China possesses abundant heavy oil resources,yet faces challenges such as high viscosity,underdeveloped production technologies,and elevated development cost.Although the in-situ catalytic viscosity-reduction technolo...China possesses abundant heavy oil resources,yet faces challenges such as high viscosity,underdeveloped production technologies,and elevated development cost.Although the in-situ catalytic viscosity-reduction technology can address certain technical,environmental,and cost problems during the extraction process,the catalysts often suffer from poor stability and low catalytic efficiency.In this study,a green and simple room-temperature stirring method was employed to synthesize a class of highly efficient and stable 2D MOF catalysts,which possess the capability to conduct in-situ catalytic pyrolysis of heavy oil and reduce the viscosity.Under the condition of 160℃,a catalyst concentration of 0.5 wt%,and a hydrogen donor(tetralin)concentration of 2 wt%,the viscosity-reduction rate of Fe-MOF is as high as 89.09%,and it can decrease the asphaltene content by 8.42%.In addition,through the structural identification and analysis of crude oil asphaltenes,the causes for the high viscosity of heavy oil are explained at the molecular level.Through the analysis of catalytic products and molecular dynamics simulation,the catalytic mechanism is studied.It is discovered that Fe-MOF can interact with heavy oil macromolecules via coordination and pore-channel effects,facilitating their cracking and dispersal.Furthermore,synergistic interactions between Fe-MOF and the hydrogen donor facilitates hydrogenation reactions and enhances the viscosity-reducing effect.This study provides a novel strategy for boosting heavy oil recovery and underscores the potential of 2D MOFs in catalytic pyrolysis applications.展开更多
A novel mechanical stirring-assisted double-melt in-situ reaction casting process was developed to prepare Cu-1TiB2(wt%)composites.The effects of preparation parameters(melting reaction temperature,stirring rate and s...A novel mechanical stirring-assisted double-melt in-situ reaction casting process was developed to prepare Cu-1TiB2(wt%)composites.The effects of preparation parameters(melting reaction temperature,stirring rate and stirring time)on the microstructure and properties of Cu-1TiB2 composites were investigated.The melt viscosity and particle motion during stirring process were analyzed.The strong turbulence and shear effects generated by mechanical stirring in the melt not only significantly improve the particle distribution but also contribute to adequate in-situ reactions and precise control of the chemical composition.The optimal preparation parameters were 1200℃,a stirring rate of 100 r·min^(−1) and a stirring time of 1 min.Combined with the cold rolling process,the tensile strength,elongation and electrical conductivity of the composite reached 475 MPa,6.0%and 88.4%IACS,respectively,which were significantly better than the composite prepared by manual stirring.The good plasticity is attributed to the uniform distribution of TiB_(2) particles,effectively retarding the crack propagation.The dispersion of particles promotes heterogeneous nucleation of Cu matrix and inhibits grain growth.On the other hand,dispersed particles contribute to grain shear fracture and dislocation multiplication during cold deformation.Therefore,the composite achieves higher dislocation strengthening and grain boundary strengthening.展开更多
Halide perovskite-based heterojunctions have emerged as promising candidates for solar energy conversion and storage due to their unique photophysical properties.However,the current bottleneck lies in the insufficient...Halide perovskite-based heterojunctions have emerged as promising candidates for solar energy conversion and storage due to their unique photophysical properties.However,the current bottleneck lies in the insufficient separation of photogenerated carriers at the interface,primarily due to challenges in the controllable growth of perovskite on the substrate.Herein,we present a growth strategy for depositing lead-free Cs_(3)Sb_(2)Br_(9)perovskite nanocrystals onto the surface of Co_(3)O_(4)with the assistance of polyacrylic acid(PAA),generating a step-scheme(S-scheme)heterojunction denoted as Co_(3)O_(4)-Cs_(3)Sb_(2)Br_(9).The utilization of PAA as a template can effectively regulate the nucleation and growth of Cs_(3)Sb_(2)Br_(9),thereby significantly enhancing the charge separation efficiency of the Co_(3)O_(4)-Cs_(3)Sb_(2)Br_(9)heterojunction compared to its counterpart formed without PAA assistance.Under simulated solar light irradiation(100 mW·cm^(-2)),the cerium-doped Co_(3)O_(4)-Cs_(3)Sb_(2)Br_(9)heterojunction exhibits excellent photocatalytic CO_(2)reduction activity without the need for any sacrificial agent.Specifically,the CO yield reaches up to 700.7μmol·g^(-1)·h^(-1),marking a 2.8-fold increase over the sample synthesized without PAA mediation.This polymer-assisted in-situ growth strategy should open up a new avenue for designing and developing more efficient photocatalytic materials based on halide perovskites.展开更多
Selective reduction of N_(2)O by CO under excess O_(2) was effectively catalyzed by Fe(0.9 wt%)-exchangedβzeolite(Fe0.9β)in the temperature range of 250–500°C.Kinetic experiments showed that the apparent activ...Selective reduction of N_(2)O by CO under excess O_(2) was effectively catalyzed by Fe(0.9 wt%)-exchangedβzeolite(Fe0.9β)in the temperature range of 250–500°C.Kinetic experiments showed that the apparent activation energy for N_(2)O reduction with CO was lower than that for the direct N_(2)O decomposition,and the rate of N_(2)O reduction with CO at 300℃ was 16 times higher than that for direct N_(2)O decomposition.Reaction order analyses showed that CO and N_(2)O were involved in the kinetically important step,while O_(2) was not involved in the important step.At 300℃,the rate of CO oxidation with 0.1%N_(2)O was two times higher than that of CO oxidation with 10%O_(2).This quantitatively demonstrates the preferential oxidation of CO by N_(2)O under excess O_(2) over Fe0.9β.Operando/in-situ diffuse reflectance ultraviolet-visible spectroscopy showed a redox-based catalytic cycle;α-Fe-O species are reduced by CO to give CO_(2) and reduced Fe species,which are then re-oxidized by N_(2)O to regenerate theα-Fe-O species.The initial rate for the regeneration ofα-Fe-O species under 0.1%N_(2)O was four times higher than that under 10%O_(2).This result shows quantitative evidence on the higher reactivity of N_(2)O than O_(2) for the regeneration ofα-Fe-O intermediates,providing a fundamental reason why the Fe0.9βcatalyst selectively promotes the CO+N_(2)O reaction under excess O_(2) rather than the undesired side reaction of CO+O_(2).The mechanistic model was verified by the results of in-situ Fe K-edge X-ray absorption spectroscopy.展开更多
An idea hits us that in-situ synthesizing ceramic phase at intergranular regions of RE-Fe-B alloys should be beneficial to the performance of the materials against corrosion,and in this work a new nanoscale(Zr,Ti)B_(2...An idea hits us that in-situ synthesizing ceramic phase at intergranular regions of RE-Fe-B alloys should be beneficial to the performance of the materials against corrosion,and in this work a new nanoscale(Zr,Ti)B_(2)with space and point groups of P6/mmm and Fmmm,respectively,was successfully synthesized in NdCeFeB sintered magnets.The hcp-structured(Zr,Ti)B_(2)phases are present in a stripe-like shape.Some of(Zr,Ti)B_(2)are developed at interfaces,and the others exist inside grain boundary phase.They coexist with REFe_(2)and RE-rich phases at intergranular regions.When proximity to RE2Fe14B grains,their orientation relationships obey[001]_(Nd_(2)Fe_(14)B)‖[110](Zr,Ti)B_(2).The formation of(Zr,Ti)B_(2)generates significant local compressive stress,being 8.48 GPa,and plenty of reliefs are developed inside the RE2Fe14B grains.The in-situ formed(Zr,Ti)B_(2)modifies the magnet microstructure,lessens the favorable sites for absorption reaction,narrows reaction channels,and reduces the potential difference between intergranular phase and main phase.Such favorable factors greatly enhance the corrosion resistance with an icorrdecrement by 70%in comparison to the unmodified magnet.These new discoveries are thought to be able to provide an insight into the method of potentially improving properties of magnets.展开更多
In-situ TiB_(2)/Al–Cu composite was processed by multidirectional forging(MDF)for six passes.The microstructure evolution of the forged workpiece was examined across various regions.The mechanical properties of the a...In-situ TiB_(2)/Al–Cu composite was processed by multidirectional forging(MDF)for six passes.The microstructure evolution of the forged workpiece was examined across various regions.The mechanical properties of the as-cast and MDFed composites were compared,and their strengthening mechanisms were analyzed.Results indicate that the grain refinement achieved through the MDF process is mainly due to the subdivision of the original grains through mechanical geometric fragmentation and the occurrence of dynamic recrystallization(DRX).DRX grains are formed through discontinuous DRX,continuous DRX,and recrystallization induced by particle-stimulated nucleation.A rise in accumulated equivalent strain(Σ?ε)results in finerα-Al grains and a more uniform distribution of TiB_(2)particles,which enhance the Vickers hardness of the composite.In addition,the tensile properties of the MDFed composite significantly improve compared with those of the as-cast composites,with ultimate tensile strength and yield strength increasing by 51.2%and 54%,respectively.This enhancement is primarily due to grain refinement strengthening and dislocation strengthening achieved by the MDF process.展开更多
Cr_(2)AlC,a representative MAX phase,gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments.However,the lack of the p...Cr_(2)AlC,a representative MAX phase,gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments.However,the lack of the phase formation mechanism has become the key bottleneck to the practical applications for Cr_(2)AlC synthesis with high purity at low temperatures.In this work,we fabricated the amorphous Cr-Al-C coating by a hybrid magnetron sputtering/cathodic arc deposition technique,in which the in-situ heating transmission electron microscopy(TEM)was conducted in a temperature range of 25-650℃ to address the real-time phase transformation for Cr_(2)AlC coating.The results demonstrated that increas-ing the temperature from 25 to 370℃ led to the structural transformation from amorphous Cr-Al-C to the crystalline Cr_(2)Al interphases.However,the high-purity Cr_(2)AlC MAX phase was distinctly formed at 500℃,accompanied by the diminished amorphous feature.With the further increase of temperature to 650℃,the decomposition of Cr_(2)AlC to Cr_(7)C_(3)impurities was observed.Similar phase evolution was also evidenced by the Ab-initio molecular dynamics calculations,where the bond energy of Cr-Cr,Cr-Al,and Cr-C played the key role in the formed crystalline stability during the heating process.The observa-tions not only provide fundamental insight into the phase formation mechanism for high-purity Cr_(2)AlC coatings but also offer a promising strategy to manipulate the advanced MAX phase materials with high tolerance to high-temperature oxidation and heavy ion radiations.展开更多
To convert carbon dioxide into high-value-added liquid products such as formate with renewable electricity(CO_(2)RR)is a promising strategy of CO_(2) resource utilization.The key is to find a highly efficient and sele...To convert carbon dioxide into high-value-added liquid products such as formate with renewable electricity(CO_(2)RR)is a promising strategy of CO_(2) resource utilization.The key is to find a highly efficient and selective electrocatalyst for CO_(2)RR.Herein,clustered Bi_(28)O_(32)(SO_(4))_(10) was found to show a high formate Faradaic efficiency(FE_(formate))of 96.2%at–1.1 V_(RHE) and FE_(formate) above 90%in a wide potential range from–0.9 to–1.3 V_(RHE) in H-type cell,surpassing the corresponding layered Bi_(2)O_(2)SO_(4)(85.6%FE_(formate) at–1.1 V_(RHE)).The advantageous CO_(2)RR performance of Bi_(28)O_(32)(SO_(4))_(10) over Bi_(2)O_(2)SO_(4) was ascribed to a special two-step in-situ reconstruction process,consisting of Bi_(28)O_(32)(SO_(4))_(10)→Bi_(-2.1)/Bi_(2)O_(2)CO_(3)→Bi_(-2.1)/Bi_(-0.6) during CO_(2)RR.It gave metallic Bi_(-2.1) with lattice distortion of–2.1%at the first step and metallic Bi_(-0.6) with lattice distortion of–0.6%at the second step.In contrast,the usual layered Bi_(2)O_(2)SO_(4) only formed metallic Bi_(-0.6) with weaker lattice strain.The metallic Bi_(-2.1) revealed higher efficiency in stabilizing*CO_(2) intermediate and reducing the energy barrier of CO_(2)RR,while suppressing hydrogen evolution reaction and CO formation.This work delivers a high-performance cluster-type Bi_(28)O_(32)(SO_(4))_(10) electrocatalyst for CO_(2)RR,and elucidates the origin of superior performance of clustered Bi_(28)O_(32)(SO_(4))_(10) electrocatalysts compared with layered Bi_(2)O_(2)SO_(4).展开更多
To investigate the key factors that cause ZrB_(2)/AA6111 and(ZrB_(2)+Al_(3)Zr)/AA6111 aluminum matrix composites(AMCs)made via in situ reaction to behave differently in terms of friction and wear.Room-temperature dry ...To investigate the key factors that cause ZrB_(2)/AA6111 and(ZrB_(2)+Al_(3)Zr)/AA6111 aluminum matrix composites(AMCs)made via in situ reaction to behave differently in terms of friction and wear.Room-temperature dry sliding tribological behavior of AA6111 Al alloys,ZrB_(2)/AA6111,and(ZrB_(2)+Al_(3)Zr)/AA6111 AMCs against silicon nitride(Si_(3)N_(4))counterparts were investigated.The study showed that AA6111/Al alloy had the highest wear rate and the most unstable coefficient of friction(COF),indicating the worst abrasion resistance.(ZrB_(2)+Al_(3)Zr)/AA6111 AMCs exhibit a lower wear rate and higher COF than ZrB_(2)/AA6111 AMCs.The result proved that the Al_(3)Zr particles prepared by the in-situ reaction are strongly bonded(lattice misfitδ=2.7%)to the Al matrix and are not easily stripped from the substrate.ZrB_(2)/AA6111 AMCs exhibited a lower COF attributed to the tribochemical reaction inducing the formation of more boric acid(H_(3)BO_(3))films with a graphite-like structure having a lubricating effect.展开更多
Dissolution kinetics of CaO·2Al_(2)O_(3)(CA_(2))particles in a synthetic CaO-Al_(2)O_(3)-SiO_(2)steelmaking slag system have been investigated using the high-temperature confocal laser scanning microscope.Effects...Dissolution kinetics of CaO·2Al_(2)O_(3)(CA_(2))particles in a synthetic CaO-Al_(2)O_(3)-SiO_(2)steelmaking slag system have been investigated using the high-temperature confocal laser scanning microscope.Effects of temperature(i.e.,1500,1550,and 1600℃)and slag composition on the dissolution time of CA_(2)particles are investigated,along with the time dependency of the projection area of the particle during the dissolution process.It is found that the dissolution rate was enhanced by either an increase in temperature or a decrease in slag viscosity.Moreover,a higher ratio of CaO/Al_(2)O_(3)(C/A)leads to an increased dissolution rate of CA_(2)particle at 1600℃.Thermodynamic calculations suggested the dissolution product,i.e.,melilite,formed on the surface of the CA_(2)particle during dissolution in slag with a C/A ratio of 3.8 at 1550℃.Scanning electron microscopy equipped with energy dispersive X-ray spectrometry analysis of as-quenched samples confirmed the dissolution path of CA_(2)particles in slags with C/A ratios of 1.8 and 3.8 as well as the melilite formed on the surface of CA_(2)particle.The formation of this layer during the dissolution process was identified as a hindrance,impeding the dissolution of CA_(2)particle.A valuable reference for designing or/and choosing the composition of top slag for clean steel production is provided,especially using calcium treatment during the secondary refining process.展开更多
Metal dichalcogenide-based 2D materials,gained considerable attention recently as a hydrogen evolution reaction(HER)electrocatalyst.In this work,we synthesized MoSe_(2)-based electrocatalyst via hydrothermal route wit...Metal dichalcogenide-based 2D materials,gained considerable attention recently as a hydrogen evolution reaction(HER)electrocatalyst.In this work,we synthesized MoSe_(2)-based electrocatalyst via hydrothermal route with varying phase contents(1T/2H)and respective HER performances were evaluated under the acidic media(0.5 M H_(2)SO_(4)),where best HER performance was obtained from the sample consisting of mixed 1T/2H phases,which was directly grown on a carbon paper(167 mV at10 mA cm^(-2))Furthermore,HER performance of electrocatalyst was further improved by in-situ electrodeposition of Pt nanoparticles(0.15 wt%)on the MoSe_(2) surface,which lead to significant enhancement in the HER performances(133 mV at 10 mA cm^(-2)).Finally,we conducted density functional theory calculations to reveal the origin of such enhanced performances when the mixed 1T/2H phases were present,where phase boundary region(1T/2H heterojunction)act as a low energy pathway for H_(2)adsorption and desorption via electron accumulation effect.Moreover,presence of the Pt nanoparticles tunes the electronic states of the MoSe_(2)based catalyst,resulting in the enhanced HER activity at heterointerface of 1T/2H MoSe_(2) while facilitating the hydrogen adsorption and desorption process providing a low energy pathway for HER.These results provide new insight on atomic level understanding of the MoSe_(2) based catalyst for HER application.展开更多
Zn-Al eutectoid alloy(ZA22)has ultra-high damping property,but its mechanical properties are still relatively low.In order to simultaneously improve the tensile strength and plasticity,a novel Al matrix composite inoc...Zn-Al eutectoid alloy(ZA22)has ultra-high damping property,but its mechanical properties are still relatively low.In order to simultaneously improve the tensile strength and plasticity,a novel Al matrix composite inoculant containing in-situ formed Al_(2)O_(3) and Al3Zr particles was designed and used to reinforce the ZA22 alloy.The microstructure of the ZA22 alloy was significantly refined.Fine Al_(2)O_(3) particles were uniformly distributed in theαphase and the lamellar eutectoid structure,whereas Al3Zr particles were distributed in theαphase and at theα/ηinterface.Property tests showed that the tensile mechanical properties of the reinforced ZA22 alloys were significantly improved.The maximum tensile strength and elongation reached 355 MPa and 7.62%,which were 1.50 and 1.89 times those of the original ZA22 alloy,respectively.The increase in mechanical properties is attributed to the multiple strengthening and toughening factors constructed in the refined microstructure.展开更多
Exploiting high-performance electrolyte holds the key for realization practical application of rechargeable magnesium batteries(RMBs).Herein,a new non-nucleophilic mononuclear electrolyte was developed and its electro...Exploiting high-performance electrolyte holds the key for realization practical application of rechargeable magnesium batteries(RMBs).Herein,a new non-nucleophilic mononuclear electrolyte was developed and its electrochemical active species was identified as[Mg(DME)_(3)][GaCl_(4)]_(2) through single-crystal X-ray diffraction analysis.The as-synthesized Mg(GaCl_(4))_(2)-IL-DME electrolyte could achieve a high ionic conductivity(9.85 m S cm^(-1)),good anodic stability(2.9 V vs.Mg/Mg^(2+)),and highly reversible Mg plating/stripping.The remarkable electrochemical performance should be attributed to the in-situ formation of Mg^(2+)-conducting Ga_(5)Mg_(2)alloy layer at the Mg/electrolyte interface during electrochemical cycling,which not only efficiently protects the Mg anode from passivation,but also allows for rapid Mg-ion transport.Significantly,the Mg(GaCl_(4))_(2)-IL-DME electrolyte showed excellent compatibility with both conversion and intercalation cathodes.The Mg/S batteries with Mg(Ga Cl_(4))_(2)-IL-DME electrolyte and KB/S cathode showed a high specific capacity of 839 m Ah g^(-1)after 50 cycles at 0.1 C with the Coulombic efficiency of~100%.Moreover,the assembled Mg|Mo_6 S_8 batteries delivered a reversible discharge capacity of 85 m Ah g^(-1)after 120 cycles at 0.2 C.This work provides a universal electrolyte for the realization of high-performance and practical RMBs,especially Mg/S batteries.展开更多
The prelithiated SiO_(x)anode showcases markedly improved Li-storage capabilities compared to its unlithiated counterparts,yet it faces hurdles such as slurry gassing,electrolyte deterioration,and capacity fade attrib...The prelithiated SiO_(x)anode showcases markedly improved Li-storage capabilities compared to its unlithiated counterparts,yet it faces hurdles such as slurry gassing,electrolyte deterioration,and capacity fade attributed to residual alkali and an unstable electrolyte/anode interface.To tackle these challenges,we propose a strategic utilization of residual alkali by creating an in-situ γ-LiAlO_(2)functional layer on the prelithiated SiO_(x)@C anode material.This is accomplished by incorporating a minor amount of Al_(2)O_(3)into the SiO_(x)@C/LiH precursor mixture before the solid-phase prelithiation process.The resulting modified prelithiated SiO_(x)@C anode with in-situ formed electrolyte-isolatingγ-LiAlO_(2)layer exhibits no discernible slurry gas generation within 7 days and substantially mitigates side reactions with the electrolyte,thereby boosting the initial coulombic efficiency and cycling stability of the SiO_(x)@C anode.In half-cell evaluations,the prelithiated SiO_(x)@C anode demonstrates a high Li-storage capacity of 1323 mAh g^(-1)and an impressive initial coulombic efficiency of 91.09%.When assessed in a 3.2 Ah 18,650 cylindrical battery,the prelithiated SiO_(x)@C anode showcases exceptional cyclability,retaining 81% of its capacity after 1000 cycles,underscoring its potential for practical applications.This study introduces a scalable and cost-effective prelithiation technique that propels the development and practical deployment of Si-based anodes by resolving persistent scientific challenges with the use of inexpensive additives.展开更多
Developing efficient and stable photocatalysts for hydrogen generation still remains a huge challenge.Herein,we adopted Cynanchum fibers as a carbon source and substrate to construct a ternary hollow core-shell carbon...Developing efficient and stable photocatalysts for hydrogen generation still remains a huge challenge.Herein,we adopted Cynanchum fibers as a carbon source and substrate to construct a ternary hollow core-shell carbon microtubes@TiO_(2)/ZnIn_(2)S_(4)(denoted as CMT@TiO_(2)/ZnIn_(2)S_(4))for photothermal-assisted photocatalytic hydrogen evolution(PHE).For the catalyst system,ZnIn_(2)S_(4)is the main visible light absorber,TiO_(2) is introduced to form a heterojunction with ZnIn_(2)S_(4)to facilitate the separation of photogenerated carriers,and hollow CMT derived from Cynanchum fibers serves as a conductive scaffold and a photothermal core to elevate the surface temperature of the localized reaction system.Benefiting from the rationally designed multicomponents and microstructures,the photocatalyst proposed enhanced PHE activity of 9.71 mmol·g^(−1)·h^(−1),which was 30.3,2.7 and 1.5 times higher than those of binary CMT@TiO_(2),pristine ZnIn_(2)S_(4)and TiO_(2)/ZnIn_(2)S_(4)composite,respectively.The outperformed PHE activity of CMT@TiO_(2)/ZnIn_(2)S_(4)could be ascribed to the synergy of the formation of intimate heterointerface,the CMT-induced photothermal effect and the hierarchical core-shell architecture.This work provides a promising approach for constructing efficient and durable photocatalysts for H_(2) evolution.展开更多
The Al-Mg_(2)Si in-situ composite is a lightweight material with great potential for application in fields such as automotive lightweighting,aerospace,and electronic components.In this research,the modification,semi-s...The Al-Mg_(2)Si in-situ composite is a lightweight material with great potential for application in fields such as automotive lightweighting,aerospace,and electronic components.In this research,the modification,semi-solid technology coupled with different types of electromagnetic stirring was applied to regulate the undesirable solidified dendritic microstructure and facilitate the composites’mechanical properties.The spheroidization and refinement of Mg_(2)Si andα-Al matrix in SM(semi-solid)+RES(rotate electromagnetic stirring)sample and SM+SHES(single winding helical electromagnetic stirring)sample are realized under the effect of fused dendrite arm,the decreased critical nucleate radius,and the increased nucleation rate and extra supercooling degree induced by electromagnetic stirring.The Mg_(2)Si phase in the SM+RES sample and SM+SHES sample is refined by 73.4%and 75.7%,respectively compared to the AC(as-cast)sample.Besides,the single winding electromagnetic stirring can lead to more homogeneously distributed physical fields,lower temperature gradient,and more significant mass transfer,mainly responsible for the more homogeneous distributed reinforced finer Mg_(2)Si particles in the SM+SHES sample.Moreover,both the tensile properties and hardness of modified semi-solid composites are improved through electromagnetic stirring.Compared with RES,the improvement effect of SHES is more excellent.The SM+SHES sample possesses the highest Brinell hardness(124.7 HB),and its quality index of tensile properties is 5.73%and 82.2%higher than that of the SM+RES and AC samples,respectively.展开更多
Perovskite solar cells(PSCs)incorporating 2D/3D heterostructures have exhibited remarkable improvements in both power conversion efficiency and operational stability.Nevertheless,the prevalent spin-coating fabrication...Perovskite solar cells(PSCs)incorporating 2D/3D heterostructures have exhibited remarkable improvements in both power conversion efficiency and operational stability.Nevertheless,the prevalent spin-coating fabrication technique presents formidable challenges for scalable manufacturing processes.Herein,we present a blade-coating compatible methodology for fabricating highperformance 2D/3D PSCs utilizing a low-volatility t-amyl alcohol(t-AmOH)-dimethylformamide(DMF)mixed solvent system.Through systematic materials characterization and comprehensive device performance analysis,we demonstrate that this approach facilitates uniform spatial distribution of butylammonium iodide(BAI)organic spacers,thereby promoting the formation of a high-quality 2D/3D perovskite architecture characterized by enhanced crystallinity and substantially reduced defect density.The optimized device achieves a champion power conversion efficiency of 22.25%while demonstrating exceptional operational stability,retaining 83%of its initial performance after prolonged exposure under ambient conditions(45%relative humidity)for 1000 h.展开更多
Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants.In this study,a series of Z-scheme heterojunction nanocomposites composed of CeO_(2)and terep...Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants.In this study,a series of Z-scheme heterojunction nanocomposites composed of CeO_(2)and terephthalic acid-modified WO_(3) was prepared and further used as photocatalysts for perfluorobutane sulfonate(PFBS)degradation.In this design,terephthalic acid was used as an electron recombination center and heterojunction mediator,which effectively enhances the migration ability of electron-hole pairs and the physicochemical stability of the catalyst.In addition,in situ synthesis of CeO_(2)onto the WO_(3) surface by the coordinate bond between terephthalic acid and Ce ions can avoid CeO_(2)agglomeration.As a result,the CeO_(2)@WO_(3) photocatalyst exhibits excellent PFBS degradation ability(94%for CeO_(2)@WO_(3) vs.19%for CeO_(2)).After the fifth cyclic degradation experiment,the CeO_(2)@WO_(3) photocatalyst still maintains stable degradation efficiency.Furthermore,the reaction mechanism of the PFBS in CeO_(2)@WO_(3) photocatalytic process was analyzed by free radical trapping experiment and liquid chromatography tandem mass spectrometry(LC-MS)technique.This study provides new insights for constructing Z-scheme heterojunction and demonstrates that CeO_(2)@WO_(3) photocatalysts possess a promising prospect for degrading PFBS pollutants.展开更多
To overcome the limited electronic conductivity and capacity of single and binary transition metal phos-phates(TMPs),highly electrochemical active materials and rational structural design of ternary TMPs composite are...To overcome the limited electronic conductivity and capacity of single and binary transition metal phos-phates(TMPs),highly electrochemical active materials and rational structural design of ternary TMPs composite are urgently required.In this study,we successfully synthesized an amorphous 3D Ni-Co-Mn phosphate@2D Ti_(3)C_(2)T_(x)(MXene)nanocomposite(NCMP series)through the electrodeposition method.The amorphous Ni-Co-Mn phosphate effectively restricts the self-accumulation of MXene nanosheets,result-ing in the development of a porous nanostructure.This structure exposes more active sites,expands the ion transport path,and enhances the conductivity of the Ni-Co-Mn phosphate@Ti_(3)C_(2)T_(x) material.Owing to the synergistic effect offered by Ni-Co-Mn phosphate and MXene nanocomposite,the anchored Ni-Co-Mn phosphate@Ti_(3)C_(2)T_(x)(NCMP-5)electrode delivers an elevated capacity of 342 mAh/g(1230 C/g)at 5.0 A/g,surpassing the pristine Ni-Co-Mn phosphate(NCMP-4,260 mAh/g)and MXene(33.3 mAh/g).Moreover,a hybrid solid-state supercapacitor(HSSC)device is assembled with NCMP-5 as a cathode and reduced graphene oxide(rGO)as an anode within a polymer gel(PVA-KOH)electrolyte.Notably,the fabricated HSSC device displays a supreme specific capacity of 27.5 mAh/g(99 C/g)and a high(volumetric)energy density of 22 Wh/kg(3.6 Wh/cm^(3))at a power density of 0.80 kW/kg(0.13 kW/cm^(3))for 1.0 A/g.Moreover,the HSSC device retains 95.4%of its initial capacity even after 10,000 cycles.Importantly,the operational potential window of two serially connected HSSC devices approaches+3.2 V,enabling different colored commercial light-emitting diodes(LEDs)to be efficiently illuminated.Eventually,the remarkable super-capacitive characteristics of the 3D@2D amorphous Ni-Co-Mn phosphate@MXene nanocomposite make it an attractive choice for advanced electroactive materials in upcoming hybrid energy storage technologies.展开更多
β-Sialon has emerged as a promising material for enhancing the service life of Al_(2)O_(3)-C refractories due to its excellent physicochemical properties.The impact of varying concentrations of nanometer Al/Si alloy ...β-Sialon has emerged as a promising material for enhancing the service life of Al_(2)O_(3)-C refractories due to its excellent physicochemical properties.The impact of varying concentrations of nanometer Al/Si alloy on the in-situ synthesis of β-Sialon within Al_(2)O_(3)-C refractory materials,as well as its oxidation behavior,was investigated.The findings indicate that the presence of Al/Si alloy promotes the formation of AlN and SiC whiskers at 1300℃,which subsequently facilitate the production of plate-like β-Sialon at 1500℃.Density functional theory analysis reveals that the(020)crystal plane of β-Sialon exhibits the lowest adsorption energy for Al2O and AlO molecules under the influence of iron atoms,suggesting a solid-liquid-vapor growth mechanism for β-Sialon formation.The introduction of these ceramic phases significantly enhances the mechanical properties of Al_(2)O_(3)-C refractories.Specifically,the addition of 6 wt.%Al/Si alloy yielded specimens with the highest cold modulus of rupture and cold crushing strength at 1500℃,achieving values of 35.2 and 127.5 MPa,respectively--representing increases of 40.1%and 37.4%.Furthermore,during high-temperature oxidation,the formation of plate-like β-Sialon leads to the development of a dense protective layer on the surface.This impedes the diffusion pathways of oxygen and consequently enhances the oxidation resistance of the refractory.展开更多
基金supported by the National Natural Science Foundation of China(52174047)Sinopec Project(No.P23138).
文摘China possesses abundant heavy oil resources,yet faces challenges such as high viscosity,underdeveloped production technologies,and elevated development cost.Although the in-situ catalytic viscosity-reduction technology can address certain technical,environmental,and cost problems during the extraction process,the catalysts often suffer from poor stability and low catalytic efficiency.In this study,a green and simple room-temperature stirring method was employed to synthesize a class of highly efficient and stable 2D MOF catalysts,which possess the capability to conduct in-situ catalytic pyrolysis of heavy oil and reduce the viscosity.Under the condition of 160℃,a catalyst concentration of 0.5 wt%,and a hydrogen donor(tetralin)concentration of 2 wt%,the viscosity-reduction rate of Fe-MOF is as high as 89.09%,and it can decrease the asphaltene content by 8.42%.In addition,through the structural identification and analysis of crude oil asphaltenes,the causes for the high viscosity of heavy oil are explained at the molecular level.Through the analysis of catalytic products and molecular dynamics simulation,the catalytic mechanism is studied.It is discovered that Fe-MOF can interact with heavy oil macromolecules via coordination and pore-channel effects,facilitating their cracking and dispersal.Furthermore,synergistic interactions between Fe-MOF and the hydrogen donor facilitates hydrogenation reactions and enhances the viscosity-reducing effect.This study provides a novel strategy for boosting heavy oil recovery and underscores the potential of 2D MOFs in catalytic pyrolysis applications.
基金supported by the National Natural Science Foundation of China(Nos.U2202255 and 52371038)the Science and Technology Innovation Program of Hunan Province(No.2023RC1019).
文摘A novel mechanical stirring-assisted double-melt in-situ reaction casting process was developed to prepare Cu-1TiB2(wt%)composites.The effects of preparation parameters(melting reaction temperature,stirring rate and stirring time)on the microstructure and properties of Cu-1TiB2 composites were investigated.The melt viscosity and particle motion during stirring process were analyzed.The strong turbulence and shear effects generated by mechanical stirring in the melt not only significantly improve the particle distribution but also contribute to adequate in-situ reactions and precise control of the chemical composition.The optimal preparation parameters were 1200℃,a stirring rate of 100 r·min^(−1) and a stirring time of 1 min.Combined with the cold rolling process,the tensile strength,elongation and electrical conductivity of the composite reached 475 MPa,6.0%and 88.4%IACS,respectively,which were significantly better than the composite prepared by manual stirring.The good plasticity is attributed to the uniform distribution of TiB_(2) particles,effectively retarding the crack propagation.The dispersion of particles promotes heterogeneous nucleation of Cu matrix and inhibits grain growth.On the other hand,dispersed particles contribute to grain shear fracture and dislocation multiplication during cold deformation.Therefore,the composite achieves higher dislocation strengthening and grain boundary strengthening.
基金supported by the National Key R&D Program of China(No.2022YFA1502902)the National Natural Science Foundation of China(Nos.U21A20286 and 22475152)+2 种基金the Natural Science Foundation of Tianjin City(No.17JCJQJC43800)the Programme of Introducing Talents of Discipline to Universities(111 Project)Tianjin Research Innovation Project for Postgraduate Students(No.2022BKY156).
文摘Halide perovskite-based heterojunctions have emerged as promising candidates for solar energy conversion and storage due to their unique photophysical properties.However,the current bottleneck lies in the insufficient separation of photogenerated carriers at the interface,primarily due to challenges in the controllable growth of perovskite on the substrate.Herein,we present a growth strategy for depositing lead-free Cs_(3)Sb_(2)Br_(9)perovskite nanocrystals onto the surface of Co_(3)O_(4)with the assistance of polyacrylic acid(PAA),generating a step-scheme(S-scheme)heterojunction denoted as Co_(3)O_(4)-Cs_(3)Sb_(2)Br_(9).The utilization of PAA as a template can effectively regulate the nucleation and growth of Cs_(3)Sb_(2)Br_(9),thereby significantly enhancing the charge separation efficiency of the Co_(3)O_(4)-Cs_(3)Sb_(2)Br_(9)heterojunction compared to its counterpart formed without PAA assistance.Under simulated solar light irradiation(100 mW·cm^(-2)),the cerium-doped Co_(3)O_(4)-Cs_(3)Sb_(2)Br_(9)heterojunction exhibits excellent photocatalytic CO_(2)reduction activity without the need for any sacrificial agent.Specifically,the CO yield reaches up to 700.7μmol·g^(-1)·h^(-1),marking a 2.8-fold increase over the sample synthesized without PAA mediation.This polymer-assisted in-situ growth strategy should open up a new avenue for designing and developing more efficient photocatalytic materials based on halide perovskites.
文摘Selective reduction of N_(2)O by CO under excess O_(2) was effectively catalyzed by Fe(0.9 wt%)-exchangedβzeolite(Fe0.9β)in the temperature range of 250–500°C.Kinetic experiments showed that the apparent activation energy for N_(2)O reduction with CO was lower than that for the direct N_(2)O decomposition,and the rate of N_(2)O reduction with CO at 300℃ was 16 times higher than that for direct N_(2)O decomposition.Reaction order analyses showed that CO and N_(2)O were involved in the kinetically important step,while O_(2) was not involved in the important step.At 300℃,the rate of CO oxidation with 0.1%N_(2)O was two times higher than that of CO oxidation with 10%O_(2).This quantitatively demonstrates the preferential oxidation of CO by N_(2)O under excess O_(2) over Fe0.9β.Operando/in-situ diffuse reflectance ultraviolet-visible spectroscopy showed a redox-based catalytic cycle;α-Fe-O species are reduced by CO to give CO_(2) and reduced Fe species,which are then re-oxidized by N_(2)O to regenerate theα-Fe-O species.The initial rate for the regeneration ofα-Fe-O species under 0.1%N_(2)O was four times higher than that under 10%O_(2).This result shows quantitative evidence on the higher reactivity of N_(2)O than O_(2) for the regeneration ofα-Fe-O intermediates,providing a fundamental reason why the Fe0.9βcatalyst selectively promotes the CO+N_(2)O reaction under excess O_(2) rather than the undesired side reaction of CO+O_(2).The mechanistic model was verified by the results of in-situ Fe K-edge X-ray absorption spectroscopy.
基金Project supported by the National Natural Science Foundation of China(52174346)Natural Science Foundation of Shandong Province(ZR2021ME031,ZR2022QE115)Innovation Capability Enhancement Project for Technology Oriented Small and Medium Sized Enterprises of Shandong Province(2022TSGC2586)。
文摘An idea hits us that in-situ synthesizing ceramic phase at intergranular regions of RE-Fe-B alloys should be beneficial to the performance of the materials against corrosion,and in this work a new nanoscale(Zr,Ti)B_(2)with space and point groups of P6/mmm and Fmmm,respectively,was successfully synthesized in NdCeFeB sintered magnets.The hcp-structured(Zr,Ti)B_(2)phases are present in a stripe-like shape.Some of(Zr,Ti)B_(2)are developed at interfaces,and the others exist inside grain boundary phase.They coexist with REFe_(2)and RE-rich phases at intergranular regions.When proximity to RE2Fe14B grains,their orientation relationships obey[001]_(Nd_(2)Fe_(14)B)‖[110](Zr,Ti)B_(2).The formation of(Zr,Ti)B_(2)generates significant local compressive stress,being 8.48 GPa,and plenty of reliefs are developed inside the RE2Fe14B grains.The in-situ formed(Zr,Ti)B_(2)modifies the magnet microstructure,lessens the favorable sites for absorption reaction,narrows reaction channels,and reduces the potential difference between intergranular phase and main phase.Such favorable factors greatly enhance the corrosion resistance with an icorrdecrement by 70%in comparison to the unmodified magnet.These new discoveries are thought to be able to provide an insight into the method of potentially improving properties of magnets.
基金supported by the Key Program for International Cooperation of the Ministry of Science and Technology,China(No.ZCGX2022001L)。
文摘In-situ TiB_(2)/Al–Cu composite was processed by multidirectional forging(MDF)for six passes.The microstructure evolution of the forged workpiece was examined across various regions.The mechanical properties of the as-cast and MDFed composites were compared,and their strengthening mechanisms were analyzed.Results indicate that the grain refinement achieved through the MDF process is mainly due to the subdivision of the original grains through mechanical geometric fragmentation and the occurrence of dynamic recrystallization(DRX).DRX grains are formed through discontinuous DRX,continuous DRX,and recrystallization induced by particle-stimulated nucleation.A rise in accumulated equivalent strain(Σ?ε)results in finerα-Al grains and a more uniform distribution of TiB_(2)particles,which enhance the Vickers hardness of the composite.In addition,the tensile properties of the MDFed composite significantly improve compared with those of the as-cast composites,with ultimate tensile strength and yield strength increasing by 51.2%and 54%,respectively.This enhancement is primarily due to grain refinement strengthening and dislocation strengthening achieved by the MDF process.
基金supported by the financial support of the National Science Fund for Distinguished Young Scholars of China(No.52025014)the National Natural Science Foundation of China(Nos.52101109 and 52171090)+1 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LD24E010003 and LZJWY23E090001)the Natural Science Foundation of Ningbo(Nos.2023J410).
文摘Cr_(2)AlC,a representative MAX phase,gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments.However,the lack of the phase formation mechanism has become the key bottleneck to the practical applications for Cr_(2)AlC synthesis with high purity at low temperatures.In this work,we fabricated the amorphous Cr-Al-C coating by a hybrid magnetron sputtering/cathodic arc deposition technique,in which the in-situ heating transmission electron microscopy(TEM)was conducted in a temperature range of 25-650℃ to address the real-time phase transformation for Cr_(2)AlC coating.The results demonstrated that increas-ing the temperature from 25 to 370℃ led to the structural transformation from amorphous Cr-Al-C to the crystalline Cr_(2)Al interphases.However,the high-purity Cr_(2)AlC MAX phase was distinctly formed at 500℃,accompanied by the diminished amorphous feature.With the further increase of temperature to 650℃,the decomposition of Cr_(2)AlC to Cr_(7)C_(3)impurities was observed.Similar phase evolution was also evidenced by the Ab-initio molecular dynamics calculations,where the bond energy of Cr-Cr,Cr-Al,and Cr-C played the key role in the formed crystalline stability during the heating process.The observa-tions not only provide fundamental insight into the phase formation mechanism for high-purity Cr_(2)AlC coatings but also offer a promising strategy to manipulate the advanced MAX phase materials with high tolerance to high-temperature oxidation and heavy ion radiations.
文摘To convert carbon dioxide into high-value-added liquid products such as formate with renewable electricity(CO_(2)RR)is a promising strategy of CO_(2) resource utilization.The key is to find a highly efficient and selective electrocatalyst for CO_(2)RR.Herein,clustered Bi_(28)O_(32)(SO_(4))_(10) was found to show a high formate Faradaic efficiency(FE_(formate))of 96.2%at–1.1 V_(RHE) and FE_(formate) above 90%in a wide potential range from–0.9 to–1.3 V_(RHE) in H-type cell,surpassing the corresponding layered Bi_(2)O_(2)SO_(4)(85.6%FE_(formate) at–1.1 V_(RHE)).The advantageous CO_(2)RR performance of Bi_(28)O_(32)(SO_(4))_(10) over Bi_(2)O_(2)SO_(4) was ascribed to a special two-step in-situ reconstruction process,consisting of Bi_(28)O_(32)(SO_(4))_(10)→Bi_(-2.1)/Bi_(2)O_(2)CO_(3)→Bi_(-2.1)/Bi_(-0.6) during CO_(2)RR.It gave metallic Bi_(-2.1) with lattice distortion of–2.1%at the first step and metallic Bi_(-0.6) with lattice distortion of–0.6%at the second step.In contrast,the usual layered Bi_(2)O_(2)SO_(4) only formed metallic Bi_(-0.6) with weaker lattice strain.The metallic Bi_(-2.1) revealed higher efficiency in stabilizing*CO_(2) intermediate and reducing the energy barrier of CO_(2)RR,while suppressing hydrogen evolution reaction and CO formation.This work delivers a high-performance cluster-type Bi_(28)O_(32)(SO_(4))_(10) electrocatalyst for CO_(2)RR,and elucidates the origin of superior performance of clustered Bi_(28)O_(32)(SO_(4))_(10) electrocatalysts compared with layered Bi_(2)O_(2)SO_(4).
基金Supported by National Natural Science Foundation of China(Grant No.51605206)Postgraduate Research&Practice Innovation Program of Jiangsu Province of China(Grant Nos.SJCX21_1769,SJCX22_1941)Ministry of Science and Technology High-end Foreign Experts Introduction Program Project of China(Grant Nos.G2022014043,G2022014134L).
文摘To investigate the key factors that cause ZrB_(2)/AA6111 and(ZrB_(2)+Al_(3)Zr)/AA6111 aluminum matrix composites(AMCs)made via in situ reaction to behave differently in terms of friction and wear.Room-temperature dry sliding tribological behavior of AA6111 Al alloys,ZrB_(2)/AA6111,and(ZrB_(2)+Al_(3)Zr)/AA6111 AMCs against silicon nitride(Si_(3)N_(4))counterparts were investigated.The study showed that AA6111/Al alloy had the highest wear rate and the most unstable coefficient of friction(COF),indicating the worst abrasion resistance.(ZrB_(2)+Al_(3)Zr)/AA6111 AMCs exhibit a lower wear rate and higher COF than ZrB_(2)/AA6111 AMCs.The result proved that the Al_(3)Zr particles prepared by the in-situ reaction are strongly bonded(lattice misfitδ=2.7%)to the Al matrix and are not easily stripped from the substrate.ZrB_(2)/AA6111 AMCs exhibited a lower COF attributed to the tribochemical reaction inducing the formation of more boric acid(H_(3)BO_(3))films with a graphite-like structure having a lubricating effect.
基金the Natural Sciences and Engineering Research Council of Canada(NSERC)for funding this researchThis research used a high temperature confocal laser scanning microscope-VL2000DX-SVF17SP funded by Canada Foundation for Innovation John Evans Leaders Fund(CFI JELF,Project Number:32826),a PANalytical X’Pert diffraction instrument located at the Centre for crystal growth,Brockhouse Institute for Materials Research,and a scanning electron microscope-JEOL 6610 located at the Canadian Centre for Electron Microscopy at McMaster University.W.Mu would like to acknowledge Swedish Iron and Steel Research Office(Jernkonteret),STINT and SSF for supporting the time for international collaboration research regarding clean steel.
文摘Dissolution kinetics of CaO·2Al_(2)O_(3)(CA_(2))particles in a synthetic CaO-Al_(2)O_(3)-SiO_(2)steelmaking slag system have been investigated using the high-temperature confocal laser scanning microscope.Effects of temperature(i.e.,1500,1550,and 1600℃)and slag composition on the dissolution time of CA_(2)particles are investigated,along with the time dependency of the projection area of the particle during the dissolution process.It is found that the dissolution rate was enhanced by either an increase in temperature or a decrease in slag viscosity.Moreover,a higher ratio of CaO/Al_(2)O_(3)(C/A)leads to an increased dissolution rate of CA_(2)particle at 1600℃.Thermodynamic calculations suggested the dissolution product,i.e.,melilite,formed on the surface of the CA_(2)particle during dissolution in slag with a C/A ratio of 3.8 at 1550℃.Scanning electron microscopy equipped with energy dispersive X-ray spectrometry analysis of as-quenched samples confirmed the dissolution path of CA_(2)particles in slags with C/A ratios of 1.8 and 3.8 as well as the melilite formed on the surface of CA_(2)particle.The formation of this layer during the dissolution process was identified as a hindrance,impeding the dissolution of CA_(2)particle.A valuable reference for designing or/and choosing the composition of top slag for clean steel production is provided,especially using calcium treatment during the secondary refining process.
基金supported by the GRRC program of Gyeonggi Province(GRRC Sungkyunkwan 2023-B01)the support of Korea Institute of Energy Technology Evaluation and Planning(KETEP)and the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(No.20224000000100)the research support of KENTECH foundation research grant supported by MOTIE。
文摘Metal dichalcogenide-based 2D materials,gained considerable attention recently as a hydrogen evolution reaction(HER)electrocatalyst.In this work,we synthesized MoSe_(2)-based electrocatalyst via hydrothermal route with varying phase contents(1T/2H)and respective HER performances were evaluated under the acidic media(0.5 M H_(2)SO_(4)),where best HER performance was obtained from the sample consisting of mixed 1T/2H phases,which was directly grown on a carbon paper(167 mV at10 mA cm^(-2))Furthermore,HER performance of electrocatalyst was further improved by in-situ electrodeposition of Pt nanoparticles(0.15 wt%)on the MoSe_(2) surface,which lead to significant enhancement in the HER performances(133 mV at 10 mA cm^(-2)).Finally,we conducted density functional theory calculations to reveal the origin of such enhanced performances when the mixed 1T/2H phases were present,where phase boundary region(1T/2H heterojunction)act as a low energy pathway for H_(2)adsorption and desorption via electron accumulation effect.Moreover,presence of the Pt nanoparticles tunes the electronic states of the MoSe_(2)based catalyst,resulting in the enhanced HER activity at heterointerface of 1T/2H MoSe_(2) while facilitating the hydrogen adsorption and desorption process providing a low energy pathway for HER.These results provide new insight on atomic level understanding of the MoSe_(2) based catalyst for HER application.
基金supported by the Foundation Strengthening Program of China(No.2019-JCJQ-ZD-142-00)the Natural Science Foundation of Hebei Province,China(No.E2021202017)the Foundation of Guangdong Academy of Sciences,China(No.2021GDASYL-20210102002)。
文摘Zn-Al eutectoid alloy(ZA22)has ultra-high damping property,but its mechanical properties are still relatively low.In order to simultaneously improve the tensile strength and plasticity,a novel Al matrix composite inoculant containing in-situ formed Al_(2)O_(3) and Al3Zr particles was designed and used to reinforce the ZA22 alloy.The microstructure of the ZA22 alloy was significantly refined.Fine Al_(2)O_(3) particles were uniformly distributed in theαphase and the lamellar eutectoid structure,whereas Al3Zr particles were distributed in theαphase and at theα/ηinterface.Property tests showed that the tensile mechanical properties of the reinforced ZA22 alloys were significantly improved.The maximum tensile strength and elongation reached 355 MPa and 7.62%,which were 1.50 and 1.89 times those of the original ZA22 alloy,respectively.The increase in mechanical properties is attributed to the multiple strengthening and toughening factors constructed in the refined microstructure.
基金financially supported by National Natural Science Foundation of China(21773291,52303130,62205231,61904118,22002102)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(19KJA210005)+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX23_1710)Postgraduate Research&Practice Innovation Program of Suzhou University of Science and Technology(CLKYCX23_06)。
文摘Exploiting high-performance electrolyte holds the key for realization practical application of rechargeable magnesium batteries(RMBs).Herein,a new non-nucleophilic mononuclear electrolyte was developed and its electrochemical active species was identified as[Mg(DME)_(3)][GaCl_(4)]_(2) through single-crystal X-ray diffraction analysis.The as-synthesized Mg(GaCl_(4))_(2)-IL-DME electrolyte could achieve a high ionic conductivity(9.85 m S cm^(-1)),good anodic stability(2.9 V vs.Mg/Mg^(2+)),and highly reversible Mg plating/stripping.The remarkable electrochemical performance should be attributed to the in-situ formation of Mg^(2+)-conducting Ga_(5)Mg_(2)alloy layer at the Mg/electrolyte interface during electrochemical cycling,which not only efficiently protects the Mg anode from passivation,but also allows for rapid Mg-ion transport.Significantly,the Mg(GaCl_(4))_(2)-IL-DME electrolyte showed excellent compatibility with both conversion and intercalation cathodes.The Mg/S batteries with Mg(Ga Cl_(4))_(2)-IL-DME electrolyte and KB/S cathode showed a high specific capacity of 839 m Ah g^(-1)after 50 cycles at 0.1 C with the Coulombic efficiency of~100%.Moreover,the assembled Mg|Mo_6 S_8 batteries delivered a reversible discharge capacity of 85 m Ah g^(-1)after 120 cycles at 0.2 C.This work provides a universal electrolyte for the realization of high-performance and practical RMBs,especially Mg/S batteries.
基金supported by the National Natural Science Foundation of China(52234001,52201254)the Science and Technology Planning Project of Hunan Province(2018TP1017)+3 种基金the Science,Technoloy and Innovation Project of Changsha Research Institute of Mining and Metallurgy(22-C5CL001)the Young Student Fundamental Research Project of Hunan Natural Science Foundation(2024JJ10036)the Introducing Major Universities and Research Institutions to Jointly Build Innovative Carrier Project of Jining City(2023DYDS022)the Scientific Research Foundation for New Talents in University of Jinan(XRC2406)。
文摘The prelithiated SiO_(x)anode showcases markedly improved Li-storage capabilities compared to its unlithiated counterparts,yet it faces hurdles such as slurry gassing,electrolyte deterioration,and capacity fade attributed to residual alkali and an unstable electrolyte/anode interface.To tackle these challenges,we propose a strategic utilization of residual alkali by creating an in-situ γ-LiAlO_(2)functional layer on the prelithiated SiO_(x)@C anode material.This is accomplished by incorporating a minor amount of Al_(2)O_(3)into the SiO_(x)@C/LiH precursor mixture before the solid-phase prelithiation process.The resulting modified prelithiated SiO_(x)@C anode with in-situ formed electrolyte-isolatingγ-LiAlO_(2)layer exhibits no discernible slurry gas generation within 7 days and substantially mitigates side reactions with the electrolyte,thereby boosting the initial coulombic efficiency and cycling stability of the SiO_(x)@C anode.In half-cell evaluations,the prelithiated SiO_(x)@C anode demonstrates a high Li-storage capacity of 1323 mAh g^(-1)and an impressive initial coulombic efficiency of 91.09%.When assessed in a 3.2 Ah 18,650 cylindrical battery,the prelithiated SiO_(x)@C anode showcases exceptional cyclability,retaining 81% of its capacity after 1000 cycles,underscoring its potential for practical applications.This study introduces a scalable and cost-effective prelithiation technique that propels the development and practical deployment of Si-based anodes by resolving persistent scientific challenges with the use of inexpensive additives.
基金supported by the National Natural Science Foundation of China(No.21701078)the PhD Initiation Foundation of Liaocheng University(No.318052140).
文摘Developing efficient and stable photocatalysts for hydrogen generation still remains a huge challenge.Herein,we adopted Cynanchum fibers as a carbon source and substrate to construct a ternary hollow core-shell carbon microtubes@TiO_(2)/ZnIn_(2)S_(4)(denoted as CMT@TiO_(2)/ZnIn_(2)S_(4))for photothermal-assisted photocatalytic hydrogen evolution(PHE).For the catalyst system,ZnIn_(2)S_(4)is the main visible light absorber,TiO_(2) is introduced to form a heterojunction with ZnIn_(2)S_(4)to facilitate the separation of photogenerated carriers,and hollow CMT derived from Cynanchum fibers serves as a conductive scaffold and a photothermal core to elevate the surface temperature of the localized reaction system.Benefiting from the rationally designed multicomponents and microstructures,the photocatalyst proposed enhanced PHE activity of 9.71 mmol·g^(−1)·h^(−1),which was 30.3,2.7 and 1.5 times higher than those of binary CMT@TiO_(2),pristine ZnIn_(2)S_(4)and TiO_(2)/ZnIn_(2)S_(4)composite,respectively.The outperformed PHE activity of CMT@TiO_(2)/ZnIn_(2)S_(4)could be ascribed to the synergy of the formation of intimate heterointerface,the CMT-induced photothermal effect and the hierarchical core-shell architecture.This work provides a promising approach for constructing efficient and durable photocatalysts for H_(2) evolution.
基金supported by the National Key R&D Projects(No.2021YFB3702000)the Institute Projects of Ansteel Beijing Research Institute(No.2023BJC-06)the Regional Company Projects in Ansteel Beijing Research Institute(No.2022BJB-18BG&No.2022BJB-13GF).
文摘The Al-Mg_(2)Si in-situ composite is a lightweight material with great potential for application in fields such as automotive lightweighting,aerospace,and electronic components.In this research,the modification,semi-solid technology coupled with different types of electromagnetic stirring was applied to regulate the undesirable solidified dendritic microstructure and facilitate the composites’mechanical properties.The spheroidization and refinement of Mg_(2)Si andα-Al matrix in SM(semi-solid)+RES(rotate electromagnetic stirring)sample and SM+SHES(single winding helical electromagnetic stirring)sample are realized under the effect of fused dendrite arm,the decreased critical nucleate radius,and the increased nucleation rate and extra supercooling degree induced by electromagnetic stirring.The Mg_(2)Si phase in the SM+RES sample and SM+SHES sample is refined by 73.4%and 75.7%,respectively compared to the AC(as-cast)sample.Besides,the single winding electromagnetic stirring can lead to more homogeneously distributed physical fields,lower temperature gradient,and more significant mass transfer,mainly responsible for the more homogeneous distributed reinforced finer Mg_(2)Si particles in the SM+SHES sample.Moreover,both the tensile properties and hardness of modified semi-solid composites are improved through electromagnetic stirring.Compared with RES,the improvement effect of SHES is more excellent.The SM+SHES sample possesses the highest Brinell hardness(124.7 HB),and its quality index of tensile properties is 5.73%and 82.2%higher than that of the SM+RES and AC samples,respectively.
基金supported by ational Natural Science Foundation of China(Nos.62405293,62301509,62304209)Key Research and Development Program of Shanxi Province(No.202302030201001)Fundamental Research Program of Shanxi Province(Nos.202303021212191,202203021222079,20210302123203,202103021223185).
文摘Perovskite solar cells(PSCs)incorporating 2D/3D heterostructures have exhibited remarkable improvements in both power conversion efficiency and operational stability.Nevertheless,the prevalent spin-coating fabrication technique presents formidable challenges for scalable manufacturing processes.Herein,we present a blade-coating compatible methodology for fabricating highperformance 2D/3D PSCs utilizing a low-volatility t-amyl alcohol(t-AmOH)-dimethylformamide(DMF)mixed solvent system.Through systematic materials characterization and comprehensive device performance analysis,we demonstrate that this approach facilitates uniform spatial distribution of butylammonium iodide(BAI)organic spacers,thereby promoting the formation of a high-quality 2D/3D perovskite architecture characterized by enhanced crystallinity and substantially reduced defect density.The optimized device achieves a champion power conversion efficiency of 22.25%while demonstrating exceptional operational stability,retaining 83%of its initial performance after prolonged exposure under ambient conditions(45%relative humidity)for 1000 h.
基金Project supported by the National Natural Science Foundation of China(52300206)the Natural Science Foundation of Jiangsu Province(BK20230705)+2 种基金Industry-University Research Cooperation Project of Jiangsu Province,China(BY20221227)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJB610014)the Talent-Recruiting Program of Nanjing Institute of Technology(YKJ202124)。
文摘Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants.In this study,a series of Z-scheme heterojunction nanocomposites composed of CeO_(2)and terephthalic acid-modified WO_(3) was prepared and further used as photocatalysts for perfluorobutane sulfonate(PFBS)degradation.In this design,terephthalic acid was used as an electron recombination center and heterojunction mediator,which effectively enhances the migration ability of electron-hole pairs and the physicochemical stability of the catalyst.In addition,in situ synthesis of CeO_(2)onto the WO_(3) surface by the coordinate bond between terephthalic acid and Ce ions can avoid CeO_(2)agglomeration.As a result,the CeO_(2)@WO_(3) photocatalyst exhibits excellent PFBS degradation ability(94%for CeO_(2)@WO_(3) vs.19%for CeO_(2)).After the fifth cyclic degradation experiment,the CeO_(2)@WO_(3) photocatalyst still maintains stable degradation efficiency.Furthermore,the reaction mechanism of the PFBS in CeO_(2)@WO_(3) photocatalytic process was analyzed by free radical trapping experiment and liquid chromatography tandem mass spectrometry(LC-MS)technique.This study provides new insights for constructing Z-scheme heterojunction and demonstrates that CeO_(2)@WO_(3) photocatalysts possess a promising prospect for degrading PFBS pollutants.
基金supported by the National Research Foundation of Korea(NRF)(NRF-2021R1A2C1005867)supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2021R1A6A1A03038996).
文摘To overcome the limited electronic conductivity and capacity of single and binary transition metal phos-phates(TMPs),highly electrochemical active materials and rational structural design of ternary TMPs composite are urgently required.In this study,we successfully synthesized an amorphous 3D Ni-Co-Mn phosphate@2D Ti_(3)C_(2)T_(x)(MXene)nanocomposite(NCMP series)through the electrodeposition method.The amorphous Ni-Co-Mn phosphate effectively restricts the self-accumulation of MXene nanosheets,result-ing in the development of a porous nanostructure.This structure exposes more active sites,expands the ion transport path,and enhances the conductivity of the Ni-Co-Mn phosphate@Ti_(3)C_(2)T_(x) material.Owing to the synergistic effect offered by Ni-Co-Mn phosphate and MXene nanocomposite,the anchored Ni-Co-Mn phosphate@Ti_(3)C_(2)T_(x)(NCMP-5)electrode delivers an elevated capacity of 342 mAh/g(1230 C/g)at 5.0 A/g,surpassing the pristine Ni-Co-Mn phosphate(NCMP-4,260 mAh/g)and MXene(33.3 mAh/g).Moreover,a hybrid solid-state supercapacitor(HSSC)device is assembled with NCMP-5 as a cathode and reduced graphene oxide(rGO)as an anode within a polymer gel(PVA-KOH)electrolyte.Notably,the fabricated HSSC device displays a supreme specific capacity of 27.5 mAh/g(99 C/g)and a high(volumetric)energy density of 22 Wh/kg(3.6 Wh/cm^(3))at a power density of 0.80 kW/kg(0.13 kW/cm^(3))for 1.0 A/g.Moreover,the HSSC device retains 95.4%of its initial capacity even after 10,000 cycles.Importantly,the operational potential window of two serially connected HSSC devices approaches+3.2 V,enabling different colored commercial light-emitting diodes(LEDs)to be efficiently illuminated.Eventually,the remarkable super-capacitive characteristics of the 3D@2D amorphous Ni-Co-Mn phosphate@MXene nanocomposite make it an attractive choice for advanced electroactive materials in upcoming hybrid energy storage technologies.
基金supported by the Natural Science Foundation of Henan Province(No.232300420329)Key Scientific Research Project of Colleges and Universities in Henan Province(Nos.23B430012,22A430028,and 25B430022)+2 种基金Henan Provincial Science and Technology Research Project(No.242102231064)National Natural Science Foundation of China(No.52202064)Luoyang Major Science and Technology Innovation Project(No.2301009A).
文摘β-Sialon has emerged as a promising material for enhancing the service life of Al_(2)O_(3)-C refractories due to its excellent physicochemical properties.The impact of varying concentrations of nanometer Al/Si alloy on the in-situ synthesis of β-Sialon within Al_(2)O_(3)-C refractory materials,as well as its oxidation behavior,was investigated.The findings indicate that the presence of Al/Si alloy promotes the formation of AlN and SiC whiskers at 1300℃,which subsequently facilitate the production of plate-like β-Sialon at 1500℃.Density functional theory analysis reveals that the(020)crystal plane of β-Sialon exhibits the lowest adsorption energy for Al2O and AlO molecules under the influence of iron atoms,suggesting a solid-liquid-vapor growth mechanism for β-Sialon formation.The introduction of these ceramic phases significantly enhances the mechanical properties of Al_(2)O_(3)-C refractories.Specifically,the addition of 6 wt.%Al/Si alloy yielded specimens with the highest cold modulus of rupture and cold crushing strength at 1500℃,achieving values of 35.2 and 127.5 MPa,respectively--representing increases of 40.1%and 37.4%.Furthermore,during high-temperature oxidation,the formation of plate-like β-Sialon leads to the development of a dense protective layer on the surface.This impedes the diffusion pathways of oxygen and consequently enhances the oxidation resistance of the refractory.
