Symmetry reduction of a class of third-order evolution equations that admit certain generalized conditionalsymmetries (GCSs) is implemented.The reducibility of the initial-value problem for an evolution equation to a ...Symmetry reduction of a class of third-order evolution equations that admit certain generalized conditionalsymmetries (GCSs) is implemented.The reducibility of the initial-value problem for an evolution equation to a Cauchyproblem for a system of ordinary differential equations (ODEs) is characterized via the GCS and its Lie symmetry.Complete classification theorems are obtained and some examples are taken to show the main reduction procedure.展开更多
Group classification of quasilinear third-order evolution equations is given by using the classical infinitesimal Lie method, the technique of equivalence transformations, and the theory of classification of abstract ...Group classification of quasilinear third-order evolution equations is given by using the classical infinitesimal Lie method, the technique of equivalence transformations, and the theory of classification of abstract low-dimensional Lie algebras. We show that there are three equations admitting simple Lie algebras of dimension three. All non-equivalent equations admitting simple Lie algebras are nothing but these three. Furthermore, we also show that there exist two, five, twenty-nine and twenty-six non- equivalent third-order nonlinear evolution equations admitting one-, two-, three-, and four-dimensional solvable Lie algebras, respectively.展开更多
A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and...A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.展开更多
The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecul...The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.展开更多
The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor ...The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor featuring a broad spectral absorption range,is successfully employed as the electron acceptor to combine with CdS for constructing a S-scheme heterojunction.The optimized photocatalyst(CdSCuO2∶1)delivers an exceptional hydrogen evolution rate of 18.89 mmol/(g·h),4.15-fold higher compared with bare CdS.X-ray photoelectron spectroscopy(XPS)and ultraviolet-visible diffuse reflection absorption spectroscopy(UV-vis DRS)confirmed the S-scheme band structure of the composites.Moreover,the surface photovoltage(SPV)and electron paramagnetic resonance(EPR)indicated that the photogenerated electrons and photogenerated holes of CdS-CuO2∶1 were respectively transferred to the conduction band(CB)of CdS with a higher reduction potential and the valence band(VB)of CuO with a higher oxidation potential under illumination,as expected for the S-scheme mechanism.Density-functional-theory calculations of the electron density difference(EDD)disclose an interfacial electric field oriented from CdS to CuO.This built-in field suppresses charge recombination and accelerates carrier migration,rationalizing the markedly enhanced PHE activity.This study offers a novel strategy for designing S-scheme heterojunctions with high light harvesting and charge utilization toward sustainable solar-tohydrogen conversion.展开更多
This study presents a comprehensive phylogenetic analysis on Batrachospermaceae based on key taxonomic identifiers(rbcL,psaA,psbA,and COI-5P)from some genera.To systematically explore the phylogenetic relationships an...This study presents a comprehensive phylogenetic analysis on Batrachospermaceae based on key taxonomic identifiers(rbcL,psaA,psbA,and COI-5P)from some genera.To systematically explore the phylogenetic relationships and taxonomy within Batrachospermaceae,we integrated molecular and morphological data,and explored the phylogeny,character evolution,and ancestral geographical origin and provided a theoretical support for the classification and geographic origination of Batrachospermaceae.Our findings reveal distinct relationships within the phylogenetic tree.Notably,10 genera(Sirodotia,Batrachospermum,Tuomeya,Volatus,Lympha,Nothocladus,Torularia,Sheathia,Nocturama,and Petrohua)are closely associated in the rbcL phylogenetic tree.Additionally,four genera(Kumanoa,Hoefkenia,Notohesperus,and Virescentia)exhibit high support ratios,indicating their close interrelations.Other genera,including Paludicola,Visia,Acarposporophycos,Macrosporophycos,Visioidea,Balliopsis,and Psilosiphon,exhibit clustering traits.Furthermore,the multigene sequences provide a robust support for Montagnia that forms a monophyletic group.Ancestral reconstruction of morphological characters identifies nine primitive character states,including whorl,fascicle length,cortical cells,secondary fascicles,the shape of carpogonical branch,spermatangia,carposporophyte,carpogonium and trichogyne,with Visia likely representing ancestral traits in Batrachospermaceae.Furthermore,geographical origin maps suggest a potential common ancestral of Batrachospermaceae origin in the American continent.Additional to conventional analyses,including evolutionary and ancestral reconstruction investigations into key morphological characters,we attempt to reconstruct the biogeography within the Batrachospermaceae,thus contributing to a nuanced understanding of its origin.展开更多
Developing efficient and durable electrocatalysts for acidic oxygen evolution reaction(OER)is pivotal for advancing proton exchange membrane water electrolysis(PEMWEs),yet balancing activity and stability remains a fo...Developing efficient and durable electrocatalysts for acidic oxygen evolution reaction(OER)is pivotal for advancing proton exchange membrane water electrolysis(PEMWEs),yet balancing activity and stability remains a formidable challenge.Herein,we propose a dual-engineering strategy to stabilize Ru-based catalysts by synergizing the oxygen vacancy site-synergized mechanism-lattice oxygen mechanism(OVSM-LOM)with Ru-N bond stabilization.The engineered RuO_(2)@NCC catalyst exhibits exceptional OER performance in 0.5 M H2SO4,achieving an ultralow overpotential of 215 mV at 10 mA cm^(-2) and prolonged stability for over 327 h.The catalyst delivers 300 h of continuous operation at 1 A cm^(-2),with a negligible degradation rate of only 0.067 mV h-1,further demonstrating its potential for practical application.Oxygen vacancies unlock the OVSM-LOM pathway,bypassing the sluggish adsorbate evolution mechanism(AEM)and accelerating reaction kinetics,while the Ru-N bonds suppress Ru dissolution by anchoring low-valent Ru centers.Quasi-in situ X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),and isotopic labeling experiments confirm the lattice oxygen participation with *O formation as the rate-determining step.The Ru-N bonds reinforce the structural integrity by stabilizing low-valent Ru centers and inhibiting overoxidation.Theoretical calculations further verify that the synergistic interaction between OVs and Ru-O(N)active sites optimizes the Ru d-band center and stabilizes intermediates,while Ru-N coordination enhances structural integrity.This study establishes a novel paradigm for designing robust acidic OER catalysts through defect and coordination engineering,bridging the gap between activity and stability for sustainable energy technologies.展开更多
Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthes...Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.展开更多
Acetolactate synthase(ALS)-targeting herbicides are among the most widely used weed-control chemicals globally.Mutations in the ALS gene can confer herbicide resistance in crops,thereby allowing selective elimination ...Acetolactate synthase(ALS)-targeting herbicides are among the most widely used weed-control chemicals globally.Mutations in the ALS gene can confer herbicide resistance in crops,thereby allowing selective elimination of weeds without harming crops.Herbicide-resistant ALS alleles were initially discovered in weeds and subsequently developed through artificial mutagenesis techniques.With the advancement of CRISPR/Cas technologies,various genome-editing tools are now available to introduce these resistant alleles,as well as novel variants,into diverse crop species.Moreover,emerging methodologies,such as directed evolution,enable the generation and screening of large populations of random ALS mutants.Consequently,ALS has become one of the most extensively targeted genes in plant gene evolution.This paper provides a comprehensive overview of both conventional and recently developed strategies for ALS evolution,with particular emphasis on CRISPR/Cas-based genome editing and directed evolution.Future perspectives on technological application are also discussed.By advancing our understanding of herbicide-resistant ALS allele development for crop improvement,these methodologies may also pave the way for their application to the evolution of other agronomically important genes.展开更多
The rationally designed ruthenium selenide(RuSe_(1.6)-500)nanocomposite with selenium vacancies was synthesized via a hydrothermal/annealing approach.During the annealing step,calcination under a H_(2)/Ar atmosphere f...The rationally designed ruthenium selenide(RuSe_(1.6)-500)nanocomposite with selenium vacancies was synthesized via a hydrothermal/annealing approach.During the annealing step,calcination under a H_(2)/Ar atmosphere facilitated the evaporation of selenium,thereby generating selenium vacancies.This study confirmed that RuSe_(1.6)-500 prepared by this method functions as an efficient electrocatalyst for the hydrogen evolution reaction(HER)in seawater.Furthermore,experiments and density functional theory calculations demonstrated that the enhanced electrocatalytic performance and resistance to Cl-induced corrosion in seawater can be attributed to the surface reconstruction of RuSe_(1.6)-500 during the HER process.Specifically,the reconstruction involves the adsorption of hydroxyl groups at selenium vacancies,leading to the formation of a hydroxy-rich surface on RuSe_(1.6)-500.The hydroxy-rich surface is responsible for the superior electrocatalytic activity and stability of RuSe_(1.6)-500 as an electrocatalyst for the HER in seawater.展开更多
To realize the practical application of anion exchange membrane water electrolysis(AEMWE),it is essential to develop highly active,durable,and cost-effective electrocatalyst for oxygen evolution reaction(OER).Herein,w...To realize the practical application of anion exchange membrane water electrolysis(AEMWE),it is essential to develop highly active,durable,and cost-effective electrocatalyst for oxygen evolution reaction(OER).Herein,we report a hollow-structured Ni_(x)Co_(1−x)O/Ni_(3)S_(2)/Co_(9)S_(8)heterostructure synthesized via sequential template-assisted growth,thermal oxidation,and controlled sulfidation process.The abundant bimetallic heterointerfaces not only provide additional active sites but also promote electronic modulation via charge redistribution.Additionally,the porous and hollow architecture enhances active surface area and mass transfer ability,thereby increasing the number of accessible active sites for alkaline OER.As a result,the prepared electrocatalyst achieves low overpotential of 310 mV at 10 mA cm^(−2)and small Tafel slope of 55.94 mV dec^(−1),demonstrating the exceptional electrocatalytic performance for alkaline OER.When integrated as the anode in an AEMWE cell,it delivers outstanding performance with only 1.657 V at 1.0 A cm^(−2)and reaches high current density of 5.0 A cm^(−2)at 1.989 V,surpassing those of commercial RuO_(2).The cell also shows excellent long-term durability over 100 h with minimal degradation.This study highlights the strong potential of rationally engineered oxide/sulfide heterostructures for next-generation alkaline water electrolysis.展开更多
Chinese civilization has continuously developed and formed on the foundation of China’s unique natural environment.Its formation process and cultural characteristics are intimately and intricately linked to the histo...Chinese civilization has continuously developed and formed on the foundation of China’s unique natural environment.Its formation process and cultural characteristics are intimately and intricately linked to the historical evolution of the natural environment,including changes in climate,hydrological systems,and land use.Currently,academic scholarship on the historical evolution of Chinese civilization is predominantly based on the findings of the humanities;the influence of natural environmental change has not been systematically and scientifically considered in unveiling the formation and development of the civilization.Adopting a perspective of deep interdisciplinary integration between the natural sciences and humanities,this study synthesizes existing research on the historical changes in natural geographical elements,such as the climate and environment,since the Holocene.It systematically reviews evidence from disciplines such as archaeology and historical geography,comprehensively analyzes the natural environmental factors within the spatiotemporal process of the formation of Chinese civilization,and reveals the significance of the human-environment relationship in shaping its evolution.Based on this systematic review,the study presents three main scientific findings:(1)The uniqueness of China’s geographical environment laid the foundation for the endogenous nature and the fundamental pattern of“unity in diversity”of Chinese civilization.(2)Climate change facilitated the early origins of Chinese civilization and subsequently drove ethnic exchange and integration throughout its historical development.(3)Throughout historical periods,the primary strategy of the human-environment relationship was human adaptation;yet,the influence of human agency on the natural world progressively increased.In conclusion,there is an urgent need to conduct systematic and scientific research on Chinese civilization from the perspective of the human-environment relationship.Through in-depth interdisciplinary exchange and collaboration between the fields of geography,climatology,history,and archaeology,we can deepen our understanding of the historical development of Chinese civilization and provide historical lessons and insights for addressing contemporary environmental challenges.展开更多
A core-shell type Co_(19)-added polyoxometalate H_(17)Na_(4)Cs_(21)[Co_(19)(μ_(3)-OH)_(12)(A-α-SiW_(10)O_(37))_(6)]·8 Cl·12H_(2)O(1)has been made under hydrothermal conditions guided by the lacunary direct...A core-shell type Co_(19)-added polyoxometalate H_(17)Na_(4)Cs_(21)[Co_(19)(μ_(3)-OH)_(12)(A-α-SiW_(10)O_(37))_(6)]·8 Cl·12H_(2)O(1)has been made under hydrothermal conditions guided by the lacunary directing synthetic strategy.Single crystal X-ray diffraction(SXRD)has shown that 19 Co^(2+)are arranged in a flat plane through edge sharing in a mode of 3-4-5-4-3,forming a core-shell type polyanion cluster{Co_(19)(SiW_(10))_6}with a diameter of approximately 2.24 nm.Visible-light-driven photocatalytic hydrogen evolution performance studies have shown that 1 is an efficient heterogeneous water reduction catalyst(WRC)with the H_(2)evolution rate of 2902.5μmol h^(-1)g^(-1).Moreover,the cycle tests indicated that 1 was also a good heterogeneous catalyst.展开更多
Cloud data sharing is an important issue in modern times.To maintain the privacy and confidentiality of data stored in the cloud,encryption is an inevitable process before uploading the data.However,the centralized ma...Cloud data sharing is an important issue in modern times.To maintain the privacy and confidentiality of data stored in the cloud,encryption is an inevitable process before uploading the data.However,the centralized management and transmission latency of the cloud makes it difficult to support real-time processing and distributed access structures.As a result,fog computing and the Internet of Things(IoT)have emerged as crucial applications.Fog-assisted proxy re-encryption is a commonly adopted technique for sharing cloud ciphertexts.It allows a semitrusted proxy to transforma data owner’s ciphertext into another re-encrypted ciphertext intended for a data requester,without compromising any information about the original ciphertext.Yet,the user revocation and cloud ciphertext renewal problems still lack effective and secure mechanisms.Motivated by it,we propose a revocable conditional proxy re-encryption scheme offering ciphertext evolution(R-CPRE-CE).In particular,a periodically updated time key is used to revoke the user’s access privileges while an access condition prevents a malicious proxy from reencrypting unauthorized ciphertext.We also demonstrate that our scheme is provably secure under the notion of indistinguishability against adaptively chosen identity and chosen ciphertext attacks in the random oracle model.Performance analysis shows that our scheme reduces the computation time for a complete data access cycle from an initial query to the final decryption by approximately 47.05%compared to related schemes.展开更多
Centromeres are indispensable for accurate chromosome segregation,but are subject to rapid sequence turnover while maintaining conserved functions--a paradox in genome evolution.To unravel this paradox,we integrated o...Centromeres are indispensable for accurate chromosome segregation,but are subject to rapid sequence turnover while maintaining conserved functions--a paradox in genome evolution.To unravel this paradox,we integrated over 400 fully resolved centromeres from 17 diploid angiosperms spanning 180 million years of divergence,along with 1,000+pan-genomic assemblies,resequencing datasets,and congeneric wholegenome sequences.We showed that angiosperm centromere organization is determined by lineagespecific combinations of satellite repeats and transposable elements(TEs),which,in turn,shape distinct epigenetic landscapes and evolutionary trajectories within centromeres.In particular,TE insertion patterns were found to be key drivers of structural diversification and positional shift of centromeres in angiosperms.Intriguingly,population-level analyses revealed considerable plasticity in centromere sequences across species,with satellite repeats serving as focal points of evolutionary change and exhibiting species-specific heterogeneity patterns.Temporal reconstructions across congeneric species revealed the emergence and subsequent differentiation of centromeric repeats,outlining a dynamic continuum from gradual sequence diversification to complete turnover during speciation,often accompanied by karyotype reorganization.By integrating intra-and inter-species comparisons,we propose a unifying framework in which centromere innovation is governed by a delicate interplay between genome evolution,chromosomal shuffling,and selection constraints,resulting in phylogenomic signatures of centromeredriven speciation.展开更多
In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order relia...In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order reliability methods exhibit limited accuracy in highly nonlinear scenarios.To overcome these challenges,a novel reliability analysis strategy based on a multimodal differential evolution algorithm and a hypersphere integration method is proposed.Initially,the penalty function method is employed to reformulate the MPP search problem as a conditionally constrained optimization task.Subsequently,a differential evolution algorithm incorporating a population delineation strategy is utilized to identify all MPPs.Finally,a paraboloid equation is constructed based on the curvature of the limit-state function at the MPPs,and the failure probability of the structure is calculated by using the hypersphere integration method.The localization effectiveness of the MPPs is compared through multiple numerical cases and two engineering examples,with accuracy comparisons of failure probabilities against the first-order reliability method(FORM)and the secondorder reliability method(SORM).The results indicate that the method effectively identifies existing MPPs and achieves higher solution precision.展开更多
Compound-specific carbon isotopic compositions(δ^(13)C)of aromatic hydrocarbons offer a promising solution to the long-standing challenge of correlating ultra-deep oils with their source rocks.However,systematic stud...Compound-specific carbon isotopic compositions(δ^(13)C)of aromatic hydrocarbons offer a promising solution to the long-standing challenge of correlating ultra-deep oils with their source rocks.However,systematic studies on the evolution of these isotopic signatures during thermal maturation remain scarce.In this study,we conducted closed-system anhydrous gold-tube pyrolysis experiments using a representative marine crude oil from the Tarim Basin to systematically investigate the evolution of polycyclic aromatic hydrocarbon(PAH)compositions and their compound-specific δ^(13)C values during thermal maturation.The results show that the abundance and relative distribution of the naphthalene,phenanthrene,fluorene,and dibenzothiophene series vary significantly with increasing maturity.Based on the variation patterns of δ^(13)C values,the aromatic hydrocarbons can be divided into two categories.The first category includes parent PAHs such as naphthalene,phenanthrene,fluorene,and dibenzothiophene,along with some alkylated dibenzothiophenes,whose δ^(13)C values remain essentially invariant during thermal evolution.The second category comprises other alkylated aromatic hydrocarbons,whose δ^(13)C values remain stable at lower temperatures but become progressively enriched in δ^(13)C at higher temperatures due to demethylation.Considering the diverse origins of PAH precursors and the thermal invariance of δ^(13)C in certain aromatic hydrocarbons,compound-specific carbon isotope analysis represents a powerful tool for identifying source rocks in ultra-deep petroleum systems,thereby advancing our understanding of ultra-deep hydrocarbon accumulation.展开更多
Structural engineering of Pt-based nanoalloys is crucial for the rational design and manufacturing of high-performance and low-cost electrocatalysts for hydrogen evolution reaction(HER).Here,we reported PtNi nanoparti...Structural engineering of Pt-based nanoalloys is crucial for the rational design and manufacturing of high-performance and low-cost electrocatalysts for hydrogen evolution reaction(HER).Here,we reported PtNi nanoparticles with a refined size of 2.71 nm and regular strains loaded on carbon black,synthesized using the high-temperature liquid shock(HTLS)method.This approach offers significant advantages over conventional synthesis methods,including high scalability,rapid reaction rates,and precise control over the size and shape of nanocrystals.Importantly,the synthesized PtNi electrocatalysts demonstrate outstanding catalytic activity and long-term stability for HER,achieving low overpotentials of 19 and 203 mV at current densities of 10 and 1000 mA/cm^(2),respectively.The superior performance can be attributed to the combination of a refined particle size,lattice strains,and synergistic effects between Pt and Ni.This rapid liquid-state synthesis demonstrated here holds great potential for scalable and industrial manufacturing of micro-/nano-catalysts.展开更多
NiMo-based catalysts show significant potential for the hydrogen evolution reaction(HER).Optimizing the electronic structure and enhancing mass transfer are two critical factors for improving catalytic performance,but...NiMo-based catalysts show significant potential for the hydrogen evolution reaction(HER).Optimizing the electronic structure and enhancing mass transfer are two critical factors for improving catalytic performance,but they remain significant challenges.Herein,we present a route for synthesizing two-dimensional(2D)porous Mo_(2)N-Ni heterojunction nanosheets with tuned Ni-Mo ratio for enhanced alkaline HER performance.A precursor can be easily synthesized by assembling polyoxometalate clusters(PMo_(12))with layered hydroxy oxides(Ni(OH)_(2)).It is found that the interaction between PMo_(12)and Ni(OH)_(2)can effectively protect the particles from significant agglomeration during pyrolysis,resulting in the formation of 2D porous sheets composed of small Mo_(2)N-Ni units.The transfer of electrons from Ni to Mo_(2)N results in the redistribution of electrons at the heterojunction,optimizing the adsorption and desorption of intermediates.Moreover,the 2D porous structure comprised of small particles enhances mass transfer,thereby reducing the impedance of the catalyst.Consequently,the catalyst with an optimized Mo/Ni ratio exhibits an overpotential of 19 mV at 10 mA cm^(-2),being comparable to that of commercial Pt/C catalyst.The anion exchange membrane(AEM)electrolyzer,consisting of optimized Mo_(2)N-Ni and NiFe-LDH,achieves a current density of 500 mA cm^(-2)at 1.80 V and can operate stably for 300 h.This assembly method offers an effective strategy for the large-scale preparation of efficient catalysts.展开更多
Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and ma...Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and magnetic field enhanced-electrochemical activity remains to be fully elucidated.Herein,single-domain CoFe_(2)O_(4) catalysts with tunable oxygen vacancies(CFO-V_(O)) were synthesized to probe how V_(O) mediates magnetism and OER activity under magnetic field.The introduction of V_(O) can simultaneously modulate saturation magnetization(M_(s)) and coercivity(H_(c)),where the increased M_(s) dominates the magnetic field-enhanced OER activity.Under a 14,000 G magnetic field,the optimized CFO-V_(O) exhibits up to 16.1 % reduction in overpotential and 365 % enhancement in magnetocurrent(MC).Electrochemical analyses and post-OER characterization reveal that the magnetic field synergistically improves OER kinetics through lattice distortion induction,magnetohydrodynamic effect,and spin charge transfer effect.Importantly,the magnetic field promotes additional Co^(3+) generation to compensate for charge imbalance caused by V_(O) filling,maintaining dynamic equilibrium of V_(O) and effective reactant adsorption-conversion processes.This work unveils the synergistic mechanism of V_(O) and magnetic parameters for enhancing OER performance under the magnetic field,providing new insights into the design of high-efficiency spinregulated OER catalysts.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.10447007 and 10671156the Natural Science Foundation of Shaanxi Province of China under Grant No.2005A13
文摘Symmetry reduction of a class of third-order evolution equations that admit certain generalized conditionalsymmetries (GCSs) is implemented.The reducibility of the initial-value problem for an evolution equation to a Cauchyproblem for a system of ordinary differential equations (ODEs) is characterized via the GCS and its Lie symmetry.Complete classification theorems are obtained and some examples are taken to show the main reduction procedure.
基金supported by the National Key Basic Research Project of China (973 Program)(No. 2004CB318000)
文摘Group classification of quasilinear third-order evolution equations is given by using the classical infinitesimal Lie method, the technique of equivalence transformations, and the theory of classification of abstract low-dimensional Lie algebras. We show that there are three equations admitting simple Lie algebras of dimension three. All non-equivalent equations admitting simple Lie algebras are nothing but these three. Furthermore, we also show that there exist two, five, twenty-nine and twenty-six non- equivalent third-order nonlinear evolution equations admitting one-, two-, three-, and four-dimensional solvable Lie algebras, respectively.
文摘A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.
文摘The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.
文摘The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor featuring a broad spectral absorption range,is successfully employed as the electron acceptor to combine with CdS for constructing a S-scheme heterojunction.The optimized photocatalyst(CdSCuO2∶1)delivers an exceptional hydrogen evolution rate of 18.89 mmol/(g·h),4.15-fold higher compared with bare CdS.X-ray photoelectron spectroscopy(XPS)and ultraviolet-visible diffuse reflection absorption spectroscopy(UV-vis DRS)confirmed the S-scheme band structure of the composites.Moreover,the surface photovoltage(SPV)and electron paramagnetic resonance(EPR)indicated that the photogenerated electrons and photogenerated holes of CdS-CuO2∶1 were respectively transferred to the conduction band(CB)of CdS with a higher reduction potential and the valence band(VB)of CuO with a higher oxidation potential under illumination,as expected for the S-scheme mechanism.Density-functional-theory calculations of the electron density difference(EDD)disclose an interfacial electric field oriented from CdS to CuO.This built-in field suppresses charge recombination and accelerates carrier migration,rationalizing the markedly enhanced PHE activity.This study offers a novel strategy for designing S-scheme heterojunctions with high light harvesting and charge utilization toward sustainable solar-tohydrogen conversion.
基金Supported by the National Natural Science Foundation of China(No.32170204)。
文摘This study presents a comprehensive phylogenetic analysis on Batrachospermaceae based on key taxonomic identifiers(rbcL,psaA,psbA,and COI-5P)from some genera.To systematically explore the phylogenetic relationships and taxonomy within Batrachospermaceae,we integrated molecular and morphological data,and explored the phylogeny,character evolution,and ancestral geographical origin and provided a theoretical support for the classification and geographic origination of Batrachospermaceae.Our findings reveal distinct relationships within the phylogenetic tree.Notably,10 genera(Sirodotia,Batrachospermum,Tuomeya,Volatus,Lympha,Nothocladus,Torularia,Sheathia,Nocturama,and Petrohua)are closely associated in the rbcL phylogenetic tree.Additionally,four genera(Kumanoa,Hoefkenia,Notohesperus,and Virescentia)exhibit high support ratios,indicating their close interrelations.Other genera,including Paludicola,Visia,Acarposporophycos,Macrosporophycos,Visioidea,Balliopsis,and Psilosiphon,exhibit clustering traits.Furthermore,the multigene sequences provide a robust support for Montagnia that forms a monophyletic group.Ancestral reconstruction of morphological characters identifies nine primitive character states,including whorl,fascicle length,cortical cells,secondary fascicles,the shape of carpogonical branch,spermatangia,carposporophyte,carpogonium and trichogyne,with Visia likely representing ancestral traits in Batrachospermaceae.Furthermore,geographical origin maps suggest a potential common ancestral of Batrachospermaceae origin in the American continent.Additional to conventional analyses,including evolutionary and ancestral reconstruction investigations into key morphological characters,we attempt to reconstruct the biogeography within the Batrachospermaceae,thus contributing to a nuanced understanding of its origin.
基金support from the National Natural Science Foundation of China(Nos.12305373 and 52276220)the Guangzhou Basic Research Program(No.SL2024A04J00234).
文摘Developing efficient and durable electrocatalysts for acidic oxygen evolution reaction(OER)is pivotal for advancing proton exchange membrane water electrolysis(PEMWEs),yet balancing activity and stability remains a formidable challenge.Herein,we propose a dual-engineering strategy to stabilize Ru-based catalysts by synergizing the oxygen vacancy site-synergized mechanism-lattice oxygen mechanism(OVSM-LOM)with Ru-N bond stabilization.The engineered RuO_(2)@NCC catalyst exhibits exceptional OER performance in 0.5 M H2SO4,achieving an ultralow overpotential of 215 mV at 10 mA cm^(-2) and prolonged stability for over 327 h.The catalyst delivers 300 h of continuous operation at 1 A cm^(-2),with a negligible degradation rate of only 0.067 mV h-1,further demonstrating its potential for practical application.Oxygen vacancies unlock the OVSM-LOM pathway,bypassing the sluggish adsorbate evolution mechanism(AEM)and accelerating reaction kinetics,while the Ru-N bonds suppress Ru dissolution by anchoring low-valent Ru centers.Quasi-in situ X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),and isotopic labeling experiments confirm the lattice oxygen participation with *O formation as the rate-determining step.The Ru-N bonds reinforce the structural integrity by stabilizing low-valent Ru centers and inhibiting overoxidation.Theoretical calculations further verify that the synergistic interaction between OVs and Ru-O(N)active sites optimizes the Ru d-band center and stabilizes intermediates,while Ru-N coordination enhances structural integrity.This study establishes a novel paradigm for designing robust acidic OER catalysts through defect and coordination engineering,bridging the gap between activity and stability for sustainable energy technologies.
基金supported by the National Natural Science Foundation of China (No.52274304)。
文摘Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.
基金Guangdong Basic and Applied Basic Research Foundation(2023B1515120050,2023A1515110529 and 2024A1515012454)Shenzhen Science and Technology Program(JCYJ20230807145759008 and KJZD20240903100206009).
文摘Acetolactate synthase(ALS)-targeting herbicides are among the most widely used weed-control chemicals globally.Mutations in the ALS gene can confer herbicide resistance in crops,thereby allowing selective elimination of weeds without harming crops.Herbicide-resistant ALS alleles were initially discovered in weeds and subsequently developed through artificial mutagenesis techniques.With the advancement of CRISPR/Cas technologies,various genome-editing tools are now available to introduce these resistant alleles,as well as novel variants,into diverse crop species.Moreover,emerging methodologies,such as directed evolution,enable the generation and screening of large populations of random ALS mutants.Consequently,ALS has become one of the most extensively targeted genes in plant gene evolution.This paper provides a comprehensive overview of both conventional and recently developed strategies for ALS evolution,with particular emphasis on CRISPR/Cas-based genome editing and directed evolution.Future perspectives on technological application are also discussed.By advancing our understanding of herbicide-resistant ALS allele development for crop improvement,these methodologies may also pave the way for their application to the evolution of other agronomically important genes.
基金supported by the National Key Research and Development Program of China(2022YFB3805600,2022YFB3805604)the National Natural Science Foundation of China(52201286)+3 种基金the National 111 Project(B20002)the Key R&D Program of Shandong Province,China(2023CXGC010314)the Hubei Provincial Natural Science Foundation of China(2024AFB195)the Fundamental Research Funds for the Central Universities(104972025KFYzxk0014,104972024KFYjlb0008)。
文摘The rationally designed ruthenium selenide(RuSe_(1.6)-500)nanocomposite with selenium vacancies was synthesized via a hydrothermal/annealing approach.During the annealing step,calcination under a H_(2)/Ar atmosphere facilitated the evaporation of selenium,thereby generating selenium vacancies.This study confirmed that RuSe_(1.6)-500 prepared by this method functions as an efficient electrocatalyst for the hydrogen evolution reaction(HER)in seawater.Furthermore,experiments and density functional theory calculations demonstrated that the enhanced electrocatalytic performance and resistance to Cl-induced corrosion in seawater can be attributed to the surface reconstruction of RuSe_(1.6)-500 during the HER process.Specifically,the reconstruction involves the adsorption of hydroxyl groups at selenium vacancies,leading to the formation of a hydroxy-rich surface on RuSe_(1.6)-500.The hydroxy-rich surface is responsible for the superior electrocatalytic activity and stability of RuSe_(1.6)-500 as an electrocatalyst for the HER in seawater.
基金supported by the Korea Institute for Advancement of Technology (KIAT)the Ministry of Trade,Industry&Energy (MOTIE) of the Republic of Korea (No. P0022130)by the Institute of Information&Communications Technology Planning&Evaluation(IITP)-Innovative Human Resource Development for Local Intellectualization program grant funded by the Korea government (MSIT)(IITP-2025-RS-2023-00259678)
文摘To realize the practical application of anion exchange membrane water electrolysis(AEMWE),it is essential to develop highly active,durable,and cost-effective electrocatalyst for oxygen evolution reaction(OER).Herein,we report a hollow-structured Ni_(x)Co_(1−x)O/Ni_(3)S_(2)/Co_(9)S_(8)heterostructure synthesized via sequential template-assisted growth,thermal oxidation,and controlled sulfidation process.The abundant bimetallic heterointerfaces not only provide additional active sites but also promote electronic modulation via charge redistribution.Additionally,the porous and hollow architecture enhances active surface area and mass transfer ability,thereby increasing the number of accessible active sites for alkaline OER.As a result,the prepared electrocatalyst achieves low overpotential of 310 mV at 10 mA cm^(−2)and small Tafel slope of 55.94 mV dec^(−1),demonstrating the exceptional electrocatalytic performance for alkaline OER.When integrated as the anode in an AEMWE cell,it delivers outstanding performance with only 1.657 V at 1.0 A cm^(−2)and reaches high current density of 5.0 A cm^(−2)at 1.989 V,surpassing those of commercial RuO_(2).The cell also shows excellent long-term durability over 100 h with minimal degradation.This study highlights the strong potential of rationally engineered oxide/sulfide heterostructures for next-generation alkaline water electrolysis.
基金supported by the Consultation and Evaluation Project of the Academic Department of the Chinese Academy of Sciences(Grant No.2022-DX05-B-021).
文摘Chinese civilization has continuously developed and formed on the foundation of China’s unique natural environment.Its formation process and cultural characteristics are intimately and intricately linked to the historical evolution of the natural environment,including changes in climate,hydrological systems,and land use.Currently,academic scholarship on the historical evolution of Chinese civilization is predominantly based on the findings of the humanities;the influence of natural environmental change has not been systematically and scientifically considered in unveiling the formation and development of the civilization.Adopting a perspective of deep interdisciplinary integration between the natural sciences and humanities,this study synthesizes existing research on the historical changes in natural geographical elements,such as the climate and environment,since the Holocene.It systematically reviews evidence from disciplines such as archaeology and historical geography,comprehensively analyzes the natural environmental factors within the spatiotemporal process of the formation of Chinese civilization,and reveals the significance of the human-environment relationship in shaping its evolution.Based on this systematic review,the study presents three main scientific findings:(1)The uniqueness of China’s geographical environment laid the foundation for the endogenous nature and the fundamental pattern of“unity in diversity”of Chinese civilization.(2)Climate change facilitated the early origins of Chinese civilization and subsequently drove ethnic exchange and integration throughout its historical development.(3)Throughout historical periods,the primary strategy of the human-environment relationship was human adaptation;yet,the influence of human agency on the natural world progressively increased.In conclusion,there is an urgent need to conduct systematic and scientific research on Chinese civilization from the perspective of the human-environment relationship.Through in-depth interdisciplinary exchange and collaboration between the fields of geography,climatology,history,and archaeology,we can deepen our understanding of the historical development of Chinese civilization and provide historical lessons and insights for addressing contemporary environmental challenges.
基金supported by the National Natural Science Foundation of China(21831001,21571016,91122028)the National Science Fund for Distinguished Young Scholars(20725101)。
文摘A core-shell type Co_(19)-added polyoxometalate H_(17)Na_(4)Cs_(21)[Co_(19)(μ_(3)-OH)_(12)(A-α-SiW_(10)O_(37))_(6)]·8 Cl·12H_(2)O(1)has been made under hydrothermal conditions guided by the lacunary directing synthetic strategy.Single crystal X-ray diffraction(SXRD)has shown that 19 Co^(2+)are arranged in a flat plane through edge sharing in a mode of 3-4-5-4-3,forming a core-shell type polyanion cluster{Co_(19)(SiW_(10))_6}with a diameter of approximately 2.24 nm.Visible-light-driven photocatalytic hydrogen evolution performance studies have shown that 1 is an efficient heterogeneous water reduction catalyst(WRC)with the H_(2)evolution rate of 2902.5μmol h^(-1)g^(-1).Moreover,the cycle tests indicated that 1 was also a good heterogeneous catalyst.
基金supported in part by the National Science and Technology Council of Republic of China under the contract numbers NSTC 114-2221-E-019-055-MY2NSTC 114-2221-E-019-069.
文摘Cloud data sharing is an important issue in modern times.To maintain the privacy and confidentiality of data stored in the cloud,encryption is an inevitable process before uploading the data.However,the centralized management and transmission latency of the cloud makes it difficult to support real-time processing and distributed access structures.As a result,fog computing and the Internet of Things(IoT)have emerged as crucial applications.Fog-assisted proxy re-encryption is a commonly adopted technique for sharing cloud ciphertexts.It allows a semitrusted proxy to transforma data owner’s ciphertext into another re-encrypted ciphertext intended for a data requester,without compromising any information about the original ciphertext.Yet,the user revocation and cloud ciphertext renewal problems still lack effective and secure mechanisms.Motivated by it,we propose a revocable conditional proxy re-encryption scheme offering ciphertext evolution(R-CPRE-CE).In particular,a periodically updated time key is used to revoke the user’s access privileges while an access condition prevents a malicious proxy from reencrypting unauthorized ciphertext.We also demonstrate that our scheme is provably secure under the notion of indistinguishability against adaptively chosen identity and chosen ciphertext attacks in the random oracle model.Performance analysis shows that our scheme reduces the computation time for a complete data access cycle from an initial query to the final decryption by approximately 47.05%compared to related schemes.
基金supported by the National Natural Science Foundation of China(32170571 and 32400451)Hubei Provincial Technological Innovation Plan Project(2025BBB014)+2 种基金the project TowArdsNextGENeration Crops(no.CZ.02.01.01/00/22_008/0004581)of the ERDF Programme Johannes Amos ComeniusProject 2662024JC010 was supported by the Fundamental Research Funds for the Central UniversitiesAdditional funding was provided by the Young Top-notch Talent Cultivation Program of Hubei Province and the Natural Science Foundation of Hubei Province of China(2024AFB116).
文摘Centromeres are indispensable for accurate chromosome segregation,but are subject to rapid sequence turnover while maintaining conserved functions--a paradox in genome evolution.To unravel this paradox,we integrated over 400 fully resolved centromeres from 17 diploid angiosperms spanning 180 million years of divergence,along with 1,000+pan-genomic assemblies,resequencing datasets,and congeneric wholegenome sequences.We showed that angiosperm centromere organization is determined by lineagespecific combinations of satellite repeats and transposable elements(TEs),which,in turn,shape distinct epigenetic landscapes and evolutionary trajectories within centromeres.In particular,TE insertion patterns were found to be key drivers of structural diversification and positional shift of centromeres in angiosperms.Intriguingly,population-level analyses revealed considerable plasticity in centromere sequences across species,with satellite repeats serving as focal points of evolutionary change and exhibiting species-specific heterogeneity patterns.Temporal reconstructions across congeneric species revealed the emergence and subsequent differentiation of centromeric repeats,outlining a dynamic continuum from gradual sequence diversification to complete turnover during speciation,often accompanied by karyotype reorganization.By integrating intra-and inter-species comparisons,we propose a unifying framework in which centromere innovation is governed by a delicate interplay between genome evolution,chromosomal shuffling,and selection constraints,resulting in phylogenomic signatures of centromeredriven speciation.
基金National Natural Science Foundation of China(No.52375236)Fundamental Research Funds for the Central Universities of China(No.23D110316)。
文摘In reliability analyses,the absence of a priori information on the most probable point of failure(MPP)may result in overlooking critical points,thereby leading to biased assessment outcomes.Moreover,second-order reliability methods exhibit limited accuracy in highly nonlinear scenarios.To overcome these challenges,a novel reliability analysis strategy based on a multimodal differential evolution algorithm and a hypersphere integration method is proposed.Initially,the penalty function method is employed to reformulate the MPP search problem as a conditionally constrained optimization task.Subsequently,a differential evolution algorithm incorporating a population delineation strategy is utilized to identify all MPPs.Finally,a paraboloid equation is constructed based on the curvature of the limit-state function at the MPPs,and the failure probability of the structure is calculated by using the hypersphere integration method.The localization effectiveness of the MPPs is compared through multiple numerical cases and two engineering examples,with accuracy comparisons of failure probabilities against the first-order reliability method(FORM)and the secondorder reliability method(SORM).The results indicate that the method effectively identifies existing MPPs and achieves higher solution precision.
基金supported by the National Natural Science Foundation of China Enterprise Innovation and Development Joint Fund Project(Grant No.U19B6003).
文摘Compound-specific carbon isotopic compositions(δ^(13)C)of aromatic hydrocarbons offer a promising solution to the long-standing challenge of correlating ultra-deep oils with their source rocks.However,systematic studies on the evolution of these isotopic signatures during thermal maturation remain scarce.In this study,we conducted closed-system anhydrous gold-tube pyrolysis experiments using a representative marine crude oil from the Tarim Basin to systematically investigate the evolution of polycyclic aromatic hydrocarbon(PAH)compositions and their compound-specific δ^(13)C values during thermal maturation.The results show that the abundance and relative distribution of the naphthalene,phenanthrene,fluorene,and dibenzothiophene series vary significantly with increasing maturity.Based on the variation patterns of δ^(13)C values,the aromatic hydrocarbons can be divided into two categories.The first category includes parent PAHs such as naphthalene,phenanthrene,fluorene,and dibenzothiophene,along with some alkylated dibenzothiophenes,whose δ^(13)C values remain essentially invariant during thermal evolution.The second category comprises other alkylated aromatic hydrocarbons,whose δ^(13)C values remain stable at lower temperatures but become progressively enriched in δ^(13)C at higher temperatures due to demethylation.Considering the diverse origins of PAH precursors and the thermal invariance of δ^(13)C in certain aromatic hydrocarbons,compound-specific carbon isotope analysis represents a powerful tool for identifying source rocks in ultra-deep petroleum systems,thereby advancing our understanding of ultra-deep hydrocarbon accumulation.
基金supported by the National Natural Science Foundation of China(No.12205165)Hebei Province Innovation Ability Improvement Plan Project(No.225676111H).
文摘Structural engineering of Pt-based nanoalloys is crucial for the rational design and manufacturing of high-performance and low-cost electrocatalysts for hydrogen evolution reaction(HER).Here,we reported PtNi nanoparticles with a refined size of 2.71 nm and regular strains loaded on carbon black,synthesized using the high-temperature liquid shock(HTLS)method.This approach offers significant advantages over conventional synthesis methods,including high scalability,rapid reaction rates,and precise control over the size and shape of nanocrystals.Importantly,the synthesized PtNi electrocatalysts demonstrate outstanding catalytic activity and long-term stability for HER,achieving low overpotentials of 19 and 203 mV at current densities of 10 and 1000 mA/cm^(2),respectively.The superior performance can be attributed to the combination of a refined particle size,lattice strains,and synergistic effects between Pt and Ni.This rapid liquid-state synthesis demonstrated here holds great potential for scalable and industrial manufacturing of micro-/nano-catalysts.
基金supported by the National Key R&D Program of China(2022YFA1503002,2022YFA1503003)the National Natural Science Foundation of China(22271081)+2 种基金the Natural Science Foundation of Heilongjiang Province(PL2024B017)the Postdoctoral Science Foundation of Heilongjiang Province(LBH-Z22240)the Heilongjiang University Excellent Youth Foundation。
文摘NiMo-based catalysts show significant potential for the hydrogen evolution reaction(HER).Optimizing the electronic structure and enhancing mass transfer are two critical factors for improving catalytic performance,but they remain significant challenges.Herein,we present a route for synthesizing two-dimensional(2D)porous Mo_(2)N-Ni heterojunction nanosheets with tuned Ni-Mo ratio for enhanced alkaline HER performance.A precursor can be easily synthesized by assembling polyoxometalate clusters(PMo_(12))with layered hydroxy oxides(Ni(OH)_(2)).It is found that the interaction between PMo_(12)and Ni(OH)_(2)can effectively protect the particles from significant agglomeration during pyrolysis,resulting in the formation of 2D porous sheets composed of small Mo_(2)N-Ni units.The transfer of electrons from Ni to Mo_(2)N results in the redistribution of electrons at the heterojunction,optimizing the adsorption and desorption of intermediates.Moreover,the 2D porous structure comprised of small particles enhances mass transfer,thereby reducing the impedance of the catalyst.Consequently,the catalyst with an optimized Mo/Ni ratio exhibits an overpotential of 19 mV at 10 mA cm^(-2),being comparable to that of commercial Pt/C catalyst.The anion exchange membrane(AEM)electrolyzer,consisting of optimized Mo_(2)N-Ni and NiFe-LDH,achieves a current density of 500 mA cm^(-2)at 1.80 V and can operate stably for 300 h.This assembly method offers an effective strategy for the large-scale preparation of efficient catalysts.
基金supported by the “Climbing Plan” of Harbin Normal University (No.XKB202301)National Natural Science Foundation of China (Nos.21871065 and 22071038)。
文摘Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and magnetic field enhanced-electrochemical activity remains to be fully elucidated.Herein,single-domain CoFe_(2)O_(4) catalysts with tunable oxygen vacancies(CFO-V_(O)) were synthesized to probe how V_(O) mediates magnetism and OER activity under magnetic field.The introduction of V_(O) can simultaneously modulate saturation magnetization(M_(s)) and coercivity(H_(c)),where the increased M_(s) dominates the magnetic field-enhanced OER activity.Under a 14,000 G magnetic field,the optimized CFO-V_(O) exhibits up to 16.1 % reduction in overpotential and 365 % enhancement in magnetocurrent(MC).Electrochemical analyses and post-OER characterization reveal that the magnetic field synergistically improves OER kinetics through lattice distortion induction,magnetohydrodynamic effect,and spin charge transfer effect.Importantly,the magnetic field promotes additional Co^(3+) generation to compensate for charge imbalance caused by V_(O) filling,maintaining dynamic equilibrium of V_(O) and effective reactant adsorption-conversion processes.This work unveils the synergistic mechanism of V_(O) and magnetic parameters for enhancing OER performance under the magnetic field,providing new insights into the design of high-efficiency spinregulated OER catalysts.
