Lithium metal batteries(LMBs)are promising candidates for next-generation high-energy-density storage devices.However,an unstable lithium metal anode poses significant issues that critically compromise battery safety ...Lithium metal batteries(LMBs)are promising candidates for next-generation high-energy-density storage devices.However,an unstable lithium metal anode poses significant issues that critically compromise battery safety and cycle life,including lithium dendrite formation,solid electrolyte interphase degradation,dead lithium accumulation,and substantial volume fluctuations during cycling.These problems can be addressed by regulating lithium deposition and suppressing side reactions through the modification of copper current collectors using three classes of materials:metal and metal oxide,carbon,and polymer materials.This review comprehensively examines recent advances in the application of these materials as current collector coatings.Particularly,their distinct roles in the lithium deposition process are analyzed to understand how they mitigate the issues associated with the lithium metal anode.Furthermore,their inherent limitations are considered to inform future research directions.While each class of materials offers specific advantages,multifunctionality is required to effectively regulate lithium deposition.In prospect,a novel composite copper current collector design that integrates the merits of the aforementioned advanced materials is proposed.The insights from this review provide valuable guidance for the rational design of modified copper current collectors,which would significantly improve the safety and cycle life of LMBs and advance their commercialization.展开更多
Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmeth...Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmethyl)butane(bib)by a hydrothermal method,respectively.X⁃ray crystallography reveals a 2D network constructed by six⁃coordinated Ni(Ⅱ)centers,bib,and Hpdc2-ligands in complex 1,while a 2D network is built by Ni(Ⅱ)and bib ligands in 2.Furthermore,the quantum⁃chemical calculations have been performed on‘molecular fragments’extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in Gaussian 16 and the VASP program.CCDC:2343794,1;2343798,2.展开更多
A combined inorganic and organic geochemical study was carried out on marls and mudstones collected from the Lower Miocene Lopare Basin,Bosnia and Herzegovina.A total of 46 samples collected from two boreholes,Pot 1(d...A combined inorganic and organic geochemical study was carried out on marls and mudstones collected from the Lower Miocene Lopare Basin,Bosnia and Herzegovina.A total of 46 samples collected from two boreholes,Pot 1(depth of 193 m)and Pot 3(depth of 344 m),showed that element abundances like boron(B),lithium(Li),strontium(Sr),uranium(U),chromium(Cr),nickel(Ni),magnesium(Mg),sodium(Na)and calcium(Ca)are much higher than average than in the upper continental crust(UCC).Chemical composition indicates at least two sources:(i)Mesozoic ophiolites occurring in the north of the investigated area,and(ii)dacito-andesitic pyroclastics(Mesozoic to Cenozoic).Lopare Basin sedimentation was influenced by strong evaporation resulting in a partly hypersaline lake,which formed during a warm climatic period,probably during the Miocene Climatic Optimum.A brief episode of humid climate conditions resulted in the basin fillingup and deposition of felsic sediments enriched in thorium(Th).Organic geochemistry shows that the majority of studied sediments contains predominantly immature to marginally mature algal organic matter(OM).The biomarker patterns are generally in agreement with the geological history of the Lopare Basin and inorganic and mineralogical data.Conversely,the molecular distribution of n-alkanes as reliable climatic andδ-MTTC as paleosalinity indicators do not support this conclusion.展开更多
Different imines were prepared.The reaction was carried out using different conditions,with aromatic aldehydes,aniline and with different energy sources.Yield,purity and experimental fusion point were calculated in ea...Different imines were prepared.The reaction was carried out using different conditions,with aromatic aldehydes,aniline and with different energy sources.Yield,purity and experimental fusion point were calculated in each case,and they were compared to the ones found in literature.The importance of structural effects of aldehyde reacting with aniline was established as well as reaction conditions.The efficacy of the reaction can not be predicted,since each aldehyde has a different structure and therefore reacts differently.The main objective of this project is academic.A methodology to carry out a structured research(it is one of the levels of problem-based learning(ABP)),was implemented.Students work in pairs using Combinatorial Chemistry,and each pair does a different exercise on the same theoretical objective.Results from every team are discussed in a seminary where conclusions regarding which was the most efficient reaction are reached.展开更多
Some basic characteristics of lanthanide-oxygen bonds in various trivalent lanthanide metal-organic complexes are quantitatively studied by the bond valence model. Some important relationships among the electronegativ...Some basic characteristics of lanthanide-oxygen bonds in various trivalent lanthanide metal-organic complexes are quantitatively studied by the bond valence model. Some important relationships among the electronegativity, bond valence parameter, bond length and lanthanide coordination number in these complexes are generally found , which show that for each trivalent lanthanide cation all calculated parameters may well be correlated with its coordination number in their coordination complexes. Specifically,32 new data for the bond valence parameter are first calculated in this work.An approximate linear relationship between the Ln-O bond valence parameter and the coordination number of Ln^(3+) is obtained.The Ln-O bond length increases with the increase in the lanthanide coordination number.The difference of electronegative values decreases with the increase in the lanthanide coordination number.展开更多
During the ongoing 2020 CoVid-19 crisis,the use of remote meeting technologies such as Zoom™,Microsoft Teams™and Google Meetings™has been paramount to theoretical teaching in a safe socially distanced environment.Howe...During the ongoing 2020 CoVid-19 crisis,the use of remote meeting technologies such as Zoom™,Microsoft Teams™and Google Meetings™has been paramount to theoretical teaching in a safe socially distanced environment.However,several problems arise when there is a need for an experimental approach.This paper looks at one of the possible solutions,including how to best separate the students,how to minimize close interactions and how a mixed environment of remote/presential teaching is required,minimizing the amount of extra materials,resources and protection equipment required,such that developing countries can quickly adopt this method,without the purchase of any external equipment.展开更多
A new method of synthesis of 2-(1,2-diferrocenylvinyl)benz- and azabenzimidazoles (3a-f), (4a-f) and 1’H,3’H(Me)-spiro-[(aza)benzimidazoline-2’,3-(1,2-diferrocenylcyclopropenes)] (5a-f) via reactions of diferroceny...A new method of synthesis of 2-(1,2-diferrocenylvinyl)benz- and azabenzimidazoles (3a-f), (4a-f) and 1’H,3’H(Me)-spiro-[(aza)benzimidazoline-2’,3-(1,2-diferrocenylcyclopropenes)] (5a-f) via reactions of diferrocenyl(methylsulfanyl)cyclopropenylium iodide (1) with aromatic o-diamines (2a-f) in the presence of Et3N (80°C - 82°C) is described. The structures of the resultant compounds are established using IR, 1H and 13C NMR spectroscopy, mass spectrometry and elemental analysis. The structure of one compound, cis-2-(1,2-diferrocenylvinyl)-1-methylbenzimidazole (3b), is confirmed by X-ray diffraction analysis. The electrochemical properties of compounds 3a, 3b, 3d and 5f are investigated using cyclic square wave voltammetry. Two electrochemical processes (I-II), attributed to oxidation of the ferrocene moieties, and the values of E0’(I), E0’(II), DE0’(II-I) and comporportionation constant Kcom are reported. The bioactivities of seven compounds 3a, 3c-f, 5d, 5f are evaluated. Compound 5f is the most active compound with a modest cytotoxic activity against six human cancer cell lines: U-251 (glioma), PC-3 (prostate cancer), K-562 (leukemia), HCT-15 (colon cancer), MCF-7 (breast cancer) and SKLU-1 (lung cancer).展开更多
The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Cova...The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Covalent organic frameworks(COFs)offer a promising approach for CO_(2)transformation but lack high efficiency and selectivity in the absence of metals.Here,we have incorporated a pyridine nitrogen component into the imine-COF conjugated structure(Tp Pym).This innovative system has set a record of producing a CO yield of 1565μmol g^(-1)within 6 h.The soft X-ray absorption fine structure measurement proves that Tp Pym has both better conjugation and electron cloud enrichment.The electronic structure distribution delays the charge-carrier recombination,as evidenced by femtosecond transient absorption spectroscopy.The energy band diagram and theoretical calculation show that the conduction-band potential of Tp Pym is lower and the reduction reaction of CO_(2)to CO is more likely to occur.展开更多
Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfull...Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfully synthesized under hydrothermal conditions and characterized structurally by IR spectroscopy,elemental analyses,single-crystal X-ray diffraction,powder X-ray diffraction,and thermogravimetric analysis.The results of single-crystal X-ray diffraction show that complex 1 presents a 1D zigzag chain structure and further extends to a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.Meanwhile,complex 2 has a zero-dimensional structure and also extends to form a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.In addition,both 1and 2 exhibited luminescent properties in the solid state.Furthermore,quantum chemical calculations were carried out on the"molecular fragments"extracted from the crystal structures of 1 and 2 using the PBE0/LANL2DZ method constructed by the Gaussian 16 program.The calculated values signify a significant covalent interaction between the coordination atoms and the Cd(Ⅱ)ions.CCDC:2332173,1;2332176,2.展开更多
Direct ethanol fuel cells(DEFCs)are a promising alternative to conventional energy sources,offering high energy density,environmental sustainability,and operational safety.Compared to methanol fuel cells,DEFCs exhibit...Direct ethanol fuel cells(DEFCs)are a promising alternative to conventional energy sources,offering high energy density,environmental sustainability,and operational safety.Compared to methanol fuel cells,DEFCs exhibit lower toxicity and a more mature preparation process.Unlike hydrogen fuel cells,DEFCs provide superior storage and transport feasibility,as well as cost-effectiveness,significantly enhancing their commercial viability.However,the stable C-C bond in ethanol creates a high activation energy barrier,often resulting in incomplete electrooxidation.Current commercial platinum(Pt)-and palladium(Pd)-based catalysts demonstrate low C-C bond cleavage efficiency(<7.5%),severely limiting DEFC energy output and power density.Furthermore,high catalyst costs and insufficient activity impede large-scale commercialization.Recent advances in DEFC anode catalyst design have focused on optimizing material composition and elucidating catalytic mechanisms.This review systematically examines developments in ethanol electrooxidation catalysts over the past five years,highlighting strategies to improve C1 pathway selectivity and C-C bond activation.Key approaches,such as alloying,nanostructure engineering,and interfacial synergy effects,are discussed alongside their mechanistic implications.Finally,we outline current challenges and future prospects for DEFC commercialization.展开更多
Rare earth elements were extracted using a sulfuric acid roasting-water leaching process.The effect of acid roasting on a new type of low-grade sedimentary rare earth ore found in Guizhou Province,China was analyzed u...Rare earth elements were extracted using a sulfuric acid roasting-water leaching process.The effect of acid roasting on a new type of low-grade sedimentary rare earth ore found in Guizhou Province,China was analyzed using X-ray diffraction and scanning electron microscopy.A systematic study was conducted on process parameters such as amount of acid,roasting temperature,roasting time,water leaching temperature,and leaching time.The results reveal that the total recove ry of rare earth elements reaches 81.37%,which is 3.1 times higher than that achieved through direct acid leaching,under the optimal conditions.In addition,the leaching rate of heavy rare earth elements reaches 72.53%.Rare earth elements and some other valuable metals are transformed into soluble sulfate through the local decomposition of clay minerals under the action of the sulfuric acid attack.The dissolution rates of aluminum,iron,and titanium ions are 34.94%,17.05%,and 62.77%,respectively.The precipitation rate of Ti reaches 99%,and the loss of rare earth ions in the solution is less than 1%.Meanwhile,the results of a leaching kinetics analysis indicate that the leaching process of rare ions is controlled by diffusion.Precious metal ions such as iron and aluminum in the leaching solution can reduce the adsorption of rare earth ions by kaolinite.This study efficiently recovered rare earth ions under conditions of low calcination te mperature and direct water leaching,resulting in reduced energy consumption of the extraction process and acidity of the leaching solution.These findings provide a solid foundation for the further separation and extraction of rare earth ions.展开更多
In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to sign...In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to significant environmental issues[1].Currently,sustainable biomass resources have attracted much attention as potential substitutes to fossil fuels for producing biofuels and commodity chemicals[2].展开更多
Density(p),speed of sound(u),viscosity(η),and refractive index(n_(D))were measured for pure acetonitrile,trichloroethene,and tetrachloroethene,as well as their binary mixtures at temperatures T=(293.15,298.15,303.15)...Density(p),speed of sound(u),viscosity(η),and refractive index(n_(D))were measured for pure acetonitrile,trichloroethene,and tetrachloroethene,as well as their binary mixtures at temperatures T=(293.15,298.15,303.15)K and at ambient pressure(81.5 kPa).From the experimental data,excess molar volume(V_(m)~E),thermal expansion coefficients(α),deviations in isentropic compressibility(Δκ_(S)),viscosity(Δ_η),and refractive index(Δn_(D))were calculated.These values were then correlated using the Redlich-Kister polynomial equation,with fitting coefficients and standard deviations determined.Additionally,the Prigogine-Flory-Patterson(PFP)theory and the Extended Real Associated Solution(ERAS)model were employed to correlate the excess molar volume,while the Perturbed Chain Statistical Associating Fluid Theory(PC-SAFT)was used to predict the density of mixtures.展开更多
Catalytic transfer hydrogenation(CTH)reaction of biomass aldehydes and ketones is a promising approach for hydrogenation.However,the development of efficient catalysts under mild conditions is a challenge.In this pape...Catalytic transfer hydrogenation(CTH)reaction of biomass aldehydes and ketones is a promising approach for hydrogenation.However,the development of efficient catalysts under mild conditions is a challenge.In this paper,a bifunctional catalyst with adjustable oxygen vacancies was prepared by controlling the calcination temperature to synthesize Ce-MOF-derived catalysts for the CTH reaction of furfural(FF)to furfuryl alcohol(FAL).Among them,Ce-500-Ar exhibited excellent FF conversion(>99.9%)and FAL selectivity(>99.9%)at a relatively low temperature of 110℃,which was much higher than that of commercial CeO_(2) catalysts.This excellent performance was mainly attributed to the synergistic effect between acid and base sites in Ce-500-Ar,and the abundant oxygen vacancies that promoted the conversion of FF.Meanwhile,the generation of high specific surface area and mesoporous structure not only exposed the catalytic active sites,but also enhanced the mass transfer.Additionally,the Ce-500-Ar catalyst still maintained excellent catalytic performance after cyclic reactions.This work provides a reference for the design of efficient bifunctional catalysts for the CTH reaction of biomass.展开更多
Layered rare-earth metal oxides,harnessing the dual properties of oxides and two-dimensional layered materials,exhibit remarkable thermal stability and quantum confinement effects.Therefore,this work adopts the first-...Layered rare-earth metal oxides,harnessing the dual properties of oxides and two-dimensional layered materials,exhibit remarkable thermal stability and quantum confinement effects.Therefore,this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound.The coexistence of weak interlayer van der Waals interactions,robust intralayer ionic bonding,and partial covalent bonding leads to remarkable bonding heterogeneity,which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction.The weakened chemical bonds induced by the antibonding states,together with the rattling-like behavior of the Zn atom,culminate in the profound anharmonicity in the layered NdZnSbO compound.The weakening bond and heavy element contribute to the softness of phonon modes,which significantly diminishes the phonon group velocity.The redistribution-dominated four-phonon scattering process spans a large optical gap,which effectively reduces the lattice thermal conductivity.The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-Ernzerhof(HSE06)functional in combination with spin–orbit coupling(SOC)effect.The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy,thus amplifying the power factor.Consequently,an optimal figure-of-merit(ZT)of 3.40 at 900 K is achieved for the n-type NdZnSbO compound.The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.展开更多
Aqueous zinc-ion batteries(AZIBs)are recognized for their commercial viability due to their low cost,high safety,and substantial theoretical capacity.However,the challenges posed by dendrite growth and side reactions ...Aqueous zinc-ion batteries(AZIBs)are recognized for their commercial viability due to their low cost,high safety,and substantial theoretical capacity.However,the challenges posed by dendrite growth and side reactions of zinc ions hinder the widespread adoption of AZIBs.In this work,a new porous phenolphthalein-based polymer(PPH-CN)is synthesized through the polymerization of phenolphthalein and 2,6-difluorobenzonitrile and served as a protective layer of zinc anode.The PPH-CN layer not only effectively separates the zinc anode from aqueous electrolyte to suppress side reactions,but also provides abundant zincophilic sites to facilitate the deposition of zinc ions.As a result,the Zn@PPH-CN symmetric batteries achieve a notably stable cycle lifespan of 1820 h at a current density of 1 mA cm^(-2),which is thirteen times longer than that of bare Zn.Under the protection of PPH-CN,the zinc anode exhibits a high average Coulombic efficiency(CE)of 99.7%after 3550 cycles in the Zn@PPH-CN//Cu asymmetric battery.The capacity retention rate of Zn@PPH-CN//NH_(4)V_(4)O_(10)full batteries reaches 89.6%after 1000 cycles at 1 Ag^(-1).Furthermore,density functional theory(DFT)simulations identified the Zn^(2+)storage sites of PPH-CN,thereby demonstrating the viability of PPH-CN as interface coatings of zinc anode.This work offers valuable insights into the development of high-performance aqueous battery.展开更多
Aqueous zinc ion batteries(AZIBs)are considered to be one of the most promising energy storage devices due to the advantages of high cost-effectiveness,safety,and environmental friendliness.However,they suffer from pr...Aqueous zinc ion batteries(AZIBs)are considered to be one of the most promising energy storage devices due to the advantages of high cost-effectiveness,safety,and environmental friendliness.However,they suffer from problems such as Zn dendrites growth and by-product generation.Carbonized polymer dots(CPDs)with polar groups as additive have been introduced to modulate the solvated structure of Zn^(2+)and reduce the water activity,promoting the uniform deposition of Zn and inhibiting the occurrence of side reactions.However,CPDs with different functional group contents from different precursor molar ratios variably affect the electrochemical performance of aqueous electrolytes.Therefore,in this work,we designed and synthesized CPDs with different molar ratios of the precursors(citric acid and urea)as electrolyte additives for AZIBs and explore the optimal molar ratios of the precursors.The Zn//Zn symmetrical cells using electrolytes with the optimal ratios CPDs achieve an extended cycle life over 615 h at 2 mA∙cm^(−2) and 1 mAh∙cm^(−2).This work offers great potential for future practical applications of CPDs.展开更多
Controlled photocatalytic conversion of CO_(2) into premium fuel such as methane(CH4)offers a sustainable pathway towards a carbon energy cycle.However,the photocatalytic efficiency and selectivity are still unsatisfa...Controlled photocatalytic conversion of CO_(2) into premium fuel such as methane(CH4)offers a sustainable pathway towards a carbon energy cycle.However,the photocatalytic efficiency and selectivity are still unsatisfactory due to the limited availability of active sites on the current photocatalysts.To resolve this issue,the design of oxygen vacancies(OVs)in metal-oxide semiconductors is an effective option.Herein,in situ deposition of TiO_(2) onto SiO_(2) nanospheres to construct a SiO_(2)@TiO_(2) core-shell structure was performed to modulate the oxygen vacancy concentrations.Meanwhile,charge redistribution led to the formation of abundant OV-regulated Ti-Ti(Ti-OV-Ti)dual sites.It is revealed that Ti-OV-Ti dual sites served as the key active site for capturing the photogenerated electrons during light-driven CO_(2) reduction reaction(CO_(2)RR).Such electron-rich active sites enabled efficient CO_(2) adsorption and activation,thus lowering the energy barrier associated with the rate-determining step.More importantly,the formation of a highly stable*CHO intermediate at Ti-OV-Ti dual sites energetically favored the reaction pathway towards the production of CH4 rather than CO,thereby facilitating the selective product of CH_(4).As a result,SiO_(2)@TiO_(2)-50 with an optimized oxygen vacancy concentration of 9.0% showed a remarkable selectivity(90.32%)for CH_(4) production with a rate of 13.21μmol g^(-1) h^(-1),which is 17.38-fold higher than that of pristine TiO_(2).This study provides a new avenue for engineering superior photocatalysts through a rational methodology towards selective reduction of CO_(2).展开更多
In conjugated polymers(CPs)photocatalytic system,the generation of reactive oxygen species(ROS)is regulated by cross-scale factors involving active site,excitonic behavior,and O_(2)activation process on the surface.Ho...In conjugated polymers(CPs)photocatalytic system,the generation of reactive oxygen species(ROS)is regulated by cross-scale factors involving active site,excitonic behavior,and O_(2)activation process on the surface.However,research on exploring the domino effect of“structure→excitonic behavior→O_(2)activation→photocatalytic reaction”through structural modification at the atomic scale remains at its early stages.Herein,two heptazine-based CPs,CP-DPA,and CP-CZ were successfully prepared by polymerization of precursors formed by reacting diphenylamine(DPA)and carbazole(CZ)with cyameluric chloride,respectively.The minute difference in single bond between DPA and CZ endows the polymers with distinct physicochemical properties.Owing to the rotation between benzene rings,CP-DPA exhibits relatively lower conjugation,resulting in increased exciton binding energy(Eb)and inhibited exciton dissociation.Meanwhile,its more triplet state excitons facilitate energy transfer to generate singlet oxygen.Therefore,CP-DPA shows excellent activity for phenylboronic acid oxidation.Conversely,CP-CZ possesses relatively higher conjugation,minimal Eb and intensified exciton dissociation,which promotes charge transfer to produce superoxide radical.Consequently,CP-CZ displays optimal activity for phe-nylacetylene oxidation and[3+2]cycloaddition.This work provides new insights into regulating ROS gener-ation by modulating the composition and structure of photocatalysts at the atomic scale.展开更多
基金supported by the National Natural Science Foundation of China(grant numbers 52071225,22179143,and 22002176)the European Union’s Horizon Europe research and innovation program Electron Beam Emergent Additive Manufacturing(EBEAM)(grant number 101087143)+2 种基金a Norway Grant through the National Science Centre(project number 2019/34/H/ST8/00547)the National Key R&D Program of China(grant number 2021YFB3800300)the Jiangsu Funding Program for Excellent Postdoctoral Talent。
文摘Lithium metal batteries(LMBs)are promising candidates for next-generation high-energy-density storage devices.However,an unstable lithium metal anode poses significant issues that critically compromise battery safety and cycle life,including lithium dendrite formation,solid electrolyte interphase degradation,dead lithium accumulation,and substantial volume fluctuations during cycling.These problems can be addressed by regulating lithium deposition and suppressing side reactions through the modification of copper current collectors using three classes of materials:metal and metal oxide,carbon,and polymer materials.This review comprehensively examines recent advances in the application of these materials as current collector coatings.Particularly,their distinct roles in the lithium deposition process are analyzed to understand how they mitigate the issues associated with the lithium metal anode.Furthermore,their inherent limitations are considered to inform future research directions.While each class of materials offers specific advantages,multifunctionality is required to effectively regulate lithium deposition.In prospect,a novel composite copper current collector design that integrates the merits of the aforementioned advanced materials is proposed.The insights from this review provide valuable guidance for the rational design of modified copper current collectors,which would significantly improve the safety and cycle life of LMBs and advance their commercialization.
文摘Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmethyl)butane(bib)by a hydrothermal method,respectively.X⁃ray crystallography reveals a 2D network constructed by six⁃coordinated Ni(Ⅱ)centers,bib,and Hpdc2-ligands in complex 1,while a 2D network is built by Ni(Ⅱ)and bib ligands in 2.Furthermore,the quantum⁃chemical calculations have been performed on‘molecular fragments’extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in Gaussian 16 and the VASP program.CCDC:2343794,1;2343798,2.
基金partly financed by the Ministry of Education,Science and Technological Development,Republic of Serbia(Grant No.451-03-68/2020-14/200026 and Project 176006)。
文摘A combined inorganic and organic geochemical study was carried out on marls and mudstones collected from the Lower Miocene Lopare Basin,Bosnia and Herzegovina.A total of 46 samples collected from two boreholes,Pot 1(depth of 193 m)and Pot 3(depth of 344 m),showed that element abundances like boron(B),lithium(Li),strontium(Sr),uranium(U),chromium(Cr),nickel(Ni),magnesium(Mg),sodium(Na)and calcium(Ca)are much higher than average than in the upper continental crust(UCC).Chemical composition indicates at least two sources:(i)Mesozoic ophiolites occurring in the north of the investigated area,and(ii)dacito-andesitic pyroclastics(Mesozoic to Cenozoic).Lopare Basin sedimentation was influenced by strong evaporation resulting in a partly hypersaline lake,which formed during a warm climatic period,probably during the Miocene Climatic Optimum.A brief episode of humid climate conditions resulted in the basin fillingup and deposition of felsic sediments enriched in thorium(Th).Organic geochemistry shows that the majority of studied sediments contains predominantly immature to marginally mature algal organic matter(OM).The biomarker patterns are generally in agreement with the geological history of the Lopare Basin and inorganic and mineralogical data.Conversely,the molecular distribution of n-alkanes as reliable climatic andδ-MTTC as paleosalinity indicators do not support this conclusion.
文摘Different imines were prepared.The reaction was carried out using different conditions,with aromatic aldehydes,aniline and with different energy sources.Yield,purity and experimental fusion point were calculated in each case,and they were compared to the ones found in literature.The importance of structural effects of aldehyde reacting with aniline was established as well as reaction conditions.The efficacy of the reaction can not be predicted,since each aldehyde has a different structure and therefore reacts differently.The main objective of this project is academic.A methodology to carry out a structured research(it is one of the levels of problem-based learning(ABP)),was implemented.Students work in pairs using Combinatorial Chemistry,and each pair does a different exercise on the same theoretical objective.Results from every team are discussed in a seminary where conclusions regarding which was the most efficient reaction are reached.
文摘Some basic characteristics of lanthanide-oxygen bonds in various trivalent lanthanide metal-organic complexes are quantitatively studied by the bond valence model. Some important relationships among the electronegativity, bond valence parameter, bond length and lanthanide coordination number in these complexes are generally found , which show that for each trivalent lanthanide cation all calculated parameters may well be correlated with its coordination number in their coordination complexes. Specifically,32 new data for the bond valence parameter are first calculated in this work.An approximate linear relationship between the Ln-O bond valence parameter and the coordination number of Ln^(3+) is obtained.The Ln-O bond length increases with the increase in the lanthanide coordination number.The difference of electronegative values decreases with the increase in the lanthanide coordination number.
文摘During the ongoing 2020 CoVid-19 crisis,the use of remote meeting technologies such as Zoom™,Microsoft Teams™and Google Meetings™has been paramount to theoretical teaching in a safe socially distanced environment.However,several problems arise when there is a need for an experimental approach.This paper looks at one of the possible solutions,including how to best separate the students,how to minimize close interactions and how a mixed environment of remote/presential teaching is required,minimizing the amount of extra materials,resources and protection equipment required,such that developing countries can quickly adopt this method,without the purchase of any external equipment.
文摘A new method of synthesis of 2-(1,2-diferrocenylvinyl)benz- and azabenzimidazoles (3a-f), (4a-f) and 1’H,3’H(Me)-spiro-[(aza)benzimidazoline-2’,3-(1,2-diferrocenylcyclopropenes)] (5a-f) via reactions of diferrocenyl(methylsulfanyl)cyclopropenylium iodide (1) with aromatic o-diamines (2a-f) in the presence of Et3N (80°C - 82°C) is described. The structures of the resultant compounds are established using IR, 1H and 13C NMR spectroscopy, mass spectrometry and elemental analysis. The structure of one compound, cis-2-(1,2-diferrocenylvinyl)-1-methylbenzimidazole (3b), is confirmed by X-ray diffraction analysis. The electrochemical properties of compounds 3a, 3b, 3d and 5f are investigated using cyclic square wave voltammetry. Two electrochemical processes (I-II), attributed to oxidation of the ferrocene moieties, and the values of E0’(I), E0’(II), DE0’(II-I) and comporportionation constant Kcom are reported. The bioactivities of seven compounds 3a, 3c-f, 5d, 5f are evaluated. Compound 5f is the most active compound with a modest cytotoxic activity against six human cancer cell lines: U-251 (glioma), PC-3 (prostate cancer), K-562 (leukemia), HCT-15 (colon cancer), MCF-7 (breast cancer) and SKLU-1 (lung cancer).
基金supported by the National Natural Science Foundation of China(Nos.22375031,22202037,22472023)the Fundamental Research Funds for the Central Universities(Nos.2412023YQ001,2412023QD019,2412024QD014)+1 种基金supported by grants from the seventh batch of Jilin Province Youth Science and Technology Talent Lifting Project(No.QT202305)Science and Technology Development Plan Project of Jilin Province,China(No.20240101192JC)。
文摘The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Covalent organic frameworks(COFs)offer a promising approach for CO_(2)transformation but lack high efficiency and selectivity in the absence of metals.Here,we have incorporated a pyridine nitrogen component into the imine-COF conjugated structure(Tp Pym).This innovative system has set a record of producing a CO yield of 1565μmol g^(-1)within 6 h.The soft X-ray absorption fine structure measurement proves that Tp Pym has both better conjugation and electron cloud enrichment.The electronic structure distribution delays the charge-carrier recombination,as evidenced by femtosecond transient absorption spectroscopy.The energy band diagram and theoretical calculation show that the conduction-band potential of Tp Pym is lower and the reduction reaction of CO_(2)to CO is more likely to occur.
文摘Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfully synthesized under hydrothermal conditions and characterized structurally by IR spectroscopy,elemental analyses,single-crystal X-ray diffraction,powder X-ray diffraction,and thermogravimetric analysis.The results of single-crystal X-ray diffraction show that complex 1 presents a 1D zigzag chain structure and further extends to a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.Meanwhile,complex 2 has a zero-dimensional structure and also extends to form a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.In addition,both 1and 2 exhibited luminescent properties in the solid state.Furthermore,quantum chemical calculations were carried out on the"molecular fragments"extracted from the crystal structures of 1 and 2 using the PBE0/LANL2DZ method constructed by the Gaussian 16 program.The calculated values signify a significant covalent interaction between the coordination atoms and the Cd(Ⅱ)ions.CCDC:2332173,1;2332176,2.
基金supported by the National Natural Science Foundation of China(22472023,22202037)the Jilin Province Science and Technology Development Program(20250102077JC)the Fundamental Research Funds for the Central Universities(2412024QD014,2412023QD019).
文摘Direct ethanol fuel cells(DEFCs)are a promising alternative to conventional energy sources,offering high energy density,environmental sustainability,and operational safety.Compared to methanol fuel cells,DEFCs exhibit lower toxicity and a more mature preparation process.Unlike hydrogen fuel cells,DEFCs provide superior storage and transport feasibility,as well as cost-effectiveness,significantly enhancing their commercial viability.However,the stable C-C bond in ethanol creates a high activation energy barrier,often resulting in incomplete electrooxidation.Current commercial platinum(Pt)-and palladium(Pd)-based catalysts demonstrate low C-C bond cleavage efficiency(<7.5%),severely limiting DEFC energy output and power density.Furthermore,high catalyst costs and insufficient activity impede large-scale commercialization.Recent advances in DEFC anode catalyst design have focused on optimizing material composition and elucidating catalytic mechanisms.This review systematically examines developments in ethanol electrooxidation catalysts over the past five years,highlighting strategies to improve C1 pathway selectivity and C-C bond activation.Key approaches,such as alloying,nanostructure engineering,and interfacial synergy effects,are discussed alongside their mechanistic implications.Finally,we outline current challenges and future prospects for DEFC commercialization.
基金supported by the Guizhou Provincial Science and Technology Program ([2022]ZD006)。
文摘Rare earth elements were extracted using a sulfuric acid roasting-water leaching process.The effect of acid roasting on a new type of low-grade sedimentary rare earth ore found in Guizhou Province,China was analyzed using X-ray diffraction and scanning electron microscopy.A systematic study was conducted on process parameters such as amount of acid,roasting temperature,roasting time,water leaching temperature,and leaching time.The results reveal that the total recove ry of rare earth elements reaches 81.37%,which is 3.1 times higher than that achieved through direct acid leaching,under the optimal conditions.In addition,the leaching rate of heavy rare earth elements reaches 72.53%.Rare earth elements and some other valuable metals are transformed into soluble sulfate through the local decomposition of clay minerals under the action of the sulfuric acid attack.The dissolution rates of aluminum,iron,and titanium ions are 34.94%,17.05%,and 62.77%,respectively.The precipitation rate of Ti reaches 99%,and the loss of rare earth ions in the solution is less than 1%.Meanwhile,the results of a leaching kinetics analysis indicate that the leaching process of rare ions is controlled by diffusion.Precious metal ions such as iron and aluminum in the leaching solution can reduce the adsorption of rare earth ions by kaolinite.This study efficiently recovered rare earth ions under conditions of low calcination te mperature and direct water leaching,resulting in reduced energy consumption of the extraction process and acidity of the leaching solution.These findings provide a solid foundation for the further separation and extraction of rare earth ions.
基金funded by the Master,PhD Scholarship Programme of Vingroup Innovation Foundation(VINIF),code VINIF.2024.TS.035funded by Vietnam National University,Ho Chi Minh City(VNUHCM)under grant number NCM2024-18-01。
文摘In the past century,industrial and economic growth relied heavily on fossil fuels such as coal,oil,and natural gas.As the society energy demands continue to grow,these fossil fuel reserves are depleted,leading to significant environmental issues[1].Currently,sustainable biomass resources have attracted much attention as potential substitutes to fossil fuels for producing biofuels and commodity chemicals[2].
基金Bu-Ali Sina University for providing financial support for conducting this study。
文摘Density(p),speed of sound(u),viscosity(η),and refractive index(n_(D))were measured for pure acetonitrile,trichloroethene,and tetrachloroethene,as well as their binary mixtures at temperatures T=(293.15,298.15,303.15)K and at ambient pressure(81.5 kPa).From the experimental data,excess molar volume(V_(m)~E),thermal expansion coefficients(α),deviations in isentropic compressibility(Δκ_(S)),viscosity(Δ_η),and refractive index(Δn_(D))were calculated.These values were then correlated using the Redlich-Kister polynomial equation,with fitting coefficients and standard deviations determined.Additionally,the Prigogine-Flory-Patterson(PFP)theory and the Extended Real Associated Solution(ERAS)model were employed to correlate the excess molar volume,while the Perturbed Chain Statistical Associating Fluid Theory(PC-SAFT)was used to predict the density of mixtures.
基金supported by National Natural Science Foundation of China(32360430,22375031)Science and Technology Planning Project of Yunnan Province(202401BD070001-030)+1 种基金the Jilin Natural Science Fund for Excellent Young Scholars(20230508116RC)the Fundamental Research Funds for the Central Universities(2412023YQ001)
文摘Catalytic transfer hydrogenation(CTH)reaction of biomass aldehydes and ketones is a promising approach for hydrogenation.However,the development of efficient catalysts under mild conditions is a challenge.In this paper,a bifunctional catalyst with adjustable oxygen vacancies was prepared by controlling the calcination temperature to synthesize Ce-MOF-derived catalysts for the CTH reaction of furfural(FF)to furfuryl alcohol(FAL).Among them,Ce-500-Ar exhibited excellent FF conversion(>99.9%)and FAL selectivity(>99.9%)at a relatively low temperature of 110℃,which was much higher than that of commercial CeO_(2) catalysts.This excellent performance was mainly attributed to the synergistic effect between acid and base sites in Ce-500-Ar,and the abundant oxygen vacancies that promoted the conversion of FF.Meanwhile,the generation of high specific surface area and mesoporous structure not only exposed the catalytic active sites,but also enhanced the mass transfer.Additionally,the Ce-500-Ar catalyst still maintained excellent catalytic performance after cyclic reactions.This work provides a reference for the design of efficient bifunctional catalysts for the CTH reaction of biomass.
基金Financial supports from the National Natural Science Foundation of China(21503039)Department of Science and Technology of Liaoning Province(2019MS164)+1 种基金Department of Education of Liaoning Province(LJ2020JCL034)Discipline Innovation Team of Liaoning Technical University(LNTU20TD-16)are greatly acknowledged。
文摘Layered rare-earth metal oxides,harnessing the dual properties of oxides and two-dimensional layered materials,exhibit remarkable thermal stability and quantum confinement effects.Therefore,this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound.The coexistence of weak interlayer van der Waals interactions,robust intralayer ionic bonding,and partial covalent bonding leads to remarkable bonding heterogeneity,which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction.The weakened chemical bonds induced by the antibonding states,together with the rattling-like behavior of the Zn atom,culminate in the profound anharmonicity in the layered NdZnSbO compound.The weakening bond and heavy element contribute to the softness of phonon modes,which significantly diminishes the phonon group velocity.The redistribution-dominated four-phonon scattering process spans a large optical gap,which effectively reduces the lattice thermal conductivity.The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-Ernzerhof(HSE06)functional in combination with spin–orbit coupling(SOC)effect.The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy,thus amplifying the power factor.Consequently,an optimal figure-of-merit(ZT)of 3.40 at 900 K is achieved for the n-type NdZnSbO compound.The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.
基金financially supported by the National Natural Science Foundation of China(Nos.22475035 and 22071021)
文摘Aqueous zinc-ion batteries(AZIBs)are recognized for their commercial viability due to their low cost,high safety,and substantial theoretical capacity.However,the challenges posed by dendrite growth and side reactions of zinc ions hinder the widespread adoption of AZIBs.In this work,a new porous phenolphthalein-based polymer(PPH-CN)is synthesized through the polymerization of phenolphthalein and 2,6-difluorobenzonitrile and served as a protective layer of zinc anode.The PPH-CN layer not only effectively separates the zinc anode from aqueous electrolyte to suppress side reactions,but also provides abundant zincophilic sites to facilitate the deposition of zinc ions.As a result,the Zn@PPH-CN symmetric batteries achieve a notably stable cycle lifespan of 1820 h at a current density of 1 mA cm^(-2),which is thirteen times longer than that of bare Zn.Under the protection of PPH-CN,the zinc anode exhibits a high average Coulombic efficiency(CE)of 99.7%after 3550 cycles in the Zn@PPH-CN//Cu asymmetric battery.The capacity retention rate of Zn@PPH-CN//NH_(4)V_(4)O_(10)full batteries reaches 89.6%after 1000 cycles at 1 Ag^(-1).Furthermore,density functional theory(DFT)simulations identified the Zn^(2+)storage sites of PPH-CN,thereby demonstrating the viability of PPH-CN as interface coatings of zinc anode.This work offers valuable insights into the development of high-performance aqueous battery.
基金supported by the National Natural Science Foundation of China(22035001 and 22275030)Jilin Provincial Education Department(JJKH20231304KJ)the Fundamental Research Funds(Science and Technology Achievements Transformation)for the Central Universities of China(CGZH202203)
文摘Aqueous zinc ion batteries(AZIBs)are considered to be one of the most promising energy storage devices due to the advantages of high cost-effectiveness,safety,and environmental friendliness.However,they suffer from problems such as Zn dendrites growth and by-product generation.Carbonized polymer dots(CPDs)with polar groups as additive have been introduced to modulate the solvated structure of Zn^(2+)and reduce the water activity,promoting the uniform deposition of Zn and inhibiting the occurrence of side reactions.However,CPDs with different functional group contents from different precursor molar ratios variably affect the electrochemical performance of aqueous electrolytes.Therefore,in this work,we designed and synthesized CPDs with different molar ratios of the precursors(citric acid and urea)as electrolyte additives for AZIBs and explore the optimal molar ratios of the precursors.The Zn//Zn symmetrical cells using electrolytes with the optimal ratios CPDs achieve an extended cycle life over 615 h at 2 mA∙cm^(−2) and 1 mAh∙cm^(−2).This work offers great potential for future practical applications of CPDs.
基金supported by the National Natural Science Foundation of China(No.21773089,22202037)the Science and Technology Development Plan Project of Jilin Province,China(No.20240101192JC)the Fundamental Research Funds for the Central Universities(No.2412023QD019).
文摘Controlled photocatalytic conversion of CO_(2) into premium fuel such as methane(CH4)offers a sustainable pathway towards a carbon energy cycle.However,the photocatalytic efficiency and selectivity are still unsatisfactory due to the limited availability of active sites on the current photocatalysts.To resolve this issue,the design of oxygen vacancies(OVs)in metal-oxide semiconductors is an effective option.Herein,in situ deposition of TiO_(2) onto SiO_(2) nanospheres to construct a SiO_(2)@TiO_(2) core-shell structure was performed to modulate the oxygen vacancy concentrations.Meanwhile,charge redistribution led to the formation of abundant OV-regulated Ti-Ti(Ti-OV-Ti)dual sites.It is revealed that Ti-OV-Ti dual sites served as the key active site for capturing the photogenerated electrons during light-driven CO_(2) reduction reaction(CO_(2)RR).Such electron-rich active sites enabled efficient CO_(2) adsorption and activation,thus lowering the energy barrier associated with the rate-determining step.More importantly,the formation of a highly stable*CHO intermediate at Ti-OV-Ti dual sites energetically favored the reaction pathway towards the production of CH4 rather than CO,thereby facilitating the selective product of CH_(4).As a result,SiO_(2)@TiO_(2)-50 with an optimized oxygen vacancy concentration of 9.0% showed a remarkable selectivity(90.32%)for CH_(4) production with a rate of 13.21μmol g^(-1) h^(-1),which is 17.38-fold higher than that of pristine TiO_(2).This study provides a new avenue for engineering superior photocatalysts through a rational methodology towards selective reduction of CO_(2).
基金supported by National Natural Science Foundation of China(22171041,22071020,52130101)National Key R&D Program of China(2023YFB3003001)+2 种基金Natural Science Foundation of Jilin Province Science and Technology Department(discipline layout project)(grant no.20230508094RC)the Fundamental Research Funds for the Central Universities(grant no.2412021QD008)the Fundamental Research Funds for the Central Universities-Excellent Youth Team Program(2412023YQ001).
文摘In conjugated polymers(CPs)photocatalytic system,the generation of reactive oxygen species(ROS)is regulated by cross-scale factors involving active site,excitonic behavior,and O_(2)activation process on the surface.However,research on exploring the domino effect of“structure→excitonic behavior→O_(2)activation→photocatalytic reaction”through structural modification at the atomic scale remains at its early stages.Herein,two heptazine-based CPs,CP-DPA,and CP-CZ were successfully prepared by polymerization of precursors formed by reacting diphenylamine(DPA)and carbazole(CZ)with cyameluric chloride,respectively.The minute difference in single bond between DPA and CZ endows the polymers with distinct physicochemical properties.Owing to the rotation between benzene rings,CP-DPA exhibits relatively lower conjugation,resulting in increased exciton binding energy(Eb)and inhibited exciton dissociation.Meanwhile,its more triplet state excitons facilitate energy transfer to generate singlet oxygen.Therefore,CP-DPA shows excellent activity for phenylboronic acid oxidation.Conversely,CP-CZ possesses relatively higher conjugation,minimal Eb and intensified exciton dissociation,which promotes charge transfer to produce superoxide radical.Consequently,CP-CZ displays optimal activity for phe-nylacetylene oxidation and[3+2]cycloaddition.This work provides new insights into regulating ROS gener-ation by modulating the composition and structure of photocatalysts at the atomic scale.
