It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,...It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).展开更多
Volcanic glass compositions and tephra layer age are critical for anchoring their sources and correlating among different sites; however, such work may be imprecise when the tephra has varied compositions. The ash fro...Volcanic glass compositions and tephra layer age are critical for anchoring their sources and correlating among different sites; however, such work may be imprecise when the tephra has varied compositions. The ash from Changbaishan Millennium eruption(940s AD), a widely distributed tephra layer, has been detected in the far-east areas of Russia, the Korean Peninsula, Japan, and in Greenland ice cores. There are some debates on the presence of this tephra from sedimentary archives to the west of Changbaishan volcano, such as lake and peat sediments in the Longgang volcanic field. In this paper, major element compositions for clinopyroxene and Fe-Ti oxides were performed on proximal tephra from Changbaishan and the Millennium eruption ash record in Lake Sihailongwan. Clinopyroxene and Fe-Ti oxides microlites from Sihailongwan show augite-ferroaugite and titanmagnetite compositions, similar to those from dark pumice in Changbaishan proximal tephra, but different from the light grey pumice, which has ferrohedenbergite and ilmenite microlite compositions. This result implies that the tephra recorded in Sihailongwan was mainly from the trachytic eruptive phase of the Millennium eruption, and the rhyolitic eruptive phase made a relatively small contribution to this area. Analyzing clinopyroxene and Fe-Ti oxides microlites is a new method for correlating tephra layers from Changbaishan Millennium eruption.展开更多
In the paper,we report a highly robust and porous bimetallic Ti-MOF(designated Mg_(2)Ti-ABTC)by utiliz-ing a trinuclear[Mg_(2)TiO(COO)_(6)]cluster and a tetradentate H_(4)ABTC(3,3′,5,5′-azobenzene tetracarboxylic ac...In the paper,we report a highly robust and porous bimetallic Ti-MOF(designated Mg_(2)Ti-ABTC)by utiliz-ing a trinuclear[Mg_(2)TiO(COO)_(6)]cluster and a tetradentate H_(4)ABTC(3,3′,5,5′-azobenzene tetracarboxylic acid)ligand.Mg_(2)Ti-ABTC exhibited permanent porosity for N_(2),CO_(2),CH_(4),C_(2)H_(2),C_(2)H_(4),and C_(2)H_(6)gas adsorption.Further-more,Mg_(2)Ti-ABTC exhibited outstanding photocatalytic activity in the oxidation of aromatic sulfides to the corre-sponding sulfoxides under ambient air conditions.Mechanism studies reveal that photoinduced holes(h^(+)),the super-oxide radical(·O_(2)^(-)),and singlet oxygen(^(1)O_(2))are pivotal species involved in the photocatalytic oxidation reaction.展开更多
Potassium-ion batteries(PIBs)were recognized for their natural abunda nce,high theoretical output voltage,and the availability of commercialized graphite anodes.However,the development of highperformance manganese-bas...Potassium-ion batteries(PIBs)were recognized for their natural abunda nce,high theoretical output voltage,and the availability of commercialized graphite anodes.However,the development of highperformance manganese-based layered oxide cathodes-a leading candidate for PIB systems-has been fundamentally constrained by irreversible phase transitions(PT)during the cycling process,manifesting as severe structural degradation and capacity fading.This review presents a transformative paradigm integrating machine learning(ML)with multiscale characterization to analyse the complex phase transition mechanisms in Mn-based cathodes.Through systematic ML-driven interrogation of structure-property relationships,we establish quantitative descriptors for phase stability and develop predictive models for transition dynamics.Furthermore,we highlight recent breakthroughs in cross-disciplinary approaches,enabling the rational design of PT-mitigated cathode architectures.By consolidating these insights into a unified knowledge framework,this work provides strategic guidelines for developing structurally robust Mn-based cathodes and outlines future research directions for next-generation PIB systems.展开更多
Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+d...Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.展开更多
Cation segregation on cathode surfaces plays a key role in determining the activity and operational stability of solid oxide fuel cells(SOFCs).The double perovskite oxide PrBa_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(PBCC)has been...Cation segregation on cathode surfaces plays a key role in determining the activity and operational stability of solid oxide fuel cells(SOFCs).The double perovskite oxide PrBa_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(PBCC)has been widely studied as an active cathode but still suffer from serious detrimental segregations.To enhance the cathode stability,a PBCC derived A-site medium-entropy Pr_(0.6)La_(0.1)Nd_(0.1)Sm_(0.1)Gd_(0.1)Ba_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(ME-PBCC)oxide was prepared and its segregation behaviors were investigated under different conditions.Compared with initial PBCC oxide,the segregations of BaO and Co_(3)O_(4)on the surface of ME-PBCC material are significantly suppressed,especially for Co_(3)O_(4),which is attributed to its higher configuration entropy.Our results also confirm the improved electrochemical performance and structural stability of ME-PBCC material,enabling it as a promising cathode for SOFCs.展开更多
With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysi...With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysis of PET to DMT is achieved over Cu-Mg-Al oxide catalyst.Next,terephthalic acid(TPA)is prepared by DMT hydrolysis.It is found that hydrolysis of DMT to TPA can be promoted by introducing trace amount of water in this catalyst system.CuO-MgO-4.5Al_2O_(3)catalyst demonstrates the excellent catalytic performance for the depolymerization of PET with high conversion rate and TPA yield(100%and 99.5%,respectively)after reaction at 160℃for 6 h,which provides a new idea for the depolymerization of PET.展开更多
The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the ...The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the long-cycling stability of batteries needs to be improved.Herein,the Mn-based Li-rich cathode materials with small amounts of Li2 MnO3 crystal domains and gradient doping of Al and Ti elements from the surface to the bulk have been developed to improve the structure and interface stability.Then the batteries with a high energy density of 600 Wh kg^(-1),excellent capacity retention of 99.7%with low voltage decay of 0.03 mV cycle^(-1) after 800 cycles,and good rates performances can be achieved.Therefore,the structure and cycling stability of low voltage Mn-based Li-rich cathode materials can be significantly improved by the bulk structure design and interface regulation,and this work has paved the way for developing low-cost and high-energy Mn-based energy storage batteries with long lifetime.展开更多
The reaction characteristics of calcium-based materials during calcium looping(CaL)process are pivotal in the efficiency of CaL thermochemical energy storage(TCES)and CO_(2)capture systems.Currently,metal oxide doping...The reaction characteristics of calcium-based materials during calcium looping(CaL)process are pivotal in the efficiency of CaL thermochemical energy storage(TCES)and CO_(2)capture systems.Currently,metal oxide doping is the primary method to enhance the reaction characteristics of calcium-based materials over multiple cycles.In particular,co-doping with variable-valence metal oxides(VVMOs)can effectively increase the oxygen vacancy content in calcium-based materials,significantly improving their cyclic reaction characteristics.However,there are so numerous VVMOs co-doping schemes that the experimental screening process is complex,consuming considerable time and economic costs.Density functional theory(DFT)calculations have been widely used to reveal the impact of metal oxide doping on the cyclic reaction characteristics of calcium-based materials,with calculation results showing good agreement with experimental conclusions.Nevertheless,there is still a lack of research on utilizing DFT to screen calcium-based materials,and a systematic research methodology has not yet been established.In this study,a systematic DFT-based screening methodology for calcium-based materials was proposed.A series of key parameters for DFT calculations including CO_(2)adsorption energy,oxygen vacancy formation energy,and sintering resistance were proposed.Furthermore,a preliminary mathematical model to predict the CaL TCES and CO_(2)capture performance of calcium-based materials was introduced.The aforementioned DFT method was employed to screen for VVMOs co-doped calcium-based materials.The results revealed that Mn and Ce co-doped calcium-based materials exhibited superior DFT-predicted reaction characteristics.These DFT predictions were validated through experimental assessments of cyclic thermochemical energy storage,CO_(2)capture,and relevant characterization.The outcomes demonstrate a high degree of consistency among DFT-based predictions,experimental results,and characterization.Hence,the DFT-based screening methodology for calcium-based materials proposed herein is a viable solution,poised to offer theoretical insights for the efficient design of calcium-based materials.展开更多
Bisphenol A(BPA)is a pervasive endocrine disruptor that enters the environment through anthropogenic activities,posing significant risks to ecosystems and human health.Advanced oxidation processes(AOPs)are promising m...Bisphenol A(BPA)is a pervasive endocrine disruptor that enters the environment through anthropogenic activities,posing significant risks to ecosystems and human health.Advanced oxidation processes(AOPs)are promising methods for the removal of organic microcontaminants in the environment.Biogenic manganese oxides(BMO)are reported as catalysts due to their transitionmetal nature,and are also readily generated bymanganeseoxidizing microorganisms in the natural environment,and therefore their roles and effects in AOPs-based environmental remediation should be investigated.However,biogenic ironmanganese oxides(BFMO)are actually generated rather than BMO due to the coexistence of ferrous ionswhich can be oxidized to iron oxides.Therefore,this study produced BFMO originating from a highly efficientmanganese-oxidizing fungus Cladosporium sp.XM01 and chose peroxymonosulfate(PMS)as a typical oxidant for the degradation of bisphenol A(BPA),a model organic micropollutant.Characterization results indicate that the formed BFMO was amorphouswith a lowcrystallinity.The BFMO/PMS system achieved a high degradation performance that 85%BPA was rapidly degraded within 60min,and therefore the contribution of BFMO cannot be ignored during PMS-based environmental remediation.Different from the findings of previous studies(mostly radicals and singlet oxygen),the degradationmechanism was first proven as a 100%electron-transfer pathway mediated by high-valence Mn under acidic conditions provided by PMS.The findings of this study provide new insights into the degradation mechanisms of pollutants using biogenic metal oxides in PMS activation and the contribution of their coexistence in AOPs-based environmental remediation.展开更多
A chain of GdCe oxides boosted biochars derived from maize straw and sewage sludge(GdyCe1-y/MPBs)were fabricated for formaldehyde(HCHO)catalytic decomposition.The ingenerate relationship between the abatement performa...A chain of GdCe oxides boosted biochars derived from maize straw and sewage sludge(GdyCe1-y/MPBs)were fabricated for formaldehyde(HCHO)catalytic decomposition.The ingenerate relationship between the abatement performance and corresponding structural feature was comprehensively evaluated by XPS,in situ DRIFTS,BET,XRD,SEM and H_(2)-TPR.Meanwhile,10%Gd0.25Ce0.75/MPB exhibited excellent performance,favorable SO_(2) and moisture toleration over a broad temperature range from 160 to 320℃,where it achieved 96.8%removal efficiency with 90.5%selectivity at 200℃.The single or united effects of O_(2),SO_(2),H_(2)O on HCHO abatement over 10%Gd_(0.25)Ce_(0.75)/MPB were tested,and the findings demonstrated that the suppressive effects of SO_(2) and H_(2)O outweighed the promoting influence of O_(2) within a specific range.Gd and Ce co-modified MPB revealed superior HCHO removal capability in contrast to that of Gd or Ce severally modified MPB,ascribing to the synergistic effect of GdO_(x) and CeO_(x) and benefitting from the augmentation of surface area and total pore volume,the aggrandizement of surface active oxygen species,the promotion of redox ability and the inhibition crystallization of CeO_(x).According to in situ DRIFTS,a series of intermediates including formate species and dioxymethylene(DOM)were produced,which would eventually decompose into H_(2)O and CO_(2).In addition,the mass transfer and diffusion of the reactants along with the accessibility of the catalytic sites were enlarged by the hierarchical porous structure of the support,which were also answerable for its distinguished catalytic performance.Furthermore,10%Gd0.25Ce0.75/MPB possessed remarkable potential for industrial applications.展开更多
The Kitaev honeycomb model has received significant attention due to its exactly solvable quantum spin liquid ground states and fractionalized excitations.Layered cobalt oxides have been considered as a promising plat...The Kitaev honeycomb model has received significant attention due to its exactly solvable quantum spin liquid ground states and fractionalized excitations.Layered cobalt oxides have been considered as a promising platform for realizing this model.However,in contrast to the conventional wisdom regarding the single-q zigzag magnetic order inferred from previous studies of the candidate materials Na_(2)IrO_(3) and α-RuCl_(3),recent experiments on two representative honeycomb cobalt oxides,hexagonal Na_(2)Co_(2)TeO_(6) and monoclinic Na_(3)Co_(2)SbO_(6),have uncovered evidence for more complex multi-q zigzag order variants.This review surveys the experimental strategies used to distinguish between single-and multi-q orders,along with the crystallographic symmetries of cobalt oxides,in comparison with previously studied systems.The general formation mechanism of multi-q order is also briefly discussed.The goal is to provide a solid ground for examining the relevance of multi-q order in honeycomb cobalt oxides and discuss its implications for the microscopic model of these intriguing quantum magnets.展开更多
The use of metal oxides has been extensively documented in the literature and applied in a variety of contexts,including but not limited to energy storage,chemical sensors,and biomedical applications.One of the most s...The use of metal oxides has been extensively documented in the literature and applied in a variety of contexts,including but not limited to energy storage,chemical sensors,and biomedical applications.One of the most significant applications of metal oxides is heterogeneous catalysis,which represents a pivotal technology in industrial production on a global scale.Catalysts serve as the primary enabling agents for chemical reactions,and among the plethora of catalysts,metal oxides including magnesium oxide(MgO),ceria(CeO_(2))and titania(TiO_(2)),have been identified to be particularly effective in catalyzing a variety of reactions[1].Theoretical calculations based on density functional theory(DFT)and a multitude of other quantum chemistry methods have proven invaluable in elucidating the mechanisms of metal-oxide-catalyzed reactions,thereby facilitating the design of high-performance catalysts[2].展开更多
To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretre...To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.展开更多
In this study,a string of Cr-Mnco-modified activated coke catalysts(XCryMn1-y/AC)were prepared to investigate toluene and Hg^(0) removal performance.Multifarious characterizations including XRD,TEM,SEM,in situ DRIFTS,...In this study,a string of Cr-Mnco-modified activated coke catalysts(XCryMn1-y/AC)were prepared to investigate toluene and Hg^(0) removal performance.Multifarious characterizations including XRD,TEM,SEM,in situ DRIFTS,BET,XPS and H_(2)-TPR showed that 4%Cr0.5Mn0.5/AC had excellent physicochemical properties and exhibited the best toluene and Hg^(0) removal efficiency at 200℃.By varying the experimental gas components and conditions,it was found that too large weight hourly space velocity would reduce the removal efficiency of toluene and Hg^(0).Although O_(2) promoted the abatement of toluene and Hg^(0),the inhibitory role of H_(2)O and SO_(2) offset the promoting effect of O_(2) to some extent.Toluene significantly inhibited Hg^(0) removal,resulting from that toluene was present at concentrations orders of magnitude greater than mercury’s or the catalyst was more prone to adsorb toluene,while Hg^(0) almost exerted non-existent influence on toluene elimination.The mechanistic analysis showed that the forms of toluene and Hg^(0) removal included both adsorption and oxidation,where the high-valent metal cations and oxygen vacancy clusters promoted the redox cycle of Cr^(3+)+Mn^(3+)/Mn^(4+)+Cr^(6+)+Mn^(2+),which facilitated the conversion and replenishment of reactive oxygen species in the oxidation process,and even the CrMn_(1.5)O_(4) spinel structure could provide a larger catalytic interface,thus enhancing the adsorption/oxidation of toluene and Hg^(0).Therefore,its excellent physicochemical properties make it a costeffective potential industrial catalyst with outstanding synergistic toluene and Hg^(0) removal performance and preeminent resistance to H_(2)O and SO_(2).展开更多
Water scarcity,driven by climate change and population growth,necessitates innovative desalination technologies.Conventional methods for brackish water desalination are limited by high-energy demands,especially in the...Water scarcity,driven by climate change and population growth,necessitates innovative desalination technologies.Conventional methods for brackish water desalination are limited by high-energy demands,especially in the low salinity range,prompting the exploration of electrochemical approaches like faradaic deionization.Sodium-manganese oxides,traditionally used in sodium-ion batteries,show promise as faradaic deionization electrode materials due to their abundance,low toxicity,and cost-effectiveness.However,capacity fading during cycling,often caused by structural changes,volume expansion,or chemical transformations,remains a critical challenge.This study investigates the impact of morphology and crystal structure on the electrochemical performance of commercial and synthesized sodium-manganese oxides for faradaic deionization applications.Structural and electrochemical characterization in three-electrode cells with low-concentration electrolytes provided insights into the charge storage mechanisms.Rocking-chair full flow cell experiments demonstrated that the mixed-phase sodium-manganese oxide exhibited superior desalination performance,achieving a high salt removal capacity of 54.5 mg g^(−1)and a mean value in the salt removal rate of 1.49 mg g^(−1)min^(-1).Notably,mixed-phase sodium-manganese oxide maintained 98%capacity retention over 870 cycles,one of the longest reported cycling experiments in this field,effectively mitigating the Jahn-Teller effect.These findings highlight the crucial role of sodium-manganese oxide structure and morphology in electrochemical performance,positioning mixed-phase sodium-manganese oxide as a strong candidate for sustainable water treatment technologies.展开更多
P2-type layered oxides are highly promising cathode candidates for sodium-ion batteries(SIBs)owing to their substantial theoretical capacity.Nevertheless,structural degradation caused by transition metal dissolution a...P2-type layered oxides are highly promising cathode candidates for sodium-ion batteries(SIBs)owing to their substantial theoretical capacity.Nevertheless,structural degradation caused by transition metal dissolution and irreversible phase transitions at high voltage severely compromises cycling stability.To address this limitation,we propose a Li/Ti co-doping strategy to design a Na_(0.67)Li_(0.06)Ni_(0.27)Mn_(0.5)7Ti_(0.1)O_(2)(NLMT) cathode for SIBs.In-situ X-ray diffraction(XRD) confirms that this deliberate strategy eliminates the adverse phase transition at high voltage and sustains the unitary P2phase throughout cycling.In addition,strengthened transition metal-oxygen(TM-O) bonding via electronic modulation suppresses transition metal dissolution and reinforces the layered oxide framework,contributing to exceptional electrochemical performance.Consequently,the NLMT cathode exhibits an outstanding capacity of 92.8 mA h g^(-1) within 2.5-4.3 V at 5 C(865 mA g^(-1)),with 87 % capacity retention over 200 cycles.Configured into a full cell,which achieves a competitive capacity of 107.7 mA h g^(-1) at0.1 C and retains 86.4 % capacity over 100 cycles at 0.5 C.This study validates co-doping as a potent strategy for significantly improving the long-term cyclability of layered oxide cathodes in SIBs.展开更多
This study delved into the corrosion behavior of ZK60 Mg alloy in saturated NaCl solution,particularly focusing on the effects of the addition of rare earth oxide,namely CeO_(2)(forming ZKC alloy)and La_(2)O_(3)(formi...This study delved into the corrosion behavior of ZK60 Mg alloy in saturated NaCl solution,particularly focusing on the effects of the addition of rare earth oxide,namely CeO_(2)(forming ZKC alloy)and La_(2)O_(3)(forming ZKL alloy).The results indicate that the introduction of CeO_(2)and La_(2)O_(3)promotes the precipita-tion of T-(Mg_(1−x),Zn_(x))_(11)RE phases(Mg-Zn-RE phases,where RE represents Ce or La)at grain boundaries.The presence and distribution pattern of the T-phase have a profound impact on the corrosion resis-tance of the Mg alloy.Specifically,the ZKC alloy exhibits the most outstanding corrosion resistance.This superior performance is attributed to the uniform distribution of(Mg_(1−x),Zn_(x))_(11)Ce phase at grain bound-aries in ZK60-0.5 wt%CeO_(2),effectively hindering the penetration of corrosive media into the matrix.Additionally,scanning kelvin probe force microscopy(SKPFM)analysis reveals that the(Mg_(1−x),Zn_(x))_(11)Ce phase exhibits the smallest potential difference with the matrix,significantly mitigating the tendency for galvanic corrosion.In contrast,the ZKL alloy displays less precipitation and uneven distribution of the(Mg_(1−x),Zn_(x))_(11)La phase,resulting in inferior corrosion resistance compared to the ZKC alloy.The dispar-ities in the precipitation of the two phases,as derived from first-principles calculations,stem from the spontaneous reduction of CeO_(2)under Mg conditions,whereas the reduction reaction between La_(2)O_(3)and Mg cannot proceed spontaneously.Furthermore,SKPFM analysis and CALPHAD method found that as the addition of CeO_(2)/La_(2)O_(3)increases,the atomic ratio of Zn in the Mg-Zn-RE ternary phase rises,accompa-nied by an increase in the potential difference between the Mg-Zn-RE phase and the Mg matrix.This suggests that fine-tuning the addition of rare earth oxides can modify the atomic ratio of the Mg-Zn-RE ternary phase,thereby enhancing the corrosion resistance of the Mg alloy.In summary,this study not only unravels the specific mechanisms of how CeO_(2)and La_(2)O_(3)affect the corrosion behavior of ZK60 Mg alloy but also provides new strategies and insights for the development of low-cost,high-performance corrosion-resistant Mg alloy materials.展开更多
Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation,they cannot be directly used for Fenton-like industrialization considering the problems of loss and re...Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation,they cannot be directly used for Fenton-like industrialization considering the problems of loss and recovery.Therefore,the membrane fixation of catalyst is an important step to realize the actual application of Fenton-like catalysts.In this work,an efficient catalyst was developed with Co-N_(x)configuration facilely reconstructed on the surface of Co_(3)O_(4)(Co-N_(x)/Co_(3)O_(4)),which exhibited superior catalytic activity.We further fixed the highly efficient Co-N_(x)/Co_(3)O_(4)onto three kinds of organic membranes and one kind of inorganic ceramic membrane installing with the residual PMS treatment device to investigate its catalytic stability and sustainability.Results indicated that the inorganic ceramic membrane(CM)can achieve high water flux of 710 L m-2h-1,and the similar water flux can be achieved by Co-N_(x)/Co_(3)O_(4)/CM even without the pressure extraction.We also employed the Co-N_(x)/Co_(3)O_(4)/CM system to the wastewater secondary effluent,and the pollutant in complicated secondary effluent could be highly removed by the Co-N_(x)/Co_(3)O_(4)/CM system.This paper provides a new point of view for the application of metal-based catalysts with M-N_(x)coordination in catalytic reaction device.展开更多
A_(2)B_(2)O_(7)high-entropy oxides are ceramic materials characterized by diverse compositions,strong structural inclusivity,and a broad range of potential applications.These materials hold significant value in fields...A_(2)B_(2)O_(7)high-entropy oxides are ceramic materials characterized by diverse compositions,strong structural inclusivity,and a broad range of potential applications.These materials hold significant value in fields such as thermal barrier coatings,energy storage,dielectric materials,and transparent ceramics.However,there are limited reports on the dielectric properties of A_(2)B_(2)O_(7)high-entropy oxides.Consequently,further investigation is required to understand the polarization mechanisms in high-entropy ceramics and analyze the formation of oxygen vacancies and their influence.In the present study,La_(2)[(TiZrSnHfGe)_((1-2x)5)(NbGa)_(x)]_(2)O_(7)(x=0.129,0.143,0.157,0.171)(LTZSHGNGO)ceramics were synthesized successfully using a conventional solidstate reaction method.Compared withLa_(2)(TiZrSnHfGe)_(2)O_(7)ceramics,LTZSHGNGO demonstrated a nearly 6.7-fold increase in dielectric constant and a 33%reduction in dielectric loss.The incorporation of Nb/Ga enhanced the high-temperature dielectric properties and improved dielectric stability.The exceptional dielectric performance is primarily attributed to the synergistic highentropy effect,while Nb/Ga doping increased the number of oxygen vacancies and generated more defect dipole clusters[Ti^(4+)·e-V_(O)^(**)-Ti^(4+)·e].This study provides novel insights into the dielectric properties of LTZSHGNGO high-entropy ceramics and offers a novel approach to understanding the performance of A_(2)B_(2)O_(7)ceramics.展开更多
文摘It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).
基金supported by the National Natural Science Foundation of China (Grant Nos. 41472320, 41320104006 and 41272369)
文摘Volcanic glass compositions and tephra layer age are critical for anchoring their sources and correlating among different sites; however, such work may be imprecise when the tephra has varied compositions. The ash from Changbaishan Millennium eruption(940s AD), a widely distributed tephra layer, has been detected in the far-east areas of Russia, the Korean Peninsula, Japan, and in Greenland ice cores. There are some debates on the presence of this tephra from sedimentary archives to the west of Changbaishan volcano, such as lake and peat sediments in the Longgang volcanic field. In this paper, major element compositions for clinopyroxene and Fe-Ti oxides were performed on proximal tephra from Changbaishan and the Millennium eruption ash record in Lake Sihailongwan. Clinopyroxene and Fe-Ti oxides microlites from Sihailongwan show augite-ferroaugite and titanmagnetite compositions, similar to those from dark pumice in Changbaishan proximal tephra, but different from the light grey pumice, which has ferrohedenbergite and ilmenite microlite compositions. This result implies that the tephra recorded in Sihailongwan was mainly from the trachytic eruptive phase of the Millennium eruption, and the rhyolitic eruptive phase made a relatively small contribution to this area. Analyzing clinopyroxene and Fe-Ti oxides microlites is a new method for correlating tephra layers from Changbaishan Millennium eruption.
文摘In the paper,we report a highly robust and porous bimetallic Ti-MOF(designated Mg_(2)Ti-ABTC)by utiliz-ing a trinuclear[Mg_(2)TiO(COO)_(6)]cluster and a tetradentate H_(4)ABTC(3,3′,5,5′-azobenzene tetracarboxylic acid)ligand.Mg_(2)Ti-ABTC exhibited permanent porosity for N_(2),CO_(2),CH_(4),C_(2)H_(2),C_(2)H_(4),and C_(2)H_(6)gas adsorption.Further-more,Mg_(2)Ti-ABTC exhibited outstanding photocatalytic activity in the oxidation of aromatic sulfides to the corre-sponding sulfoxides under ambient air conditions.Mechanism studies reveal that photoinduced holes(h^(+)),the super-oxide radical(·O_(2)^(-)),and singlet oxygen(^(1)O_(2))are pivotal species involved in the photocatalytic oxidation reaction.
基金financially supported by the National Natural Science Foundation of China(U20A20247)the National Key Research and Development Program of the Ministry of Science and Technology(2022YFA1402504)+1 种基金Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion(MATEC2023KF002)Guangdong Science and Technology Department(STKJ2021016)。
文摘Potassium-ion batteries(PIBs)were recognized for their natural abunda nce,high theoretical output voltage,and the availability of commercialized graphite anodes.However,the development of highperformance manganese-based layered oxide cathodes-a leading candidate for PIB systems-has been fundamentally constrained by irreversible phase transitions(PT)during the cycling process,manifesting as severe structural degradation and capacity fading.This review presents a transformative paradigm integrating machine learning(ML)with multiscale characterization to analyse the complex phase transition mechanisms in Mn-based cathodes.Through systematic ML-driven interrogation of structure-property relationships,we establish quantitative descriptors for phase stability and develop predictive models for transition dynamics.Furthermore,we highlight recent breakthroughs in cross-disciplinary approaches,enabling the rational design of PT-mitigated cathode architectures.By consolidating these insights into a unified knowledge framework,this work provides strategic guidelines for developing structurally robust Mn-based cathodes and outlines future research directions for next-generation PIB systems.
基金supported by the National Natural Science Foundation of China(No.21805018)by Sichuan Science and Technology Program(Nos.2022ZHCG0018,2023NSFSC0117 and 2023ZHCG0060)Yibin Science and Technology Program(No.2022JB005)and China Postdoctoral Science Foundation(No.2022M722704).
文摘Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.
基金Project supported by the National Natural Science Foundation of China(22279025,21773048,52302119)the Fundamental Research Funds for the Central Universities(2023FRFK06005,HIT.NSRIF202204)。
文摘Cation segregation on cathode surfaces plays a key role in determining the activity and operational stability of solid oxide fuel cells(SOFCs).The double perovskite oxide PrBa_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(PBCC)has been widely studied as an active cathode but still suffer from serious detrimental segregations.To enhance the cathode stability,a PBCC derived A-site medium-entropy Pr_(0.6)La_(0.1)Nd_(0.1)Sm_(0.1)Gd_(0.1)Ba_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(ME-PBCC)oxide was prepared and its segregation behaviors were investigated under different conditions.Compared with initial PBCC oxide,the segregations of BaO and Co_(3)O_(4)on the surface of ME-PBCC material are significantly suppressed,especially for Co_(3)O_(4),which is attributed to its higher configuration entropy.Our results also confirm the improved electrochemical performance and structural stability of ME-PBCC material,enabling it as a promising cathode for SOFCs.
文摘With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysis of PET to DMT is achieved over Cu-Mg-Al oxide catalyst.Next,terephthalic acid(TPA)is prepared by DMT hydrolysis.It is found that hydrolysis of DMT to TPA can be promoted by introducing trace amount of water in this catalyst system.CuO-MgO-4.5Al_2O_(3)catalyst demonstrates the excellent catalytic performance for the depolymerization of PET with high conversion rate and TPA yield(100%and 99.5%,respectively)after reaction at 160℃for 6 h,which provides a new idea for the depolymerization of PET.
基金supported by the National Key R&D Program of China(No.2022YFB2404400)the National Natural Science Foundation of China(Nos.U23A20577,52372168,92263206 and 21975006)+1 种基金the“The Youth Beijing Scholars program”(No.PXM2021_014204_000023)the Beijing Natural Science Foundation(Nos.2222001 and KM202110005009).
文摘The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the long-cycling stability of batteries needs to be improved.Herein,the Mn-based Li-rich cathode materials with small amounts of Li2 MnO3 crystal domains and gradient doping of Al and Ti elements from the surface to the bulk have been developed to improve the structure and interface stability.Then the batteries with a high energy density of 600 Wh kg^(-1),excellent capacity retention of 99.7%with low voltage decay of 0.03 mV cycle^(-1) after 800 cycles,and good rates performances can be achieved.Therefore,the structure and cycling stability of low voltage Mn-based Li-rich cathode materials can be significantly improved by the bulk structure design and interface regulation,and this work has paved the way for developing low-cost and high-energy Mn-based energy storage batteries with long lifetime.
基金supported by the National Natural Science Foundation of China(52276204 and U22A20435)。
文摘The reaction characteristics of calcium-based materials during calcium looping(CaL)process are pivotal in the efficiency of CaL thermochemical energy storage(TCES)and CO_(2)capture systems.Currently,metal oxide doping is the primary method to enhance the reaction characteristics of calcium-based materials over multiple cycles.In particular,co-doping with variable-valence metal oxides(VVMOs)can effectively increase the oxygen vacancy content in calcium-based materials,significantly improving their cyclic reaction characteristics.However,there are so numerous VVMOs co-doping schemes that the experimental screening process is complex,consuming considerable time and economic costs.Density functional theory(DFT)calculations have been widely used to reveal the impact of metal oxide doping on the cyclic reaction characteristics of calcium-based materials,with calculation results showing good agreement with experimental conclusions.Nevertheless,there is still a lack of research on utilizing DFT to screen calcium-based materials,and a systematic research methodology has not yet been established.In this study,a systematic DFT-based screening methodology for calcium-based materials was proposed.A series of key parameters for DFT calculations including CO_(2)adsorption energy,oxygen vacancy formation energy,and sintering resistance were proposed.Furthermore,a preliminary mathematical model to predict the CaL TCES and CO_(2)capture performance of calcium-based materials was introduced.The aforementioned DFT method was employed to screen for VVMOs co-doped calcium-based materials.The results revealed that Mn and Ce co-doped calcium-based materials exhibited superior DFT-predicted reaction characteristics.These DFT predictions were validated through experimental assessments of cyclic thermochemical energy storage,CO_(2)capture,and relevant characterization.The outcomes demonstrate a high degree of consistency among DFT-based predictions,experimental results,and characterization.Hence,the DFT-based screening methodology for calcium-based materials proposed herein is a viable solution,poised to offer theoretical insights for the efficient design of calcium-based materials.
基金supported by the National Key Research and Development Program of China(No.2021YFC3200700)the National Natural Science Foundation of China(No.52400010)+1 种基金the Science and Technology Commission of Shanghai Municipality(No.24ZR1472300)the Fundamental Research Funds for the Central Universities.
文摘Bisphenol A(BPA)is a pervasive endocrine disruptor that enters the environment through anthropogenic activities,posing significant risks to ecosystems and human health.Advanced oxidation processes(AOPs)are promising methods for the removal of organic microcontaminants in the environment.Biogenic manganese oxides(BMO)are reported as catalysts due to their transitionmetal nature,and are also readily generated bymanganeseoxidizing microorganisms in the natural environment,and therefore their roles and effects in AOPs-based environmental remediation should be investigated.However,biogenic ironmanganese oxides(BFMO)are actually generated rather than BMO due to the coexistence of ferrous ionswhich can be oxidized to iron oxides.Therefore,this study produced BFMO originating from a highly efficientmanganese-oxidizing fungus Cladosporium sp.XM01 and chose peroxymonosulfate(PMS)as a typical oxidant for the degradation of bisphenol A(BPA),a model organic micropollutant.Characterization results indicate that the formed BFMO was amorphouswith a lowcrystallinity.The BFMO/PMS system achieved a high degradation performance that 85%BPA was rapidly degraded within 60min,and therefore the contribution of BFMO cannot be ignored during PMS-based environmental remediation.Different from the findings of previous studies(mostly radicals and singlet oxygen),the degradationmechanism was first proven as a 100%electron-transfer pathway mediated by high-valence Mn under acidic conditions provided by PMS.The findings of this study provide new insights into the degradation mechanisms of pollutants using biogenic metal oxides in PMS activation and the contribution of their coexistence in AOPs-based environmental remediation.
基金supported by the Scientific Research Project of Hunan Provincial EducationDepartment(No.22B0458)the National Natural Science Foundation of China(No.52270102).
文摘A chain of GdCe oxides boosted biochars derived from maize straw and sewage sludge(GdyCe1-y/MPBs)were fabricated for formaldehyde(HCHO)catalytic decomposition.The ingenerate relationship between the abatement performance and corresponding structural feature was comprehensively evaluated by XPS,in situ DRIFTS,BET,XRD,SEM and H_(2)-TPR.Meanwhile,10%Gd0.25Ce0.75/MPB exhibited excellent performance,favorable SO_(2) and moisture toleration over a broad temperature range from 160 to 320℃,where it achieved 96.8%removal efficiency with 90.5%selectivity at 200℃.The single or united effects of O_(2),SO_(2),H_(2)O on HCHO abatement over 10%Gd_(0.25)Ce_(0.75)/MPB were tested,and the findings demonstrated that the suppressive effects of SO_(2) and H_(2)O outweighed the promoting influence of O_(2) within a specific range.Gd and Ce co-modified MPB revealed superior HCHO removal capability in contrast to that of Gd or Ce severally modified MPB,ascribing to the synergistic effect of GdO_(x) and CeO_(x) and benefitting from the augmentation of surface area and total pore volume,the aggrandizement of surface active oxygen species,the promotion of redox ability and the inhibition crystallization of CeO_(x).According to in situ DRIFTS,a series of intermediates including formate species and dioxymethylene(DOM)were produced,which would eventually decompose into H_(2)O and CO_(2).In addition,the mass transfer and diffusion of the reactants along with the accessibility of the catalytic sites were enlarged by the hierarchical porous structure of the support,which were also answerable for its distinguished catalytic performance.Furthermore,10%Gd0.25Ce0.75/MPB possessed remarkable potential for industrial applications.
基金supported by the National Basic Research Program of China(Grant No.2021YFA1401901)the National Natural Science Foundation of China(Grant No.12474138)。
文摘The Kitaev honeycomb model has received significant attention due to its exactly solvable quantum spin liquid ground states and fractionalized excitations.Layered cobalt oxides have been considered as a promising platform for realizing this model.However,in contrast to the conventional wisdom regarding the single-q zigzag magnetic order inferred from previous studies of the candidate materials Na_(2)IrO_(3) and α-RuCl_(3),recent experiments on two representative honeycomb cobalt oxides,hexagonal Na_(2)Co_(2)TeO_(6) and monoclinic Na_(3)Co_(2)SbO_(6),have uncovered evidence for more complex multi-q zigzag order variants.This review surveys the experimental strategies used to distinguish between single-and multi-q orders,along with the crystallographic symmetries of cobalt oxides,in comparison with previously studied systems.The general formation mechanism of multi-q order is also briefly discussed.The goal is to provide a solid ground for examining the relevance of multi-q order in honeycomb cobalt oxides and discuss its implications for the microscopic model of these intriguing quantum magnets.
基金financial support from the National Key R&D Program of China(2021YFB3500700)the National Natural Science Foundation of China(22473042,22003016,and 92145302).
文摘The use of metal oxides has been extensively documented in the literature and applied in a variety of contexts,including but not limited to energy storage,chemical sensors,and biomedical applications.One of the most significant applications of metal oxides is heterogeneous catalysis,which represents a pivotal technology in industrial production on a global scale.Catalysts serve as the primary enabling agents for chemical reactions,and among the plethora of catalysts,metal oxides including magnesium oxide(MgO),ceria(CeO_(2))and titania(TiO_(2)),have been identified to be particularly effective in catalyzing a variety of reactions[1].Theoretical calculations based on density functional theory(DFT)and a multitude of other quantum chemistry methods have proven invaluable in elucidating the mechanisms of metal-oxide-catalyzed reactions,thereby facilitating the design of high-performance catalysts[2].
基金National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.
基金supported by the Scientific Research Project of Hunan Provincial Department of Education (No.22B0458)the National Natural Science Foundation of China (No.52270102).
文摘In this study,a string of Cr-Mnco-modified activated coke catalysts(XCryMn1-y/AC)were prepared to investigate toluene and Hg^(0) removal performance.Multifarious characterizations including XRD,TEM,SEM,in situ DRIFTS,BET,XPS and H_(2)-TPR showed that 4%Cr0.5Mn0.5/AC had excellent physicochemical properties and exhibited the best toluene and Hg^(0) removal efficiency at 200℃.By varying the experimental gas components and conditions,it was found that too large weight hourly space velocity would reduce the removal efficiency of toluene and Hg^(0).Although O_(2) promoted the abatement of toluene and Hg^(0),the inhibitory role of H_(2)O and SO_(2) offset the promoting effect of O_(2) to some extent.Toluene significantly inhibited Hg^(0) removal,resulting from that toluene was present at concentrations orders of magnitude greater than mercury’s or the catalyst was more prone to adsorb toluene,while Hg^(0) almost exerted non-existent influence on toluene elimination.The mechanistic analysis showed that the forms of toluene and Hg^(0) removal included both adsorption and oxidation,where the high-valent metal cations and oxygen vacancy clusters promoted the redox cycle of Cr^(3+)+Mn^(3+)/Mn^(4+)+Cr^(6+)+Mn^(2+),which facilitated the conversion and replenishment of reactive oxygen species in the oxidation process,and even the CrMn_(1.5)O_(4) spinel structure could provide a larger catalytic interface,thus enhancing the adsorption/oxidation of toluene and Hg^(0).Therefore,its excellent physicochemical properties make it a costeffective potential industrial catalyst with outstanding synergistic toluene and Hg^(0) removal performance and preeminent resistance to H_(2)O and SO_(2).
基金supported by the SELECTVALUE project(2020-T1/AMB-19799,PI:J.J.L.)from the Community of Madrid,funded through the Talent Attraction Programfinancial support of the project RED2022-134552-T funded by MICIN/AEI/10.13039/501100011033financial support from“Comunidad de Madrid”to the project ADEMOSSBat(2022-T1/IND-23776)。
文摘Water scarcity,driven by climate change and population growth,necessitates innovative desalination technologies.Conventional methods for brackish water desalination are limited by high-energy demands,especially in the low salinity range,prompting the exploration of electrochemical approaches like faradaic deionization.Sodium-manganese oxides,traditionally used in sodium-ion batteries,show promise as faradaic deionization electrode materials due to their abundance,low toxicity,and cost-effectiveness.However,capacity fading during cycling,often caused by structural changes,volume expansion,or chemical transformations,remains a critical challenge.This study investigates the impact of morphology and crystal structure on the electrochemical performance of commercial and synthesized sodium-manganese oxides for faradaic deionization applications.Structural and electrochemical characterization in three-electrode cells with low-concentration electrolytes provided insights into the charge storage mechanisms.Rocking-chair full flow cell experiments demonstrated that the mixed-phase sodium-manganese oxide exhibited superior desalination performance,achieving a high salt removal capacity of 54.5 mg g^(−1)and a mean value in the salt removal rate of 1.49 mg g^(−1)min^(-1).Notably,mixed-phase sodium-manganese oxide maintained 98%capacity retention over 870 cycles,one of the longest reported cycling experiments in this field,effectively mitigating the Jahn-Teller effect.These findings highlight the crucial role of sodium-manganese oxide structure and morphology in electrochemical performance,positioning mixed-phase sodium-manganese oxide as a strong candidate for sustainable water treatment technologies.
基金supported by the National Science Foundation of China (Grant No.22179094)the Science and Technology Program of Cangzhou (Grant No.222103001)the research funding of Cangzhou Institute of Tiangong University (Grant No.TGCYY-Z0202)。
文摘P2-type layered oxides are highly promising cathode candidates for sodium-ion batteries(SIBs)owing to their substantial theoretical capacity.Nevertheless,structural degradation caused by transition metal dissolution and irreversible phase transitions at high voltage severely compromises cycling stability.To address this limitation,we propose a Li/Ti co-doping strategy to design a Na_(0.67)Li_(0.06)Ni_(0.27)Mn_(0.5)7Ti_(0.1)O_(2)(NLMT) cathode for SIBs.In-situ X-ray diffraction(XRD) confirms that this deliberate strategy eliminates the adverse phase transition at high voltage and sustains the unitary P2phase throughout cycling.In addition,strengthened transition metal-oxygen(TM-O) bonding via electronic modulation suppresses transition metal dissolution and reinforces the layered oxide framework,contributing to exceptional electrochemical performance.Consequently,the NLMT cathode exhibits an outstanding capacity of 92.8 mA h g^(-1) within 2.5-4.3 V at 5 C(865 mA g^(-1)),with 87 % capacity retention over 200 cycles.Configured into a full cell,which achieves a competitive capacity of 107.7 mA h g^(-1) at0.1 C and retains 86.4 % capacity over 100 cycles at 0.5 C.This study validates co-doping as a potent strategy for significantly improving the long-term cyclability of layered oxide cathodes in SIBs.
基金financial support from the National Natural Science Foundation of China(No.52201104)the Natural Science Foundation of Hunan Province(No.2023JJ40032)the Education Department of Hunan Province of China(No.24B0321).
文摘This study delved into the corrosion behavior of ZK60 Mg alloy in saturated NaCl solution,particularly focusing on the effects of the addition of rare earth oxide,namely CeO_(2)(forming ZKC alloy)and La_(2)O_(3)(forming ZKL alloy).The results indicate that the introduction of CeO_(2)and La_(2)O_(3)promotes the precipita-tion of T-(Mg_(1−x),Zn_(x))_(11)RE phases(Mg-Zn-RE phases,where RE represents Ce or La)at grain boundaries.The presence and distribution pattern of the T-phase have a profound impact on the corrosion resis-tance of the Mg alloy.Specifically,the ZKC alloy exhibits the most outstanding corrosion resistance.This superior performance is attributed to the uniform distribution of(Mg_(1−x),Zn_(x))_(11)Ce phase at grain bound-aries in ZK60-0.5 wt%CeO_(2),effectively hindering the penetration of corrosive media into the matrix.Additionally,scanning kelvin probe force microscopy(SKPFM)analysis reveals that the(Mg_(1−x),Zn_(x))_(11)Ce phase exhibits the smallest potential difference with the matrix,significantly mitigating the tendency for galvanic corrosion.In contrast,the ZKL alloy displays less precipitation and uneven distribution of the(Mg_(1−x),Zn_(x))_(11)La phase,resulting in inferior corrosion resistance compared to the ZKC alloy.The dispar-ities in the precipitation of the two phases,as derived from first-principles calculations,stem from the spontaneous reduction of CeO_(2)under Mg conditions,whereas the reduction reaction between La_(2)O_(3)and Mg cannot proceed spontaneously.Furthermore,SKPFM analysis and CALPHAD method found that as the addition of CeO_(2)/La_(2)O_(3)increases,the atomic ratio of Zn in the Mg-Zn-RE ternary phase rises,accompa-nied by an increase in the potential difference between the Mg-Zn-RE phase and the Mg matrix.This suggests that fine-tuning the addition of rare earth oxides can modify the atomic ratio of the Mg-Zn-RE ternary phase,thereby enhancing the corrosion resistance of the Mg alloy.In summary,this study not only unravels the specific mechanisms of how CeO_(2)and La_(2)O_(3)affect the corrosion behavior of ZK60 Mg alloy but also provides new strategies and insights for the development of low-cost,high-performance corrosion-resistant Mg alloy materials.
基金supported by National Natural Science Fundation of China(Nos.52170086,22308194,U22A20423)Natural Science Foundation of Shandong Province(No.ZR2021ME013)+1 种基金Taishan Scholars Program of Shandong Province(No.tsqn202211012)Shandong Provincial Excellent Youth(No.ZR2022YQ47)。
文摘Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation,they cannot be directly used for Fenton-like industrialization considering the problems of loss and recovery.Therefore,the membrane fixation of catalyst is an important step to realize the actual application of Fenton-like catalysts.In this work,an efficient catalyst was developed with Co-N_(x)configuration facilely reconstructed on the surface of Co_(3)O_(4)(Co-N_(x)/Co_(3)O_(4)),which exhibited superior catalytic activity.We further fixed the highly efficient Co-N_(x)/Co_(3)O_(4)onto three kinds of organic membranes and one kind of inorganic ceramic membrane installing with the residual PMS treatment device to investigate its catalytic stability and sustainability.Results indicated that the inorganic ceramic membrane(CM)can achieve high water flux of 710 L m-2h-1,and the similar water flux can be achieved by Co-N_(x)/Co_(3)O_(4)/CM even without the pressure extraction.We also employed the Co-N_(x)/Co_(3)O_(4)/CM system to the wastewater secondary effluent,and the pollutant in complicated secondary effluent could be highly removed by the Co-N_(x)/Co_(3)O_(4)/CM system.This paper provides a new point of view for the application of metal-based catalysts with M-N_(x)coordination in catalytic reaction device.
基金financially supported by the National Natural Science Foundation of China(No.52201173)the S&T Program of Hebei(No.22567627H)+3 种基金the Natural Science Foundation of Hebei Province(No.E2021501017)Henan key Laboratory of Aeronautical Materials and Application Technology Open fund(No.ZHKF-230113)Hebei Key Laboratory of Dielectric and Electrolyte Functional Material,Northeastern University at Qinhuangdao(HKDEFM2021301)the Fundamental Research Funds for the Central Universities(No.2024GFYD002,N2323021)
文摘A_(2)B_(2)O_(7)high-entropy oxides are ceramic materials characterized by diverse compositions,strong structural inclusivity,and a broad range of potential applications.These materials hold significant value in fields such as thermal barrier coatings,energy storage,dielectric materials,and transparent ceramics.However,there are limited reports on the dielectric properties of A_(2)B_(2)O_(7)high-entropy oxides.Consequently,further investigation is required to understand the polarization mechanisms in high-entropy ceramics and analyze the formation of oxygen vacancies and their influence.In the present study,La_(2)[(TiZrSnHfGe)_((1-2x)5)(NbGa)_(x)]_(2)O_(7)(x=0.129,0.143,0.157,0.171)(LTZSHGNGO)ceramics were synthesized successfully using a conventional solidstate reaction method.Compared withLa_(2)(TiZrSnHfGe)_(2)O_(7)ceramics,LTZSHGNGO demonstrated a nearly 6.7-fold increase in dielectric constant and a 33%reduction in dielectric loss.The incorporation of Nb/Ga enhanced the high-temperature dielectric properties and improved dielectric stability.The exceptional dielectric performance is primarily attributed to the synergistic highentropy effect,while Nb/Ga doping increased the number of oxygen vacancies and generated more defect dipole clusters[Ti^(4+)·e-V_(O)^(**)-Ti^(4+)·e].This study provides novel insights into the dielectric properties of LTZSHGNGO high-entropy ceramics and offers a novel approach to understanding the performance of A_(2)B_(2)O_(7)ceramics.
