We present a theoretical study of interactions of anionic and neutral serine （Ser） on pure or metal-doped graphene surfaces using density functional theory calculations. Interactions of both types of Ser with the pu...We present a theoretical study of interactions of anionic and neutral serine （Ser） on pure or metal-doped graphene surfaces using density functional theory calculations. Interactions of both types of Ser with the pure graphene surface show weak non-covalent interactions due to the formation of-COOH…π, -COO^-…π, and -OH…π interactions. On metal- doped graphene, covalent interactions to the surface dominate, due to the formation of strong metal-O and O-metal-O interactions. Furthermore, the doped Fe, Cr, Mn, A1, or Ti enhances the ability of graphene to attract both types of Ser by a combination of the adsorption energy, the density of states, the Mulliken atomic charges, and differences of electron density. At the same time, the interaction strengths of anionic Ser on various graphene surfaces are stronger than those of neutral Ser. These results provide useful insights for the rational design and development of graphene-based sensors for the two forms of Ser by introducing appropriate doped atoms. Ti and Fe are suggested to be the best choices among all doped atoms for the anionic Ser and neutral Ser, respectively.展开更多
Lithium metal batteries(LMBs)of an ultrahigh theoretical energy density have attracted lots of attentions for a wide range of practical applications.However,there are still numerous challenges in LMBs system,such as p...Lithium metal batteries(LMBs)of an ultrahigh theoretical energy density have attracted lots of attentions for a wide range of practical applications.However,there are still numerous challenges in LMBs system,such as poor cycling performance,complicated interfacial reactions,low Coulombic efficiency,and uncontrollable lithium dendrites.Understanding Li^+ions’nucleation mechanism is essential to tackle the uncontrolled growth of lithium dendrites.However,the nucleation behavior of Li+ions is interfered by the structural complexities of existing substrates during the reduplicative plating/stripping process and the rational mechanism of uniform nucleation of Li^+ions has not been clearly understood from the theoretical point of view.In our work,first-principles theoretical calculations are carried out to investigate the Li^+ions nucleation performance on metal-doped Cu surfaces(MDCSs)and the key descriptors that determines the properties of various MDCSs are systematically summarized.It is found that the introduction of heterogeneous doping Ag and Zn atoms will induce a gradient adsorption energy on MDCSs,and such gradient deposition sites can reduce the diffusion barriers and accelerate the diffusion rates of Li+ions dynamically.By maneuvering the Li+ions nucleation on MDCSs,a dendrite-free lithium metal anode can be achieved without the use of porous matrixes and complex synthesis process,which can be attributed to suppress the uncontrollable lithium dendrites for realizing the high-efficiency LMBs.展开更多
Pure metal-doped(Cu,Zn)Fe2O4 was synthesized from Zn-containing electric arc furnace dust(EAFD)by solid-state reaction using copper salt as additive.The effects of pretreated EAFD-to-Cu2(OH)2CO3·6H2O mass ratio,c...Pure metal-doped(Cu,Zn)Fe2O4 was synthesized from Zn-containing electric arc furnace dust(EAFD)by solid-state reaction using copper salt as additive.The effects of pretreated EAFD-to-Cu2(OH)2CO3·6H2O mass ratio,calcination time,and calcination temperature on the structure and catalytic ability were systematically studied.Under the optimum conditions,the decolorization efficiency and total organic carbon(TOC)removal efficiency of the as-prepared ferrite for treating a Rhodamine B solution were approximately 90.0%and 45.0%,respectively,and the decolorization efficiency remained 83.0%after five recycles,suggesting that the as-prepared(Cu,Zn)Fe2O4 was an efficient heterogeneous Fenton-like catalyst with high stability.The high catalytic activity mainly depended on the synergistic effect of iron and copper ions occupying octahedral positions.More importantly,the toxicity characteristic leaching procedure(TCLP)analysis illustrated that the toxic Zncontaining EAFD was transformed into harmless(Cu,Zn)Fe2O4 and that the concentrations of toxic ions in the degraded solution were all lower than the national emission standard(GB/31574-2015),further confirming that the as obtained sample is an environment-friendly heterogeneous Fenton-like catalyst.展开更多
Recently, the incorporation of transition metals into magnetite increasing the heterogeneous Fenton catalytic activity of magnetite with high efficiency and interesting magnetic properties applied for degradation of o...Recently, the incorporation of transition metals into magnetite increasing the heterogeneous Fenton catalytic activity of magnetite with high efficiency and interesting magnetic properties applied for degradation of organic pollutants in water purification and wastewater treatment have attracted more and more researchers. In this review, using of one or some metal doped magnetite based systems in heterogeneous Fenton, or photo-Fenton processes are discussed. Then, the role of metal doped species for the enhanced efficiency of degradation process is presented. Finally, possible reaction mechanism for the photo-Fenton degradation pollutants in the present of metal doped magnetite is also given.展开更多
Advances in nano-lubricant additives are vital to the pursuit of energy efficiency and sustainable development.Carbon dots(CDs)have been widely investigated in the domain of lubricant additives owing to their extraord...Advances in nano-lubricant additives are vital to the pursuit of energy efficiency and sustainable development.Carbon dots(CDs)have been widely investigated in the domain of lubricant additives owing to their extraordinary tribological properties,in particular,their friction-reducing and anti-wear properties.Metal-doped CDs are a new type of CDs,and their friction-reducing and anti-wear properties are attracting increasing attention.Therefore,a series of CDs doped with various divalent metal ions have been successfully synthesized via one-pot pyrolysis.The tribological properties of the synthesized CDs as water-based lubricant additives are in the following order:Zn-CDs>Cu-CDs>>Mg-CDs>Fe-CDs>U-CDs.Specifically,adding 1.0 wt%of Zn-CDs into water-based lubricant results in 62.5%friction and 81.8%wear reduction.Meanwhile,the load-carrying capacity of the water-based lubricant increases from 120 N to at least 500 N.Zn-CDs as an additive have long service life.Additionally,anion-tuned Zn-CDs fabricated via anion exchange exhibit promise as lubricant additives for poly(ethylene glycol).Based on the results of wear scar surface analyses,it is discovered that tribochemical films,primarily composed of iron oxides,nitrides,metal carbonates,zinc oxides,zinc carbonates,organic compounds,and embedded carbon cores,formed on the rubbing surfaces with a thickness of approximately 270 nm when Zn-CDs are used as additives.This film combined with the“ball-bearing”and third-particle effects of Zn-CDs contributed to excellent lubrication performance.展开更多
Electronic structure and magnetic properties of wurtzite ZnO semiconductor doped with rare earth （RE=La, Ce, Pr, Pm, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb） atoms were studied using spin-polarized density functio...Electronic structure and magnetic properties of wurtzite ZnO semiconductor doped with rare earth （RE=La, Ce, Pr, Pm, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb） atoms were studied using spin-polarized density functional theory based on the full-potential linear augmented plane wave （FP-LAPW） method as implemented in the Wien2k code. In this approach the generalized gradient approximation （GGA） was used for the exchange-correlation （XC） potential. Our results showed that the substitution of RE ions in ZnO induced spins polarized localized states in the band gap. Moreover, the studied DMSs compounds retained half metallicity at dopant concentration x=0.625%for most of the studied elements, with 100%spin polarization at the Fermi level （EF）. The total magnetic moments of these compounds existed due to RE 4f states present at EF, while small induced magnetic moments existed on other non-magnetic atoms as well. Finally, the energy difference between far and near configurations was investigated. It was found that the room temperature ferromagnetism was possible for RE-doped ZnO at near configuration. Since the RE-RE separation was long enough （far configuration） for magnetic coupling, the system became paramagnetic or antiferromagnetic ground state.展开更多
文摘We present a theoretical study of interactions of anionic and neutral serine （Ser） on pure or metal-doped graphene surfaces using density functional theory calculations. Interactions of both types of Ser with the pure graphene surface show weak non-covalent interactions due to the formation of-COOH…π, -COO^-…π, and -OH…π interactions. On metal- doped graphene, covalent interactions to the surface dominate, due to the formation of strong metal-O and O-metal-O interactions. Furthermore, the doped Fe, Cr, Mn, A1, or Ti enhances the ability of graphene to attract both types of Ser by a combination of the adsorption energy, the density of states, the Mulliken atomic charges, and differences of electron density. At the same time, the interaction strengths of anionic Ser on various graphene surfaces are stronger than those of neutral Ser. These results provide useful insights for the rational design and development of graphene-based sensors for the two forms of Ser by introducing appropriate doped atoms. Ti and Fe are suggested to be the best choices among all doped atoms for the anionic Ser and neutral Ser, respectively.
基金supported by the National Key Research and Development Program of China(No.2017YFB0702100)the National Natural Science Foundation of China(11404017)+2 种基金the Technology Foundation for Selected Overseas Chinese Scholar,Ministry of Human Resources and Social Security of Chinasupport by the European Regional Development Fund in the IT4Innovations national supercomputing center-Path to Exascale project,No.CZ.02.1.01/0.0/0.0/16_013/0001791 within the Operational Programme Research,Development and Educationby the Ministry of Education by the Ministry of Education,Youth,and Sport of the Czech Republic and grant No.17-27790S of the Czech Science Foundations
文摘Lithium metal batteries(LMBs)of an ultrahigh theoretical energy density have attracted lots of attentions for a wide range of practical applications.However,there are still numerous challenges in LMBs system,such as poor cycling performance,complicated interfacial reactions,low Coulombic efficiency,and uncontrollable lithium dendrites.Understanding Li^+ions’nucleation mechanism is essential to tackle the uncontrolled growth of lithium dendrites.However,the nucleation behavior of Li+ions is interfered by the structural complexities of existing substrates during the reduplicative plating/stripping process and the rational mechanism of uniform nucleation of Li^+ions has not been clearly understood from the theoretical point of view.In our work,first-principles theoretical calculations are carried out to investigate the Li^+ions nucleation performance on metal-doped Cu surfaces(MDCSs)and the key descriptors that determines the properties of various MDCSs are systematically summarized.It is found that the introduction of heterogeneous doping Ag and Zn atoms will induce a gradient adsorption energy on MDCSs,and such gradient deposition sites can reduce the diffusion barriers and accelerate the diffusion rates of Li+ions dynamically.By maneuvering the Li+ions nucleation on MDCSs,a dendrite-free lithium metal anode can be achieved without the use of porous matrixes and complex synthesis process,which can be attributed to suppress the uncontrollable lithium dendrites for realizing the high-efficiency LMBs.
基金financially supported by the National Natural Science Foundation of China(No.U1810205)the National Basic Research Program of China(No.2014CB 643401)Shanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related Wastes。
文摘Pure metal-doped(Cu,Zn)Fe2O4 was synthesized from Zn-containing electric arc furnace dust(EAFD)by solid-state reaction using copper salt as additive.The effects of pretreated EAFD-to-Cu2(OH)2CO3·6H2O mass ratio,calcination time,and calcination temperature on the structure and catalytic ability were systematically studied.Under the optimum conditions,the decolorization efficiency and total organic carbon(TOC)removal efficiency of the as-prepared ferrite for treating a Rhodamine B solution were approximately 90.0%and 45.0%,respectively,and the decolorization efficiency remained 83.0%after five recycles,suggesting that the as-prepared(Cu,Zn)Fe2O4 was an efficient heterogeneous Fenton-like catalyst with high stability.The high catalytic activity mainly depended on the synergistic effect of iron and copper ions occupying octahedral positions.More importantly,the toxicity characteristic leaching procedure(TCLP)analysis illustrated that the toxic Zncontaining EAFD was transformed into harmless(Cu,Zn)Fe2O4 and that the concentrations of toxic ions in the degraded solution were all lower than the national emission standard(GB/31574-2015),further confirming that the as obtained sample is an environment-friendly heterogeneous Fenton-like catalyst.
文摘Recently, the incorporation of transition metals into magnetite increasing the heterogeneous Fenton catalytic activity of magnetite with high efficiency and interesting magnetic properties applied for degradation of organic pollutants in water purification and wastewater treatment have attracted more and more researchers. In this review, using of one or some metal doped magnetite based systems in heterogeneous Fenton, or photo-Fenton processes are discussed. Then, the role of metal doped species for the enhanced efficiency of degradation process is presented. Finally, possible reaction mechanism for the photo-Fenton degradation pollutants in the present of metal doped magnetite is also given.
基金This work was financially supported by the Science and Technology Innovation Seedling Project of Sichuan Province(No.2020068).
文摘Advances in nano-lubricant additives are vital to the pursuit of energy efficiency and sustainable development.Carbon dots(CDs)have been widely investigated in the domain of lubricant additives owing to their extraordinary tribological properties,in particular,their friction-reducing and anti-wear properties.Metal-doped CDs are a new type of CDs,and their friction-reducing and anti-wear properties are attracting increasing attention.Therefore,a series of CDs doped with various divalent metal ions have been successfully synthesized via one-pot pyrolysis.The tribological properties of the synthesized CDs as water-based lubricant additives are in the following order:Zn-CDs>Cu-CDs>>Mg-CDs>Fe-CDs>U-CDs.Specifically,adding 1.0 wt%of Zn-CDs into water-based lubricant results in 62.5%friction and 81.8%wear reduction.Meanwhile,the load-carrying capacity of the water-based lubricant increases from 120 N to at least 500 N.Zn-CDs as an additive have long service life.Additionally,anion-tuned Zn-CDs fabricated via anion exchange exhibit promise as lubricant additives for poly(ethylene glycol).Based on the results of wear scar surface analyses,it is discovered that tribochemical films,primarily composed of iron oxides,nitrides,metal carbonates,zinc oxides,zinc carbonates,organic compounds,and embedded carbon cores,formed on the rubbing surfaces with a thickness of approximately 270 nm when Zn-CDs are used as additives.This film combined with the“ball-bearing”and third-particle effects of Zn-CDs contributed to excellent lubrication performance.
文摘Electronic structure and magnetic properties of wurtzite ZnO semiconductor doped with rare earth （RE=La, Ce, Pr, Pm, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb） atoms were studied using spin-polarized density functional theory based on the full-potential linear augmented plane wave （FP-LAPW） method as implemented in the Wien2k code. In this approach the generalized gradient approximation （GGA） was used for the exchange-correlation （XC） potential. Our results showed that the substitution of RE ions in ZnO induced spins polarized localized states in the band gap. Moreover, the studied DMSs compounds retained half metallicity at dopant concentration x=0.625%for most of the studied elements, with 100%spin polarization at the Fermi level （EF）. The total magnetic moments of these compounds existed due to RE 4f states present at EF, while small induced magnetic moments existed on other non-magnetic atoms as well. Finally, the energy difference between far and near configurations was investigated. It was found that the room temperature ferromagnetism was possible for RE-doped ZnO at near configuration. Since the RE-RE separation was long enough （far configuration） for magnetic coupling, the system became paramagnetic or antiferromagnetic ground state.
