The Journal of Physical Chemistry C最新文献

{"title":"Effect of the Ti2CTx (Tx = O, OH, and H) Functionalization on the Formation of (TiO2)5/Ti2CTx Composites","authors":"Néstor García-Romeral, Ángel Morales-García, Francesc Viñes","doi":"10.1021/acs.jpcc.4c06909","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06909","url":null,"abstract":"First-principles density functional theory calculations are carried out on the (TiO₂)₅ cluster supported on the Ti₂CT_<i>x</i>(0001) surface with different chemical terminations, <i>i.e.</i>, −H, −O, and −OH, to study the interaction and understand the Ti₂CT_<i>x</i> functionalization effect on the formation of (TiO₂)₅/Ti₂CT_<i>x</i> composites. Results show an exothermic interaction for all cases, whose strength is driven by the surface termination, promoting weaker bonds when the MXene is functionalized with H atoms. For Ti₂CH₂ and Ti₂C(OH)₂ MXenes, the interaction is accompanied by a charge transfer towards the titania cluster. All adsorptions are accompanied by a significant structural deformation of the titania nanocluster. The analysis of the density of states of (TiO₂)₅/Ti₂CH₂ and (TiO₂)₅/Ti₂C(OH)₂ composites shows a clear almost metallic character with titania-related states close to the Fermi level. However, for (TiO₂)₅/Ti₂CO₂, the band positions are similar to those of a Type-I heterojunction. Overall, the MXene surface termination influence on the TiO₂/MXene interaction is unveiled, providing more stable composite formations when the MXene surface is functionalized with −H and −OH groups, where the adsorption process is accompanied by significant charge transfer.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"11 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849793","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}

{"title":"Supported Lipid Bilayers as Stochastic Conveyor Belt for Delivery to the Near Field of Nanoscopic Structures","authors":"Yazgan Tuna, Vahid Sandoghdar","doi":"10.1021/acs.jpcc.4c06908","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06908","url":null,"abstract":"Placement of nanoscopic entities in the optical near field of a structure such as a plasmonic nanoantenna or the aperture of a scanning near-field optical microscopy (SNOM) remains a nontrivial task, which often requires sophisticated nanofabrication techniques. Here, we show that the fluidity and diffusion of lipid molecules in bilayer geometries can be exploited for facile delivery of nano-objects such as organic dye molecules, semiconductor quantum dots, and gold nanoparticles to the near field of well-defined surface structures. We demonstrate this in three different scenarios with substantial plasmonic enhancement of fluorescence.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"13 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849830","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}

{"title":"Impact of Anions and Water Content on [Li–Al] Layered Double-Hydroxide Stability","authors":"Christopher Hoban, Natalie Parkinson, K. Jayanthi, M. Parans Paranthaman, Alexandra Navrotsky, Brian F. Woodfield","doi":"10.1021/acs.jpcc.4c06793","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06793","url":null,"abstract":"[Li–Al] layered double hydroxides (LDHs) are compounds with potential as sorbents for lithium extraction from brine solutions. In this work, heat capacities were measured from approximately 2.5 to 300 K for six [Li–Al] LDHs with differing anions (Cl^–, OH^–, and SO₄^2–) and water content (denoted A for air-dried and O for oven-dried). These measurements were used to calculate the standard entropy at 298.15 K, and the results were combined with previously performed enthalpy measurements to calculate Gibbs energies of formation from the binary compounds. The calculated order of stability based on Gibbs energies of formation was Cl-LDH-O &gt; OH-LDH-O &gt; Cl-LDH-A &gt; SO₄-LDH-O &gt; SO₄-LDH-A &gt; OH-LDH-A. Results support previous findings that higher water content generally raises the Gibbs energy of the LDH.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"20 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142857887","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}

{"title":"Effect of Internal Electron Donors on Butadiene Polymerization Catalyzed by the TiCl4/MgCl2 Ziegler–Natta Catalyst","authors":"RunChuan Zhou, Ang Zhao, Jian Liu, AiHua He, Xia Yang","doi":"10.1021/acs.jpcc.4c05978","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05978","url":null,"abstract":"Ziegler–Natta (ZN) catalysts recognized as mainstream and efficient polymerization reaction catalysts are widely used for the polymerization of monolefins and diolefins due to their excellent properties. The addition of electron donors to the catalyst can effectively improve its regularity. In this article, the chelate coordination of the internal electron donors 2,3-dimethyl diethylsuccinate (DES), 2,3-diisopropyl diethylsuccinate (DIS), 2,2-dimethyl-1,3-dimethoxypropane (DMMP), and 2,2-diisopropyl-1,3-dimethoxypropane (DIMP) on the catalyst support was investigated by the density functional theory (DFT). By calculating the activation energy of the reaction before and after the addition of the internal electron donor, the effect of the internal electron donor on the stereoselectivity of the polymerization reaction was analyzed. The results indicate that all four internal electron donors can be stably adsorbed onto the support, forming closer interactions with adjacent active centers. In the butadiene insertion process, the si configuration is more favorable than the re configuration. With the addition of DES, DIS, DMMP, and DIMP, the stereoselectivity of the polymerization reaction increased from 0.7 kcal/mol on the bare active center model to 0.9, 1.2, 0.8, and 1.5 kcal/mol, respectively. Particularly noteworthy is the fact that the addition of DIMP showed the most pronounced improvement in reaction stereoselectivity.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"28 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849766","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}

{"title":"Bimetallic Pd–Rh Nanoparticles Supported on Co3O4(111): Atomic Ordering and Stability","authors":"Alexander Simanenko, Jan Škvára, Pankaj Kumar Samal, Lukáš Fusek, Maximilian Kastenmeier, Michal Ronovský, Tomáš Skála, Nataliya Tsud, Sascha Mehl, Viktor Johánek, Josef Mysliveček, Olaf Brummel, Yaroslava Lykhach, Jörg Libuda","doi":"10.1021/acs.jpcc.4c07406","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c07406","url":null,"abstract":"We have investigated the atomic ordering and stability of monometallic Rh and Pd nanoparticles and bimetallic Pd@Rh and Rh@Pd core@shell nanoparticles supported on well-ordered Co₃O₄(111) films on Ir(100) by means of synchrotron radiation photoelectron spectroscopy and scanning tunneling microscopy. The thermal stabilities of these model systems are controlled by the electronic metal support interaction associated with charge transfer at the metal/oxide interface. This effect is most pronounced in the Rh/Co₃O₄(111) model system. It is associated with the formation of atomically dispersed Rh³⁺ species at the metal/oxide interface and the growth of highly dispersed Rh nanoparticles. The system is stable up to 450 K. Annealing of the Rh/Co₃O₄(111) model system triggers sintering of the Rh nanoparticles above 450 K and Rh dissolution into the Co₃O₄(111) substrate above 550 K. The morphologies of the Pd@Rh and Rh@Pd core@shell nanoparticles are similar to those observed for the Rh/Co₃O₄(111) model system. With respect to atomic ordering, the Rh@Pd core@shell nanoparticles are fairly stable, while segregation of Pd in the Pd@Rh core@shell nanoparticles occurs upon annealing to 550 K. Above 550 K, redistribution of the charge at the metal/oxide interface leads to sintering, dissolution of Rh into the Co₃O₄(111) substrate and collapse of the core@shell nanoparticles. In particular, phase separation in the Pd@Rh and Rh@Pd core@shell nanoparticles occurs upon annealing above 550 K, yielding Rh-rich and Pd-rich nanoparticles on Co₃O₄(111).","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"129 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142857890","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}

{"title":"Mechanical Nonlinearity and Microscale Deformation of Gas Diffusion Layer in Proton Exchange Membrane Fuel Cell","authors":"Kai Lu, Shunbo Lan, Liang An, Rui Lin","doi":"10.1021/acs.jpcc.4c07281","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c07281","url":null,"abstract":"The gas diffusion layer (GDL) is one of the core components of the proton exchange membrane fuel cell. The complex internal structure of the GDL makes it challenging to accurately predict the mechanical response during clamping compression. In this study, the mechanical properties of the carbon paper-based GDL were investigated using a combination of experimental and numerical simulation. The explicit finite element method (FEM) was used to perform quasi-static compression simulations on the reconstructed GDL. The simulation accounted for the fiber dynamic contact, predicting the true deformation of the GDL. Validation between simulation and experiments was conducted, identifying the initiation point of fiber fracture failure during the compression. The effective range of the elastic constitutive model was determined. The changes in tortuosity, effective diffusivity, absolute permeability, and conductivity in different directions were examined. Reliable experimental results were obtained when the sample quantity was five. Initially, the stress–strain curve exhibited distinct nonlinear characteristics. The equivalent elastic modulus of the GDL continuously increased, stabilizing after a certain compression ratio. With a compression ratio of 27%, the elastic model could accurately reflect the mechanical properties of GDL. Beyond this range, the fiber began to fracture, at which point the stress was 0.064 MPa. Bending and frictional sliding were the main deformation modes of the carbon fibers. The gas diffusion capacity increased first and then decreased; for in-plane direction and through-plane direction, the maximum value appeared at 10 and 5% compression ratio, respectively. The permeability was reduced monotonously. The mass transfer capacity in the in-plane direction of the carbon paper was superior to that in the through-plane direction. The effective conductivity increases in through-plane and in-plane directions were 1354.8 and 57.9%, respectively, at a compression ratio of 35%. Combined with the macroscopic and microscopic levels, it provides a reference for an in-depth understanding of the compressive mechanical properties of fiber porous media and improving the performance of fuel cells.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"12 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849771","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}

{"title":"Cold-Welding Mechanism and Tensile Behaviors of Cu–Al Nanowires: A Molecular Dynamics Simulation","authors":"Zhiheng Guo, Dong Chen, Lizhi Li, Danting Zheng, Haosheng Zhao, Zuncheng Zhao","doi":"10.1021/acs.jpcc.4c06953","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06953","url":null,"abstract":"The technology of welding heterobimetallic nanowires (NWs) at the nanoscale is of importance for the fabrication of optoelectronic devices. In this work, molecular dynamics simulations are performed to simulate nanojoining of Cu and Al NWs by head-to-head cold-welding as well as tensile properties of obtained welding joints. The results of the climbing image nudged elastic band calculations show that Cu and Al NWs can be successfully connected by cold-welding with high-efficiency and few defects, owing to recrystallization and interfacial diffusion of atoms. Moreover, pressure, temperature, and welding velocity will exert significant influence on tensile properties of joints, including strength and plasticity. The tensile test shows that the fracture usually occurs on the Al NWs rather than the joints of the Cu–Al NW, which demonstrates the high quality of joints. Simulation results obtained in this work will provide atomic scale insights into the cold-welding of heterobimetallic NWs and helpful theoretical guidance for the application of nanojoining.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"18 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849795","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}

{"title":"Investigating the Influence of the Spacer Length on Anion-Exchange Membrane Properties Using a Reactive Molecular Model","authors":"Thibaut Flottat, Benoit Latour, Florent Goujon, Patrice Hauret, Patrice Malfreyt","doi":"10.1021/acs.jpcc.4c07011","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c07011","url":null,"abstract":"This study investigates the influence of the spacer length within anion-exchange membranes (AEMs) on their diffusion properties. Using reactive molecular dynamics with ReaxFF, three polyphenylene oxide (PPO)-based AEMs functionalized with trimethylamine (TMA) cationic groups at two hydration levels (λ = 10 and 20) were simulated at the molecular scale through three alkyl spacer chains lengths: methyl (PPO1-TMA), pentyl (PPO5-TMA), and decyl (PPO10-TMA). Our simulations capture the nanophase separation due to the amphiphilic nature of the simulated materials, where a water channel emerges to enable OH^– transport through Grotthuss and classical mechanisms. We find that the number of hydrogen bonds formed between OH^– and H₂O molecules is a key parameter governing the diffusion properties of OH^–. At a lower hydration level, PPO1-TMA has the lowest diffusion properties, whereas PPO5 and PPO10-TMA membranes show the same diffusion because pentyl and decyl spacers bend and remain stuck on the backbone because of their hydrophobicity. At a higher hydration level, the three membranes exhibit identical diffusion properties, irrespective of their spacer length, as the OH^– molecule approaches its bulk-like behavior.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"30 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849770","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}

{"title":"Absence of Anomalous Electron–Phonon Coupling in the Near-Ambient Gap Temperature Renormalization of CsPbBr3 Nanocrystals","authors":"Shima Fasahat, Benedikt Schäfer, Kai Xu, Nadesh Fiuza-Maneiro, Sergio Gómez-Graña, M. Isabel Alonso, Lakshminarayana Polavarapu, Alejandro R. Goñi","doi":"10.1021/acs.jpcc.4c06265","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06265","url":null,"abstract":"Metal halide perovskites exhibit a fairly linear increase of the bandgap with increasing temperature, when crystallized in a tetragonal or cubic phase. In general, both thermal expansion and electron–phonon interaction effects contribute equally to this variation of the gap with temperature. Herein, we have disentangled both contributions in the case of colloidal CsPbBr₃ nanocrystals (NCs) by means of photoluminescence (PL) measurements as a function of temperature (from 80 K to ambient) and hydrostatic pressure (from atmospheric to ca. 1 GPa). At around room temperature, CsPbBr₃ NCs also show a linear increase of the bandgap with temperature with a slope similar to that of the archetypal methylammonium lead iodide (MAPbI₃) perovskite. This is somehow unexpected in view of the recent observations in mixed-cation Cs_<i>x</i>MA_1–<i>x</i>PbI₃ single crystals with low Cs content, for which Cs incorporation caused a reduction by a factor of 2 in the temperature slope of the gap. This effect was ascribed to an anomalous electron–phonon interaction induced by the coupling with vibrational modes admixed with the Cs translational dynamics inside the cage voids. Thus, no trace of anomalous coupling is found in CsPbBr₃ NCs. However, we managed to show that the linear temperature renormalization exhibited by the gap of CsPbBr₃ NCs is shared with most metal halide perovskites, due to a common bonding/antibonding and atomic orbital character of the electronic band-edge states. In this way, we provide a deeper understanding of the gap temperature dependence in the general case when the A-site cation dynamics is not involved in the electron–phonon interaction.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"24 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142857886","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}

{"title":"Defect-Mediated Crystallization of the Particulate TiO2 Photocatalyst Grown by Atomic Layer Deposition","authors":"Bela D. Bhuskute, Harri Ali-Löytty, Jesse Saari, Arto Hiltunen, Tero-Petri Ruoko, Turkka Salminen, Mika Valden","doi":"10.1021/acs.jpcc.4c07091","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c07091","url":null,"abstract":"Nanopowders or films of pure and mixed oxides in nanoparticulate form have gained specific interest due to their applicability in functionalizing high-surface-area substrates. Among various other applications, our presented work primarily focuses on the behavior of TiO₂ as a photocatalyst deposited by atomic layer deposition (ALD) on a quartz particle. The photocatalytic activity of TiO₂ on quartz particles grown by ALD was studied in terms of ALD growth temperature and post-treatment heating rate. Amorphous TiO₂ thin films (30 nm) were grown from tetrakis(dimethylamido)titanium (TDMAT) at 100 and 200 °C on quartz particles (0.35–3.5 μm) and crystallized using oxidative heat treatment at 500 °C with variable heating rates. The growth temperature was found to affect the TiO₂ defect structure: TiO₂ grown at 200 °C is black due to Ti³⁺ defects, whereas the film grown at 100 °C is white but contains some traces of the TDMAT ALD precursor. During the oxidative heat treatment, precursor traces desorbed and Ti³⁺ defects were oxidized. ALD TiO₂ grown at 100 °C crystallized as anatase, whereas the rutile-to-anatase ratio of 200 °C grown TiO₂ increased with the heating rate. The hydrogen production rate of mixed-phase TiO₂ was found to outperform that of anatase TiO₂.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"14 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142857888","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}