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
In this work,a new ZnO/CoNiO_(2)/CoO/C metal oxides composite is prepared by cost-effective hydrothermal method coupled with annealing process under N_(2) atmosphere.Notably,the oxidation-defect annealing environment ...In this work,a new ZnO/CoNiO_(2)/CoO/C metal oxides composite is prepared by cost-effective hydrothermal method coupled with annealing process under N_(2) atmosphere.Notably,the oxidation-defect annealing environment is conducive to both morphology and component of the composite,which flower-like ZnO/CoNiO_(2)/CoO/C is obtained.Benefited from good chemical stability of ZnO,high energy capacity of CoNiO_(2) and CoO and good conductivity of C,the as-prepared sample shows promising electrochemical behavior,including the specific capacity of 1435 C·g^(-1) at 1 A·g^(-1),capacity retention of 87.3%at 20 A·g^(-1),and cycling stability of 90.5%for 3000 cycles at 5 A·g^(-1),respectively.Furthermore,the prepared ZnO/CoNiO_(2)/CoO/C/NF//AC aqueous hybrid supercapacitors device delivers the best specific energy of 55.9 W·h·kg^(-1) at 850 W·kg^(-1).The results reflect that the as-prepared ZnO/CoNiO_(2)/CoO/C microflowers are considered as high performance electrode materials for supercapacitor,and the strategy mentioned in this paper is benefit to prepare mixed metal oxides composite for energy conversion and storage.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
In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,...In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,especially at the interface between the semiconductor and cocatalyst,has received insufficient attention.In this study,we report a Co,Ni and Mn trimetallic fluoride-modified BVO photoanode featuring a unique interfacial chemical bond(V-F).Under AM 1.5 G illumination,an exciting photocurrent density of 6.05 mA cm^(-2)was achieved at 1.23 V vs.RHE by the integrated BVO/CoNi_(0.18)Mn_(0.12)(OH)_(x)F photoanode and over 98%of the initial photocurrent was maintained after 10 h of photoelectrolysis.Control experiments and theoretical calculations demonstrate that the V-F interfacial bond stabilizes the Co^(2+)active sites.It serves as a transmission gear,interlinking the migration of interfacial charge and the regeneration of cocatalyst,endowing the photoanode with significant activity and stability.Furthermore,we have systematically elucidated the role of the individual Co,Ni,and Mn components in the synergistic cocatalyst layer.The interfacial modification provides novel insights into developing advanced photoanodes towards PEC water splitting.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
Multi-metal porous crystalline materials(MPCM),integrating the functions of both multi-metal centres and porous crystalline materials(e.g.,metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)),are an ex...Multi-metal porous crystalline materials(MPCM),integrating the functions of both multi-metal centres and porous crystalline materials(e.g.,metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)),are an extended class of porous materials that have attracted much attention for a broad range of applications.Owing to the advantages of these materials,they generally display high porosity,multimetal active sites,well-tuned functions,and pre-designable structures,etc.,serving as desired platforms for the study of structure-property relationships.In view of the clean and sustainable target,a series of MPCM have been explored as electrocatalysts for electrocatalytic reactions like hydrogen evolution reaction,oxygen evolution reaction and electrocatalytic CO_(2)reduction reaction.Concerning the progress achieved for MPCM in electrocatalytic field during past years,this review will provide a brief introduction on the recent breakthrough of MPCM based electrocatalysts including their synthesis methods,structure design,component/morphology tuning,electrocatalytic property and structure-property relationship,etc.Besides,it will also conclude the current challenges and present perspectives for the MPCM based electrocatalysts,which might promote the development of porous crystalline materials in electrocatalysis and hope to provide new insights for scientists in related fields.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
The effect of Ce on the structure of MoVNbCeO multi-metal oxide catalysts and the performance of ethane selective oxidation was investigated.These multi-metal oxide catalysts with superior oxidizability exhibit high c...The effect of Ce on the structure of MoVNbCeO multi-metal oxide catalysts and the performance of ethane selective oxidation was investigated.These multi-metal oxide catalysts with superior oxidizability exhibit high catalytic activity,and vanadium acts as the active center for ethane oxidation reaction.The improved catalytic activity is related to the increased V^(5+) content on the catalyst surface,which results from the enhanced transformation of the electrons between V and Ce.Moreover,Ce effectively promotes oxygen adsorption,activation,and mobility.And the presence of Ce can also prevent MoO_(3) formation and stabilize the Mo_(5)O_(14)-like structure.In addition,the catalyst with a moderate amount of Ce exhibits outstanding catalytic performance.Especially,the MVN-Ce catalyst with a Ce/V ratio of 0.1 exhibits the best performance:the total selectivity of the catalyst toward C_(2)H_(4) and CH_(3) COOH is the highest(72%) at the ethane conversion of 31%.Therefore,MoVNbCeO multi-metal oxides are promising candidates for selective oxidation.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
Strategic design and synergistic interactions between the electrodes and electroactive materials profoundly influence the energy storage efficiency of supercapacitor devices. Herein, we present the interfacial enginee...Strategic design and synergistic interactions between the electrodes and electroactive materials profoundly influence the energy storage efficiency of supercapacitor devices. Herein, we present the interfacial engineering of CoMoS_(4)-NiS_(2) with a well-defined construction of amorphous/crystalline hetero-phases deposited on carbon cloth using a hydrothermal technique. The optimal in-situ growth of CoMoS_(4)-NiS_(2)@CFC boasts an impressive areal capacity of 1341 mC cm^(-2) and retains ∼91 % capacity after 5000 cycles, attributed to the synergy effect and improved conductivity of multi-metallic sulfide ions over the CFC substrate. Density functional theory (DFT) reveals the metallic nature of CoMoS_(4)-NiS_(2)@CFC and favorable OH- ion adsorption energy of -4.35 eV, enhancing its charge storage capabilities. Furthermore, a hybrid supercapacitor (HSC) and Pouch HSC are assembled utilizing the CoMoS_(4)-NiS_(2)@CFC as a positrode and marine waste jellyfish-derived AC as a negatrode with an aqueous electrolyte. The HSC and PHSC demonstrate superior specific energies of 51.99 and 58.4 W h kg^(-1), respectively, along with corresponding specific powers of 800 and 780 W kg^(-1), maintaining robust stability of ∼90 % stability over 10000 cycles. Additionally, the HSC and PHSC have successfully illuminated several light-emitting diodes (LEDs) demonstrating superior energy storage performance. This work advances the design of hetero-phase multi-metal sulfides, paving the way for high-performance supercapacitor devices.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
Morphology of zinc alloy layer,from zincate solution with zinc sulfate and zinc oxide respectively,together with the consequent deposit was observed with SEM and back scattering electron image.EDS was applied to analy...Morphology of zinc alloy layer,from zincate solution with zinc sulfate and zinc oxide respectively,together with the consequent deposit was observed with SEM and back scattering electron image.EDS was applied to analyze the components of zinc alloy layer and the interface of high-Si aluminum alloy substrate-zinc alloy-deposit.Besides,the surface morphology of the zincated aluminum alloy after immersing in 3.5%NaCl solution for 7 d,is observed and the corrosion rate was calculate.Finally,tension test is conducted to quantify the adhesion between high-Si aluminum cast substrate and the deposit.The results show that,the zinc oxide contained zincating solution with sodium potassium tartrate and sodium citrate is a better one in multi-metal zincating solutions.The zinc alloy layer from this one gets stable performance,perfect adhesion with deposit,and good corrosion resistance.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
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(22078215)Research Project by Shanxi Scholarship Council of China(2021-055)。
文摘In this work,a new ZnO/CoNiO_(2)/CoO/C metal oxides composite is prepared by cost-effective hydrothermal method coupled with annealing process under N_(2) atmosphere.Notably,the oxidation-defect annealing environment is conducive to both morphology and component of the composite,which flower-like ZnO/CoNiO_(2)/CoO/C is obtained.Benefited from good chemical stability of ZnO,high energy capacity of CoNiO_(2) and CoO and good conductivity of C,the as-prepared sample shows promising electrochemical behavior,including the specific capacity of 1435 C·g^(-1) at 1 A·g^(-1),capacity retention of 87.3%at 20 A·g^(-1),and cycling stability of 90.5%for 3000 cycles at 5 A·g^(-1),respectively.Furthermore,the prepared ZnO/CoNiO_(2)/CoO/C/NF//AC aqueous hybrid supercapacitors device delivers the best specific energy of 55.9 W·h·kg^(-1) at 850 W·kg^(-1).The results reflect that the as-prepared ZnO/CoNiO_(2)/CoO/C microflowers are considered as high performance electrode materials for supercapacitor,and the strategy mentioned in this paper is benefit to prepare mixed metal oxides composite for energy conversion and storage.
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.
文摘In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,especially at the interface between the semiconductor and cocatalyst,has received insufficient attention.In this study,we report a Co,Ni and Mn trimetallic fluoride-modified BVO photoanode featuring a unique interfacial chemical bond(V-F).Under AM 1.5 G illumination,an exciting photocurrent density of 6.05 mA cm^(-2)was achieved at 1.23 V vs.RHE by the integrated BVO/CoNi_(0.18)Mn_(0.12)(OH)_(x)F photoanode and over 98%of the initial photocurrent was maintained after 10 h of photoelectrolysis.Control experiments and theoretical calculations demonstrate that the V-F interfacial bond stabilizes the Co^(2+)active sites.It serves as a transmission gear,interlinking the migration of interfacial charge and the regeneration of cocatalyst,endowing the photoanode with significant activity and stability.Furthermore,we have systematically elucidated the role of the individual Co,Ni,and Mn components in the synergistic cocatalyst layer.The interfacial modification provides novel insights into developing advanced photoanodes towards PEC water splitting.
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.2023YFA1507204)the National Natural Science Foundation of China(Nos.22171139,22225109,22309054,22071109,22371080,21775048)+2 种基金Natural Science Foundation of Guangdong Province(No.2023B1515020076)China Postdoctoral Science Foundation(No.2023M731154)China National Postdoctoral Program for Innovative Talents(No.BX20220116)。
文摘Multi-metal porous crystalline materials(MPCM),integrating the functions of both multi-metal centres and porous crystalline materials(e.g.,metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)),are an extended class of porous materials that have attracted much attention for a broad range of applications.Owing to the advantages of these materials,they generally display high porosity,multimetal active sites,well-tuned functions,and pre-designable structures,etc.,serving as desired platforms for the study of structure-property relationships.In view of the clean and sustainable target,a series of MPCM have been explored as electrocatalysts for electrocatalytic reactions like hydrogen evolution reaction,oxygen evolution reaction and electrocatalytic CO_(2)reduction reaction.Concerning the progress achieved for MPCM in electrocatalytic field during past years,this review will provide a brief introduction on the recent breakthrough of MPCM based electrocatalysts including their synthesis methods,structure design,component/morphology tuning,electrocatalytic property and structure-property relationship,etc.Besides,it will also conclude the current challenges and present perspectives for the MPCM based electrocatalysts,which might promote the development of porous crystalline materials in electrocatalysis and hope to provide new insights for scientists in related fields.
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Project supported by Petro China Innovation Foundation(2019D-5007-0404)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2017460)。
文摘The effect of Ce on the structure of MoVNbCeO multi-metal oxide catalysts and the performance of ethane selective oxidation was investigated.These multi-metal oxide catalysts with superior oxidizability exhibit high catalytic activity,and vanadium acts as the active center for ethane oxidation reaction.The improved catalytic activity is related to the increased V^(5+) content on the catalyst surface,which results from the enhanced transformation of the electrons between V and Ce.Moreover,Ce effectively promotes oxygen adsorption,activation,and mobility.And the presence of Ce can also prevent MoO_(3) formation and stabilize the Mo_(5)O_(14)-like structure.In addition,the catalyst with a moderate amount of Ce exhibits outstanding catalytic performance.Especially,the MVN-Ce catalyst with a Ce/V ratio of 0.1 exhibits the best performance:the total selectivity of the catalyst toward C_(2)H_(4) and CH_(3) COOH is the highest(72%) at the ethane conversion of 31%.Therefore,MoVNbCeO multi-metal oxides are promising candidates for selective oxidation.
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 Technology Devel-opment Program(No.S3218794)funded by the Ministry of SMEs and Startups(MSS,Korea)supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by the Min-istry of Science and ICT(No.RS-2024-00446825).
文摘Strategic design and synergistic interactions between the electrodes and electroactive materials profoundly influence the energy storage efficiency of supercapacitor devices. Herein, we present the interfacial engineering of CoMoS_(4)-NiS_(2) with a well-defined construction of amorphous/crystalline hetero-phases deposited on carbon cloth using a hydrothermal technique. The optimal in-situ growth of CoMoS_(4)-NiS_(2)@CFC boasts an impressive areal capacity of 1341 mC cm^(-2) and retains ∼91 % capacity after 5000 cycles, attributed to the synergy effect and improved conductivity of multi-metallic sulfide ions over the CFC substrate. Density functional theory (DFT) reveals the metallic nature of CoMoS_(4)-NiS_(2)@CFC and favorable OH- ion adsorption energy of -4.35 eV, enhancing its charge storage capabilities. Furthermore, a hybrid supercapacitor (HSC) and Pouch HSC are assembled utilizing the CoMoS_(4)-NiS_(2)@CFC as a positrode and marine waste jellyfish-derived AC as a negatrode with an aqueous electrolyte. The HSC and PHSC demonstrate superior specific energies of 51.99 and 58.4 W h kg^(-1), respectively, along with corresponding specific powers of 800 and 780 W kg^(-1), maintaining robust stability of ∼90 % stability over 10000 cycles. Additionally, the HSC and PHSC have successfully illuminated several light-emitting diodes (LEDs) demonstrating superior energy storage performance. This work advances the design of hetero-phase multi-metal sulfides, paving the way for high-performance supercapacitor devices.
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This work is financially supported by the Foundation of Basic Research of Harbin Engineering Universi-ty(HEUFT06030)
文摘Morphology of zinc alloy layer,from zincate solution with zinc sulfate and zinc oxide respectively,together with the consequent deposit was observed with SEM and back scattering electron image.EDS was applied to analyze the components of zinc alloy layer and the interface of high-Si aluminum alloy substrate-zinc alloy-deposit.Besides,the surface morphology of the zincated aluminum alloy after immersing in 3.5%NaCl solution for 7 d,is observed and the corrosion rate was calculate.Finally,tension test is conducted to quantify the adhesion between high-Si aluminum cast substrate and the deposit.The results show that,the zinc oxide contained zincating solution with sodium potassium tartrate and sodium citrate is a better one in multi-metal zincating solutions.The zinc alloy layer from this one gets stable performance,perfect adhesion with deposit,and good corrosion resistance.
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).
