Experts and officials shared their insights on poverty reduction cooperation and sustainable development during the 2025 International Seminar on Global Poverty Reduction Partnerships.
Controllable synthesis of ultrathin metallene nanosheets and rational design of their spatial arrangement in favor of electrochemical catalysis are critical for their renewable energy applications.Here,a biomimetic de...Controllable synthesis of ultrathin metallene nanosheets and rational design of their spatial arrangement in favor of electrochemical catalysis are critical for their renewable energy applications.Here,a biomimetic design of“Trunk-Branch-Leaf”strategy is proposed to prepare the ultrathin edge-riched Zn-ene“leaves”with a thickness of~2.5 nm,adjacent Zn-ene cross-linked with each other,which are supported by copper nanoneedle“branches”on copper mesh“trunks,”named as Zn-ene/Cu-CM.The resulting superstructure enables the formation of an interconnected network and multiple channels,which can be used as an electrocatalytic CO_(2) reduction reaction(CO_(2)RR)electrode to allow a fast charge and mass transfer as well as a large electrolyte reservoir.By virtue of the distinctive structure,the obtained Zn-ene/Cu-CM electrode exhibits excellent selectivity and activity toward CO production with a maximum Faradaic efficiency of 91.3%and incredible partial current density up to 40 mA cm^(−2),outperforming most of the state-of-the-art Zn-based electrodes for CO_(2) reduction.The phenolphthalein color probe combined with in situ attenuated total reflection-infrared spectroscopy uncovered the formation of the localized pseudo-alkaline microenvironment at the interface of the Zn-ene/Cu-CM electrode.Theoretical calculations confirmed that the localized pH as the origin is responsible for the adsorption of CO_(2) at the interface and the generation of *COOH and *CO intermediates.This study offers valuable insights into developing efficient electrodes through synergistic regulation of reaction microenvironments and active sites,thereby facilitating the electrolysis of practical CO_(2) conversion.展开更多
The development of Pt-free catalysts for the oxygen reduction reaction(ORR)is a great issue for meeting the cost challenges of proton exchange membrane fuel cells(PEMFCs)in commercial applications.In this work,a serie...The development of Pt-free catalysts for the oxygen reduction reaction(ORR)is a great issue for meeting the cost challenges of proton exchange membrane fuel cells(PEMFCs)in commercial applications.In this work,a series of RuCo/C catalysts were synthesized by NaBH4 reduction method under the premise that the total metal mass percentage was 20%.X-ray diffraction(XRD)patterns and scanning electron microscopy(SEM)confirmed the formation of single-phase nanoparticles with an average size of 33 nm.Cyclic voltammograms(CV)and linear sweep voltammograms(LSV)tests indicated that RuCo(2:1)/C catalyst had the optimal ORR properties.Additionally,the RuCo(2:1)/C catalyst remarkably sustained 98.1% of its activity even after 3000 cycles,surpassing the performance of Pt/C(84.8%).Analysis of the elemental state of the catalyst surface after cycling using X-ray photoelectron spectroscopy(XPS)revealed that the Ru^(0) percentage of RuCo(2:1)/C decreased by 2.2%(from 66.3% to 64.1%),while the Pt^(0) percentage of Pt/C decreased by 7.1%(from 53.3% to 46.2%).It is suggested that the synergy between Ru and Co holds the potential to pave the way for future low-cost and highly stable ORR catalysts,offering significant promise in the context of PEMFCs.展开更多
Heteroatom-doped carbon is considered a promising alternative to commercial Pt/C as an efficient catalyst for the oxygen reduction reaction(ORR).This study presents the synthesis of iron-loaded,sulfur and nitrogen co-...Heteroatom-doped carbon is considered a promising alternative to commercial Pt/C as an efficient catalyst for the oxygen reduction reaction(ORR).This study presents the synthesis of iron-loaded,sulfur and nitrogen co-doped carbon(Fe/SNC)via in situ incorporation of 2-aminothiazole molecules into zeolitic imidazolate framework-8(ZIF-8)through coordination between metal ions and organic ligands.Sulfur and nitrogen doping in carbon supports effectively modulates the electronic structure of the catalyst,increases the Brunauer-Emmett-Teller surface area,and exposes more Fe-N_(x)active centers.Fe-loaded,S and N co-doped carbon with Fe/S molar ratio of 1:10(Fe/SNC-10)exhibits a half-wave potential of 0.902 V vs.RHE.After 5000 cycles of cyclic voltammetry,its half-wave potential decreases by only 20 mV vs.RHE,indicating excellent stability.Due to sulfur s lower electronegativity,the electronic structure of the Fe-N_(x)active center is modulated.Additionally,the larger atomic radius of sulfur introduces defects into the carbon support.As a result,Fe/SNC-10 demonstrates superior ORR activity and stability in alkaline solution compared with Fe-loaded N-doped carbon(Fe/NC).Furthermore,the zinc-air battery assembled with the Fe/SNC-10 catalyst shows enhanced performance relative to those assembled with Fe/NC and Pt/C catalysts.This work offers a novel design strategy for advanced energy storage and conversion applications.展开更多
Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespr...Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.展开更多
Seawater zinc-air batteries are promising energy storage devices due to their high energy density and utilization of seawater electrolytes.However,their efficiency is hindered by the sluggish oxygen reduction reaction...Seawater zinc-air batteries are promising energy storage devices due to their high energy density and utilization of seawater electrolytes.However,their efficiency is hindered by the sluggish oxygen reduction reaction(ORR)and chlorideinduced degradation over conventional catalysts.In this study,we proposed a universal synthetic strategy to construct heteroatom axially coordinated Fe–N_(4) single-atom seawater catalyst materials(Cl–Fe–N_(4) and S–Fe–N_(4)).X-ray absorption spectroscopy confirmed their five-coordinated square pyramidal structure.Systematic evaluation of catalytic activities revealed that compared with S–Fe–N_(4),Cl–Fe–N_(4) exhibits smaller electrochemical active surface area and specific surface area,yet demonstrates higher limiting current density(5.8 mA cm^(−2)).The assembled zinc-air batteries using Cl–Fe–N_(4) showed superior power density(187.7 mW cm^(−2) at 245.1 mA cm^(−2)),indicating that Cl axial coordination more effectively enhances the intrinsic ORR activity.Moreover,Cl–Fe–N_(4) demonstrates stronger Cl−poisoning resistance in seawater environments.Chronoamperometry tests and zinc-air battery cycling performance evaluations confirmed its enhanced stability.Density functional theory calculations revealed that the introduction of heteroatoms in the axial direction regulates the electron center of Fe single atom,leading to more active reaction intermediates and increased electron density of Fe single sites,thereby enhancing the reduction in adsorbed intermediates and hence the overall ORR catalytic activity.展开更多
Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when ta...Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when tackling high-dimensional optimization challenges.To effectively address these challenges,this study introduces cooperative metaheuristics integrating dynamic dimension reduction(DR).Building upon particle swarm optimization(PSO)and differential evolution(DE),the proposed cooperative methods C-PSO and C-DE are developed.In the proposed methods,the modified principal components analysis(PCA)is utilized to reduce the dimension of design variables,thereby decreasing computational costs.The dynamic DR strategy implements periodic execution of modified PCA after a fixed number of iterations,resulting in the important dimensions being dynamically identified.Compared with the static one,the dynamic DR strategy can achieve precise identification of important dimensions,thereby enabling accelerated convergence toward optimal solutions.Furthermore,the influence of cumulative contribution rate thresholds on optimization problems with different dimensions is investigated.Metaheuristic algorithms(PSO,DE)and cooperative metaheuristics(C-PSO,C-DE)are examined by 15 benchmark functions and two engineering design problems(speed reducer and composite pressure vessel).Comparative results demonstrate that the cooperative methods achieve significantly superior performance compared to standard methods in both solution accuracy and computational efficiency.Compared to standard metaheuristic algorithms,cooperative metaheuristics achieve a reduction in computational cost of at least 40%.The cooperative metaheuristics can be effectively used to tackle both high-dimensional unconstrained and constrained optimization problems.展开更多
Chiral compounds have a huge market demand in the fields of pharmaceuticals,pesticides,and fine chemicals.Enzymatic electrosynthesis can couple enzyme catalysis,possessing high product purity,high efficiency,and mild ...Chiral compounds have a huge market demand in the fields of pharmaceuticals,pesticides,and fine chemicals.Enzymatic electrosynthesis can couple enzyme catalysis,possessing high product purity,high efficiency,and mild conditions,with electrochemical regeneration of expensive cofactor nicotinamide adenine dinucleotide(NADH),possessing easy process monitoring and simple operation for efficient chiral synthesis.In this study,hydrophobic covalent organic framework(COF)was synthesized as the immobilized carrier,which not only enhanced the enzyme catalysis through enriching substrate but also enhanced the stability and reuse of the enzyme.Besides,Rh complex was anchored on hydrophilically-modified electrode to promote the regeneration of NADH,where the anchor of Rh complex can effectively avoid the mutual deactivation from the interference between electron mediator and enzyme,and simplify the separation of products.The immobilized enzyme catalysis and the electrochemical cofactor regeneration were coupled to construct an enzymatic electrosynthesis system for the efficient asymmetric reduction to obtain chiral alcohols,with a maximum turnover frequency(TOF)of 101.1 h^(-1).Furthermore,the relevant parameters of the system were optimized,and the substrate scope was expanded.展开更多
The oxygen reduction reaction(ORR)critical for electrochemical energy conversion systems suffers from sluggish kinetics and high overpotentials that hinder the efficiency of these technologies.Herein,a curvature-domin...The oxygen reduction reaction(ORR)critical for electrochemical energy conversion systems suffers from sluggish kinetics and high overpotentials that hinder the efficiency of these technologies.Herein,a curvature-dominated microenvironment modulation strategy is demonstrated to enhance ORR performance via engineering a helical hollow carbon nanotube with embedded sub-nanometer tungsten nitride(W_(2)N)clusters.This architecture yields optimized electrostatic field distributions and reduced d-band center of W_(2)N,thereby promoting the enrichment of OH-,the adsorption of oxygen,and the desorption of oxygen intermediates(OH).The catalyst shows remarkable ORR activity with a high onset potential of 1.00 V and a half-wave potential of 0.89 V,outperforming both Pt/C and other W_(2)N-based catalysts.Theoretical calculations verify that the curved support enhances the electron delocalization within the W_(2)N clusters,regulating the interaction between the catalyst and reactants.Our findings establish a general design principle of curvature-induced microenvironment modulation and offer a new pathway toward designing efficient electrocatalysts for sustainable energy storage applications.展开更多
Photocatalytic carbon dioxide(CO_(2))reduction offers an alternative strategy for converting CO_(2)into high-value added gaseous fuels,thereby paving the way for the development of clean and renewable energy.Metal-org...Photocatalytic carbon dioxide(CO_(2))reduction offers an alternative strategy for converting CO_(2)into high-value added gaseous fuels,thereby paving the way for the development of clean and renewable energy.Metal-organic frameworks(MOFs),characterized by their highly porous structure,exceptional CO_(2)adsorption capacity,and tunable architecture,have emerged as promising candidates for photocatalytic CO_(2)reduction.This review systematically examines the recent advancement in MOFs-based photocatalysts for CO_(2)reduction to CO.It begins with the overview of the fundamental mechanisms and processes of MOFs towards photocatalytic CO_(2)reduction.Subsequently,common strategies for the modulation of MOFs-based photocatalysts are summarized,including metallic site modification,functionalized ligand incorporation,morphological control,defect engineering,and heterostructure construction.Notably,the review analyzes the critical factors contributing to the high selectivity of CO_(2)photoreduction to CO from both thermodynamic and kinetic perspectives.The conclusion addresses current challenges and future perspectives in designing highly efficient photocatalysts with abundant active sites,providing valuable insights for their continued development.展开更多
Single-atom catalysts(SACs)have garnered tremendous and continuous attention in photocatalytic CO_(2)reduction reactions(CO_(2)RR),due to their compelling potential in broadening the light-harvesting range,elevating t...Single-atom catalysts(SACs)have garnered tremendous and continuous attention in photocatalytic CO_(2)reduction reactions(CO_(2)RR),due to their compelling potential in broadening the light-harvesting range,elevating the charge separation/transfer efficiency,and enhancing surface reaction.Despite the surge in research and the expanding range of potential central metal candidates—including d-block,p-block,and rare metal elements,etc.—the comprehension of the structure-function relationships between the central metal and its performance remains elusive.Hence,categorized by different areas of the central metal element from periodic table,we outline the recent progress and challenges on SACs for photocatalytic CO_(2)RR.We begin by describing various synthetic strategies employed for SACs.Subsequently,a clear classification of the SACs applications in photocatalytic CO_(2)RR is provided,according to the central metal elements in different blocks of the periodic table.We also discussed how isolated metal single-atom sites from different blocks of the periodic table improve the performance of photocatalytic CO_(2)reduction from the perspective of charge separation and transfer.Finally,we end this review with some perspectives and challenges associated with SACs for photocatalytic CO_(2)reduction.Through this review,we aim to enrich the element diversity of SACs for photocatalytic CO_(2)RR,reveal trends in element evolution,and propose directions for future development in this flourishing field.展开更多
Accelerated industrialization combined with over-applied nitrogen fertilizers results in serious nitrate pollution insurface and ground water,disrupting the balance of the global nitrogen cycle.Electrochemical nitrate...Accelerated industrialization combined with over-applied nitrogen fertilizers results in serious nitrate pollution insurface and ground water,disrupting the balance of the global nitrogen cycle.Electrochemical nitrate reduction(eNO_(3)RR)emerges as an attractive strategy to simultaneously enable nitrate removal and decentralized ammo-nia fabrication,restoring the globally perturbed nitrogen cycle.However,complex deoxygenation-hydrogenationprocesses and sluggish proton-electron transfer kinetics significantly hinder practical application of eNO_(3)RR.In this study,we developed carbon-coated Cu-Ni bimetallic catalysts derived from metal-organic frameworks(MOFs)to facilitate eNO_(3)RR.The unique structural features of catalyst promote enhanced synergy between Cuand Ni,effectively addressing critical challenges in nitrate reduction.Comprehensive structural and electrochem-ical analysis demonstrate that electrochemical nitrate-to-nitrite conversion mainly takes place on active Cu sites,the introduction of Ni could efficiently accelerate the generation of aquatic active hydrogen,promoting the hy-drogenation of oxynitrides during eNO_(3)RR.In addition,Ni introduction could push up the d-band center of thecatalyst,thus enhancing the adsorption and activation of nitrate and the corresponding intermediates.Detailedreaction pathways for nitrate-to-ammonia conversion are illuminated by rotating disk electrode(RDE),in-situFourier-transform infrared spectroscopy,in-situ Raman spectrum and electrochemical impedance spectroscopy(EIS).Benefiting from the synergistic effect of Cu and Ni,optimum catalyst exhibited excellent nitrate reductionperformance.This work provides a new idea for elucidating the underlying eNO_(3)RR reaction mechanisms andcontributes a promising strategy for designing efficient bimetallic electrocatalysts.展开更多
Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(...Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.展开更多
Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)into value-added products has been regarded as an effective way to achieve the goal of carbon neutrality.The intrinsic activity of electrocatalysts,as well as the rea...Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)into value-added products has been regarded as an effective way to achieve the goal of carbon neutrality.The intrinsic activity of electrocatalysts,as well as the reaction microenvironment,play an important role in improving the conversion efficiency of CO_(2).Herein,we report an ionic liquidfunctionalized Au/Pd heterostructure as the electrocatalyst for CO_(2)RR via introducing 1-butyl-1-methylpyrrolidine bis(trifluoromethylsulfonyl)imide([BMPyrr][NTf_(2)])ionic liquid.Au nanoclusters are epitaxially confined on Pd nanosheets in heterostructure,resulting in abundant and well-defined heterointerfaces that work as highly active catalytic sites.Notably,the[BMPyrr][NTf_(2)]achieves charge redistribution at the Au-Pd heterointerfaces,which helps to stabilize*CO_(2)^(˙-)intermediate and further reduce the energy barrier of *COOH formation.Furthermore,the[BMPyrr][NTf_(2)]molecules with high CO_(2)adsorption ability is beneficial to construct a CO_(2)-rich reaction microenvironment at the gas-liquid-solid three-phase interface.The hybrid electrocatalyst exhibits greatly improved CO Faradaic efficiency in a broad potential range and CO partial current density.This work provides a novel strategy for designing robust CO_(2)RR electrocatalysts via ionic liquid-mediated surface modification.展开更多
While thermal air exfoliation is widely used to prepare graphitic carbon nitride(g-C_(3)N_(4))nanosheets,the effects of calcination conditions and atmosphere on their electronic structure and photocatalytic CO_(2)redu...While thermal air exfoliation is widely used to prepare graphitic carbon nitride(g-C_(3)N_(4))nanosheets,the effects of calcination conditions and atmosphere on their electronic structure and photocatalytic CO_(2)reduction reaction(CO_(2)RR)performance remain systematically unexplored.We prepared g-C_(3)N_(4)nanosheets with varying thickness and defects by controlling exfoliation parameters.The obtained nanosheets calcined longest in air exhibited highest CO_(2)RR activity,twice that of bulk g-C_(3)N_(4).The comprehensive analysis of structural characterizations indicates the thickness of g-C_(3)N_(4)nanosheets became thinner,and the defects increased as the calcination time increased.The N vacancies(N_(v))and O-doping caused by N_(2) and O_(2)from air,respectively,enable valence band elevation(N_(v))and conduction band depression(O-doping)that collectively redistribute the electronic structure.Nitrogen/oxygen dual-defects generated impurity levels,reduced the work function and band gap of g-C_(3)N_(4)nanosheets,and served as shallow traps for photogenerated e^(-).The results of in-situ spectroscopy indicate these increased effective e^(-)are enriched around of N atoms to react with the adsorbed CO_(2).During the CO_(2)reduction process,the N_(v) promoted the formation of*COOH,and this dual-defect co-promoted the*CO desorption,resulting in the improved CO_(2)RR activity.These results comprehensively analyze the regulatory effect of thermal air calcination on the electronic structure of g-C_(3)N_(4),providing valuable insights for designing g-C_(3)N_(4)nanosheets based photocatalysts for CO_(2)RR.展开更多
This letter introduces the novel concept of Painlevé solitons—waves arising from the interaction between Painlevé waves and solitons in integrable systems.Painlevé solitons can also be viewed as solito...This letter introduces the novel concept of Painlevé solitons—waves arising from the interaction between Painlevé waves and solitons in integrable systems.Painlevé solitons can also be viewed as solitons propagating against a Painlevé wave background,in analogy to the established notion of elliptic solitons,which refers to solitons on an elliptic wave background.By employing a novel symmetry decomposition method aided by nonlocal residual symmetries,we explicitly construct (extended) Painlevé Ⅱ solitons for the Korteweg-de Vries equation and (extended) Painlevé Ⅳ solitons for the Boussinesq equation.展开更多
It is an important way to realize low carbon in China’s iron and steel industry by hydrogen-rich blast furnace smelting process.Sinter is the main blast furnace burden,and its reduction characteristics have a signifi...It is an important way to realize low carbon in China’s iron and steel industry by hydrogen-rich blast furnace smelting process.Sinter is the main blast furnace burden,and its reduction characteristics have a significant influence on ironmaking.The reduction behaviors,including reduction index(RI)and low-temperature reduction disintegration index(RDI),and the reduction mechanism of sinter in hydrogen-rich blast furnace were investigated.The results show that RI increased from 82.85 to 95.53 wt.%with an increase in H_(2)content from 0 to 30 vol.%,and the main phase of the reduction product was metallic iron.In the research of RDI,when the H_(2)content was increased from 0 to 20 vol.%,RDI+3.15 increased from 69.61 to 75.38 wt.%,and the main reaction was the reduction of hematite to magnetite.At 600-950℃,the reduction of sinter in CO and hydrogen-rich atmospheres(H_(2):CO=2)was both controlled by the first-order reaction model,and the apparent activation energy was 33.64 and 44.57 kJ/mol,respectively.展开更多
To recover the valuable elements in Bayan Obo tailings,Fe-Si bath smelting reduction was adopted to separate and enrich rare earth elements(REE),niobium and titanium from the REE-Nb-Ti-containing slag.The reduction re...To recover the valuable elements in Bayan Obo tailings,Fe-Si bath smelting reduction was adopted to separate and enrich rare earth elements(REE),niobium and titanium from the REE-Nb-Ti-containing slag.The reduction reaction process of the Fe-Si bath and the migration behavior of valuable elements in the solidification and crystallization process of silicothermic reduction tailings were investigated,and a treatment method for efficiently separating and enriching REE,Nb and Ti was explored.Thermodynamic analysis indicated that at 1600℃,with a 6 wt.%addition of Si as the reducing agent,the niobium oxide in the REE-Nb-Ti-containing slag could be selectively reduced to metallic Nb.In the Fe-Si bath reduction process,the Nb mass fraction in the metal phase increased with prolonged reaction time,peaking at 2.77%,while the Ti mass fraction consistently stayed below 0.12%.Lowering the w(CaO)/w(SiO_(2))enhanced the migration of Nb from slag to metal phase and reduced the Ti impurities.During solidification and crystallization,a significant quantity of perovskite precipitated from reduction tailings,with the REE dissolving into this perovskite.By adjusting the w(CaO)/w(SiO_(2))in tailings to 1.2-1.9 and maintaining a temperature of 1100℃for 4 h,the perovskite area fraction in the final slag could exceed 37%.Finally,a method was proposed to separate and enrich valuable elements in REE-Nb-Ti-containing slags via Fe-Si bath smelting reduction and crystallization control.展开更多
The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large de...The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large deformation during the LCR process and to minimize the thickness of the slab in bending segments,the maximum theoretical reduction amount and the corresponding reduction scheme for the LCR process must be determined.With SPA-H weathering steel as a specific research steel grade,the distributions of tem-perature and deformation fields of a slab with the LCR process were analyzed using a three-dimensional thermal-mechanical finite ele-ment model.High-temperature tensile tests were designed to determine the critical strain of corner crack propagation and intermediate crack initiation with various strain rates and temperatures,and a prediction model of the critical strain for two typical cracks,combining the effects of strain rate and temperature,was proposed by incorporating the Zener-Hollomon parameter.The crack risks with different LCR schemes were calculated using the crack risk prediction model,and the maximum theoretical reduction amount for the SPA-H slab with a transverse section of 145 mm×1600 mm was 41.8 mm,with corresponding reduction amounts for Segment 0 to Segment 4 of 15.8,7.3,6.5,6.4,and 5.8 mm,respectively.展开更多
The electrochemical conversion of nitrate,a widespread water pollutant,into valuable ammonia represents a green and decentralized approach to ammonia synthesis.However,the sluggish multielectronproton coupling path an...The electrochemical conversion of nitrate,a widespread water pollutant,into valuable ammonia represents a green and decentralized approach to ammonia synthesis.However,the sluggish multielectronproton coupling path and the low reactive species(nitrate and proton)concentration at the catalyst interface inhibit the efficiency of ammonia production from nitrate reduction reaction(NitRR).Herein,we introduce a novel iron-based tandem catalyst encapsulated by reduced graphene oxide(denoted as Fe-rGO),with a superior ammonia production rate of 47.815 mg h^(-1)mg_(ca)^(t-1)and a high Faraday efficiency(FE)of 96.51%at an applied potential of-0.5 V.It also delivers a robust stability with FE above90%under a current density of 250 mA cm^(-2)for 50 h.In situ X-ray absorption spectroscopy reveals that the FeO_(x)is dynamically translated to Fe~0 site concurrently with the enhancement of the NH_(3)production rate,suggesting the Fe^(0) site as hydrogenation active center.The asymmetric distribution of surface charges of rGO not only enriches nitrate ions at the catalytic interface and promotes the hydrogenation process in NitRR,but also protects the iron species and ensures their stability during electrolysis.The Zn-NO_(3)^(-)battery demonstrates an impressive FE of 88.6%,highlighting its exceptional potential for practical applications.展开更多
文摘Experts and officials shared their insights on poverty reduction cooperation and sustainable development during the 2025 International Seminar on Global Poverty Reduction Partnerships.
基金supports of the National Natural Science Foundation of China(NSFC)(52021004,52394202)key project of the Joint Fund for Innovation and Development of Chongqing Natural Science Foundation(CSTB2022NSCQ-LZX0013)+1 种基金the National Natural Science Foundation of China(NSFC)(52301232,and 52476056)the Natural Science Foundation of Chongqing Province(2024NSCQ-MSX1109).
文摘Controllable synthesis of ultrathin metallene nanosheets and rational design of their spatial arrangement in favor of electrochemical catalysis are critical for their renewable energy applications.Here,a biomimetic design of“Trunk-Branch-Leaf”strategy is proposed to prepare the ultrathin edge-riched Zn-ene“leaves”with a thickness of~2.5 nm,adjacent Zn-ene cross-linked with each other,which are supported by copper nanoneedle“branches”on copper mesh“trunks,”named as Zn-ene/Cu-CM.The resulting superstructure enables the formation of an interconnected network and multiple channels,which can be used as an electrocatalytic CO_(2) reduction reaction(CO_(2)RR)electrode to allow a fast charge and mass transfer as well as a large electrolyte reservoir.By virtue of the distinctive structure,the obtained Zn-ene/Cu-CM electrode exhibits excellent selectivity and activity toward CO production with a maximum Faradaic efficiency of 91.3%and incredible partial current density up to 40 mA cm^(−2),outperforming most of the state-of-the-art Zn-based electrodes for CO_(2) reduction.The phenolphthalein color probe combined with in situ attenuated total reflection-infrared spectroscopy uncovered the formation of the localized pseudo-alkaline microenvironment at the interface of the Zn-ene/Cu-CM electrode.Theoretical calculations confirmed that the localized pH as the origin is responsible for the adsorption of CO_(2) at the interface and the generation of *COOH and *CO intermediates.This study offers valuable insights into developing efficient electrodes through synergistic regulation of reaction microenvironments and active sites,thereby facilitating the electrolysis of practical CO_(2) conversion.
基金Funded by the 111 Project(No.B17034)Open Project of Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle(No.ZDSYS202212)+1 种基金Innovative Research Team Development Program of Ministry of Education of China(No.IRT_17R83)the Science and Technology Project of China Southern Power Grid Co.,Ltd.(No.GDKJXM20222546)。
文摘The development of Pt-free catalysts for the oxygen reduction reaction(ORR)is a great issue for meeting the cost challenges of proton exchange membrane fuel cells(PEMFCs)in commercial applications.In this work,a series of RuCo/C catalysts were synthesized by NaBH4 reduction method under the premise that the total metal mass percentage was 20%.X-ray diffraction(XRD)patterns and scanning electron microscopy(SEM)confirmed the formation of single-phase nanoparticles with an average size of 33 nm.Cyclic voltammograms(CV)and linear sweep voltammograms(LSV)tests indicated that RuCo(2:1)/C catalyst had the optimal ORR properties.Additionally,the RuCo(2:1)/C catalyst remarkably sustained 98.1% of its activity even after 3000 cycles,surpassing the performance of Pt/C(84.8%).Analysis of the elemental state of the catalyst surface after cycling using X-ray photoelectron spectroscopy(XPS)revealed that the Ru^(0) percentage of RuCo(2:1)/C decreased by 2.2%(from 66.3% to 64.1%),while the Pt^(0) percentage of Pt/C decreased by 7.1%(from 53.3% to 46.2%).It is suggested that the synergy between Ru and Co holds the potential to pave the way for future low-cost and highly stable ORR catalysts,offering significant promise in the context of PEMFCs.
基金financial support of the National Natural Science Foundation of China(No.52472271)the National Key Research and Development Program of China(No.2023YFE0115800)。
文摘Heteroatom-doped carbon is considered a promising alternative to commercial Pt/C as an efficient catalyst for the oxygen reduction reaction(ORR).This study presents the synthesis of iron-loaded,sulfur and nitrogen co-doped carbon(Fe/SNC)via in situ incorporation of 2-aminothiazole molecules into zeolitic imidazolate framework-8(ZIF-8)through coordination between metal ions and organic ligands.Sulfur and nitrogen doping in carbon supports effectively modulates the electronic structure of the catalyst,increases the Brunauer-Emmett-Teller surface area,and exposes more Fe-N_(x)active centers.Fe-loaded,S and N co-doped carbon with Fe/S molar ratio of 1:10(Fe/SNC-10)exhibits a half-wave potential of 0.902 V vs.RHE.After 5000 cycles of cyclic voltammetry,its half-wave potential decreases by only 20 mV vs.RHE,indicating excellent stability.Due to sulfur s lower electronegativity,the electronic structure of the Fe-N_(x)active center is modulated.Additionally,the larger atomic radius of sulfur introduces defects into the carbon support.As a result,Fe/SNC-10 demonstrates superior ORR activity and stability in alkaline solution compared with Fe-loaded N-doped carbon(Fe/NC).Furthermore,the zinc-air battery assembled with the Fe/SNC-10 catalyst shows enhanced performance relative to those assembled with Fe/NC and Pt/C catalysts.This work offers a novel design strategy for advanced energy storage and conversion applications.
基金supports from the National Natural Science Foundation of China(Grant Nos.12305372 and 22376217)the National Key Research&Development Program of China(Grant Nos.2022YFA1603802 and 2022YFB3504100)+1 种基金the projects of the key laboratory of advanced energy materials chemistry,ministry of education(Nankai University)key laboratory of Jiangxi Province for persistent pollutants prevention control and resource reuse(2023SSY02061)are gratefully acknowledged.
文摘Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.
基金funded by the Innovative Research Group Project of the National Natural Science Foundation of China(52121004)the Research Development Fund(No.RDF-21-02-060)by Xi’an Jiaotong-Liverpool University+1 种基金support received from the Suzhou Industrial Park High Quality Innovation Platform of Functional Molecular Materials and Devices(YZCXPT2023105)the XJTLU Advanced Materials Research Center(AMRC).
文摘Seawater zinc-air batteries are promising energy storage devices due to their high energy density and utilization of seawater electrolytes.However,their efficiency is hindered by the sluggish oxygen reduction reaction(ORR)and chlorideinduced degradation over conventional catalysts.In this study,we proposed a universal synthetic strategy to construct heteroatom axially coordinated Fe–N_(4) single-atom seawater catalyst materials(Cl–Fe–N_(4) and S–Fe–N_(4)).X-ray absorption spectroscopy confirmed their five-coordinated square pyramidal structure.Systematic evaluation of catalytic activities revealed that compared with S–Fe–N_(4),Cl–Fe–N_(4) exhibits smaller electrochemical active surface area and specific surface area,yet demonstrates higher limiting current density(5.8 mA cm^(−2)).The assembled zinc-air batteries using Cl–Fe–N_(4) showed superior power density(187.7 mW cm^(−2) at 245.1 mA cm^(−2)),indicating that Cl axial coordination more effectively enhances the intrinsic ORR activity.Moreover,Cl–Fe–N_(4) demonstrates stronger Cl−poisoning resistance in seawater environments.Chronoamperometry tests and zinc-air battery cycling performance evaluations confirmed its enhanced stability.Density functional theory calculations revealed that the introduction of heteroatoms in the axial direction regulates the electron center of Fe single atom,leading to more active reaction intermediates and increased electron density of Fe single sites,thereby enhancing the reduction in adsorbed intermediates and hence the overall ORR catalytic activity.
基金funded by National Natural Science Foundation of China(Nos.12402142,11832013 and 11572134)Natural Science Foundation of Hubei Province(No.2024AFB235)+1 种基金Hubei Provincial Department of Education Science and Technology Research Project(No.Q20221714)the Opening Foundation of Hubei Key Laboratory of Digital Textile Equipment(Nos.DTL2023019 and DTL2022012).
文摘Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when tackling high-dimensional optimization challenges.To effectively address these challenges,this study introduces cooperative metaheuristics integrating dynamic dimension reduction(DR).Building upon particle swarm optimization(PSO)and differential evolution(DE),the proposed cooperative methods C-PSO and C-DE are developed.In the proposed methods,the modified principal components analysis(PCA)is utilized to reduce the dimension of design variables,thereby decreasing computational costs.The dynamic DR strategy implements periodic execution of modified PCA after a fixed number of iterations,resulting in the important dimensions being dynamically identified.Compared with the static one,the dynamic DR strategy can achieve precise identification of important dimensions,thereby enabling accelerated convergence toward optimal solutions.Furthermore,the influence of cumulative contribution rate thresholds on optimization problems with different dimensions is investigated.Metaheuristic algorithms(PSO,DE)and cooperative metaheuristics(C-PSO,C-DE)are examined by 15 benchmark functions and two engineering design problems(speed reducer and composite pressure vessel).Comparative results demonstrate that the cooperative methods achieve significantly superior performance compared to standard methods in both solution accuracy and computational efficiency.Compared to standard metaheuristic algorithms,cooperative metaheuristics achieve a reduction in computational cost of at least 40%.The cooperative metaheuristics can be effectively used to tackle both high-dimensional unconstrained and constrained optimization problems.
基金supported by the National Key Research and Development Program of China(No.2023YFA0914500)the National Natural Science Foundation of China(Nos.22378096,22308083,and 22178083)+1 种基金the Natural Science Foundation of Hebei Province(No.B2022202014)the Educational Commission of Hebei Province(No.JZX2023012).
文摘Chiral compounds have a huge market demand in the fields of pharmaceuticals,pesticides,and fine chemicals.Enzymatic electrosynthesis can couple enzyme catalysis,possessing high product purity,high efficiency,and mild conditions,with electrochemical regeneration of expensive cofactor nicotinamide adenine dinucleotide(NADH),possessing easy process monitoring and simple operation for efficient chiral synthesis.In this study,hydrophobic covalent organic framework(COF)was synthesized as the immobilized carrier,which not only enhanced the enzyme catalysis through enriching substrate but also enhanced the stability and reuse of the enzyme.Besides,Rh complex was anchored on hydrophilically-modified electrode to promote the regeneration of NADH,where the anchor of Rh complex can effectively avoid the mutual deactivation from the interference between electron mediator and enzyme,and simplify the separation of products.The immobilized enzyme catalysis and the electrochemical cofactor regeneration were coupled to construct an enzymatic electrosynthesis system for the efficient asymmetric reduction to obtain chiral alcohols,with a maximum turnover frequency(TOF)of 101.1 h^(-1).Furthermore,the relevant parameters of the system were optimized,and the substrate scope was expanded.
基金the financial support provided by the National Natural Science Foundation of China(Nos.52302220 and 22405052)the China Postdoctoral Science Foundation(No.2024M750491).
文摘The oxygen reduction reaction(ORR)critical for electrochemical energy conversion systems suffers from sluggish kinetics and high overpotentials that hinder the efficiency of these technologies.Herein,a curvature-dominated microenvironment modulation strategy is demonstrated to enhance ORR performance via engineering a helical hollow carbon nanotube with embedded sub-nanometer tungsten nitride(W_(2)N)clusters.This architecture yields optimized electrostatic field distributions and reduced d-band center of W_(2)N,thereby promoting the enrichment of OH-,the adsorption of oxygen,and the desorption of oxygen intermediates(OH).The catalyst shows remarkable ORR activity with a high onset potential of 1.00 V and a half-wave potential of 0.89 V,outperforming both Pt/C and other W_(2)N-based catalysts.Theoretical calculations verify that the curved support enhances the electron delocalization within the W_(2)N clusters,regulating the interaction between the catalyst and reactants.Our findings establish a general design principle of curvature-induced microenvironment modulation and offer a new pathway toward designing efficient electrocatalysts for sustainable energy storage applications.
基金supported by the National Key Research and Development Program of China(No.2021YFC2901100)the National Natural Science Foundation of China(No.22478425).
文摘Photocatalytic carbon dioxide(CO_(2))reduction offers an alternative strategy for converting CO_(2)into high-value added gaseous fuels,thereby paving the way for the development of clean and renewable energy.Metal-organic frameworks(MOFs),characterized by their highly porous structure,exceptional CO_(2)adsorption capacity,and tunable architecture,have emerged as promising candidates for photocatalytic CO_(2)reduction.This review systematically examines the recent advancement in MOFs-based photocatalysts for CO_(2)reduction to CO.It begins with the overview of the fundamental mechanisms and processes of MOFs towards photocatalytic CO_(2)reduction.Subsequently,common strategies for the modulation of MOFs-based photocatalysts are summarized,including metallic site modification,functionalized ligand incorporation,morphological control,defect engineering,and heterostructure construction.Notably,the review analyzes the critical factors contributing to the high selectivity of CO_(2)photoreduction to CO from both thermodynamic and kinetic perspectives.The conclusion addresses current challenges and future perspectives in designing highly efficient photocatalysts with abundant active sites,providing valuable insights for their continued development.
基金financially supported by Talent Start-up Fund of Fuzhou University(No.0180-511208)Fuzhou University Testing Fund of precious apparatus(No.2023T002)+1 种基金the National Natural Science Foundation of China(Nos.21703038 and 22072025)The financial support from State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences is acknowledged(No.20240018).
文摘Single-atom catalysts(SACs)have garnered tremendous and continuous attention in photocatalytic CO_(2)reduction reactions(CO_(2)RR),due to their compelling potential in broadening the light-harvesting range,elevating the charge separation/transfer efficiency,and enhancing surface reaction.Despite the surge in research and the expanding range of potential central metal candidates—including d-block,p-block,and rare metal elements,etc.—the comprehension of the structure-function relationships between the central metal and its performance remains elusive.Hence,categorized by different areas of the central metal element from periodic table,we outline the recent progress and challenges on SACs for photocatalytic CO_(2)RR.We begin by describing various synthetic strategies employed for SACs.Subsequently,a clear classification of the SACs applications in photocatalytic CO_(2)RR is provided,according to the central metal elements in different blocks of the periodic table.We also discussed how isolated metal single-atom sites from different blocks of the periodic table improve the performance of photocatalytic CO_(2)reduction from the perspective of charge separation and transfer.Finally,we end this review with some perspectives and challenges associated with SACs for photocatalytic CO_(2)reduction.Through this review,we aim to enrich the element diversity of SACs for photocatalytic CO_(2)RR,reveal trends in element evolution,and propose directions for future development in this flourishing field.
基金supported by the Natural Science Foundation of China(No.52101279)the Key Scientific Research Foundation of Education department of Hunan Province(No.24A0003)the Scientific Research Project of Education Department of Hunan Province(No.21B000)and the Fundamental Research Funds for the Central Universities of Central South University.
文摘Accelerated industrialization combined with over-applied nitrogen fertilizers results in serious nitrate pollution insurface and ground water,disrupting the balance of the global nitrogen cycle.Electrochemical nitrate reduction(eNO_(3)RR)emerges as an attractive strategy to simultaneously enable nitrate removal and decentralized ammo-nia fabrication,restoring the globally perturbed nitrogen cycle.However,complex deoxygenation-hydrogenationprocesses and sluggish proton-electron transfer kinetics significantly hinder practical application of eNO_(3)RR.In this study,we developed carbon-coated Cu-Ni bimetallic catalysts derived from metal-organic frameworks(MOFs)to facilitate eNO_(3)RR.The unique structural features of catalyst promote enhanced synergy between Cuand Ni,effectively addressing critical challenges in nitrate reduction.Comprehensive structural and electrochem-ical analysis demonstrate that electrochemical nitrate-to-nitrite conversion mainly takes place on active Cu sites,the introduction of Ni could efficiently accelerate the generation of aquatic active hydrogen,promoting the hy-drogenation of oxynitrides during eNO_(3)RR.In addition,Ni introduction could push up the d-band center of thecatalyst,thus enhancing the adsorption and activation of nitrate and the corresponding intermediates.Detailedreaction pathways for nitrate-to-ammonia conversion are illuminated by rotating disk electrode(RDE),in-situFourier-transform infrared spectroscopy,in-situ Raman spectrum and electrochemical impedance spectroscopy(EIS).Benefiting from the synergistic effect of Cu and Ni,optimum catalyst exhibited excellent nitrate reductionperformance.This work provides a new idea for elucidating the underlying eNO_(3)RR reaction mechanisms andcontributes a promising strategy for designing efficient bimetallic electrocatalysts.
基金supported by the National Key Research and Development Project(No.2020YFA0907500)the National Natural Science Foundation of China(No.22476206)+1 种基金the supports from the National Young Top-Notch Talents(No.W03070030)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y202011).
文摘Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.
基金supported by the National Natural Science Foundation Joint Fund Project(No.U24A2042)Basic Research Foundation of Zhejiang Provincial Universities(No.G23224161033)the National Natural Science Foundation of China(Nos.52072342 and 52377216).
文摘Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)into value-added products has been regarded as an effective way to achieve the goal of carbon neutrality.The intrinsic activity of electrocatalysts,as well as the reaction microenvironment,play an important role in improving the conversion efficiency of CO_(2).Herein,we report an ionic liquidfunctionalized Au/Pd heterostructure as the electrocatalyst for CO_(2)RR via introducing 1-butyl-1-methylpyrrolidine bis(trifluoromethylsulfonyl)imide([BMPyrr][NTf_(2)])ionic liquid.Au nanoclusters are epitaxially confined on Pd nanosheets in heterostructure,resulting in abundant and well-defined heterointerfaces that work as highly active catalytic sites.Notably,the[BMPyrr][NTf_(2)]achieves charge redistribution at the Au-Pd heterointerfaces,which helps to stabilize*CO_(2)^(˙-)intermediate and further reduce the energy barrier of *COOH formation.Furthermore,the[BMPyrr][NTf_(2)]molecules with high CO_(2)adsorption ability is beneficial to construct a CO_(2)-rich reaction microenvironment at the gas-liquid-solid three-phase interface.The hybrid electrocatalyst exhibits greatly improved CO Faradaic efficiency in a broad potential range and CO partial current density.This work provides a novel strategy for designing robust CO_(2)RR electrocatalysts via ionic liquid-mediated surface modification.
基金supported by the National Natural Science Foundation of China(Nos.62004143 and 22502150)the Key Project of Scientific Research Plan of Hubei Provincial Department of Education(No.D20241501)+5 种基金the China Postdoctoral Science Foundation(No.2024M762505)the Postdoctoral Fellowship Program(Grade C)(No.GZC20250787)the China Postdoctoral Science Foundation-Hubei Joint Support Program(No.2025T032HB)the Scientific Research Fund Project of Wuhan Institute of Technology(Nos.K2024053,K2025102,and 25QD010)the Open Fund of the Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices(No.EFMD2024006Z)the Innovation Project of Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education(No.LCX202404).
文摘While thermal air exfoliation is widely used to prepare graphitic carbon nitride(g-C_(3)N_(4))nanosheets,the effects of calcination conditions and atmosphere on their electronic structure and photocatalytic CO_(2)reduction reaction(CO_(2)RR)performance remain systematically unexplored.We prepared g-C_(3)N_(4)nanosheets with varying thickness and defects by controlling exfoliation parameters.The obtained nanosheets calcined longest in air exhibited highest CO_(2)RR activity,twice that of bulk g-C_(3)N_(4).The comprehensive analysis of structural characterizations indicates the thickness of g-C_(3)N_(4)nanosheets became thinner,and the defects increased as the calcination time increased.The N vacancies(N_(v))and O-doping caused by N_(2) and O_(2)from air,respectively,enable valence band elevation(N_(v))and conduction band depression(O-doping)that collectively redistribute the electronic structure.Nitrogen/oxygen dual-defects generated impurity levels,reduced the work function and band gap of g-C_(3)N_(4)nanosheets,and served as shallow traps for photogenerated e^(-).The results of in-situ spectroscopy indicate these increased effective e^(-)are enriched around of N atoms to react with the adsorbed CO_(2).During the CO_(2)reduction process,the N_(v) promoted the formation of*COOH,and this dual-defect co-promoted the*CO desorption,resulting in the improved CO_(2)RR activity.These results comprehensively analyze the regulatory effect of thermal air calcination on the electronic structure of g-C_(3)N_(4),providing valuable insights for designing g-C_(3)N_(4)nanosheets based photocatalysts for CO_(2)RR.
基金supported by the National Natural Science Foundations of China (Grant Nos.12235007,12001424,12271324,and 12501333)the Natural Science Basic research program of Shaanxi Province (Grant Nos.2021JZ-21 and 2024JC-YBQN-0069)+3 种基金the China Postdoctoral Science Foundation (Grant Nos.2020M673332 and 2024M751921)the Fundamental Research Funds for the Central Universities (Grant No.GK202304028)the 2023 Shaanxi Province Postdoctoral Research Project (Grant No.2023BSHEDZZ186)Xi’an University,Xi’an Science and Technology Plan Wutongshu Technology Transfer Action Innovation Team(Grant No.25WTZD07)。
文摘This letter introduces the novel concept of Painlevé solitons—waves arising from the interaction between Painlevé waves and solitons in integrable systems.Painlevé solitons can also be viewed as solitons propagating against a Painlevé wave background,in analogy to the established notion of elliptic solitons,which refers to solitons on an elliptic wave background.By employing a novel symmetry decomposition method aided by nonlocal residual symmetries,we explicitly construct (extended) Painlevé Ⅱ solitons for the Korteweg-de Vries equation and (extended) Painlevé Ⅳ solitons for the Boussinesq equation.
基金supported by National Natural Science Foundation of China(Nos.52274343 and 52474370)the China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202102).
文摘It is an important way to realize low carbon in China’s iron and steel industry by hydrogen-rich blast furnace smelting process.Sinter is the main blast furnace burden,and its reduction characteristics have a significant influence on ironmaking.The reduction behaviors,including reduction index(RI)and low-temperature reduction disintegration index(RDI),and the reduction mechanism of sinter in hydrogen-rich blast furnace were investigated.The results show that RI increased from 82.85 to 95.53 wt.%with an increase in H_(2)content from 0 to 30 vol.%,and the main phase of the reduction product was metallic iron.In the research of RDI,when the H_(2)content was increased from 0 to 20 vol.%,RDI+3.15 increased from 69.61 to 75.38 wt.%,and the main reaction was the reduction of hematite to magnetite.At 600-950℃,the reduction of sinter in CO and hydrogen-rich atmospheres(H_(2):CO=2)was both controlled by the first-order reaction model,and the apparent activation energy was 33.64 and 44.57 kJ/mol,respectively.
基金supported by the National Key R&D Program of China(No.2021YFC2901200)National Natural Science Foundation of China(Nos.52174383 and 52374412)Liaoning Provincial Natural Science Foundation of China(No.2022-YQ-09).
文摘To recover the valuable elements in Bayan Obo tailings,Fe-Si bath smelting reduction was adopted to separate and enrich rare earth elements(REE),niobium and titanium from the REE-Nb-Ti-containing slag.The reduction reaction process of the Fe-Si bath and the migration behavior of valuable elements in the solidification and crystallization process of silicothermic reduction tailings were investigated,and a treatment method for efficiently separating and enriching REE,Nb and Ti was explored.Thermodynamic analysis indicated that at 1600℃,with a 6 wt.%addition of Si as the reducing agent,the niobium oxide in the REE-Nb-Ti-containing slag could be selectively reduced to metallic Nb.In the Fe-Si bath reduction process,the Nb mass fraction in the metal phase increased with prolonged reaction time,peaking at 2.77%,while the Ti mass fraction consistently stayed below 0.12%.Lowering the w(CaO)/w(SiO_(2))enhanced the migration of Nb from slag to metal phase and reduced the Ti impurities.During solidification and crystallization,a significant quantity of perovskite precipitated from reduction tailings,with the REE dissolving into this perovskite.By adjusting the w(CaO)/w(SiO_(2))in tailings to 1.2-1.9 and maintaining a temperature of 1100℃for 4 h,the perovskite area fraction in the final slag could exceed 37%.Finally,a method was proposed to separate and enrich valuable elements in REE-Nb-Ti-containing slags via Fe-Si bath smelting reduction and crystallization control.
基金supported by the National Natural Science Foundation of China(No.52474355)the Liaoning Province Science and Technology Plan Joint Program(Key Research and Development Program Project),China(Nos.2022JH25/10200003 and 2023JH2/101800058).
文摘The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large deformation during the LCR process and to minimize the thickness of the slab in bending segments,the maximum theoretical reduction amount and the corresponding reduction scheme for the LCR process must be determined.With SPA-H weathering steel as a specific research steel grade,the distributions of tem-perature and deformation fields of a slab with the LCR process were analyzed using a three-dimensional thermal-mechanical finite ele-ment model.High-temperature tensile tests were designed to determine the critical strain of corner crack propagation and intermediate crack initiation with various strain rates and temperatures,and a prediction model of the critical strain for two typical cracks,combining the effects of strain rate and temperature,was proposed by incorporating the Zener-Hollomon parameter.The crack risks with different LCR schemes were calculated using the crack risk prediction model,and the maximum theoretical reduction amount for the SPA-H slab with a transverse section of 145 mm×1600 mm was 41.8 mm,with corresponding reduction amounts for Segment 0 to Segment 4 of 15.8,7.3,6.5,6.4,and 5.8 mm,respectively.
基金supported by the National Natural Science Foundation of China(12205300(H.S.),12405377(M.H.L))the Postdoctoral Science Foundation of China(2024M763694(M.H.L))+3 种基金the Natural Science Foundation of Hunan Province(2024JJ4027(H.S.))the Postdoctoral Fellowship Program of CPSF under Grant Number GZB20240859(M.H.L)financial support from the Hunan Normal University Program(grant05311204666)financial support from the 2024 Large Instrument Testing Open Fund of Hunan Normal University(24CSY033,24CSY086)。
文摘The electrochemical conversion of nitrate,a widespread water pollutant,into valuable ammonia represents a green and decentralized approach to ammonia synthesis.However,the sluggish multielectronproton coupling path and the low reactive species(nitrate and proton)concentration at the catalyst interface inhibit the efficiency of ammonia production from nitrate reduction reaction(NitRR).Herein,we introduce a novel iron-based tandem catalyst encapsulated by reduced graphene oxide(denoted as Fe-rGO),with a superior ammonia production rate of 47.815 mg h^(-1)mg_(ca)^(t-1)and a high Faraday efficiency(FE)of 96.51%at an applied potential of-0.5 V.It also delivers a robust stability with FE above90%under a current density of 250 mA cm^(-2)for 50 h.In situ X-ray absorption spectroscopy reveals that the FeO_(x)is dynamically translated to Fe~0 site concurrently with the enhancement of the NH_(3)production rate,suggesting the Fe^(0) site as hydrogenation active center.The asymmetric distribution of surface charges of rGO not only enriches nitrate ions at the catalytic interface and promotes the hydrogenation process in NitRR,but also protects the iron species and ensures their stability during electrolysis.The Zn-NO_(3)^(-)battery demonstrates an impressive FE of 88.6%,highlighting its exceptional potential for practical applications.
