arXiv: Chemical Physics最新文献

{"title":"Eppur Si Riscalda - and yet, It (Just) Heats Up: Further Comments on “Quantifying Hot Carrier and Thermal Contributions in Plasmonic Photocatalysis”","authors":"Y. Sivan, J. Baraban, Y. Dubi","doi":"10.26434/chemrxiv.8850518.v1","DOIUrl":"https://doi.org/10.26434/chemrxiv.8850518.v1","url":null,"abstract":"<div>Our Comment [1] on recent attempts to distinguish thermal and non-thermal (``hot carrier'') contributions to plasmon-assisted photocatalysis [2] initiated a re-evaluation process of previous literature on the topic within the nano-plasmonics and chemistry communities. The Response of Zhou et al [3] attempts to defend the claims of the original paper [2].</div><div><br></div><div>In this manuscript, we show that the Response [3] presents additional data that further validates our central criticism: inaccurately measured temperatures (that are lower than the actual temperature of the catalyst) led Zhou etal to incorrectly claim conclusive evidence of non-thermal effects. We identify flaws in the experimental setup (e.g. the use of the default settings for the thermal camera and incorrect positioning of the thermometer) that may have led Zhou et al to make such claims. We further show that the Response contains several factual errors and does not address the technical problems we identified with the data acquisition in [2]. We demonstrate that both the Response [3] and the original paper [2] contain additional faults, for example, in the power determination and in the normalization of the rate to the catalyst volume, and exhibit misconceptions regarding the thermo-optic response of metal nanostructures. The burden of proof required by the proposal of a novel physical mechanism has simply not been met, especially when the existing data can be modeled exquisitely by conventional theory.</div><div>[1] Y. Sivan, J. Baraban, I. W. Un & Y. Dubi, Science Vol. 364, Issue 6439, eaaw9367. <a href=\"https://science.sciencemag.org/content/364/6439/eaaw9367.abstract\">https://science.sciencemag.org/content/364/6439/eaaw9367.abstract</a> </div><div><br></div><div>[2] <a href=\"https://science.sciencemag.org/content/362/6410/69\">https://science.sciencemag.org/content/362/6410/69</a></div><div><br></div><div>[3] <a href=\"https://science.sciencemag.org/content/364/6439/eaaw9545\">https://science.sciencemag.org/content/364/6439/eaaw9545</a></div>","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86203461","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":"Non-Uniqueness of Parameters Extracted from Resonant Second-Order Nonlinear Optical Spectroscopies.","authors":"B. Busson, A. Tadjeddine","doi":"10.1021/jp908240d","DOIUrl":"https://doi.org/10.1021/jp908240d","url":null,"abstract":"Experimental data from second-order nonlinear optical spectroscopies (SFG, DFG, and SHG) provide parameters relevant to the physical chemistry of interfaces and thin films. We show that there are in general 2 N or 2 N-1 equivalent sets of parameters to fit an experimental curve comprising N resonant features, of vibrational or electronic origin for example. We provide the algorithm to calculate these sets, among which the most appropriate has to be selected. The main consequences deal with the existence of \"ghost resonances\", the need of a critical analysis of fit results, and the procedure to search for better sets of parameters coherent with applied constraints.","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90990761","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":"Direct CO2 Electroreduction from Carbonate","authors":"Yuguang C. Li, Geonhui Lee, T. Yuan, Ying Wang, Dae-Hyun Nam, Ziyun Wang, F. P. G. Arquer, Yanwei Lum, C. Dinh, O. Voznyy, E. Sargent","doi":"10.26434/chemrxiv.8081777","DOIUrl":"https://doi.org/10.26434/chemrxiv.8081777","url":null,"abstract":"The process of CO2 valorization – all the way from capture/concentration of CO2 to its electrochemical upgrade - requires significant inputs in each of the capture, upgrade, and separation steps. The gas-phase CO2 feed following the capture-and-release stage and into the CO2 electroreduction stage produce a large waste of CO2 (between 80 and 95% of CO2 is wasted due to carbonate formation or electrolyte crossover) that adds cost and energy consumption to the CO2 management aspect of the system. Here we report an electrolyzer that instead directly upgrades carbonate electrolyte from CO2 capture solution to syngas, achieving 100% carbon utilization across the system. A bipolar membrane is used to produce proton in situ, under applied potential, which facilitates CO2 releasing at the membrane:catalyst interface from the carbonate solution. Using an Ag catalyst, we generate pure syngas at a 3:1 H2:CO ratio, with no CO2 dilution at the gas outlet, at a current density of 150 mA/cm2, and achieve a full cell energy efficiency of 35%. The direct carbonate cell was stable under a continuous 145 h of catalytic operation at ca. 180 mA/cm2. The work demonstrates that coupling CO2 electrolysis directly with a CO2 capture system can accelerate the path towards viable CO2 conversion technologies.","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91404898","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":"Sodium Metal Battery using CobaltOxide through in Situ Plating of Sodium Metal","authors":"Saurav L. Chaudhari, Ketan P Pise","doi":"10.13140/RG.2.2.15903.20646","DOIUrl":"https://doi.org/10.13140/RG.2.2.15903.20646","url":null,"abstract":"In this work, we demonstrate that an impugn of energy density for sodium chemistries can be prevail through an anode-free architecture enabled by the use of a (nanocarbon/Cobaltoxide) nucleation layer formed on Aluminium current collectors. Electrochemical studies show this configuration to provide highly stable and efficient plating and stripping of sodium metal over a range of currents up to 5 mA/cm2, sodium loading up to 14 mAh/cm2, and with long-term endurance exceeding 1000 cycles at a current of 0.7 mA/cm2. Building upon this anode-free architecture, we demonstrate a full cell using a presodiated pyrite cathode to achieve energy densities of 400 Wh/kg, far surpassing recent reports on SIBs and even the theoretical maximum for LIB technology while still relying on naturally abundant raw materials and cost-effective aqueous processing.","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74524166","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":"A Transferable Machine-Learning Model of the Electron Density","authors":"Andrea Grisafi, Alberto Fabrizio, Benjamin Meyer, D. Wilkins, C. Corminboeuf, M. Ceriotti","doi":"10.26434/chemrxiv.7093589.v1","DOIUrl":"https://doi.org/10.26434/chemrxiv.7093589.v1","url":null,"abstract":"We introduce an atom-centered, symmetry-adapted framework to machine-learn the valence charge density based on a small number of reference calculations. The model is highly transferable, meaning it can be trained on electronic-structure data of small molecules and used to predict the charge density of larger compounds with low, linear-scaling cost.","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75053173","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":"Alchemical perturbation density functional theory","authors":"G. F. von Rudorff, O. A. von Lilienfeld","doi":"10.1103/physrevresearch.2.023220","DOIUrl":"https://doi.org/10.1103/physrevresearch.2.023220","url":null,"abstract":"We introduce an orbital free electron density functional approximation based on alchemical perturbation theory. Given convergent perturbations of a suitable reference system, the accuracy of popular self-consistent Kohn-Sham density functional estimates of properties of new molecules can be systematically surpassed---at negligible cost. The associated energy functional is an approximation to the integrated energy derivative, requiring only perturbed reference electron densities: No self-consistent field equations are necessary to estimate energies and electron densities. Electronic ground state properties considered include covalent bonding potentials, atomic forces, as well as dipole and quadropole moments.","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83030538","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":"水的结构和反常物性 = Perspective : structures and properties of liquid water","authors":"Lei Li, Chuanggang Yao, Xi Zhang, Yongli Huang, Zengsheng Ma, Changqing Sun","doi":"10.7536/PC171013","DOIUrl":"https://doi.org/10.7536/PC171013","url":null,"abstract":"Introduction of the principles of the asymmetrical, short-range O:H-O coupled oscillater pair and the basic rule for water ice, which reconciles the structure and anomalies of water ice.","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87354689","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":"Excimer laser cleaning of black sulphur encrustation from silver surface.","authors":"M. Raza, Sankha Shuvra Das, Parimal Tudu, P. Saha","doi":"10.1016/j.optlastec.2018.12.012.","DOIUrl":"https://doi.org/10.1016/j.optlastec.2018.12.012.","url":null,"abstract":"","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80330121","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":"The fundamentals of quantum machine learning","authors":"B. Huang, Nadine O. Symonds, O. A. V. Lilienfeld","doi":"10.1007/978-3-319-42913-7_67-1","DOIUrl":"https://doi.org/10.1007/978-3-319-42913-7_67-1","url":null,"abstract":"","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87717857","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":"Solar Energy Harvesting with Carbon Nitrides: Do We Understand the Mechanism?","authors":"W. Domcke, Johannes Ehrmaier, A. Sobolewski","doi":"10.26434/chemrxiv.6843812.v1","DOIUrl":"https://doi.org/10.26434/chemrxiv.6843812.v1","url":null,"abstract":"The photocatalytic splitting of water into molecular hydrogen and molecular oxygen with sunlight is the dream reaction for solar energy conversion. Since decades, transition-metal-oxide semiconductors and supramolecular organometallic structures have been extensively explored as photocatalysts for solar water splitting. More recently, polymeric carbon nitride materials consisting of triazine or heptazine building blocks have attracted considerable attention as hydrogen-evolution photocatalysts. The mechanism of hydrogen evolution with polymeric carbon nitrides is discussed throughout the current literature in terms of the familiar concepts developed for photoelectrochemical water splitting with semiconductors since the 1970s. We discuss in this perspective an alternative mechanistic paradigm for photoinduced water splitting with carbon nitrides, which focusses on the specific features of the photochemistry of aromatic N-heterocycles in aqueous environments. It is shown that a water molecule which is hydrogen-bonded to an N-heterocycle can be decomposed into hydrogen and hydroxyl radicals by two simple sequential photochemical reactions. This concept is illustrated by first-principles calculations of excited-state reaction paths and their energy profiles for hydrogen-bonded complexes of pyridine, triazine and heptazine with a water molecule. It is shown that the excited-state hydrogen-transfer and hydrogen-detachment reactions are essentially barrierless, in sharp contrast to water oxidation in the electronic ground state, where high barriers prevail. We also discuss in some detail the products of possible reactions of the highly reactive hydroxyl radicals with the chromophores. We hypothesize that the challenge of efficient solar hydrogen generation with carbon-nitride materials is less the decomposition of water as such, but rather the controlled recombination of the photogenerated radicals to the closed-shell products H2 and H2O2.","PeriodicalId":8439,"journal":{"name":"arXiv: Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81687957","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}