation for methanol in DMFC.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"589 ","pages":"Article 112516"},"PeriodicalIF":2.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654878","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 : 2024-11-12DOI: 10.1016/j.chemphys.2024.112526
Mustafa Bilici, Adem Zengin
In the present study, a novel analytical method was developed for selective and sensitive detection of ametryn in tap and lake water samples based on molecular imprinting technology with high performance liquid chromatography-ultraviolet detection. For this purpose, molecularly-imprinted magnetic MoS2 (MIP@mag-MoS2) particles were synthesized via surface initiated reversible addition-fragmentation chain transfer polymerization. The investigation of the rebinding properties, selective recognition ability, and reusability of the MIP@mag-MoS2 demonstrated their high adsorption capacity, outstanding selectivity, rapid adsorption kinetics, and capability for multiple uses, with an imprinting factor of 4.39. The detection limits for ametryn were 0.031 µ g/L and 0.041 µ g/L in tap water and lake water, respectively. The proposed method also had high recovery percentage and low relative standard deviations for the water samples spiked with ametryn. The results suggest that the combination of mag-MoS2 with MIP layer is a prospective alternative analytical method for quantification of ametryn.
{"title":"Facile synthesis of molecularly-imprinted magnetic-MoS2 nanosheets for selective and sensitive detection of ametryn","authors":"Mustafa Bilici, Adem Zengin","doi":"10.1016/j.chemphys.2024.112526","DOIUrl":"10.1016/j.chemphys.2024.112526","url":null,"abstract":"<div><div>In the present study, a novel analytical method was developed for selective and sensitive detection of ametryn in tap and lake water samples based on molecular imprinting technology with high performance liquid chromatography-ultraviolet detection. For this purpose, molecularly-imprinted magnetic MoS<sub>2</sub> (MIP@mag-MoS<sub>2</sub>) particles were synthesized via surface initiated reversible addition-fragmentation chain transfer polymerization. The investigation of the rebinding properties, selective recognition ability, and reusability of the MIP@mag-MoS<sub>2</sub> demonstrated their high adsorption capacity, outstanding selectivity, rapid adsorption kinetics, and capability for multiple uses, with an imprinting factor of 4.39. The detection limits for ametryn were 0.031 µ g/L and 0.041 µ g/L in tap water and lake water, respectively. The proposed method also had high recovery percentage and low relative standard deviations for the water samples spiked with ametryn. The results suggest that the combination of mag-MoS<sub>2</sub> with MIP layer is a prospective alternative analytical method for quantification of ametryn.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"589 ","pages":"Article 112526"},"PeriodicalIF":2.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654876","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 deformation and breakup of droplets are widely observed in various aspects of production and daily life. Using molecular dynamics simulations, this study primarily investigated the deformation and breakup of droplets in a nitrogen environment under pulsed electric fields of different frequencies. The results indicate that the droplet deformation undergoes periodic changes under the influence of the pulsed electric field. At equivalent electric field strengths, droplets are more likely to break under a 6.25 GHz pulsed electric field compared to a 25 GHz pulsed electric field, where droplet deformation remains stable without breaking. At every frequency, the bond energy of water molecules consistently decreases. The solvent-accessible surface area changes with the electric field at 6.25 GHz. Furthermore, the minimum value of hydrogen bond quantity reached under high-frequency pulsed fields is higher than that under low-frequency fields. The change in hydrogen bond quantity is inversely proportional to the solvent-accessible surface area. These findings provide insights into the microscopic mechanisms of droplet deformation and breakup, offering a reference for future studies.
{"title":"Molecular dynamics of deformation and fragmentation processes in liquid droplets under pulsed electric field","authors":"Chuanke Liang, Zexin Liu, Yeqi Yan, Yancheng Tao, Tao Li, Hailong Chen","doi":"10.1016/j.chemphys.2024.112519","DOIUrl":"10.1016/j.chemphys.2024.112519","url":null,"abstract":"<div><div>The deformation and breakup of droplets are widely observed in various aspects of production and daily life. Using molecular dynamics simulations, this study primarily investigated the deformation and breakup of droplets in a nitrogen environment under pulsed electric fields of different frequencies. The results indicate that the droplet deformation undergoes periodic changes under the influence of the pulsed electric field. At equivalent electric field strengths, droplets are more likely to break under a 6.25 GHz pulsed electric field compared to a 25 GHz pulsed electric field, where droplet deformation remains stable without breaking. At every frequency, the bond energy of water molecules consistently decreases. The solvent-accessible surface area changes with the electric field at 6.25 GHz. Furthermore, the minimum value of hydrogen bond quantity reached under high-frequency pulsed fields is higher than that under low-frequency fields. The change in hydrogen bond quantity is inversely proportional to the solvent-accessible surface area. These findings provide insights into the microscopic mechanisms of droplet deformation and breakup, offering a reference for future studies.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"590 ","pages":"Article 112519"},"PeriodicalIF":2.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701716","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 : 2024-11-12DOI: 10.1016/j.chemphys.2024.112522
Hamza Ahmad , Xianshan Li , Basheer Ahmed Kalwar , Xinyu Tan , Muhammad Rafique Naich
During frequent arc-quenching operations, SF6 gas in SF6 power circuit breakers decomposes into sulfur-based gases, which eventually causes weakening of quenching ability of SF6 gas. Therefore, such decompositions must be sensed and captured timely to avoid any malfunctioning of SF6 circuit breaker. Here we investigate the sensing/adsorption and release of SF6 decompositions (SO2, SOF2, SO2F2, H2S, and HF) on a monolayer B4CN3 through first-principles calculations. Pure B4CN3 is unable to capture gas molecules due to insufficient adsorption energy, resulting in their rapid release. However, with Fe and Cu decoration on B4CN3, adsorption and release are greatly improved. The mechanism included evaluating band structure, work functions (Φ), and transport transmission (I-V). The order of gas adsorption/sensitivity of Fe and Cu decorated B4CN3 to target gases is SOF2 > SO2F2 > SO2 > H2S > HF. Moreover, despite having lower adsorption energies, Cu decorated B4CN3 is more sensitive to all gas molecules than Fe decorated, indicating no direct impact of higher adsorption energy to sensitivity. Gas molecule release time at room temperature can be reduced to nanoseconds either by rising the temperature to 499 K or by just exposing to UV radiation. Our study presents theoretical insights into the gas sensing capabilities of Fe and Cu decorated B4CN3 monolayers for SF6 decompositions.
{"title":"Adsorption and work function type sensing of SF6 decompositions (SO2, SOF2, SO2F2, H2S and HF) based on Fe and Cu decorated B4CN3 monolayer. A first-principles study","authors":"Hamza Ahmad , Xianshan Li , Basheer Ahmed Kalwar , Xinyu Tan , Muhammad Rafique Naich","doi":"10.1016/j.chemphys.2024.112522","DOIUrl":"10.1016/j.chemphys.2024.112522","url":null,"abstract":"<div><div>During frequent arc-quenching operations, SF<sub>6</sub> gas in SF<sub>6</sub> power circuit breakers decomposes into sulfur-based gases, which eventually causes weakening of quenching ability of SF<sub>6</sub> gas. Therefore, such decompositions must be sensed and captured timely to avoid any malfunctioning of SF<sub>6</sub> circuit breaker. Here we investigate the sensing/adsorption and release of SF<sub>6</sub> decompositions (SO<sub>2</sub>, SOF<sub>2</sub>, SO<sub>2</sub>F<sub>2</sub>, H<sub>2</sub>S, and HF) on a monolayer B<sub>4</sub>CN<sub>3</sub> through first-principles calculations. Pure B<sub>4</sub>CN<sub>3</sub> is unable to capture gas molecules due to insufficient adsorption energy, resulting in their rapid release. However, with Fe and Cu decoration on B<sub>4</sub>CN<sub>3</sub>, adsorption and release are greatly improved. The mechanism included evaluating band structure, work functions (Φ), and transport transmission (I-V). The order of gas adsorption/sensitivity of Fe and Cu decorated B<sub>4</sub>CN<sub>3</sub> to target gases is SOF<sub>2</sub> > SO<sub>2</sub>F<sub>2</sub> > SO<sub>2</sub> > H<sub>2</sub>S > HF. Moreover, despite having lower adsorption energies, Cu decorated B<sub>4</sub>CN<sub>3</sub> is more sensitive to all gas molecules than Fe decorated, indicating no direct impact of higher adsorption energy to sensitivity. Gas molecule release time at room temperature can be reduced to nanoseconds either by rising the temperature to 499 K or by just exposing to UV radiation. Our study presents theoretical insights into the gas sensing capabilities of Fe and Cu decorated B<sub>4</sub>CN<sub>3</sub> monolayers for SF<sub>6</sub> decompositions.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"589 ","pages":"Article 112522"},"PeriodicalIF":2.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654960","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 recent years, the advancement of perovskite solar cells has accelerated, leading to continuous performance improvements. Over the past few years, machine learning (ML) has gained popularity among scientists researching perovskite solar cells. In this study, ML is used to screen hole-transporting materials for perovskite solar cells. To construct machine-learning (ML) models, data from prior investigations are collected. Out of four machine learning algorithms trained for predicting reorganization energy (Rh), the gradient boosting regression model stood out as the most effective, attaining an R2 value of 0.89. Data visualization analysis is then utilized to scrutinize the patterns within the dataset. 10,000 new compounds are generated. Chemical space of generated compounds is visualized using various measures. Minor structural modifications resulted in only a slight alteration in reorganization energy (Rh). The newly introduced multidimensional framework has the potential to efficiently screen materials in a short amount of time.
{"title":"Machine learning assisted designing of hole-transporting materials for high performance perovskite solar cells","authors":"Muhammad Saqib , Uzma Shoukat , Mohamed Mohamed Soliman , Shahida Bashir , Mudassir Hussain Tahir , Hamdy Khamees Thabet , Mohamed Kallel","doi":"10.1016/j.chemphys.2024.112515","DOIUrl":"10.1016/j.chemphys.2024.112515","url":null,"abstract":"<div><div>In recent years, the advancement of perovskite solar cells has accelerated, leading to continuous performance improvements. Over the past few years, machine learning (ML) has gained popularity among scientists researching perovskite solar cells. In this study, ML is used to screen hole-transporting materials for perovskite solar cells. To construct machine-learning (ML) models, data from prior investigations are collected. Out of four machine learning algorithms trained for predicting reorganization energy (Rh), the gradient boosting regression model stood out as the most effective, attaining an R<sup>2</sup> value of 0.89. Data visualization analysis is then utilized to scrutinize the patterns within the dataset. 10,000 new compounds are generated. Chemical space of generated compounds is visualized using various measures. Minor structural modifications resulted in only a slight alteration in reorganization energy (Rh). The newly introduced multidimensional framework has the potential to efficiently screen materials in a short amount of time.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"589 ","pages":"Article 112515"},"PeriodicalIF":2.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654974","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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