A type of home-made reduced activation martensitic steel, high silicon （SIMP） steel, is homogeneously irradiated with energetic Fe ions to the doses of 0.1, 0.25 and 1 displacement per atom （dpa）, respectively, at...A type of home-made reduced activation martensitic steel, high silicon （SIMP） steel, is homogeneously irradiated with energetic Fe ions to the doses of 0.1, 0.25 and 1 displacement per atom （dpa）, respectively, at 300℃ and i dpa, at 400℃. MicrostructurM changes are investigated in detail by transmission electron microscopy with cross-section technique. Interstitial defects and defect dusters induced by Fe-ion irradiation are observed in ali the specimens under different conditions. It is found that with increasing irradiation temperature, size of defect clusters increases while the density drops quickly. The results of element chemical mapping from the STEM images indicate that the Si element enrichment and Ta element depletion occur inside the precipitates in the matrix of SIMP steel irradiated to a dose of 1 dpa at 300℃. Correlations between the microstructure and irradiation conditions are briefly discussed.展开更多
Bi VO_(4)is a promising semiconducting photoanode for photoelectrochemical(PEC)water splitting due to its suitable bandgap.However,the dissolution of V^(5+)and sluggish reaction kinetics at the surface in the oxygen e...Bi VO_(4)is a promising semiconducting photoanode for photoelectrochemical(PEC)water splitting due to its suitable bandgap.However,the dissolution of V^(5+)and sluggish reaction kinetics at the surface in the oxygen evolution reaction(OER)limit its applications.Herein,we report a convenient strategy to change the microenvironment by adding Fe(Ⅲ)into the electrolyte.During the PEC process,Fe(Ⅲ)ions not only improve the current density,but also show excellent stability toward Bi VO_(4).Consequently,the current increases by more than 1.7 times compared to that without Fe(Ⅲ).Photoelectrochemical,morphological,and structural characterizations reveal that the FeOOH co-catalyst produced in situ on the Bi VO_(4)photoanode by cyclical formation of the intermediates at the electrode/electrolyte interface during OER accelerates the OER kinetics and prevents photo-corrosion by suppressing the dissolution of V^(5+).The results reveal a new strategy for the multifunctional modification of photoanodes for efficient solar conversion.展开更多
Fe ions in the fluence range of 2×1015 to 1×1017 cm-2 were implanted into diamond-like carbon (DLC) thin film of 100 nm thick, which were deposited on silicon substrate by plasma enhanced chemical vapor depo...Fe ions in the fluence range of 2×1015 to 1×1017 cm-2 were implanted into diamond-like carbon (DLC) thin film of 100 nm thick, which were deposited on silicon substrate by plasma enhanced chemical vapor deposition. Effects of Fe ion implantation on microstructure and friction coefficient of the DLC were studied. With increasing Fe ion fluence, friction coefficient of the DLC film increased as compared with that of DLC without implantation, and then decreased. The Raman spectra characteristics also show a dependence on the Fe ion fluence. With increasing the ion fluence, the sp2 bonding increased in the DLC film, resulting in the decrease of friction coefficient of the film af- ter implantation. Substantial surface roughness was also measured.展开更多
The dissolution of iron from the cathode and electrode/electrolyte interface(EEI)during long cycles significantly accelerates the aging process of LiFePO_(4)(LFP)/graphite batteries;there is a lack of systematic under...The dissolution of iron from the cathode and electrode/electrolyte interface(EEI)during long cycles significantly accelerates the aging process of LiFePO_(4)(LFP)/graphite batteries;there is a lack of systematic understanding of the spatial distribution of the EEI interface layer and the dissolve of Fe ions,especially in terms of the mechanism of the cathode-electrolyte interphase(CEI),solid electrolyte interphase(SEI),and iron dissolution.In this study,aged cells were subjected to continuous activation with constant current and multi-step segmented indirect activation(IA)and analyzed for capacity fade,impedance growth,and active Li^(+)mass loss at the EEI and nanoscale levels.The interaction between dissolved Fe^(2+)and the EEI in LFP/graphite pouch batteries was proposed and verified.The findings indicate that during IA process,the electric field facilitates the migration of solvated ions toward the electrodes,while simultaneously inhibiting the formation of organic species such as ROCO_(2)Li.The SEI primarily consists of a mixture of organic and inorganic small molecules,forming a continuous and uniform film on the electrode surface.This study demonstrates that IA favors the formation of a uniform EEI and offers constructive insights for advancing accelerated lifetime prediction strategies in lithium-ion batteries.展开更多
Lanthanum-bearing iron lithium borate glass is a quaternary system for oxide glasses and was prepared via the melt-quenching method.The present article correlates the structure,optical,ligand field and M?ssbauer data ...Lanthanum-bearing iron lithium borate glass is a quaternary system for oxide glasses and was prepared via the melt-quenching method.The present article correlates the structure,optical,ligand field and M?ssbauer data on iron lithium borate glass co ntaining La^(3+).The density was measured,while the molar volume was calculated.Other physical parameters are well-described.With increasing the La_(2)O_(3) content within the glass network,infrared spectra analysis reveals structural modifications such as the increase in BO_(4) units and the decline in both BO_(3) units and NBO bonds content.Furthermore,optical absorption spectra were measured.The absorption spectra disclose a plethora of electronic transitions that are related to Fe^(3+)in tetrahedral and octahedral sites,however,Fe^(2+)phase is not observed in optical spectra,but it has a clear signature in M?ssbauer spectra.Besides,the glass absorption edges undergo a clear blue shift,reflecting an increased band gap energy(1.96-2.28 eV).The decline in NBO bonds justifies this trend.Bewitchingly,the values of crystal field splitting are increased,while the values of Racah parameters are decreased.This trend is justified by the decline in NBO bonds and increases electron localization around Fe cations.M?ssbauer spectra confirm the existence of Fe^(3+)in tetrahedral and octahedral sites,while Fe^(2+)exists in only a tetrahedral state.With increasing La_(2)O_(3) content,the isomer shift of Fe^(3+)in tetrahedral sites changes to be 0.312-0.329 mm/s,while the isomer shift of octahedral Fe^(3+)is 0.424-0.456 mm/s.These findings coincide with optical data.While the isomer shift of tetrahedral Fe^(2+)is 0.902-0.911 mm/s.Our results of structural,optical and ligand field associated with M?ssbauer spectra open more vistas toward the utility of these samples in the optics realm.展开更多
Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the me...Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the metal salt solution during ion exchange influenced the ion exchange capacity of Fe, and resulted in different activities of the Fe-Beta catalyst. Fe-Beta catalysts with the Fe contents of （2.6, 6.3 and 9） wt% were synthesized using different amounts of 0.02 mol/L Fe salt solution. These catalysts were studied by various characterization techniques and their NH3-SCR activities were evaluated. The Fe-Beta catalyst with the Fe content of 6.3 wt% exhibited the highest activity, with a temperature range of 202-616℃ where the NOx conversion was 〉 80%. The Fe content in Beta zeolite did not influence the structure of Beta zeolite and valence state of Fe. Compared with the Fe-Beta catalysts with low Fe content （2.6 wt%）, Fe-Beta catalysts with 6.3 wt% Fe content possessed more isolated Fe3. active sites which led to its higher NH3-SCR activity. A high capacity for NH3 and NO adsorption, and a high activity for NO oxidation also contributed to the high NH3-SCR activity of the Fe-Beta catalyst with 6.3 wt%. However, when the Fe content was further increased to 9.0 wt%, the amount of FexOy nanoparticles increased while the amount of isolated Fe3＋ active sites was unchanged, which promoted NH3 oxidation and decreased the NH3-SCR activity at high temperature.展开更多
Titanium dioxide coated on activated carbon(AC)with Fe ions doping(Fe-TiO2/AC)composite was prepared by an improved sol-gel method.The photocatalytic activities were tested by photocatalytic degradation of reactive br...Titanium dioxide coated on activated carbon(AC)with Fe ions doping(Fe-TiO2/AC)composite was prepared by an improved sol-gel method.The photocatalytic activities were tested by photocatalytic degradation of reactive brilliant red K2G in solution.The results show that in comparison with the agglomeration of pure TiO2,the TiO2 nanoparticles are well dispersed in the AC matrix,of which sizes are decreased with Fe ions doping.Additionally,the iron species on TiO2 of composite are Fe2O3 and FeO,which do not affect the crystalline structures of TiO2 nanoparticles.The AC matrix and iron doping content influence the fluorescence intensity of composite due to their effects on recombination probability of hole-electron pairs.Compared with TiO2,0.3%Fe-TiO2,TiO2/AC,0.5%Fe-TiO2/AC and 0.1%Fe-TiO2/AC,the 0.3%Fe-TiO2/AC shows the highest photoactivity with the complete mineralization of K2G for finite time due to the optimum Fe ions content and AC matrix.Furthermore,the kinetic constant(k=0.0229 min-1)of 0.3%Fe-TiO2/AC composite is more than the sum of both TiO2/AC(0.0154 min-1)and 0.3%Fe-TiO2(0.0057 min-1)because coexistence of the AC and Fe ions has an enlarging effect on improving the photoactivity of TiO2.展开更多
Humic substances are ubiquitous redox-active organic compounds of environment. In this study, experiments were conducted to determine the reduction capacity of humic acid in the man-ix of bromate and Fe（Ⅲ） solution...Humic substances are ubiquitous redox-active organic compounds of environment. In this study, experiments were conducted to determine the reduction capacity of humic acid in the man-ix of bromate and Fe（Ⅲ） solutions and the role of Fe（Ⅲ） in this redox process. The results showed that the humic acid regenerated Fe（Ⅱ） and reduced bromate abiotically. The addition of Fe（Ⅲ） could accelerate the bromate reduction rate by forming humic acid-Fe（Ⅲ） complexes. Iron species acts as electron mediator and catalyst for the bromate reduction by humic acid, in which humic acid transfers electrons to the complexed Fe（Ⅲ） to form Fe（Ⅱ）, and the regenerated Fe（Ⅱ） donate the electrons to bromate. The kinetics study on bromate reduction further indicated that bromate reduction by humic acid-Fe（Ⅲ） complexes is pH dependent. The rate decreased by 2-fold with the increase in solution pH by one unit. The reduction capacity of Aldrich humic acid was observed to be lower than that of humic acid or natural organic matter of Suwanne River, indicating that such redox process is expected to occur in the environment.展开更多
The excitation wavelength-dependent and-independent emissions are two crucial fluorescent properties of carbon dots(CDs).However,CDs reported till date exhibit only one of these properties,which limits their practical...The excitation wavelength-dependent and-independent emissions are two crucial fluorescent properties of carbon dots(CDs).However,CDs reported till date exhibit only one of these properties,which limits their practical applications.Herein,dual-property carbon dots(DCDs)with both the excitation wavelength-dependent and-independent emissions were synthesized via a facile onestep solvothermal method using 4-(2-pyridylazo)-resorcinol as the carbon precursor.The multi-functional applications of the resulting DCDs were also evaluated.The asprepared DCDs exhibited not only excellent monodispersity,high photostability,and storage stability,but also low toxicity,good biocompatibility,and cellular bioimaging capability.In addition,the DCDs exhibited excitation-dependent emission photoluminescence under low excitation wavelengths.The DCDs exhibited good Fe3+detection by quenching the blue emission fluorescence and showed a relatively low Fe3+detection limit of 0.067 lmol·L-1 based on three times signal-to-noise criteria(R2=0.99).Furthermore,the DCDs showed excitation-independent emission at low excitation wavelengths and exhibited red emission at about 598 nm to avoid damage to the body.These results demonstrate the excellent bioimaging properties of the DCDs.Owing to their dual PL properties,the as-prepared DCDs exhibited multi-functional applications:Fe3+detection and A549 cell bioimaging.These results will be helpful in developing novel CDs for applications in various fields.展开更多
During the process of KDP crystal growth, metal ions strongly affect the growth habit and optical properties of KDP single crystal. In this paper, KDP crystals were grown from an aqueous solution doped with different ...During the process of KDP crystal growth, metal ions strongly affect the growth habit and optical properties of KDP single crystal. In this paper, KDP crystals were grown from an aqueous solution doped with different concentration of Fe^3＋ dopant by traditional temperaturereduction method and ＂point-seed＂ rapid growth method. Furthermore, we examined the light scatter and measured the transmission of these KDP crystals. It is found that the dopant of Fe^3＋ ion can improve the stability of the KDP growth solution when its concentration is less than 30 ppm. The effects of Fe^3＋ ion on the growth habit and optical properties of KDP crystal are also obvious.展开更多
Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been design...Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been designed and synthesized. Complex 1 is a 2-dimensional(2 D) 3,4-connected network with 3,4 L13 topology, complex 2 features a 3-dimensional(3D) 3,4-connected tfa topology with a 2-fold interpenetrating structure and complex 3 has a 3D 4-connected dia topology with a 4-fold interpenetrating structure. Interestingly, 2 exhibits permanent pores and selective adsorption of CO_2 over CH_4. In addition, 2 shows fluorescence sensing of Fe^(3+) ion and rapid detection of nitroaromatic compounds(NACs) through fluorescence quenching.展开更多
The spherical macroporous cellulose(SMC) was fabricated using medical absorbent cotton as raw material and nano CaCO3 as porogenic agents.And then,the phenylglycine was grafted onto the SMC to obtain the novel spheric...The spherical macroporous cellulose(SMC) was fabricated using medical absorbent cotton as raw material and nano CaCO3 as porogenic agents.And then,the phenylglycine was grafted onto the SMC to obtain the novel spherical macroporous cellulose derivative adsorbent(PSMC).FT-IR and scanning electron microscope(SEM) were employed to characterize the adsorbents and Fe3+ ions served as model solute to evaluate the adsorption property of the adsorbents.The experimental results show that the amount of porogenic agents and the value of pH have obvious influence on adsorption capacity of the adsorbents.The data of adsorption kinetic and isotherm display that the adsorbents possess excellent equilibrium adsorption capacity(348.94 mg/g) and have a bright prospect and considerable potential in the treatment of Fe3+ ions in wastewater.展开更多
For constructing next-generation lithium-ion batteries with advanced performances,pursuit of highcapacity Li-rich cathodes has caused considerable attention.So far,the low discharge specific capacity and serious capac...For constructing next-generation lithium-ion batteries with advanced performances,pursuit of highcapacity Li-rich cathodes has caused considerable attention.So far,the low discharge specific capacity and serious capacity fading are strangling the development of Fe-based Li-rich materials.To activate the extra-capacity of Fe-based Li-rich cathode materials,a facile molten salt method is exploited using an alkaline mixture of LiOH–LiNO3–Li2O2 in this work.The prepared Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2 material yields high discharge specific capacity and good cycling stability.The discharge specific capacity shows an upward tendency at 0.1 C.After 60 cycles,a high reversible specific capacity of ~250 m Ah g-1is delivered.The redox of Fe3+/Fe4+and Mn3+/Mn4+are gradually activated during cycling.Notably,the redox reaction of Fe2+/Fe3+can be observed reversibly below 2 V,which is quite different from the material prepared by a traditional co-precipitation method.The stable morphology of fine nanoparticles(100–300 nm)is considered benefiting for the distinctive electrochemical performances of Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2.This study demonstrates that molten salt method is an inexpensive and effective approach to activate the extra capacity of Fe-based Li-rich cathode material for high-performance lithium-ion batteries.展开更多
In the production process of titanium dioxide with sulfuric acid, the contamination of the titanium sulfate solution (the ilmenite leaching solution) in the Fe 3+ reduction stage by iron scraps is a practical problem ...In the production process of titanium dioxide with sulfuric acid, the contamination of the titanium sulfate solution (the ilmenite leaching solution) in the Fe 3+ reduction stage by iron scraps is a practical problem because it is difficult to guarantee the quality of the iron scraps. In this research, a new method, called the ion exchange membrane primary cell method, for reduction of Fe 3+ in the titanium sulfate solution has been advanced. The positive compartment of the primary cell consists of lead (copper) electrode and the titanium sulfate solution, and the negative compartment consists of iron electrode and acidic FeSO 4 solution. The anion ion exchange membrane is used as the diaphragm between two compartments. Fe 3+ in the titanium sulfate solution is reduced by the electric discharge of the primary cell. The effects of temperature, stirring strength of the solution and membrane area on the reduction rate have been investigated. The experimental result shows that the optimum current density can be higher than 100 A/m 2.展开更多
Ni/Fe-Fe3O4 nanocomposites were synthesized for dechlorination of 2,4-dichlorophenol （2,4-DCP）. The effects of the Ni content in Ni/Fe-Fe3O4 nanocomposites, solution pH, and common dissolved ions on the dechlorinati...Ni/Fe-Fe3O4 nanocomposites were synthesized for dechlorination of 2,4-dichlorophenol （2,4-DCP）. The effects of the Ni content in Ni/Fe-Fe3O4 nanocomposites, solution pH, and common dissolved ions on the dechlorination efficiency were investigated, in addition to the reusability of the nanocomposites. The results showed that increasing content of Ni in Ni/Fe-FesO4 nanocomposites, from 1 to 5 wt.%, greatly increased the dechlorination efficiency; the Ni/Fe-Fe3O4 nanocomposites had much higher dechlorination efficiency than bare Ni/Fe nanoparticles. Ni content of S wt.% and initial pH below 6.0 was found to be the optimal conditions for the catalytic dechlorination of 2,4-DCP. Both 2,4-DCP and the intermediate product 2-chlorophenol （2-CP） were completely removed, and the concentra- tion of the final product phenol was close to the theoretical phenol production from complete dechlorination of 20 mg/L of 2,4-DCP, after 3 hr reaction at initial pH value of 6.0, 3 g/L Ni/Fe-Fe3O4, S wt.% Ni content in the composite, and temperature of 22℃ 2,4-DCP dechlorination was enhanced by C1- and inhibited by NO3- and SO42-. The nanocomposites were easily separated from the solution by an applied magnetic field. When the catalyst was reused, the removal efficiency of 2,4-DCP was almost 100% for the first seven uses, and gradually decreased to 75% in cycles 8-10. Therefore, the Ni/Fe-Fe3O4 nanocomposites can be considered as a potentially effective tool for remediation of Pollution bv 2.4-DCP.展开更多
In this study, nanosized TiO2 co-doped with Fe3+ and Nd3+ ions was synthesized via a sol-gel method. The metallic ion doped TiO2 was thoroughly characterized with XRD and UV-vis, and the photocatalytic activity was ev...In this study, nanosized TiO2 co-doped with Fe3+ and Nd3+ ions was synthesized via a sol-gel method. The metallic ion doped TiO2 was thoroughly characterized with XRD and UV-vis, and the photocatalytic activity was evaluated by degrading methylene blue (MB) solution. The results indicated that TiO2 crystalline size was reduced and phase transformation of anatase to rutile was suppressed as the content of doped Nd3+ ion increased in the co-doped TiO2. The UV-vis spectra of co-doped TiO2 seemed to simply overlay two spectra of single metal doped TiO2, and had significantly increased absorbance in the ranges of 400～500 nm, 565～600 nm and 730～765 nm as compared to pure TiO2. The photocatalytic activity of co-doped TiO2 was obviously enhanced, and raised about 30% compared to that of pure TiO2 as doped Nd3+ content was 0.15% and Fe3+ content was 0.05%, respectively. The enhanced catalytic activity was attributed to a synergistic effect of two doped ions, where doped Fe3+ ion inhibited the recombination of photogenerated electron and hole, and Nd3+ ion brought more surface carboxyl to promote the degradation reaction.展开更多
The implanted ion range, the depth profile and the film sttucture of the implanted layer were studied; the carrier concentration and the mobility were measured; the conductivity mechanism of the film implanted Fe into...The implanted ion range, the depth profile and the film sttucture of the implanted layer were studied; the carrier concentration and the mobility were measured; the conductivity mechanism of the film implanted Fe into Al_2O_3 ceramic was discussed. The conclusion is that the implanted Fe^(2+) ions move into Al_2O_3 lattice and replace Al^(3+) to form subs- titution impurities so that the ion implanted lat- tice, as compared with the original one, presents an effective negative charge which forms a negative charge center. A vacancy is bound arround it, and an acceptor is introduced in the forbidden band.展开更多
The Fe78Si8B14 and Fe78P8B14 ribbons with different wheel speeds were prepared by melt-spinning, and their responses to He＋ ion irradiation were investigated. Previous studies had shown that the ion beam resistance c...The Fe78Si8B14 and Fe78P8B14 ribbons with different wheel speeds were prepared by melt-spinning, and their responses to He＋ ion irradiation were investigated. Previous studies had shown that the ion beam resistance capability of amorphous ribbons was better than their corresponding crystalline counterparts. However, no significant changes on the surface at low fluence are observed. At a relatively higher fluence, both the ribbons prepared at low and high wheel speeds behave the similar irradiation responses： peeling, flaking and multi-layer damages occur. The fully amorphous ribbons prepared at a high wheel speed can accommodate partial incident ions owing to the inherent disordered structure. As the irradiation fluence increases, they fail to accommodate the excess incident ions, which easily aggregate to result in the surface damage. While the partial amorphous ribbons prepared at a low wheel speed possess lots of unstable crystalline grain boundaries owing to the precipitation of Si-or P-rich phase, which may act as the source for the irradiation-induced defects annihilation. Results show that the size and the fraction of precipitate phases in amorphous matrix may play a dominated role in resisting the ion irradiation.展开更多
基金Supported by the Young Scientists Fund of the National Natural Science Foundation of China under Grant No 11505246the Major Research Plan of the National Natural Science Foundation of China under Grant No 91426301
文摘A type of home-made reduced activation martensitic steel, high silicon （SIMP） steel, is homogeneously irradiated with energetic Fe ions to the doses of 0.1, 0.25 and 1 displacement per atom （dpa）, respectively, at 300℃ and i dpa, at 400℃. MicrostructurM changes are investigated in detail by transmission electron microscopy with cross-section technique. Interstitial defects and defect dusters induced by Fe-ion irradiation are observed in ali the specimens under different conditions. It is found that with increasing irradiation temperature, size of defect clusters increases while the density drops quickly. The results of element chemical mapping from the STEM images indicate that the Si element enrichment and Ta element depletion occur inside the precipitates in the matrix of SIMP steel irradiated to a dose of 1 dpa at 300℃. Correlations between the microstructure and irradiation conditions are briefly discussed.
基金financially supported by the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110212)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(Nos.STKJ202209077,STKJ202209083,and STKJ202209021)+1 种基金Scientific Research Foundation of Shantou University(No.NTF21022)City University of Hong Kong Strategic Research Grant(SRG)(No.7005505)。
文摘Bi VO_(4)is a promising semiconducting photoanode for photoelectrochemical(PEC)water splitting due to its suitable bandgap.However,the dissolution of V^(5+)and sluggish reaction kinetics at the surface in the oxygen evolution reaction(OER)limit its applications.Herein,we report a convenient strategy to change the microenvironment by adding Fe(Ⅲ)into the electrolyte.During the PEC process,Fe(Ⅲ)ions not only improve the current density,but also show excellent stability toward Bi VO_(4).Consequently,the current increases by more than 1.7 times compared to that without Fe(Ⅲ).Photoelectrochemical,morphological,and structural characterizations reveal that the FeOOH co-catalyst produced in situ on the Bi VO_(4)photoanode by cyclical formation of the intermediates at the electrode/electrolyte interface during OER accelerates the OER kinetics and prevents photo-corrosion by suppressing the dissolution of V^(5+).The results reveal a new strategy for the multifunctional modification of photoanodes for efficient solar conversion.
文摘Fe ions in the fluence range of 2×1015 to 1×1017 cm-2 were implanted into diamond-like carbon (DLC) thin film of 100 nm thick, which were deposited on silicon substrate by plasma enhanced chemical vapor deposition. Effects of Fe ion implantation on microstructure and friction coefficient of the DLC were studied. With increasing Fe ion fluence, friction coefficient of the DLC film increased as compared with that of DLC without implantation, and then decreased. The Raman spectra characteristics also show a dependence on the Fe ion fluence. With increasing the ion fluence, the sp2 bonding increased in the DLC film, resulting in the decrease of friction coefficient of the film af- ter implantation. Substantial surface roughness was also measured.
基金supported by the National Key R&D Program of China(2021YFB2401800)the support from Beijing Nova Program(20230484241)+2 种基金the support from the China Postdoctoral Science Foundation(2024M754084)the Postdoctoral Fellowship Program of CPSF(GZB20230931)the support from Initial Energy Science&Technology Co.,Ltd(IEST)。
文摘The dissolution of iron from the cathode and electrode/electrolyte interface(EEI)during long cycles significantly accelerates the aging process of LiFePO_(4)(LFP)/graphite batteries;there is a lack of systematic understanding of the spatial distribution of the EEI interface layer and the dissolve of Fe ions,especially in terms of the mechanism of the cathode-electrolyte interphase(CEI),solid electrolyte interphase(SEI),and iron dissolution.In this study,aged cells were subjected to continuous activation with constant current and multi-step segmented indirect activation(IA)and analyzed for capacity fade,impedance growth,and active Li^(+)mass loss at the EEI and nanoscale levels.The interaction between dissolved Fe^(2+)and the EEI in LFP/graphite pouch batteries was proposed and verified.The findings indicate that during IA process,the electric field facilitates the migration of solvated ions toward the electrodes,while simultaneously inhibiting the formation of organic species such as ROCO_(2)Li.The SEI primarily consists of a mixture of organic and inorganic small molecules,forming a continuous and uniform film on the electrode surface.This study demonstrates that IA favors the formation of a uniform EEI and offers constructive insights for advancing accelerated lifetime prediction strategies in lithium-ion batteries.
文摘Lanthanum-bearing iron lithium borate glass is a quaternary system for oxide glasses and was prepared via the melt-quenching method.The present article correlates the structure,optical,ligand field and M?ssbauer data on iron lithium borate glass co ntaining La^(3+).The density was measured,while the molar volume was calculated.Other physical parameters are well-described.With increasing the La_(2)O_(3) content within the glass network,infrared spectra analysis reveals structural modifications such as the increase in BO_(4) units and the decline in both BO_(3) units and NBO bonds content.Furthermore,optical absorption spectra were measured.The absorption spectra disclose a plethora of electronic transitions that are related to Fe^(3+)in tetrahedral and octahedral sites,however,Fe^(2+)phase is not observed in optical spectra,but it has a clear signature in M?ssbauer spectra.Besides,the glass absorption edges undergo a clear blue shift,reflecting an increased band gap energy(1.96-2.28 eV).The decline in NBO bonds justifies this trend.Bewitchingly,the values of crystal field splitting are increased,while the values of Racah parameters are decreased.This trend is justified by the decline in NBO bonds and increases electron localization around Fe cations.M?ssbauer spectra confirm the existence of Fe^(3+)in tetrahedral and octahedral sites,while Fe^(2+)exists in only a tetrahedral state.With increasing La_(2)O_(3) content,the isomer shift of Fe^(3+)in tetrahedral sites changes to be 0.312-0.329 mm/s,while the isomer shift of octahedral Fe^(3+)is 0.424-0.456 mm/s.These findings coincide with optical data.While the isomer shift of tetrahedral Fe^(2+)is 0.902-0.911 mm/s.Our results of structural,optical and ligand field associated with M?ssbauer spectra open more vistas toward the utility of these samples in the optics realm.
基金supported by the National Key Basic Research Program of China (973 Program, 2013CB933201)the National Natural Science Foun-dation of China (21577034, 21333003, 91545103)+1 种基金Science and Technology Commission of Shanghai Municipality (16ZR1407900)Fundamental Research Funds for the Central Universities (WJ1514020)~~
文摘Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the metal salt solution during ion exchange influenced the ion exchange capacity of Fe, and resulted in different activities of the Fe-Beta catalyst. Fe-Beta catalysts with the Fe contents of （2.6, 6.3 and 9） wt% were synthesized using different amounts of 0.02 mol/L Fe salt solution. These catalysts were studied by various characterization techniques and their NH3-SCR activities were evaluated. The Fe-Beta catalyst with the Fe content of 6.3 wt% exhibited the highest activity, with a temperature range of 202-616℃ where the NOx conversion was 〉 80%. The Fe content in Beta zeolite did not influence the structure of Beta zeolite and valence state of Fe. Compared with the Fe-Beta catalysts with low Fe content （2.6 wt%）, Fe-Beta catalysts with 6.3 wt% Fe content possessed more isolated Fe3. active sites which led to its higher NH3-SCR activity. A high capacity for NH3 and NO adsorption, and a high activity for NO oxidation also contributed to the high NH3-SCR activity of the Fe-Beta catalyst with 6.3 wt%. However, when the Fe content was further increased to 9.0 wt%, the amount of FexOy nanoparticles increased while the amount of isolated Fe3＋ active sites was unchanged, which promoted NH3 oxidation and decreased the NH3-SCR activity at high temperature.
基金Supported by the Education Department Foundation of Hunan Province(Grant No.08B063)Science and Natural Science Foundation of Hunan Province(Grant No.09JJ6101)
文摘Titanium dioxide coated on activated carbon(AC)with Fe ions doping(Fe-TiO2/AC)composite was prepared by an improved sol-gel method.The photocatalytic activities were tested by photocatalytic degradation of reactive brilliant red K2G in solution.The results show that in comparison with the agglomeration of pure TiO2,the TiO2 nanoparticles are well dispersed in the AC matrix,of which sizes are decreased with Fe ions doping.Additionally,the iron species on TiO2 of composite are Fe2O3 and FeO,which do not affect the crystalline structures of TiO2 nanoparticles.The AC matrix and iron doping content influence the fluorescence intensity of composite due to their effects on recombination probability of hole-electron pairs.Compared with TiO2,0.3%Fe-TiO2,TiO2/AC,0.5%Fe-TiO2/AC and 0.1%Fe-TiO2/AC,the 0.3%Fe-TiO2/AC shows the highest photoactivity with the complete mineralization of K2G for finite time due to the optimum Fe ions content and AC matrix.Furthermore,the kinetic constant(k=0.0229 min-1)of 0.3%Fe-TiO2/AC composite is more than the sum of both TiO2/AC(0.0154 min-1)and 0.3%Fe-TiO2(0.0057 min-1)because coexistence of the AC and Fe ions has an enlarging effect on improving the photoactivity of TiO2.
基金supported by the National Natural Science Foundation of China(No.50608056)the Hong Kong Research Grants(No.HKUST6106/03E)the Program for Young Excellent Talents in Tongji University in part(No.2006KJ033).
文摘Humic substances are ubiquitous redox-active organic compounds of environment. In this study, experiments were conducted to determine the reduction capacity of humic acid in the man-ix of bromate and Fe（Ⅲ） solutions and the role of Fe（Ⅲ） in this redox process. The results showed that the humic acid regenerated Fe（Ⅱ） and reduced bromate abiotically. The addition of Fe（Ⅲ） could accelerate the bromate reduction rate by forming humic acid-Fe（Ⅲ） complexes. Iron species acts as electron mediator and catalyst for the bromate reduction by humic acid, in which humic acid transfers electrons to the complexed Fe（Ⅲ） to form Fe（Ⅱ）, and the regenerated Fe（Ⅱ） donate the electrons to bromate. The kinetics study on bromate reduction further indicated that bromate reduction by humic acid-Fe（Ⅲ） complexes is pH dependent. The rate decreased by 2-fold with the increase in solution pH by one unit. The reduction capacity of Aldrich humic acid was observed to be lower than that of humic acid or natural organic matter of Suwanne River, indicating that such redox process is expected to occur in the environment.
基金the National Natural Science Foundation of China(No.81660708)the Natural Science Foundation of Jiangsu Province of China(No.BK20171389)+2 种基金the Qinglan Project of Young Academic Leaders of Jiangsu Provincethe Key Project of Science and Technology of Tibet(No.2015XZ01G70)the Key Project of Tibetan Medical Administration(No.2017005)。
文摘The excitation wavelength-dependent and-independent emissions are two crucial fluorescent properties of carbon dots(CDs).However,CDs reported till date exhibit only one of these properties,which limits their practical applications.Herein,dual-property carbon dots(DCDs)with both the excitation wavelength-dependent and-independent emissions were synthesized via a facile onestep solvothermal method using 4-(2-pyridylazo)-resorcinol as the carbon precursor.The multi-functional applications of the resulting DCDs were also evaluated.The asprepared DCDs exhibited not only excellent monodispersity,high photostability,and storage stability,but also low toxicity,good biocompatibility,and cellular bioimaging capability.In addition,the DCDs exhibited excitation-dependent emission photoluminescence under low excitation wavelengths.The DCDs exhibited good Fe3+detection by quenching the blue emission fluorescence and showed a relatively low Fe3+detection limit of 0.067 lmol·L-1 based on three times signal-to-noise criteria(R2=0.99).Furthermore,the DCDs showed excitation-independent emission at low excitation wavelengths and exhibited red emission at about 598 nm to avoid damage to the body.These results demonstrate the excellent bioimaging properties of the DCDs.Owing to their dual PL properties,the as-prepared DCDs exhibited multi-functional applications:Fe3+detection and A549 cell bioimaging.These results will be helpful in developing novel CDs for applications in various fields.
基金the State High Technology Program for Inertial Confinement Fusion and National Science Foundation (No.59823003)Project of United Foundation (No.10676019)Youth Scientist Fund of Shandong Province (Nos. 2004BS04022 and 03BS079)
文摘During the process of KDP crystal growth, metal ions strongly affect the growth habit and optical properties of KDP single crystal. In this paper, KDP crystals were grown from an aqueous solution doped with different concentration of Fe^3＋ dopant by traditional temperaturereduction method and ＂point-seed＂ rapid growth method. Furthermore, we examined the light scatter and measured the transmission of these KDP crystals. It is found that the dopant of Fe^3＋ ion can improve the stability of the KDP growth solution when its concentration is less than 30 ppm. The effects of Fe^3＋ ion on the growth habit and optical properties of KDP crystal are also obvious.
基金supported by the National Natural Science Foundation of China(NSFC, No. 21771191)the Shandong Natural Science Fund (No. ZR2017QB012)+2 种基金the Applied Basic Research Projects of Qingdao (No.16-5-1-95-jch)the Fundamental Research Funds for the Central Universities (Nos.16CX05015A,18CX06003A, YCX2018071)the Foundation of State Key Laboratory of Structural Chemistry (No. 20160006)
文摘Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been designed and synthesized. Complex 1 is a 2-dimensional(2 D) 3,4-connected network with 3,4 L13 topology, complex 2 features a 3-dimensional(3D) 3,4-connected tfa topology with a 2-fold interpenetrating structure and complex 3 has a 3D 4-connected dia topology with a 4-fold interpenetrating structure. Interestingly, 2 exhibits permanent pores and selective adsorption of CO_2 over CH_4. In addition, 2 shows fluorescence sensing of Fe^(3+) ion and rapid detection of nitroaromatic compounds(NACs) through fluorescence quenching.
基金Projects(81373284,81102344) supported by the National Natural Science Foundation of China
文摘The spherical macroporous cellulose(SMC) was fabricated using medical absorbent cotton as raw material and nano CaCO3 as porogenic agents.And then,the phenylglycine was grafted onto the SMC to obtain the novel spherical macroporous cellulose derivative adsorbent(PSMC).FT-IR and scanning electron microscope(SEM) were employed to characterize the adsorbents and Fe3+ ions served as model solute to evaluate the adsorption property of the adsorbents.The experimental results show that the amount of porogenic agents and the value of pH have obvious influence on adsorption capacity of the adsorbents.The data of adsorption kinetic and isotherm display that the adsorbents possess excellent equilibrium adsorption capacity(348.94 mg/g) and have a bright prospect and considerable potential in the treatment of Fe3+ ions in wastewater.
基金supported by the Nature Science Foundations of Hebei Province (B2016210071, B2016210111)the Natural Science Foundation of Hebei Education Department (QN2016057, ZD2015082, ZC2016045)+3 种基金the National College Students’ Innovative Entrepreneurial Training Project of Chinasupported by the Chinese National 973 Program (2015CB251106)the Joint Funds of the National Natural Science Foundation of China (U1564206)Major achievements Transformation Project for Central University in Beijing
文摘For constructing next-generation lithium-ion batteries with advanced performances,pursuit of highcapacity Li-rich cathodes has caused considerable attention.So far,the low discharge specific capacity and serious capacity fading are strangling the development of Fe-based Li-rich materials.To activate the extra-capacity of Fe-based Li-rich cathode materials,a facile molten salt method is exploited using an alkaline mixture of LiOH–LiNO3–Li2O2 in this work.The prepared Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2 material yields high discharge specific capacity and good cycling stability.The discharge specific capacity shows an upward tendency at 0.1 C.After 60 cycles,a high reversible specific capacity of ~250 m Ah g-1is delivered.The redox of Fe3+/Fe4+and Mn3+/Mn4+are gradually activated during cycling.Notably,the redox reaction of Fe2+/Fe3+can be observed reversibly below 2 V,which is quite different from the material prepared by a traditional co-precipitation method.The stable morphology of fine nanoparticles(100–300 nm)is considered benefiting for the distinctive electrochemical performances of Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2.This study demonstrates that molten salt method is an inexpensive and effective approach to activate the extra capacity of Fe-based Li-rich cathode material for high-performance lithium-ion batteries.
文摘In the production process of titanium dioxide with sulfuric acid, the contamination of the titanium sulfate solution (the ilmenite leaching solution) in the Fe 3+ reduction stage by iron scraps is a practical problem because it is difficult to guarantee the quality of the iron scraps. In this research, a new method, called the ion exchange membrane primary cell method, for reduction of Fe 3+ in the titanium sulfate solution has been advanced. The positive compartment of the primary cell consists of lead (copper) electrode and the titanium sulfate solution, and the negative compartment consists of iron electrode and acidic FeSO 4 solution. The anion ion exchange membrane is used as the diaphragm between two compartments. Fe 3+ in the titanium sulfate solution is reduced by the electric discharge of the primary cell. The effects of temperature, stirring strength of the solution and membrane area on the reduction rate have been investigated. The experimental result shows that the optimum current density can be higher than 100 A/m 2.
基金supported by the National High Technology Research and Development Program of China (863 Program) (No. 2013AA06A305)the Science Project of Zhejiang Province (No. 2013C31107)the Science Project of Jiaxing City (No. 2014AY21018)
文摘Ni/Fe-Fe3O4 nanocomposites were synthesized for dechlorination of 2,4-dichlorophenol （2,4-DCP）. The effects of the Ni content in Ni/Fe-Fe3O4 nanocomposites, solution pH, and common dissolved ions on the dechlorination efficiency were investigated, in addition to the reusability of the nanocomposites. The results showed that increasing content of Ni in Ni/Fe-FesO4 nanocomposites, from 1 to 5 wt.%, greatly increased the dechlorination efficiency; the Ni/Fe-Fe3O4 nanocomposites had much higher dechlorination efficiency than bare Ni/Fe nanoparticles. Ni content of S wt.% and initial pH below 6.0 was found to be the optimal conditions for the catalytic dechlorination of 2,4-DCP. Both 2,4-DCP and the intermediate product 2-chlorophenol （2-CP） were completely removed, and the concentra- tion of the final product phenol was close to the theoretical phenol production from complete dechlorination of 20 mg/L of 2,4-DCP, after 3 hr reaction at initial pH value of 6.0, 3 g/L Ni/Fe-Fe3O4, S wt.% Ni content in the composite, and temperature of 22℃ 2,4-DCP dechlorination was enhanced by C1- and inhibited by NO3- and SO42-. The nanocomposites were easily separated from the solution by an applied magnetic field. When the catalyst was reused, the removal efficiency of 2,4-DCP was almost 100% for the first seven uses, and gradually decreased to 75% in cycles 8-10. Therefore, the Ni/Fe-Fe3O4 nanocomposites can be considered as a potentially effective tool for remediation of Pollution bv 2.4-DCP.
基金Project supported by Beijing Excellent Talents Training Fund (20061D0502200299)
文摘In this study, nanosized TiO2 co-doped with Fe3+ and Nd3+ ions was synthesized via a sol-gel method. The metallic ion doped TiO2 was thoroughly characterized with XRD and UV-vis, and the photocatalytic activity was evaluated by degrading methylene blue (MB) solution. The results indicated that TiO2 crystalline size was reduced and phase transformation of anatase to rutile was suppressed as the content of doped Nd3+ ion increased in the co-doped TiO2. The UV-vis spectra of co-doped TiO2 seemed to simply overlay two spectra of single metal doped TiO2, and had significantly increased absorbance in the ranges of 400～500 nm, 565～600 nm and 730～765 nm as compared to pure TiO2. The photocatalytic activity of co-doped TiO2 was obviously enhanced, and raised about 30% compared to that of pure TiO2 as doped Nd3+ content was 0.15% and Fe3+ content was 0.05%, respectively. The enhanced catalytic activity was attributed to a synergistic effect of two doped ions, where doped Fe3+ ion inhibited the recombination of photogenerated electron and hole, and Nd3+ ion brought more surface carboxyl to promote the degradation reaction.
文摘The implanted ion range, the depth profile and the film sttucture of the implanted layer were studied; the carrier concentration and the mobility were measured; the conductivity mechanism of the film implanted Fe into Al_2O_3 ceramic was discussed. The conclusion is that the implanted Fe^(2+) ions move into Al_2O_3 lattice and replace Al^(3+) to form subs- titution impurities so that the ion implanted lat- tice, as compared with the original one, presents an effective negative charge which forms a negative charge center. A vacancy is bound arround it, and an acceptor is introduced in the forbidden band.
基金Acknowledgements The authors would like to acknowledge the support by the National Natural Science Foundation of China （Grant Nos. 51401028, 51271193, 11402277） and the Strategic Priority Research Program of the Chinese Academy of Sciences （Grant No. XDB22 040303）. The authors also thank to the support of Opening Fund of State Key Lab of Nuclear Physics and Technology at Peking University.
文摘The Fe78Si8B14 and Fe78P8B14 ribbons with different wheel speeds were prepared by melt-spinning, and their responses to He＋ ion irradiation were investigated. Previous studies had shown that the ion beam resistance capability of amorphous ribbons was better than their corresponding crystalline counterparts. However, no significant changes on the surface at low fluence are observed. At a relatively higher fluence, both the ribbons prepared at low and high wheel speeds behave the similar irradiation responses： peeling, flaking and multi-layer damages occur. The fully amorphous ribbons prepared at a high wheel speed can accommodate partial incident ions owing to the inherent disordered structure. As the irradiation fluence increases, they fail to accommodate the excess incident ions, which easily aggregate to result in the surface damage. While the partial amorphous ribbons prepared at a low wheel speed possess lots of unstable crystalline grain boundaries owing to the precipitation of Si-or P-rich phase, which may act as the source for the irradiation-induced defects annihilation. Results show that the size and the fraction of precipitate phases in amorphous matrix may play a dominated role in resisting the ion irradiation.
