Rationally design the morphology and structure of electroactive nanomaterials is an effective approach to enhance the performance of aqueous batteries.Herein,we co-engineered the hollow architecture and interlayer spa...Rationally design the morphology and structure of electroactive nanomaterials is an effective approach to enhance the performance of aqueous batteries.Herein,we co-engineered the hollow architecture and interlayer spacing of layered double hydroxides(LDH)to achieve high electrochemical activity.The hierarchical hollow LDH was prepared from bimetallic zeolitic imidazolate frameworks(ZIF)by a facile cation exchange strategy.Zn and Cu elements were selected as the second metals incorporated in Co-ZIF.The characteristics of the corresponding derivatives were studied.Besides,the transformation mechanism of CoZn-ZIF into nanosheet-assembled hollow Co Zn Ni LDH(denoted as CoZnNi-OH)was systematically investigated.Importantly,the interlayer spacing of CoZnNi-OH expands due to Zn^(2+)incorporation.The prepared CoZnNi-OH offers large surface area,exposed active sites,and rapid mass transfer/diffusion rate,which lead to a significant enhancement in the specific capacitance,rate performance,and cycle stability of CoZnNi-OH electrode.In addition,the aqueous alkaline CoZnNi-OH//Zn showed a maximum energy density/power density of 0.924 m Wh/cm^(2),8.479 m W/cm^(2).This work not only raises an insightful strategy for regulating the morphology and interlayer spacing of LDH,but also provides a reference of designing hollow nickel-based nanomaterials for aqueous batteries.展开更多
Aqueous hybrid-ion batteries(AHBs)are a promising class of energy storage devices characterized by low cost,high safety,and high energy density.However,aqueous Cu-Al hybrid-ion batteries face challenges such as sluggi...Aqueous hybrid-ion batteries(AHBs)are a promising class of energy storage devices characterized by low cost,high safety,and high energy density.However,aqueous Cu-Al hybrid-ion batteries face challenges such as sluggish reaction kinetics and severe structural collapse of cathode materials,which limit their practical application.Here,a high-performance aqueous Cu-Al hybrid-ion battery is developed using aluminum pre-inserted Cu_(9)S_(5)(Al-Cu_(9)S_(5))as the cathode material,derived from CuAl-layered double hydroxide(CuAl-LDH).The Al^(3+)pre-intercalation strategy narrows the band gap,enhancing electron transport and improving electrochemical kinetics.The battery exhibits excellent rate performance(463 and 408 mA h g^(-1)at current densities of 500 and 1000 mA g^(-1),respectively)and good cycle stability(with a capacity retention ratio of 81% after 300 cycles at a current density of 1000 mA g^(-1)).Its performance surpasses that of most reported Al-ion batteries.Ex situ characterization and density functional theory(DFT)calculations reveal that the pre-intercalated Al^(3+)in Al-Cu9S5participates in the reversible embedding/removal of Al ions during charge/discharge processes.These findings provide valuable insights for designing pre-intercalated cathodes in aqueous Cu-Al hybrid-ion batteries with stable cycle life.展开更多
Layered double hydroxides(LDHs)are potential cathode materials for aqueous magnesium-ion batteries(AMIBs).However,the low capacity and sluggish kinetics significantly limit their electrochemical performance in AMIBs.H...Layered double hydroxides(LDHs)are potential cathode materials for aqueous magnesium-ion batteries(AMIBs).However,the low capacity and sluggish kinetics significantly limit their electrochemical performance in AMIBs.Herein,we find that oxygen vacancies can significantly boost the capacity,electrochemical kinetics,and structure stability of LDHs.The corresponding structure-performance relationship and energy storage mechanism are elaborated through exhaustive in/ex-situ experimental characterizations and density functional theory(DFT)calculations.Specially,in-situ Raman and DFT calculations reveal that oxygen vacancies elevate orbital energy of O 2p and electron density of O atoms,thereby enhancing the orbital hybridization of O 2p with Ni/Co 3d.This facilitates electron transfer between O and adjacent Ni/Co atoms and improves the covalency of Ni–O and Co–O bonds,which activates Ni/Co atoms to release more capacity and stabilizes the Ov-NiCo-LDH structure.Moreover,the distribution of relaxation times(DRT)and molecular dynamics(MD)simulations disclose that the enhanced d-p orbital hybridization optimizes the electronic structure of Ov-NiCo-LDH,which distinctly reduces the diffusion energy barriers of Mg^(2+)and improves the charge transfer kinetics of Ov-NiCo-LDH.Consequently,the assembled Ov-NiCo-LDH//active carbon(AC)and Ov-NiCo-LDH//perylenediimide(PTCDI)AMIBs can both deliver high specific discharge capacity(182.7 and 59.4 mAh g^(−1)at 0.5 A g^(−1),respectively)and long-term cycling stability(85.4%and 89.0%of capacity retentions after 2500 and 2400 cycles at 1.0 A g^(−1),respectively).In addition,the practical prospects for Ov-NiCo-LDH-based AMIBs have been demonstrated in different application scenarios.This work not only provides an effective strategy for obtaining high-performance cathodes of AMIBs,but also fundamentally elucidates the inherent mechanisms.展开更多
Layered double hydroxides(LDHs)have emerged as a promising class of photocatalysts with remarkable properties for diverse energy and environmental-related applications.This review offers insights into recent advances ...Layered double hydroxides(LDHs)have emerged as a promising class of photocatalysts with remarkable properties for diverse energy and environmental-related applications.This review offers insights into recent advances in LDH-based photocatalysts,focusing on their synthesis methods,structural properties,and photocatalytic performance.The unique structure of LDHs,characterized by positively charged metal hydroxide layers and intercalated anions,presents opportunities for tailoring their properties to enhance photocatalytic performance.The mechanisms for pollutant degradation,water splitting,and CO_(2) reduction are discussed,along with strategies to enhance the efficacy and stability of LDH-based photocatalysts.The photocatalytic mechanisms of LDHs for various reactions,including pollutant degradation,water splitting,and CO_(2) reduction,are discussed.Additionally,strategies for enriching the efficacy and stability of LDH-based photocatalysts are explored.This review underscores the significant potential of LDHs as versatile and efficient photocatalysts for addressing current environmental and energy challenges.展开更多
Electrically driven water splitting is an efficient method for green hydrogen production;however,its practical application is substantially constrained by the kinetically sluggish anodic oxygen evolution reaction(OER)...Electrically driven water splitting is an efficient method for green hydrogen production;however,its practical application is substantially constrained by the kinetically sluggish anodic oxygen evolution reaction(OER).Ruthenium(Ru)and its oxides are widely recognized as highly active OER catalysts.Although Ru is significantly cheaper than iridium(Ir),further reducing its content remains desirable.Herein,atomically dispersed Ru is doped into iron-nickel layered double hydroxides(Ru-FeNi-LDH)to decrease the Ru usage.We found that the Ru doping limit is roughly 9 wt%,and the Ru doping content significantly alters the OER kinetics-note that the high Ru concentration remarkably damages the Ru-FeNi-LDH structure and leads to agglomeration formation.By optimizing the Ru doping content to 3.3 wt%,the Ru-FeNi-LDH presents a low overpotential of 230 mV to reach a current density of 10 mA cm^(-2) in 1 M KOH,which is far better than the reference FeNi-LDH(280 mV)and RuO_(2)(350 mV).In the overall water splitting test,the current density of 10 mA cm^(-2) can be reached at a low voltage of 1.52 V,with stable operation for 80 h.Interestingly,Ru and Fe form an asymmetric Ru-Fe dipole,which is likely doped together into the LDH because the content of Fe instead of Ni is dependent on Ru content in experimental results.The electron-deficient feature of the Ru-Fe dipole thus facilitates the OER process.This work demonstrates a dual-transition metal synergy,providing a design strategy for OER and related catalysts.展开更多
ZnO/NiO/ZnAl2O4 mixed-metal oxides were successfully synthesized through a hydrotalcite-like precursor route, in which appropriate amounts of metal salts solutions were mixed to obtain a new series of ZnNiAl layered d...ZnO/NiO/ZnAl2O4 mixed-metal oxides were successfully synthesized through a hydrotalcite-like precursor route, in which appropriate amounts of metal salts solutions were mixed to obtain a new series of ZnNiAl layered double hydroxides（LDHs） as precursors, followed by calcination under different temperatures. The as-obtained samples were characterized by SEM, HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. The photocatalytic activities of the samples were evaluated by degradation of methyl orange（MO） under the simulated sunlight irradiation. The effects of Zn/Ni/Al mole ratio and calcination temperature on the composition, morphology and photocatalytic activity of the samples were investigated in detail. The results indicated that compared with ZnNiAl-LDHs, the mixed-metal oxide showed superior photocatalytic performance for the degradation of MO. A maximum of 97.3% photocatalytic decoloration rate within 60 min was achieved from the LDH with the Zn/Ni/Al mole ratio of 2：1：1 and the calcination temperature of 500 ℃, which much exceeded that of Degussa P25 under the same conditions. The possible mechanism of photocatalytic degradation over ZnO/NiO/ZnAl2O4 was discussed.展开更多
A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can ...A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can improve light‐absorption capacities and facilitate efficient hole transfer to the surface,were deposited on the surface of the BiVO4 photoanode by a hydrothermal method.All the samples were characterized using X‐ray diffraction,scanning electron microscopy,and diffuse‐reflectance spectroscopy.Linear sweep voltammetry and current‐time plots were used to investigate the PEC activity.The photocurrent response of NiFe‐LDH/BiVO4 at 1.23 V vs the reversible hydrogen electrode was higher than those of Ni(OH)2/BiVO4,Fe(OH)2/BiVO4 and pure BiVO4 electrodes under visible‐light illumination.NiFe‐LDH/BiVO4 also gave a superior PEC hydrogen evolution performance.Furthermore,the stability of the NiFe‐LDH/BiVO4 photoanode was excellent compared with that of the bare BiVO4 photoanode,and offers a novel method for solar‐assisted water splitting.展开更多
Layered double Mg-Fe-CO3 hydroxide （Mg-Fe-LDH） with a mole ratio of Mg to Fe of 3 was synthesized by coprecipitation method and calcined product Mg-Fe-CLDH was obtained by heating Mg-Fe-LDH at 500 ℃ for 6 h. The as...Layered double Mg-Fe-CO3 hydroxide （Mg-Fe-LDH） with a mole ratio of Mg to Fe of 3 was synthesized by coprecipitation method and calcined product Mg-Fe-CLDH was obtained by heating Mg-Fe-LDH at 500 ℃ for 6 h. The as prepared Mg-Fe-LDH and calcined Mg-Fe-CLDH were used for removal of glutamic acid （Glu） from aqueous solution, respectively. Batch studies were carried out to address various experimental parameters such as contact time, pH, initial glutamic acid （Glu） concentration, co-existing anions and temperature. Glu was removed effectively （99.9%） under the optimized experimental conditions with Mg-Fe-CLDH. The adsorption kinetics follows the Ho’s pseudo second-order model. Isotherms for adsorption with Mg-Fe-CLDH at different solution temperatures were well described using the Langmuir model with a good correlation coefficient. The intraparticle diffusion model fitted the data well, which suggests that the intraparticle diffusion is not only the rate-limiting step.展开更多
Mg/Al-CO3 layered double hydroxide （LDH2） with Mg（II）：Al（III） molar ratio of 2：1 was synthesized by co-precipitation method and its calcined product Mg2Al-CLDH（CLDH2） was prepared by heating Mg2Al-LDH at 773...Mg/Al-CO3 layered double hydroxide （LDH2） with Mg（II）：Al（III） molar ratio of 2：1 was synthesized by co-precipitation method and its calcined product Mg2Al-CLDH（CLDH2） was prepared by heating Mg2Al-LDH at 773 K for 6 h. Removal of vanadate anion （ 3-4VO ） from aqueous solution on CLDH2 was studied. Batch studies were carried out to address various experimental parameters such as Mg/Al molar ratio, adsorbent dosage, initial concentration of solution, contact time and temperature. Vanadate was removed effectively at the optimized experimental conditions. The adsorption kinetics data fitted the pseudo-first-order model. Isotherms for adsorption vanadate by CLDH2 at different solution temperatures were well described using the Langmuir and Freundlich equations, and the isotherm parameters were calculated using linear regression analysis. The adsorption data fitted the langmuir model with good values of the correlation coefficient （R2〉0.999）. The negative value ofΔGΘand the positive value ofΔHΘindicate that the adsorption processes are spontaneous endothermic in nature. The mechanism of adsorption suggests that the surface adsorption is the main process.展开更多
Colored layered double hydroxides （LDHs） can be synthesized by introducing colored cations such as Fe^3＋ and Cr^3 ＋, which call be used as thermal stabilizers for polyvinyl chloride （PVC）. The yellowish Mg/Fe an...Colored layered double hydroxides （LDHs） can be synthesized by introducing colored cations such as Fe^3＋ and Cr^3 ＋, which call be used as thermal stabilizers for polyvinyl chloride （PVC）. The yellowish Mg/Fe and bluish Mg/Cr LDHs are prepared by the co-precipitation method. The results show that the MgsCr_ CO3 and Mg3Fe_ CO3 colored layered double hydroxides can stabilize PVC for more than 30 min under the thermal aging temperature of 180 ℃. The preparation can use cheap Mg（OH） 2 instead of MgCl2, which produces a much smaller amount of the by-product NH4Cl. It is known that NH4Cl is a cheap fertilizer that is difficult to sell; therefore, the preparation is much greener and more economic than the one using magnesium salt.展开更多
The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter per...The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.展开更多
Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen ba...Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen batteries(LOBs)due to their poor OER performance,resulting from poor electrical conductivity and overly strong intermediate adsorption.In this work,fancy double heterojunctions on 1T/2H-MoS_(2)@Co_(3)S_(4)(1T/2H-MCS)were constructed derived from the charge donation from Co to Mo ions,thus inducing the phase transformation of Mo S_(2)from 2H to 1T.The unique features of these double heterojunctions endow the1T/2H-MCS with complementary catalysis during charging and discharging processes.It is worth noting that 1T-Mo S2@Co3S4could provide fast Co-S-Mo electron transport channels to promote ORR/OER kinetics,and 2H-MoS_(2)@Co_(3)S_(4)contributed to enabling moderate egorbital occupancy when adsorbed with oxygen-containing intermediates.On the basis,the Li_(2)O_(2)nucleation route was changed to solution and surface dual pathways,improving reversible deposition and decomposition kinetics.As a result,1T/2H-MCS cathodes exhibit an improved electrocatalytic performance compared with those of Co_(3)S_(4)and Mo S2cathodes.This innovative heterostructure design provides a reliable strategy to construct efficient transition metal sulfide catalysts by improving electrical conductivity and modulating adsorption toward oxygenated intermediates for LOBs.展开更多
Layered double hydroxides（LDHs） as a class of anionic clays have extensive applications due to their unique structures. Nowadays, the emphasis is laid on the development of LDH coatings for corrosion resistance and ...Layered double hydroxides（LDHs） as a class of anionic clays have extensive applications due to their unique structures. Nowadays, the emphasis is laid on the development of LDH coatings for corrosion resistance and medical applications. Thus, this review highlights synthetic methods of LDH coatings and LDH-based composite coatings on magnesium alloys. Special attention is focused on self-healing,biocompatible and self-cleaning LDH-based composite coatings on magnesium alloys.展开更多
Mg(OH)2/Mg-Al-layered double hydroxide (LDH) coatings were modified with methyltrimethoxysilane (MTMS) on magnesium alloys. Effect of hydrolysis degree of silane solution on coating formation was investigated. Chemica...Mg(OH)2/Mg-Al-layered double hydroxide (LDH) coatings were modified with methyltrimethoxysilane (MTMS) on magnesium alloys. Effect of hydrolysis degree of silane solution on coating formation was investigated. Chemical compositions and surface morphologies of the coatings were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electronic microscopy (FESEM). Results indicated that the composite coatings consisted of polymethyltrimethoxysilane (PMTMS), LDH and Mg(OH)2. Electrochemical and hydrogen evolution measurements revealed that the composite coatings possessed good corrosion resistance, especially the ones prepared in a high hydrolysis degree of silane. The optimum corrosion resistance of the composite coati ng was LDH/PMTMS-3 coating, which had the lowest value of corrosion current density (5.537×10^-9 A·cm^-2) and a dense surface.Plausible mechanism for coating formation and corrosion process of MTMS-modified Mg(OH)2/Mg-Al-LDH coatings were discussed.展开更多
The mesoporous Cu/Mg/Fe layered double hydroxide（Cu/Mg/Fe-LDH） with carbonate intercalation was synthesized and used for the removal of arsenate from aqueous solutions.The Cu/Mg/Fe-LDH was characterized by Fourier t...The mesoporous Cu/Mg/Fe layered double hydroxide（Cu/Mg/Fe-LDH） with carbonate intercalation was synthesized and used for the removal of arsenate from aqueous solutions.The Cu/Mg/Fe-LDH was characterized by Fourier transform infrared spectrometry,X-ray diffraction crystallography,scanning electron microscopy,X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller.Effects of various physico-chemical parameters such as pH,adsorbent dosage,contact time and initial arsenate concentration on the adsorption of arsenate onto Cu/Mg/Fe-LDH were investigated.Results showed that it was efficient for the removal of arsenate,and the removal efficiency of arsenate increased with the increment of the adsorbent dosage,while the arsenate adsorption capacity decreased with increase of initial pH from 3 to 11.The adsorption isotherms can be well described by the Langmuir model with R 2 〉 0.99.Its adsorption kinetics followed the pseudo second-order kinetic model.Coexisting ions such as HPO42-,CO32-,SO42and NO3could compete with arsenate for adsorption sites on the Cu/Mg/Fe-LDH.The adsorption of arsenate on the adsorbent can be mainly attributed to the ion exchange process.It was found that the synthesized Cu/Mg/Fe-LDH can reduce the arsenate concentration down to a final level of 〈 10 μg/L under the experimental conditions,and makes it a potential material for the decontamination of arsenate polluted water.展开更多
Abiotic oxygen formation predates photosynthesis,sustaining early chemical evolution,yet its elementary mechanisms remain contested.Here,we show the production pathways for molecular oxygen from doubly ionized carbon ...Abiotic oxygen formation predates photosynthesis,sustaining early chemical evolution,yet its elementary mechanisms remain contested.Here,we show the production pathways for molecular oxygen from doubly ionized carbon dioxide upon electron-impact.Through fragment ions and electron coincidence momentum imaging,we unambiguously determine the ionization mechanism by measuring the projectile energy loss in association with the C^(+) +O_(2)^(+) channel.Further potential energy and trajectory calculations enable us to elucidate the dynamical details of this fragmentation process,in which a bond rearrangement pathway is found to proceed via the structural deformation to a triangular intermediate.Moreover,we demonstrate a further roaming pathway for the formation of O_(2)^(+) from CO_(2)^(+) 2,in which a frustrated C-O bond cleavage leaves the O atom without sufficient energy to escape.The O atom then wanders around varied configuration spaces of the flat potential energy regions and forms a C-O-O_(2)^(+) intermediate prior to the final products C^(+) +O_(2)^(+).Considering the large quantities of free electrons in interstellar space,the processes revealed here are expected to be significant and should be incorporated into atmospheric evolution models.展开更多
With exhaustion of fossil fuels and the deterioration of global environment,widespread and intensive researches have been concentrated on clean and sustainable alternative energy sources,such as metal-air batteries[1]...With exhaustion of fossil fuels and the deterioration of global environment,widespread and intensive researches have been concentrated on clean and sustainable alternative energy sources,such as metal-air batteries[1],fuel cells[2]and water splitting devices[3].Electrocatalytic oxidation of water to O2(oxygen evolution reaction,OER)is a vital chemical process involved in energy storage and conversion from renewable sources in form of molecular fuels such as H2 via water electrolysis,which has attracted a great amount of research efforts in the past few years[4,5].Nowadays,RuO2 and IrO2 are widely used as typical excellent OER electrocatalysts.However,their high-cost and scarce nature restricts the broadly commercial application of those materials[6,7].Hence,there is an urgent demand to develop low cost,highly efficient,and superb stable OER catalysts.展开更多
A superhydrophobic surface was successfully constructed to modify the layered double hydroxide （LDH） coatings on aluminum alloy using stearic acid. The characteristics of the coatings were investigated using SEM, XR...A superhydrophobic surface was successfully constructed to modify the layered double hydroxide （LDH） coatings on aluminum alloy using stearic acid. The characteristics of the coatings were investigated using SEM, XRD, FT- IR and XPS. The corrosion resistance of the prepared coatings was studied using potentiodynamic polarization and electrochemical impedance spectrum. The results revealed that the superhydrophobic surface considerably improved the corrosion-resistant performance of the LDH coatings on the aluminum alloy substrate. The formation mechanism of the superhydrophobic surface was proposed.展开更多
For many two-dimensional(2D)materials,low coordination edges and corner sites offer greatly enhanced catalytic performance compared to basal sites,motivating the search for new synthetic approaches towards ultrathin a...For many two-dimensional(2D)materials,low coordination edges and corner sites offer greatly enhanced catalytic performance compared to basal sites,motivating the search for new synthetic approaches towards ultrathin and ultrafine 2D nanomaterials with high specific surface areas.To date,the synthesis of catalysts that are both ultrathin(monolayer)and ultrafine(lateral size<10nm)has proven extremely challenging.Herein,using a facile ultrasonic exfoliation procedure,we describe the successful synthesis of ultrafine ZnCo-LDH nanosheets(denoted as ZnCo-UF)with a size^3.5 nm and thickness^0.5 nm.The single layer ZnCo-UF nanosheets possess an abundance of oxygen vacancies(Vo)and unsaturated coordination s让es,thereby affording outstanding electrocatalytic water oxidation performance.DFT calculations confirmed that Vo on the surface of ZnCo-UF enhanced H20 adsorption via increasing the electropositivity of the nanosheets.展开更多
Remaining largely under-appreciated, a majority of metal ion sorbents are limited in their target selectivity. In this work, a 3D sulfide intercalated NiFe-layered double hydroxide (NFL-S) hierarchical sorbent has bee...Remaining largely under-appreciated, a majority of metal ion sorbents are limited in their target selectivity. In this work, a 3D sulfide intercalated NiFe-layered double hydroxide (NFL-S) hierarchical sorbent has been synthesized for selective heavy metal removal. The intercalation of sulfurated groups in the interlayer of the layered double hydroxide (LDH) nanosheets endows NFL-S as a selective heavy metal ion filter;the selectivity of NFL-S for heavy metals is in the order of Pb^2+> Cu^2+≥ Zn^2+> Cd^2+> Mn^2+, and NFL-S has high kd values for Pb2+(~10^6 mL/g) and Cu2+(~10^5 mL/g). Scanning electron microscopy. X-ray photoelectron spectroscopy and powder X-ray diffraction were used to analyze the composition of the as-prepared nanoadsorbent. The selective adsorption behavior was systematically studied using batch experiments, and the performance was evaluated through kinetic and isotherm studies. Moreover, the adsorption mechanism of heavy metals by NFL-S through surface complexation was also investigated, which shows great potential for water decontamination.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52371240,U1904215)Natural Science Foundation of Jiangsu Province(No.BK20200044)Changjiang scholars’program of the Ministry of Education(No.Q2018270)。
文摘Rationally design the morphology and structure of electroactive nanomaterials is an effective approach to enhance the performance of aqueous batteries.Herein,we co-engineered the hollow architecture and interlayer spacing of layered double hydroxides(LDH)to achieve high electrochemical activity.The hierarchical hollow LDH was prepared from bimetallic zeolitic imidazolate frameworks(ZIF)by a facile cation exchange strategy.Zn and Cu elements were selected as the second metals incorporated in Co-ZIF.The characteristics of the corresponding derivatives were studied.Besides,the transformation mechanism of CoZn-ZIF into nanosheet-assembled hollow Co Zn Ni LDH(denoted as CoZnNi-OH)was systematically investigated.Importantly,the interlayer spacing of CoZnNi-OH expands due to Zn^(2+)incorporation.The prepared CoZnNi-OH offers large surface area,exposed active sites,and rapid mass transfer/diffusion rate,which lead to a significant enhancement in the specific capacitance,rate performance,and cycle stability of CoZnNi-OH electrode.In addition,the aqueous alkaline CoZnNi-OH//Zn showed a maximum energy density/power density of 0.924 m Wh/cm^(2),8.479 m W/cm^(2).This work not only raises an insightful strategy for regulating the morphology and interlayer spacing of LDH,but also provides a reference of designing hollow nickel-based nanomaterials for aqueous batteries.
基金supported by the National Natural Science Foundation of China(Nos.22278020 and 2177060378)the Fundamental Research Funds for the Central Universities(Nos.12060093063 and XK1803-05)the Program for Changjiang Scholars and Innovative Research Teams in University(No.IRT1205)。
文摘Aqueous hybrid-ion batteries(AHBs)are a promising class of energy storage devices characterized by low cost,high safety,and high energy density.However,aqueous Cu-Al hybrid-ion batteries face challenges such as sluggish reaction kinetics and severe structural collapse of cathode materials,which limit their practical application.Here,a high-performance aqueous Cu-Al hybrid-ion battery is developed using aluminum pre-inserted Cu_(9)S_(5)(Al-Cu_(9)S_(5))as the cathode material,derived from CuAl-layered double hydroxide(CuAl-LDH).The Al^(3+)pre-intercalation strategy narrows the band gap,enhancing electron transport and improving electrochemical kinetics.The battery exhibits excellent rate performance(463 and 408 mA h g^(-1)at current densities of 500 and 1000 mA g^(-1),respectively)and good cycle stability(with a capacity retention ratio of 81% after 300 cycles at a current density of 1000 mA g^(-1)).Its performance surpasses that of most reported Al-ion batteries.Ex situ characterization and density functional theory(DFT)calculations reveal that the pre-intercalated Al^(3+)in Al-Cu9S5participates in the reversible embedding/removal of Al ions during charge/discharge processes.These findings provide valuable insights for designing pre-intercalated cathodes in aqueous Cu-Al hybrid-ion batteries with stable cycle life.
基金financial support of the National Natural Science Foundation of China (22379063)
文摘Layered double hydroxides(LDHs)are potential cathode materials for aqueous magnesium-ion batteries(AMIBs).However,the low capacity and sluggish kinetics significantly limit their electrochemical performance in AMIBs.Herein,we find that oxygen vacancies can significantly boost the capacity,electrochemical kinetics,and structure stability of LDHs.The corresponding structure-performance relationship and energy storage mechanism are elaborated through exhaustive in/ex-situ experimental characterizations and density functional theory(DFT)calculations.Specially,in-situ Raman and DFT calculations reveal that oxygen vacancies elevate orbital energy of O 2p and electron density of O atoms,thereby enhancing the orbital hybridization of O 2p with Ni/Co 3d.This facilitates electron transfer between O and adjacent Ni/Co atoms and improves the covalency of Ni–O and Co–O bonds,which activates Ni/Co atoms to release more capacity and stabilizes the Ov-NiCo-LDH structure.Moreover,the distribution of relaxation times(DRT)and molecular dynamics(MD)simulations disclose that the enhanced d-p orbital hybridization optimizes the electronic structure of Ov-NiCo-LDH,which distinctly reduces the diffusion energy barriers of Mg^(2+)and improves the charge transfer kinetics of Ov-NiCo-LDH.Consequently,the assembled Ov-NiCo-LDH//active carbon(AC)and Ov-NiCo-LDH//perylenediimide(PTCDI)AMIBs can both deliver high specific discharge capacity(182.7 and 59.4 mAh g^(−1)at 0.5 A g^(−1),respectively)and long-term cycling stability(85.4%and 89.0%of capacity retentions after 2500 and 2400 cycles at 1.0 A g^(−1),respectively).In addition,the practical prospects for Ov-NiCo-LDH-based AMIBs have been demonstrated in different application scenarios.This work not only provides an effective strategy for obtaining high-performance cathodes of AMIBs,but also fundamentally elucidates the inherent mechanisms.
基金supported by Karpagam Academy of Higher Education,India(No.KAHE/R-Acad/A1/Seed Money/024/2981)。
文摘Layered double hydroxides(LDHs)have emerged as a promising class of photocatalysts with remarkable properties for diverse energy and environmental-related applications.This review offers insights into recent advances in LDH-based photocatalysts,focusing on their synthesis methods,structural properties,and photocatalytic performance.The unique structure of LDHs,characterized by positively charged metal hydroxide layers and intercalated anions,presents opportunities for tailoring their properties to enhance photocatalytic performance.The mechanisms for pollutant degradation,water splitting,and CO_(2) reduction are discussed,along with strategies to enhance the efficacy and stability of LDH-based photocatalysts.The photocatalytic mechanisms of LDHs for various reactions,including pollutant degradation,water splitting,and CO_(2) reduction,are discussed.Additionally,strategies for enriching the efficacy and stability of LDH-based photocatalysts are explored.This review underscores the significant potential of LDHs as versatile and efficient photocatalysts for addressing current environmental and energy challenges.
基金supported by Guangdong Basic and Applied Basic Research Foundation(2022B1515120079)Tertiary Education Scientific research project of Guangzhou Municipal Education Bureau(2024312194)+1 种基金the Science and Technology Projects in Guangzhou(2024A03J0308)the Outstanding Youth Project of Natural Science Foundation of Guangdong Province(2022B1515020020).
文摘Electrically driven water splitting is an efficient method for green hydrogen production;however,its practical application is substantially constrained by the kinetically sluggish anodic oxygen evolution reaction(OER).Ruthenium(Ru)and its oxides are widely recognized as highly active OER catalysts.Although Ru is significantly cheaper than iridium(Ir),further reducing its content remains desirable.Herein,atomically dispersed Ru is doped into iron-nickel layered double hydroxides(Ru-FeNi-LDH)to decrease the Ru usage.We found that the Ru doping limit is roughly 9 wt%,and the Ru doping content significantly alters the OER kinetics-note that the high Ru concentration remarkably damages the Ru-FeNi-LDH structure and leads to agglomeration formation.By optimizing the Ru doping content to 3.3 wt%,the Ru-FeNi-LDH presents a low overpotential of 230 mV to reach a current density of 10 mA cm^(-2) in 1 M KOH,which is far better than the reference FeNi-LDH(280 mV)and RuO_(2)(350 mV).In the overall water splitting test,the current density of 10 mA cm^(-2) can be reached at a low voltage of 1.52 V,with stable operation for 80 h.Interestingly,Ru and Fe form an asymmetric Ru-Fe dipole,which is likely doped together into the LDH because the content of Fe instead of Ni is dependent on Ru content in experimental results.The electron-deficient feature of the Ru-Fe dipole thus facilitates the OER process.This work demonstrates a dual-transition metal synergy,providing a design strategy for OER and related catalysts.
基金Project(21306041)supported by the National Natural Science Young Foundation of ChinaProject(21271071)supported by the National Natural Science Foundation of ChinaProject(15A076)supported by the Scientific Research Foundation of Hunan Provincial Education Department of China
文摘ZnO/NiO/ZnAl2O4 mixed-metal oxides were successfully synthesized through a hydrotalcite-like precursor route, in which appropriate amounts of metal salts solutions were mixed to obtain a new series of ZnNiAl layered double hydroxides（LDHs） as precursors, followed by calcination under different temperatures. The as-obtained samples were characterized by SEM, HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. The photocatalytic activities of the samples were evaluated by degradation of methyl orange（MO） under the simulated sunlight irradiation. The effects of Zn/Ni/Al mole ratio and calcination temperature on the composition, morphology and photocatalytic activity of the samples were investigated in detail. The results indicated that compared with ZnNiAl-LDHs, the mixed-metal oxide showed superior photocatalytic performance for the degradation of MO. A maximum of 97.3% photocatalytic decoloration rate within 60 min was achieved from the LDH with the Zn/Ni/Al mole ratio of 2：1：1 and the calcination temperature of 500 ℃, which much exceeded that of Degussa P25 under the same conditions. The possible mechanism of photocatalytic degradation over ZnO/NiO/ZnAl2O4 was discussed.
基金supported by the National Natural Science Foundation of China(21663027,51262028,21261021)the Science and Technology Support Project of Gansu Province(1504GKCA027)+2 种基金the Program for the Young Innovative Talents of Longyuanthe Program for Innovative Research Team(NWNULKQN-15-2)the Undergraduate Academic Innovative Research Team of Northwest Normal University~~
文摘A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can improve light‐absorption capacities and facilitate efficient hole transfer to the surface,were deposited on the surface of the BiVO4 photoanode by a hydrothermal method.All the samples were characterized using X‐ray diffraction,scanning electron microscopy,and diffuse‐reflectance spectroscopy.Linear sweep voltammetry and current‐time plots were used to investigate the PEC activity.The photocurrent response of NiFe‐LDH/BiVO4 at 1.23 V vs the reversible hydrogen electrode was higher than those of Ni(OH)2/BiVO4,Fe(OH)2/BiVO4 and pure BiVO4 electrodes under visible‐light illumination.NiFe‐LDH/BiVO4 also gave a superior PEC hydrogen evolution performance.Furthermore,the stability of the NiFe‐LDH/BiVO4 photoanode was excellent compared with that of the bare BiVO4 photoanode,and offers a novel method for solar‐assisted water splitting.
基金Project(21176263)supported by the National Natural Science Foundation of China
文摘Layered double Mg-Fe-CO3 hydroxide （Mg-Fe-LDH） with a mole ratio of Mg to Fe of 3 was synthesized by coprecipitation method and calcined product Mg-Fe-CLDH was obtained by heating Mg-Fe-LDH at 500 ℃ for 6 h. The as prepared Mg-Fe-LDH and calcined Mg-Fe-CLDH were used for removal of glutamic acid （Glu） from aqueous solution, respectively. Batch studies were carried out to address various experimental parameters such as contact time, pH, initial glutamic acid （Glu） concentration, co-existing anions and temperature. Glu was removed effectively （99.9%） under the optimized experimental conditions with Mg-Fe-CLDH. The adsorption kinetics follows the Ho’s pseudo second-order model. Isotherms for adsorption with Mg-Fe-CLDH at different solution temperatures were well described using the Langmuir model with a good correlation coefficient. The intraparticle diffusion model fitted the data well, which suggests that the intraparticle diffusion is not only the rate-limiting step.
基金Projects(21176263,21175155)supported by the National Natural Science Foundation of China
文摘Mg/Al-CO3 layered double hydroxide （LDH2） with Mg（II）：Al（III） molar ratio of 2：1 was synthesized by co-precipitation method and its calcined product Mg2Al-CLDH（CLDH2） was prepared by heating Mg2Al-LDH at 773 K for 6 h. Removal of vanadate anion （ 3-4VO ） from aqueous solution on CLDH2 was studied. Batch studies were carried out to address various experimental parameters such as Mg/Al molar ratio, adsorbent dosage, initial concentration of solution, contact time and temperature. Vanadate was removed effectively at the optimized experimental conditions. The adsorption kinetics data fitted the pseudo-first-order model. Isotherms for adsorption vanadate by CLDH2 at different solution temperatures were well described using the Langmuir and Freundlich equations, and the isotherm parameters were calculated using linear regression analysis. The adsorption data fitted the langmuir model with good values of the correlation coefficient （R2〉0.999）. The negative value ofΔGΘand the positive value ofΔHΘindicate that the adsorption processes are spontaneous endothermic in nature. The mechanism of adsorption suggests that the surface adsorption is the main process.
基金The Fundamental Research Funds for the Central Universities,the Scientific Innovation Research of College Graduates in Jiangsu Province(No.CXLX12-0105)the Analysis and Test Fund of Southeast University(No.201226)
文摘Colored layered double hydroxides （LDHs） can be synthesized by introducing colored cations such as Fe^3＋ and Cr^3 ＋, which call be used as thermal stabilizers for polyvinyl chloride （PVC）. The yellowish Mg/Fe and bluish Mg/Cr LDHs are prepared by the co-precipitation method. The results show that the MgsCr_ CO3 and Mg3Fe_ CO3 colored layered double hydroxides can stabilize PVC for more than 30 min under the thermal aging temperature of 180 ℃. The preparation can use cheap Mg（OH） 2 instead of MgCl2, which produces a much smaller amount of the by-product NH4Cl. It is known that NH4Cl is a cheap fertilizer that is difficult to sell; therefore, the preparation is much greener and more economic than the one using magnesium salt.
基金supported by the National Natural Science Foundation of China(52471240)the Natural Science Foundation of Zhejiang Province(LZ23B030003)+2 种基金the Fundamental Research Funds for the Central Universities(226-2024-00075)support from the Engineering and Physical Sciences Research Council(EPSRC,UK)RiR grant-RIR18221018-1EU COST CA23155。
文摘The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.
基金financially supported by the National Natural Science Foundation of China(U21A20311,U24A2040,52171141,52272117)the Natural Science Foundation of Shandong Province(ZR2022JQ19)+3 种基金the Key Technology Research Project of Shandong Province(2023CXGC010202)the Taishan Industrial Experts Program(TSCX202306142)the Core Facility Sharing Platform of Shandong Universitythe Foundation of Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Nankai University。
文摘Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen batteries(LOBs)due to their poor OER performance,resulting from poor electrical conductivity and overly strong intermediate adsorption.In this work,fancy double heterojunctions on 1T/2H-MoS_(2)@Co_(3)S_(4)(1T/2H-MCS)were constructed derived from the charge donation from Co to Mo ions,thus inducing the phase transformation of Mo S_(2)from 2H to 1T.The unique features of these double heterojunctions endow the1T/2H-MCS with complementary catalysis during charging and discharging processes.It is worth noting that 1T-Mo S2@Co3S4could provide fast Co-S-Mo electron transport channels to promote ORR/OER kinetics,and 2H-MoS_(2)@Co_(3)S_(4)contributed to enabling moderate egorbital occupancy when adsorbed with oxygen-containing intermediates.On the basis,the Li_(2)O_(2)nucleation route was changed to solution and surface dual pathways,improving reversible deposition and decomposition kinetics.As a result,1T/2H-MCS cathodes exhibit an improved electrocatalytic performance compared with those of Co_(3)S_(4)and Mo S2cathodes.This innovative heterostructure design provides a reliable strategy to construct efficient transition metal sulfide catalysts by improving electrical conductivity and modulating adsorption toward oxygenated intermediates for LOBs.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51601108, 51571134)the Natural Science Foundation of Shandong Province (Grant No. 2016ZRB01A62)the SDUST Research Fund (No. 2014TDJH104) and the Ministry-province jointly-constructed cultivation base for state key laboratory of Processing for non-ferrous metal and featured materials, "Guangxi Zhuang Autonomous Region"
文摘Layered double hydroxides（LDHs） as a class of anionic clays have extensive applications due to their unique structures. Nowadays, the emphasis is laid on the development of LDH coatings for corrosion resistance and medical applications. Thus, this review highlights synthetic methods of LDH coatings and LDH-based composite coatings on magnesium alloys. Special attention is focused on self-healing,biocompatible and self-cleaning LDH-based composite coatings on magnesium alloys.
基金financially supported by the National Natural Science Foundation of China (Nos.51601108 and 51571134)the Natural Science Foundation of Shandong Province (No. 2016ZRB01A62)+1 种基金the Shandong University of Science and Technology Research Fund (No. 2014TDJH104)the Opening Fund of Ministry-Province Jointly Constructed Cultivation Base for State Key Laboratory of Processing for Non-ferrous Metal and Featured Materials
文摘Mg(OH)2/Mg-Al-layered double hydroxide (LDH) coatings were modified with methyltrimethoxysilane (MTMS) on magnesium alloys. Effect of hydrolysis degree of silane solution on coating formation was investigated. Chemical compositions and surface morphologies of the coatings were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electronic microscopy (FESEM). Results indicated that the composite coatings consisted of polymethyltrimethoxysilane (PMTMS), LDH and Mg(OH)2. Electrochemical and hydrogen evolution measurements revealed that the composite coatings possessed good corrosion resistance, especially the ones prepared in a high hydrolysis degree of silane. The optimum corrosion resistance of the composite coati ng was LDH/PMTMS-3 coating, which had the lowest value of corrosion current density (5.537×10^-9 A·cm^-2) and a dense surface.Plausible mechanism for coating formation and corrosion process of MTMS-modified Mg(OH)2/Mg-Al-LDH coatings were discussed.
基金supported by the National Natural Science Foundation of China (No. 41072173)the National High Technology Research and Development Program(863) of China (No. 2009AA062905)
文摘The mesoporous Cu/Mg/Fe layered double hydroxide（Cu/Mg/Fe-LDH） with carbonate intercalation was synthesized and used for the removal of arsenate from aqueous solutions.The Cu/Mg/Fe-LDH was characterized by Fourier transform infrared spectrometry,X-ray diffraction crystallography,scanning electron microscopy,X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller.Effects of various physico-chemical parameters such as pH,adsorbent dosage,contact time and initial arsenate concentration on the adsorption of arsenate onto Cu/Mg/Fe-LDH were investigated.Results showed that it was efficient for the removal of arsenate,and the removal efficiency of arsenate increased with the increment of the adsorbent dosage,while the arsenate adsorption capacity decreased with increase of initial pH from 3 to 11.The adsorption isotherms can be well described by the Langmuir model with R 2 〉 0.99.Its adsorption kinetics followed the pseudo second-order kinetic model.Coexisting ions such as HPO42-,CO32-,SO42and NO3could compete with arsenate for adsorption sites on the Cu/Mg/Fe-LDH.The adsorption of arsenate on the adsorbent can be mainly attributed to the ion exchange process.It was found that the synthesized Cu/Mg/Fe-LDH can reduce the arsenate concentration down to a final level of 〈 10 μg/L under the experimental conditions,and makes it a potential material for the decontamination of arsenate polluted water.
基金supported by the National Natural Science Foundation of China (Grant Nos.12325406,92261201,12404305,and W2512072)the Shaanxi Province Natural Science Fundamental Research Project (Grant Nos.2023JC-XJ-03 and23JSQ013)the China Postdoctoral Science Foundation (Grant Nos.BX20240286 and 2024M7625)。
文摘Abiotic oxygen formation predates photosynthesis,sustaining early chemical evolution,yet its elementary mechanisms remain contested.Here,we show the production pathways for molecular oxygen from doubly ionized carbon dioxide upon electron-impact.Through fragment ions and electron coincidence momentum imaging,we unambiguously determine the ionization mechanism by measuring the projectile energy loss in association with the C^(+) +O_(2)^(+) channel.Further potential energy and trajectory calculations enable us to elucidate the dynamical details of this fragmentation process,in which a bond rearrangement pathway is found to proceed via the structural deformation to a triangular intermediate.Moreover,we demonstrate a further roaming pathway for the formation of O_(2)^(+) from CO_(2)^(+) 2,in which a frustrated C-O bond cleavage leaves the O atom without sufficient energy to escape.The O atom then wanders around varied configuration spaces of the flat potential energy regions and forms a C-O-O_(2)^(+) intermediate prior to the final products C^(+) +O_(2)^(+).Considering the large quantities of free electrons in interstellar space,the processes revealed here are expected to be significant and should be incorporated into atmospheric evolution models.
基金financially supported by the National Natural Science Foundation of China(U1707603,21521005,21975013,21901017)the National Key Research and Development Program of China(2017YFA0206500,2018YFA0702000)+2 种基金Beijing Natural Science Foundation(2172042)PetroChina Innovation Foundationthe Fundamental Research Funds for the Central Universities。
文摘With exhaustion of fossil fuels and the deterioration of global environment,widespread and intensive researches have been concentrated on clean and sustainable alternative energy sources,such as metal-air batteries[1],fuel cells[2]and water splitting devices[3].Electrocatalytic oxidation of water to O2(oxygen evolution reaction,OER)is a vital chemical process involved in energy storage and conversion from renewable sources in form of molecular fuels such as H2 via water electrolysis,which has attracted a great amount of research efforts in the past few years[4,5].Nowadays,RuO2 and IrO2 are widely used as typical excellent OER electrocatalysts.However,their high-cost and scarce nature restricts the broadly commercial application of those materials[6,7].Hence,there is an urgent demand to develop low cost,highly efficient,and superb stable OER catalysts.
基金financially supported by the National Natural Science Foundation of China(No.21306214)the Doctoral Program Foundation of the State Education Ministry(No. 20133718120003)+2 种基金the Applied Basic Research Foundation of Qingdao(No.13-1-4-217-jch)the Scientific Research Foundation of Shandong for Outstanding Young Scientists(No.BS2013CL009)SDUST Research Fund(No.2014TDJH104)
文摘A superhydrophobic surface was successfully constructed to modify the layered double hydroxide （LDH） coatings on aluminum alloy using stearic acid. The characteristics of the coatings were investigated using SEM, XRD, FT- IR and XPS. The corrosion resistance of the prepared coatings was studied using potentiodynamic polarization and electrochemical impedance spectrum. The results revealed that the superhydrophobic surface considerably improved the corrosion-resistant performance of the LDH coatings on the aluminum alloy substrate. The formation mechanism of the superhydrophobic surface was proposed.
基金financial support from the National Key R&D Program of China (Grant Nos.: 2017YFA0206904, 2017YFA0206900, and 2016YFB0600901)the National Program on Key Basic Research Project (Grant No.: 2014CB239402)+6 种基金the National Natural Science Foundation of China (Grant Nos.: 51772305, 51572270, U1662118, 31671489, U1332205, and 21701131)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.: XDB17000000)the Royal Society Newton Advanced Fellowship (Grant No.: NA170422)the Young Elite Scientist Sponsorship Program by CAST (Grant No.: YESS20160137)the Youth Innovation Promotion Association of the CASthe Fund of Xi’an University of Science and Technology (Grant No.:2018QDJ014)funding support from the Energy Education Trust of New Zealand
文摘For many two-dimensional(2D)materials,low coordination edges and corner sites offer greatly enhanced catalytic performance compared to basal sites,motivating the search for new synthetic approaches towards ultrathin and ultrafine 2D nanomaterials with high specific surface areas.To date,the synthesis of catalysts that are both ultrathin(monolayer)and ultrafine(lateral size<10nm)has proven extremely challenging.Herein,using a facile ultrasonic exfoliation procedure,we describe the successful synthesis of ultrafine ZnCo-LDH nanosheets(denoted as ZnCo-UF)with a size^3.5 nm and thickness^0.5 nm.The single layer ZnCo-UF nanosheets possess an abundance of oxygen vacancies(Vo)and unsaturated coordination s让es,thereby affording outstanding electrocatalytic water oxidation performance.DFT calculations confirmed that Vo on the surface of ZnCo-UF enhanced H20 adsorption via increasing the electropositivity of the nanosheets.
基金financially supported by the National Natural Science Foundation of China (No. 21675127)the Shaanxi Provincial Science Fund for Distinguished Young Scholars (No. 2018JC-011)
文摘Remaining largely under-appreciated, a majority of metal ion sorbents are limited in their target selectivity. In this work, a 3D sulfide intercalated NiFe-layered double hydroxide (NFL-S) hierarchical sorbent has been synthesized for selective heavy metal removal. The intercalation of sulfurated groups in the interlayer of the layered double hydroxide (LDH) nanosheets endows NFL-S as a selective heavy metal ion filter;the selectivity of NFL-S for heavy metals is in the order of Pb^2+> Cu^2+≥ Zn^2+> Cd^2+> Mn^2+, and NFL-S has high kd values for Pb2+(~10^6 mL/g) and Cu2+(~10^5 mL/g). Scanning electron microscopy. X-ray photoelectron spectroscopy and powder X-ray diffraction were used to analyze the composition of the as-prepared nanoadsorbent. The selective adsorption behavior was systematically studied using batch experiments, and the performance was evaluated through kinetic and isotherm studies. Moreover, the adsorption mechanism of heavy metals by NFL-S through surface complexation was also investigated, which shows great potential for water decontamination.
