化学•材料最新文献

{"title":"Reduced CO2 Release from Arctic Soils Due to CO2 Binding to Calcium Forming Aragonite","authors":"Peter Stimmler, Martin Obst, Johannes Lehmann, Mathias Stein, Kerstin Hockmann, Mathias Goeckede, Joerg Schaller","doi":"10.1021/acs.est.4c07496","DOIUrl":"https://doi.org/10.1021/acs.est.4c07496","url":null,"abstract":"Arctic soils are the largest pool of organic carbon compared with other soils globally and serve as a main source for greenhouse gases, especially in the course of the predicted future temperature increase. With increasing temperatures, substantial thawing of the permafrost layer of soils is expected, altering the availability of calcium in those soils, with an increase by ∼5 mg Ca g^–1 DW predicted for Alaska. Here we show for two representative soils in Alaska (initially Ca-poor or Ca-rich) that this increase in Ca availability will lead to decreases in CO₂ release by 50% and 57%. It is already well-known that the cation bridging of Ca ions to organic carbon renders this carbon unavailable for microbial respiration and that Ca is altering the transformation of C_org by microbes. Here we show that the decrease of the soil CO₂ release may be also due to enhanced aragonite formation (by 300% for Ca-poor and 90–200% for Ca-rich soils), as revealed by synchrotron-based scanning transmission X-ray microscopy. We therefore call upon field experiments for validation of this process and inclusion of this process in global and local carbon budget models.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":9.028,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Trail of Challenges: Autobiographical Notes of Hiroaki Misawa","authors":"Hiroaki Misawa","doi":"10.1021/acs.jpcc.4c05539","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05539","url":null,"abstract":"Published as part of <i>The Journal of Physical Chemistry C</i> special issue “Hiroaki Misawa Festschrift”. When Prof. Kosei Ueno (Hokkaido University), the guest editor of this Festschrift, invited me to write an autobiographical note, I felt a bit perplexed. However, I realized that reflecting on the circumstances of that era, and how I conceived and pursued my research themes within those circumstances, is crucial for determining the future direction of my ongoing research. Thus, from this perspective, I decided to write this autobiographical note. Let me begin by recounting the early stages of my life. I was born in 1955 in Chofu City, Tokyo, as the eldest son of my father, Sukeo Misawa, and my mother, Toshie. My father was a public school teacher, and both of my parents were enthusiastic about educating their children. I was raised in such an environment with my younger brother Naoaki, who is two years my junior. Though we were a middle-class family, our parents encouraged us to pursue our interests. We lived in a nature-rich area near the Tama River, where I often played with my brother and friends during my early elementary school years. In the upper grades of elementary school, students interested in science from several local schools, about ten from each, gathered once a month in the science room of a representative school to participate in a science club and conduct various experiments. In middle school, my science teacher provided fascinating and easily understandable explanations, which fostered my interest in pursuing a career in science. In high school, I was fortunate to have two excellent teachers who were passionate about teaching physics and chemistry. The numerous experiments I experienced in physics classes had a significant impact on my future academic and career choices. When choosing my major in university, I was torn between physics and chemistry. Ultimately, I decided to major in chemistry and enrolled in the Faculty of Engineering at Tokyo Metropolitan University. For my fourth-year graduation research, I wanted to deepen my understanding of molecular reaction dynamics. Believing that studying photochemistry and/or excited state chemistry would be ideal, I sought the guidance of Prof. Haruo Inoue, who was conducting photochemistry research in Prof. Mitsuhiko Hida’s lab at the time. Under Prof. Inoue’s mentorship, I conducted a year-long research project on the photochromism of anthraquinone derivatives. Through Prof. Inoue’s meticulous guidance, I cultivated foundational knowledge in photochemistry and the basis of my logical thinking in science. Even now, I continue to discuss with Prof. Inoue the reaction mechanisms of water splitting using visible light, through strong coupling between plasmons and nano-optical resonators, which I am currently researching. After graduating from Tokyo Metropolitan University, I continued my photochemistry research at the graduate school of Tsukuba University, joining the lab of Prof. K","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321452","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":"Anti-cancer activity and optoelectronic properties via DFT calculations of rare-earth dually doped wurtzite-type ZnO nano-systems","authors":"","doi":"10.1016/j.nanoso.2024.101348","DOIUrl":"10.1016/j.nanoso.2024.101348","url":null,"abstract":"<div><div>The application of zinc oxide (ZnO) in the biomedical field and electronic devices is attributed to its physical and chemical properties. In this research, a comprehensive investigation was performed to explore the role of Eu and Dy dual-doping on the electronic structure, optical characteristics, and anti-cancer capability of ZnO. The structural analysis using the XRD experiment demonstrated the formation of a wurtzite hexagonal structured ZnO phase for the undoped sample. The crystal structure was maintained but with a slight distortion of the system with the co-doping effect. The crystallite size disclosed a reduction with increasing the co-doping concentration. TEM and EDX analysis proved the formation of the desired compositions. In the theoretical part, the density functional theory (DFT) is adopted to probe the electronic structure and optical characteristics of proposed samples. The band gap energy (E_g) of undoped ZnO is found to be 3.45 eV. For the dual-doped systems, the E_g values reduced progressively as the content of co-dopants increased. A prominent absorption peak revealed in the UV regime for the undoped ZnO is shifted to lower energies upon doping, implying the band gap reduction. DFT results demonstrate that the impurity states due to rare earth dopants are important for optic/electronic characteristics and can be harnessed to develop photoelectric devices. According to the anti-cancer in vitro analysis, the prepared nanoparticles show strong cytotoxicity against HeLa and HCT-116 cells. The cell viability for colon cancer HCT-116 cells was C0 (37.18 %), C1 (31.96 %), C2 (64.27 %) and C3 (58.12 %), and the cell viability for cervical cancer HeLa cells was C0 (39.05 %), C1 (42.30 %), C2 (57.68 %), and C3 (45.29 %). Furthermore, DAPI staining indicated that the treatment with the Eu and Dy dual-doped ZnO NPs produced a cancer apoptotic cell death. The results of this work will be useful for further examination and choosing the appropriate nanomaterials for the targeted fields of applications.</div></div>","PeriodicalId":397,"journal":{"name":"Nano-Structures & Nano-Objects","volume":null,"pages":null},"PeriodicalIF":5.45,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Braving the Elements: Learning from 60+ Dopants in Battery Materials","authors":"Eric McCalla","doi":"10.1021/acs.jpcc.4c04870","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c04870","url":null,"abstract":"The transition toward renewable energy sources is motivating a great deal of research into new secondary battery materials for important applications such as electric vehicles and grid storage. This research is generally very fragmented with each study only looking at a few compositions and each research team using their own methods/protocols, which greatly limits comparisons between studies. Recently, high-throughput methods have been developed and used to screen the impact of a very high number of dopants simultaneously (72 different elements at the latest count). These studies have focused on both electrodes in Li-ion batteries, Na-ion cathodes, and solid electrolytes for both Li and Na batteries. This large-data-driven research is highly efficient in generating advanced materials for practical devices, but it also provides a great opportunity to enhance our understanding of how substitutions impact the wide variety of intrinsic properties of importance for battery materials. Here, I summarize the key trends seen across these studies and provide a perspective of where this research is leading. This will include a discussion of progress toward a global understanding of how to predict whether a dopant will in fact dope into a structure (this has to date been poorly predicted by computational approaches) and also the potential to develop codoping strategies to optimize multiple key properties at once. Finally, opportunities to make use of these large data sets with artificial intelligence/machine-learning will be discussed. These will dramatically enhance our ability to rationally design advanced battery materials without limiting open exploration.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321919","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":"Singlet–Triplet Inversions in Through-Bond Charge-Transfer States","authors":"J. Terence Blaskovits, Clémence Corminboeuf, Marc H. Garner","doi":"10.1021/acs.jpclett.4c02317","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02317","url":null,"abstract":"Molecules where the lowest excited singlet state is lower in energy than the lowest triplet are highly promising for a number of organic materials applications as efficiency limitations stemming from spin statistics are overcome. All molecules known to possess such singlet–triplet inversions exhibit a pattern of spatially alternating but nonoverlapping HOMO and LUMO orbitals, meaning the lowest excited states are of a local character. Here, we demonstrate that derivatives of the bicyclic hydrocarbon calicene exhibit Hund’s rule violations in charge-transfer (CT) states between its rings. These CT states can be tuned with substituents, so that the first excited singlet and triplet state are energetically inverted. This provides a conceptual connection between the emerging fields of inverted gap molecules and existing molecular design rules for state-of-the-art thermally activated delayed fluorescence materials.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":6.475,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and Dynamics of ATP and the ATP–Zn2+ Complex in Solution","authors":"Emma Rossi, Achintya Kundu, Alberta Ferrarini, Thomas Elsaesser, Marialore Sulpizi","doi":"10.1021/acs.jpclett.4c02296","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02296","url":null,"abstract":"Despite the crucial role of ATP in life and artificial life-like applications, fundamental aspects relevant to its function, such as its conformational properties and its interaction with water and ions, remain unclear. Here, by integrating linear and two-dimensional infrared spectroscopy with <i>ab initio</i> molecular dynamics, we provide a detailed characterization of the vibrational spectra of the phosphate groups in ATP and in its complex with Zn²⁺ in water. Our study highlights the role of conformational disorder and solvation dynamics, beyond the harmonic normal-mode analysis, and reveals a complex scenario in which electronic and environmental effects tune the coupling between phosphate vibrations. We identify βγ-bidentate and αβγ-tridentate modes as the preferential coordination modes of Zn²⁺, as was proposed in the literature for Mg²⁺, although this conclusion is reached by a different spectral interpretation.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":null,"pages":null},"PeriodicalIF":6.475,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ab Initio Molecular Dynamics Approach for Oxidation of SiC Surface in Contact with Aqueous H2O2 Solutions","authors":"Tetsuya Morishita, Megumi Kayanuma, Tomohisa Kato","doi":"10.1021/acs.jpcc.4c03112","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c03112","url":null,"abstract":"Controlling the oxidation of silicon carbide (SiC) is a key factor in fabricating SiC-based devices, such as power-integrated circuits and thermal protection systems. Oxidation is particularly utilized for machining SiC in conjunction with chemical–mechanical polishing. However, a thorough understanding of SiC oxidation at the microscopic level is lacking. Here, we performed <i>ab initio</i> molecular dynamics simulations to elucidate the microscopic mechanisms of the oxidation of OH- and H-terminated SiC surfaces in contact with an oxidizing solution─aqueous H₂O₂ solution. We found that the OH-terminated (000<span>1</span>) C-face surface of SiC is more easily oxidized than the OH-terminated (0001) Si-face and H-terminated C- and Si-faces. The stability of the C–O and Si–O species on the surface plays a key role in the oxidation of the OH-terminated surfaces. The effect of H₂O₂ concentration on the oxidation of the C-face was also examined. We found that the OH radicals generated from H₂O₂ molecules undergo a facile conversion to H₂O molecules in a pure H₂O₂ solution. This phenomenon may explain the counterintuitive dependence of oxidation on the H₂O₂ concentration observed in the experiments.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321449","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":"Exploring the Computational Aspects of Propylene Oligomerization Catalysis Using M′2M Type Trimetallic MOF Nodes","authors":"Rishu Khurana, Valay Agarawal, Cong Liu","doi":"10.1021/acs.jpcc.4c04992","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c04992","url":null,"abstract":"Metal–organic frameworks have emerged as promising materials in the field of catalysis. They offer an optimal ground for screening catalysts and tailoring their catalytic properties. In this work, via density functional theory (DFT) calculations, we investigated the catalytic activity of the trimetallic MOF nodes, M′₂M for propylene oligomerization, by varying the active metal M from Sc to Cu with M′ being Fe, aiming to grasp the impact of altering the active atoms on the catalyst’s activity. Additionally, we examined how substituting the spectator atom, M′, with other transition metals, i.e., from Sc to Cu, affects these energy barriers, keeping Ni as the active metal. We proposed several cases with lower or comparable energy barriers to the experimentally reported Fe₂Ni trimetallic MOF node. In addition, we found a correlative relationship between spin-density from natural population analysis and energy barriers in the realm of C–C bond formation, whereby an elevation in spin-density is found to be inversely proportional to the magnitude of the energy barriers. Moreover, we calculated the energy barriers for C–C coupling and β-hydride elimination using multireference NEVPT2 calculations on top of the CASSCF wave function to validate the rate-determining step that is predicted by DFT.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":null,"pages":null},"PeriodicalIF":4.126,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321875","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":"Development and Evaluation of Aquatic and Terrestrial Food Web Bioaccumulation Models for Per- and Polyfluoroalkyl Substances","authors":"Barry C. Kelly, Jennifer M. Sun, Mandy R. R. McDougall, Elsie M. Sunderland, Frank A. P. C. Gobas","doi":"10.1021/acs.est.4c02134","DOIUrl":"https://doi.org/10.1021/acs.est.4c02134","url":null,"abstract":"There is a need for reliable models to predict the food web bioaccumulation and assess ecological and human health risks of per- and polyfluoroalkyl substances (PFAS). This present study presents (i) the development of novel mechanistic aquatic and terrestrial food web bioaccumulation models for PFAS and (ii) an evaluation of model performance using available laboratory and field data. Model predictions of laboratory-measured bioconcentration factors and field-based bioaccumulation factors of PFAS in fish were in good agreement with observed data as measured by the mean model bias (MB), representing systematic over- or under-estimation and the standard deviation of the MB, representing general uncertainty. The models provide a mechanistic framework for evaluating the combined effect of simultaneously occurring uptake and elimination processes and indicate food web-specific magnification of PFAS, with the highest degree of biomagnification occurring in food webs composed of air-breathing wildlife. Albumin-water, structural protein–water, membrane-water distribution coefficients, and renal clearance rate are among the most important model parameters. With further development and testing, these models may be useful for future PFAS screening and risk assessment initiatives and advance bioaccumulation studies of PFAS by providing a mechanistic framework for PFAS bioaccumulation.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":9.028,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polar-Effect-Directed Control in Site-Selectivity of Radical Substitution Enables C–H Perfluoroalkylation of Coumarins","authors":"Shashank Singh, Ravi P. Singh","doi":"10.1021/acs.joc.4c01469","DOIUrl":"https://doi.org/10.1021/acs.joc.4c01469","url":null,"abstract":"A novel Ru-catalyzed protocol for C-7 selective C–H trifluoromethylation of coumarins in the presence of light is presented. This reaction undergoes a radical type nucleophilic substitution instead of a radical type electrophilic substitution owing to the benzocore activation as a result of lowering the lowest unoccupied molecular orbital (LUMO).","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.354,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}