Crystalized CeO_(2)structures were typically considered potential photocatalysts due to their great capacity to alter the active sites’size and ability to absorb light.However,the controllable fabrication of well-def...Crystalized CeO_(2)structures were typically considered potential photocatalysts due to their great capacity to alter the active sites’size and ability to absorb light.However,the controllable fabrication of well-defined hierarchical structures of CeO_(2)with high reactive facets is significant and challenging.Herein,a series of CeO_(2)supports including hierarchical flower-like(F-CeO_(2)),ball-like(B-CeO_(2)),cube-like(C-CeO_(2)),and rod-like CeO_(2)(R-CeO_(2))supports were prepared by hydrothermal method(BCeO_(2),R-CeO_(2)and C-CeO_(2))or ice-bath method(F-CeO_(2))respectively.V atoms were selected as the active atoms and loaded on these supports.Their structure-activity relationship in photo-assisted thermal propane dehydrogenation(PTPDH)was investigated systematically.The samples were characterized by Xray diffraction,scanning electron microscopy,transmission electron microscopy,N2 adsorption-desorption isotherms,and Fourier transform infrared spectrum.Results show that R-CeO_(2)support exhibits the biggest surface area thus achieving the best dispersion of VOx species.UV-vis spectrum and photoluminescence spectrum indicate that V/F-CeO_(2)has the best light adsorption property and V/R-CeO_(2)has the best carrier migration capacity.The activity tests demonstrate that the V/R-CeO_(2)has the largest net growth rate and the V/F-CeO_(2)has the biggest relative growth ratio.Furthermore,the non-thermal effect was confirmed by the kinetic method,which lowers the propane reaction orders,selectively promoting the first C-H bond activation.The light radiation TPSR experiment confirmed this point.DFT calculations show a good linear relationship between the energy barrier and the exchanged electron number.It inspires the design of high-reactive facets for boosting the intrinsic activity of the C-H bond in photoassisted thermal chemical processes.展开更多
The facets effect on the catalytic properties of inorganic compounds and metal-organic frameworks(MOFs)has been widely demonstrated,but the intrinsic facets effect free of interference of capping agents has not been d...The facets effect on the catalytic properties of inorganic compounds and metal-organic frameworks(MOFs)has been widely demonstrated,but the intrinsic facets effect free of interference of capping agents has not been discussed.Here we give a proof-of-concept illustration on the intrinsic facets effect by employing the popularly investigated NH2-MIL-125(Ti)MOFs with{001},{111}and{100}facets controllably exposed as model photocatalysts,which were synthesized via a simple supersaturation strategy free of any capping agents.Compared to conventional synthetic routes with capping agents employed,the NH2-MIL-125(Ti)MOFs obtained in this work exhibit remarkably different physical and chemical properties such as surface wettability,charge separation as well as trend of facets effect on photocatalytic water splitting performance.The main reason has been unraveled to originate from unavoidable residue/influence of capping agents during the conventional facets-controlled synthetic routes leading to changed local surface structural environment as well as distinct charge separation property.Our results demonstrate the importance and feasibility of facets-controllable synthesis free of capping agents in getting insight into the intrinsic facets effect of MOFs-related materials.展开更多
Crack initiation mechanism of dwell fatigue has always been a key problem in rationalizing the dwell effect,and it is not completely understood yet.This study conducted stress-controlled low-cycle fatigue and dwell fa...Crack initiation mechanism of dwell fatigue has always been a key problem in rationalizing the dwell effect,and it is not completely understood yet.This study conducted stress-controlled low-cycle fatigue and dwell fatigue tests on Ti-6Al-3Nb-2Zr-1Mo alloy with bimodal microstructure to reveal its microstructural characteristics and crack initiation mechanisms.The study demonstrated that the faceted primaryα nodules located near the specimen surface acted as crack initiation sites during both fatigue and dwell fatigue tests.Slip trace analysis revealed that faceted cracking occurred at(0001)basal plane with the maximum Schmid factor value through a special cracking mode referred to as(0001)twist boundary cracking.Innovative criteria of parameters C1 and C2 were proposed based on experimental observation and molecular dynamics simulations,which well identify candidates for(0001)twist boundary crack nucleation.It demonstrated that grain pairs combining a moderately high Schmid factor for basal slip and a well-orientated Burgers vector in the out-of-surface plane was the preferable location for surface(0001)twist-boundary crack initiation,and grain pairs combining a high Schmid factor for basal slip and a high normal stress on basal plane are perfect candidates for subsurface cracking.Based on this,phenomeno-logical models are proposed to explain the surface(0001)twist-boundary cracking mechanism from the perspective of surface extrusion-intrusion-induced micro-notches.展开更多
Lithium-sulfur(Li-S)batteries are promising for high-energy-density storage,but their performance is limited by sluggish lithium polysulfide(LiPS)conversion kinetics.Here,we tackle this issue by synthesizing ultrafine...Lithium-sulfur(Li-S)batteries are promising for high-energy-density storage,but their performance is limited by sluggish lithium polysulfide(LiPS)conversion kinetics.Here,we tackle this issue by synthesizing ultrafine truncated octahedral TiO_(2) nanocrystals(P-O_(v)-TiO_(2)),featuring specific{101}facets and dual defects—phosphorus doping and oxygen vacancies.Acting as an efficient electrocatalyst in the separator,P-O_(v)-TiO_(2) exhibits superior catalytic properties,where oxygen vacancies modulate the electronic structure,enhancing electron enrichment and charge transfer;phosphorus doping tailors the d-band center of the catalyst,strengthening Ti-S interactions between the{101}facets and LiPSs.As a result,Li-S coin cells modified with P-O_(v)-TiO_(2) achieve a high specific capacity of 895 mAh g^(−1) at 5 C and exhibit a minimal decay rate of 0.14%per cycle over 200 cycles.Furthermore,Li-S pouch cells deliver a high capacity of 1004 mAh g^(−1) at 0.1 C under lean electrolyte conditions.This study elucidates the mechanisms of charge states on specific crystal planes and deepens our understanding of dual-defect engineering in Li-S electrochemistry,offering a promising approach for developing efficient and cost-effective catalysts for Li-S battery applications.展开更多
ASEAN’s major power balancing strategy refers to the balancing strategy adopted by ASEAN and its member states to seek national and regional security and development by maintaining multi-faceted friendship and impart...ASEAN’s major power balancing strategy refers to the balancing strategy adopted by ASEAN and its member states to seek national and regional security and development by maintaining multi-faceted friendship and impartiality with surrounding major powers.The evolution of this strategy is a process of dynamic adjustment,with ASEAN and its members being the implementing subjects,major powers the objects.展开更多
Photocatalysis is a promising technology for purification of indoor air by oxidation of volatile organic compounds.This study provides a comprehensive analysis of the adsorption and photo-oxidation of surface-adsorbed...Photocatalysis is a promising technology for purification of indoor air by oxidation of volatile organic compounds.This study provides a comprehensive analysis of the adsorption and photo-oxidation of surface-adsorbed acetone on three SrTiO_(3)morphologies:cubes(for which exclusively{100}facets are exposed),{110}-truncated cubes,and{100}-truncated rhombic dodecahedrons,respectively,all prepared by hydrothermal synthesis.In situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy shows that cubic crystals contain a high quantity of surface-OH groups,enabling significant quantities of adsorbed acetone in the form ofη^(1)-enolate when exposed to gas phase acetone.Contrary,{110}facets exhibit fewer surface-OH groups,resulting in relatively small quantities of adsorbedη^(1)-acetone,without observable quantities of enolate.Interestingly,acetate and formate signatures appear in the spectra of cubic,surfaceη^(1)-enolate containing,SrTiO_(3)upon illumination,while besides acetate and formate,the formation of(surface)formaldehyde was observed on truncated cubes,and dodecahedrons,by conversion of adsorbedη^(1)-acetone.Time-Resolved Photoluminescence studies demonstrate that the lifetimes of photogenerated charge carriers vary with crystal morphology.The shortest carrier lifetime(τ_(1)=33±0.1 ps)was observed in{110}-truncated cube SrTiO_(3),likely due to a relatively strong built-in electric field promoting electron transport to{100}facets and hole transport to{110}facets.The second lifetime(τ_(2)=259±1 ps)was also the shortest for this morphology,possibly due to a higher amount of surface trap states.Our results demonstrate that SrTiO_(3)crystal morphology can be tuned to optimize performance in photocatalytic oxidation.展开更多
Nanostructured ceria has attracted much attention in the field of redox catalysts due to the numerous active sites with excellent redox ability.Based on the acidic medium etching strategy,we constructed the strong bin...Nanostructured ceria has attracted much attention in the field of redox catalysts due to the numerous active sites with excellent redox ability.Based on the acidic medium etching strategy,we constructed the strong binding centers(hydroxyl sites and strong acid sites)on the surfaces of nanostructured ceria,which regulate the adsorption process of KA-Oil(the mixture of cyclohexanol and cyclohexanone)and to promote high KA-Oil selectivity in cyclohexane oxidation.The three CeO_(2)(nanocube,nanorod and nanopolyhedron)with different exposed crystal planes were treated by acid etching to change the surface sites and catalytic properties.The transition behavior of surface sites during etching was revealed,abundant strong binding centers were proved to be constructed successfully.And especially for the nanorod treated by acid(Acid@CeO_(2)-NR)with the strongest response for sulfuric acid etching,the strong adsorption of cyclohexanone by strong binding centers was confirmed based on the in-situ DRIFTs.The sulfuric acid etching strategy to enhance the selective oxidation of cyclohexane based on the construction of strong binding centers was proved to be feasible and effective,Acid@CeO_(2)-NR with strongest etching response achieved the dramatic promotion of KA-Oil selectivity from 64.1%to 92.3%.展开更多
Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks,but limited work has been explored for achieving modulation of crystal facet...Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks,but limited work has been explored for achieving modulation of crystal facets and metal doping in a single system.MIL-68(In)was promising for photocatalytic applications due to its low toxicity and excellent photoresponsivity.However,its catalytic activity was constrained by severe carrier recombination and a lack of active sites.Herein,increased(001)facet ratio and active sites exposure were simultaneously realized by cobalt doping in MIL-68(In)through a one-pot solvothermal strategy.Optimized MIL-68(In/Co)-2.5 exhibited remarkable catalytic performance in comparison with pristine MIL-68(In)and other MIL-68(In/Co).The reaction kinetic constant and degradation efficiency of MIL-68(In/Co)were approximately twice and 17%higher than the pristine MIL-68(In)in 36 min reaction,respectively.Density functional theory calculations revealed that Co dopant could modulate the orientation of MIL-68(In)facets,facilitate the exchange of electrons and reduce the adsorption energy of peroxymonosulfate(PMS).This work provides a novel pathway for improvement of In-based MOFs in PMS/vis system,it also promotes the profound comprehension of the correlation between crystal facet regulation and catalytic activation in the PMS/vis system.展开更多
Micro-sized anatase TiO_(2) displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg^(2+)in anatase TiO_(2) lattice.Herein,we report that nanosize...Micro-sized anatase TiO_(2) displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg^(2+)in anatase TiO_(2) lattice.Herein,we report that nanosized anatase TiO_(2) exposed(001)facet doubles the capacity compared to the micro-sized sample ascribed to the interfacial Mg^(2+)ion storage.First-principles calculations reveal that the diffusion energy barrier of Mg^(2+)on the(001)facet is significantly lower than those in the bulk phase and on(100)facet,and the adsorption energy of Mg^(2+)on the(001)facet is also considerably lower than that on(100)facet,which guarantees superior interfacial Mg^(2+)storage of(001)facet.Moreover,anatase TiO_(2) exposed(001)facet displays a significantly higher capacity of 312.9 mAh g^(−1) in Mg-Li dual-salt electrolyte compared to 234.3 mAh g^(−1) in Li salt electrolyte.The adsorption energies of Mg^(2+)on(001)facet are much lower than the adsorption energies of Li+on(001)facet,implying that the Mg^(2+)ion interfacial storage is more favorable.These results highlight that controlling the crystal facet of the nanocrystals effectively enhances the interfacial storage of multivalent ions.This work offers valuable guidance for the rational design of high-capacity storage systems.展开更多
Developing high-performance narrow-bandgap (NBG) perovskite solar cells based on tin-lead (Sn-Pb) perovskite is critical for the advancement of all-perovskite tandem solar cells. However, the limitations of the device...Developing high-performance narrow-bandgap (NBG) perovskite solar cells based on tin-lead (Sn-Pb) perovskite is critical for the advancement of all-perovskite tandem solar cells. However, the limitations of the device current density and efficiency are magnified by the issues concerning poor carrier transport caused by a substantial number of defects in thick NBG films. This problem is further exacerbated by the quality of film crystallization, which is associated with the rapid and uncontrolled crystallization of Sn-rich perovskite chemistry using the antisolvent approach. We regulate the crystallization of Sn-contained perovskite with a mild gas-quench approach to fabricate a highly crystal-oriented and well-arranged NBG perovskite absorber. This strategy effectively boosts electron transport and light absorption of the NBG perovskite. Consequently, the average power conversion efficiency (PCE) of the NBG perovskite solar cells increases from 19.50% to 21.18%, with the best device achieving an excellent PCE of 21.84%. Furthermore, when combined with a wide-bandgap perovskite subcell to form an all-perovskite tandem solar cell, a PCE of 25.23% is achieved. After being stored in the glovebox for 1000 h, the unencapsulated device maintains over 90% of its initial PCE, demonstrating long-term stability and durability. This work presents a promising approach for developing high-efficiency NBG perovskite solar cells.展开更多
Photocatalytic ozonation holds promise for advanced water purification,yet its development has been hindered by a limited understanding of ozone activation mechanisms and its related photogenerated electron transfer d...Photocatalytic ozonation holds promise for advanced water purification,yet its development has been hindered by a limited understanding of ozone activation mechanisms and its related photogenerated electron transfer dynamics.Herein,we employed in-situ DRIFTS and Raman spectroscopy to elucidate the distinct adsorption and activation behaviors of ozone(O_(3))on the{001}and{110}crystal facets of Bi_(2)O_(2)CO_(3)(BOC)nanosheets.BOC-{001}demonstrates superior photocatalytic ozonation performance,with 85%phenol mineralization and excellent durability,significantly outperforming the 53%mineralization rate of BOC-{110}.This enhanced activity is attributed to non-dissociative ozone adsorption and favorable adsorption energy over{001}facet,which facilitate the one-electron O_(3) reduction pathway.Furthermore,crystal facet engineering strengthens the built-in electric field,promoting exciton dissociation and the generation of localized charge carriers.The synergistic effects of optimized electron availability and ozone adsorption significantly boost the production of reactive oxygen species.These findings provide a deeper understanding of the critical roles of O_(3) adsorption and electron transfer in radical generation,which could provide some guidance for the strategic development of highly effective photocatalytic ozonation catalysts.展开更多
The electrochemical CO_(2)reduction(ECR)to hydrocarbon products is an attractive pathway to decrease CO_(2)emission and advance a carbon-neutral process.Among the products of ECR,methane(CH_(4))stands out due to its h...The electrochemical CO_(2)reduction(ECR)to hydrocarbon products is an attractive pathway to decrease CO_(2)emission and advance a carbon-neutral process.Among the products of ECR,methane(CH_(4))stands out due to its high calorific value,serving as the main component of natural gas.However,the development of ECR catalysts capable of producing CH_(4)with both high activity and stability remains critically urgent.This review summarizes and explores the research progress and future application strategies for ECR toward CH_(4)production.Combining experiments,in-situ characterizations,and theoretical calculations,this review examines mechanism of CH_(4)formation in ECR.It then clarifies key factors affecting Cu-based catalysts for CH_(4)production,including facet dependence,size effects,and valence states.Next,this review details emerging strategies such as sub-nanoscale catalysts,Cu/oxides interface engineering,and Cu surface modification.Finally,future directions highlight in-situ characterization,reactor design,and high-throughput screening,guiding industrial CH_(4)production.展开更多
Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and non-toxicity.However,its inadequate catalytic activity results in difficulty in e...Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and non-toxicity.However,its inadequate catalytic activity results in difficulty in effectively degrading pollutants in the catalytic degradation system that it constitutes.Thus,we constructed a photochemical system composed of hematite with{001}facet of high activity facet and low-cost and non-toxic oxalic acid(OA)for the removal of various types of pollutants.The removal rate for the degradation of metronidazole,tetracycline hydrochloride,Rhodamine B,and hexavalent chromium by hematite nanoplate with the exposed{001}facet activating OA under visible light irradiation was 4.75,2.25,2.33,and 2.74 times than that by the exposed{110}facet,respectively.Density functional theory(DFT)calculation proved that the OA molecule was more easily adsorbed on the{001}facet of hematite than that on the{110}facet,which would favor the formation of the more Fe(Ⅲ)-OA complex and reactive species.In addition,the reactive site of metronidazole for the attraction of radicals was identified on the basis of the DFT calculation on the molecular occupied orbitals,and the possible degradation pathway for metronidazole included carbon chain fracture,hydroxyethyl-cleavage,denitrogenation,and hydroxylation.Thus,this finding may offer a valuable direction in designing an efficient iron-based catalyst based on facet engineering for the improved activity of Fenton-like systems such as OA activation.展开更多
Photocatalysis has been a research hotspot in recent years,and the design and modification of photocat-alysts have been the key points.Common methods for designing photocatalysts,including constructing heterojunctions...Photocatalysis has been a research hotspot in recent years,and the design and modification of photocat-alysts have been the key points.Common methods for designing photocatalysts,including constructing heterojunctions and homojunctions,have been developed on the basis of heterojunctions.In this study,two homojunctions of manganese dioxide(MnO_(2)),including a high-index crystal plane homojunction and a general homojunction,are prepared using a stepwise hydrothermal method.Using a capping agent,the high-index crystal surface of the MnO_(2)is exposed.It is found that the electron transport efficiency be-tween the two components of the homojunction with high-index planes is higher and the adsorption capacity of the oxygen is stronger,which leads to higher photocatalytic efficiency.In addition,the newly designed high-index homojunction is used for the treatment of bacterial infections,and it kills Staphy-lococcus aureus(S.aureus)and Escherichia coli(E.coli)at rates of 99.95%±0.04%and 99.31%±0.25%,respectively.It also has excellent therapeutic effects on mouse wounds,which implies superb practical application value.This work provides a new strategy for the improved design of homojunctions and the application of photocatalytic materials.展开更多
Depending on the production process,copper(Cu)foils can be classified into two types,i.e.,rolled copper(r-Cu)foils and electrolytic copper(e-Cu)foils.Owing to their high electrical conductivity and ductility at low co...Depending on the production process,copper(Cu)foils can be classified into two types,i.e.,rolled copper(r-Cu)foils and electrolytic copper(e-Cu)foils.Owing to their high electrical conductivity and ductility at low cost,e-Cu foils are employed extensively in modern industries and account for more than 98%of the Cu foil market share.However,industrial e-Cu foils have never been single-crystallized due to their high density of grain boundaries,various grain orientations and vast impurities originating from the electrochemical deposition process.Here,we report a methodology of transforming industrial e-Cu foils into single crystals by facet copy from a single-crystal template.Different facets of both low and high indices are successfully produced,and the thickness of the single crystal can reach 500μm.Crystallographic characterizations directly recognized the single-crystal copy process,confirming the complete assimilation impact from the template.The obtained single-crystal e-Cu foils exhibit remarkably improved ductility(elongation-to-fracture of 105%vs.25%),fatigue performance(the average numbers of cycles to failure of 1600 vs.200)and electrical property(electrical conductivity of 102.6%of the international annealed copper standard(IACS)vs.98.5%)than original ones.This work opens up a new avenue for the preparation of single-crystal e-Cu foils and may expand their applications in high-speed,flexible,and wearable devices.展开更多
The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode active materials(CAMs)are considered a promising alternative to commercially available cathodes such as layered and polyanion oxide cathodes,primarily due to their notab...The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode active materials(CAMs)are considered a promising alternative to commercially available cathodes such as layered and polyanion oxide cathodes,primarily due to their notable safety and high energy density,particularly in their single-crystal type.Nevertheless,the industrial application of the LNMO CAMs is severely inhibited due to the interfacial deterioration and corrosion under proton-rich and high-voltage conditions.This study successfully designed and synthesized two typical types of crystal facets-exposed single-crystal LNMO CAMs.By tracking the electrochemical deterioration and chemical corrosion evolution,this study elucidates the surface degradation mechanisms and intrinsic instability of the LNMO,contingent upon their crystal facets.The(111)facet,due to its elevated surface energy,is found to be more susceptible to external attack compared to the(100)and(110)facets.Our study highlights the electrochemical corrosion stability of crystal plane engineering for spinel LNMO CAMs.展开更多
Non-layered two-dimensional(2D)materials have sparked much interest recently due to their atomic thickness,large surface area,thickness-and facet-dependent properties.Currently,these materials are mainly grown from we...Non-layered two-dimensional(2D)materials have sparked much interest recently due to their atomic thickness,large surface area,thickness-and facet-dependent properties.Currently,these materials are mainly grown from wet-chemistry methods but suffer from small size,low quality,and multi-facets,which is a major challenge hindering their facet-dependent property studies and applications.Here,we report the facet-engineered growth(FEG)of non-layered 2D manganese chalcogenides(MnX,X=S,Se,Te)based on the chemical vapor deposition method.The as-grown samples exhibit large-area surfaces of single facet,high-crystallinity,and ordered domain orientation.As a proof-of-concept,we show the facet-dependent electrocatalytic property of non-layered 2D MnSe,proving they are ideal candidates for fundamental research.Furthermore,we elucidate the underlying mechanism of FEG during the vapor growth process by the interfacial energy derived nucleation models.The method developed in this work provides new opportunities for regulating and designing the structure of 2D materials.展开更多
The nanoscale zinc oxide(n-ZnO)was used in food packages due to its superior antibac terial activity,resulting in potential intake of n-ZnO through the digestive system,wherein n-ZnO interacted with saliva.In recent,f...The nanoscale zinc oxide(n-ZnO)was used in food packages due to its superior antibac terial activity,resulting in potential intake of n-ZnO through the digestive system,wherein n-ZnO interacted with saliva.In recent,facet engineering,a technique for controlling the exposed facets,was applied to n-ZnO,whereas risk of n-ZnO with specific exposed facets in saliva was ignored.ZnO nanoflakes(ZnO-0001)and nanoneedles(ZnO-1010)with the pri mary exposed facets of{0001}and{1010}respectively were prepared in this study,investigat ing stability and toxicity of ZnO-0001 and ZnO-1010 in synthetic saliva.Both ZnO-0001 and ZnO-1010 partially transformed into amorphous Zn_(3)(PO_(4))_(2)within 1 hr in the saliva even containing orgnaic components,forming a ZnO-Zn_(3)(PO_(4))_(2)core-shell structure.Neverthe less,ZnO-1010 relative to ZnO-0001 would likely transform into Zn_(3)(PO_(4))_(2),being attributed to superior dissolution of{1010}facet due to its lower vacancy formation energy(1.15 eV than{0001}facet(3.90 eV)).The toxicity of n-ZnO to Caco-2 cells was also dependent on the primary exposed facet;ZnO-0001 caused cell toxicity through oxidative stress,whereas ZnO-1010 resulted in lower cells viability than ZnO-0001 through oxidative stress and mem brane damage.Density functional theory calculations illustrated that·O_(2)^(-)was formed and released on{1010}facet,yet O_(2)^(2-)instead of·O_(2)^(-)was generated on{0001}facet,leading to low oxidative stress from ZnO-0001.All findings demonstrated that stability and toxicity of n-ZnO were dependent on the primary exposed facet,improving our understanding o health risk of nanomaterials.展开更多
基金the National Key R&D Program of China(Nos.2021YFA1501301,2021YFC2901100)the National Natural Science Foundation of China(Nos.22178381,22035009).
文摘Crystalized CeO_(2)structures were typically considered potential photocatalysts due to their great capacity to alter the active sites’size and ability to absorb light.However,the controllable fabrication of well-defined hierarchical structures of CeO_(2)with high reactive facets is significant and challenging.Herein,a series of CeO_(2)supports including hierarchical flower-like(F-CeO_(2)),ball-like(B-CeO_(2)),cube-like(C-CeO_(2)),and rod-like CeO_(2)(R-CeO_(2))supports were prepared by hydrothermal method(BCeO_(2),R-CeO_(2)and C-CeO_(2))or ice-bath method(F-CeO_(2))respectively.V atoms were selected as the active atoms and loaded on these supports.Their structure-activity relationship in photo-assisted thermal propane dehydrogenation(PTPDH)was investigated systematically.The samples were characterized by Xray diffraction,scanning electron microscopy,transmission electron microscopy,N2 adsorption-desorption isotherms,and Fourier transform infrared spectrum.Results show that R-CeO_(2)support exhibits the biggest surface area thus achieving the best dispersion of VOx species.UV-vis spectrum and photoluminescence spectrum indicate that V/F-CeO_(2)has the best light adsorption property and V/R-CeO_(2)has the best carrier migration capacity.The activity tests demonstrate that the V/R-CeO_(2)has the largest net growth rate and the V/F-CeO_(2)has the biggest relative growth ratio.Furthermore,the non-thermal effect was confirmed by the kinetic method,which lowers the propane reaction orders,selectively promoting the first C-H bond activation.The light radiation TPSR experiment confirmed this point.DFT calculations show a good linear relationship between the energy barrier and the exchanged electron number.It inspires the design of high-reactive facets for boosting the intrinsic activity of the C-H bond in photoassisted thermal chemical processes.
文摘The facets effect on the catalytic properties of inorganic compounds and metal-organic frameworks(MOFs)has been widely demonstrated,but the intrinsic facets effect free of interference of capping agents has not been discussed.Here we give a proof-of-concept illustration on the intrinsic facets effect by employing the popularly investigated NH2-MIL-125(Ti)MOFs with{001},{111}and{100}facets controllably exposed as model photocatalysts,which were synthesized via a simple supersaturation strategy free of any capping agents.Compared to conventional synthetic routes with capping agents employed,the NH2-MIL-125(Ti)MOFs obtained in this work exhibit remarkably different physical and chemical properties such as surface wettability,charge separation as well as trend of facets effect on photocatalytic water splitting performance.The main reason has been unraveled to originate from unavoidable residue/influence of capping agents during the conventional facets-controlled synthetic routes leading to changed local surface structural environment as well as distinct charge separation property.Our results demonstrate the importance and feasibility of facets-controllable synthesis free of capping agents in getting insight into the intrinsic facets effect of MOFs-related materials.
基金supported by the National Natural Science Foundation of China(Nos.52074231,52274396 and 52001258)the Chongqing Natural Science Foundation(No.cstc2020jcyj-msxmX1056).
文摘Crack initiation mechanism of dwell fatigue has always been a key problem in rationalizing the dwell effect,and it is not completely understood yet.This study conducted stress-controlled low-cycle fatigue and dwell fatigue tests on Ti-6Al-3Nb-2Zr-1Mo alloy with bimodal microstructure to reveal its microstructural characteristics and crack initiation mechanisms.The study demonstrated that the faceted primaryα nodules located near the specimen surface acted as crack initiation sites during both fatigue and dwell fatigue tests.Slip trace analysis revealed that faceted cracking occurred at(0001)basal plane with the maximum Schmid factor value through a special cracking mode referred to as(0001)twist boundary cracking.Innovative criteria of parameters C1 and C2 were proposed based on experimental observation and molecular dynamics simulations,which well identify candidates for(0001)twist boundary crack nucleation.It demonstrated that grain pairs combining a moderately high Schmid factor for basal slip and a well-orientated Burgers vector in the out-of-surface plane was the preferable location for surface(0001)twist-boundary crack initiation,and grain pairs combining a high Schmid factor for basal slip and a high normal stress on basal plane are perfect candidates for subsurface cracking.Based on this,phenomeno-logical models are proposed to explain the surface(0001)twist-boundary cracking mechanism from the perspective of surface extrusion-intrusion-induced micro-notches.
基金supported by the Hebei Province Key R&D Technology Project(23314401D)2023 Hebei Province High-level Talent Team Construction Special Project(235A4401D)+6 种基金Hebei North University Youth Fund Project(XJ2024013)School-level Cultivation Research Project of Hebei North University(XJPY2024025)First Batch of School-level Scientific Research Projects of Hebei North University in 2023(B2023405004)Hebei North University High-level Talent Research Start-up Fund(BSJJ202303,BSJJ202313,BSJJ202421)Science and Technology Research Project of Higher Education Institutions in Hebei Province(QN2023222)Central Guided Local Science and Technology Development Funding Program(236Z4401G)Natural Science Foundation of Hebei Province(B2022405005).
文摘Lithium-sulfur(Li-S)batteries are promising for high-energy-density storage,but their performance is limited by sluggish lithium polysulfide(LiPS)conversion kinetics.Here,we tackle this issue by synthesizing ultrafine truncated octahedral TiO_(2) nanocrystals(P-O_(v)-TiO_(2)),featuring specific{101}facets and dual defects—phosphorus doping and oxygen vacancies.Acting as an efficient electrocatalyst in the separator,P-O_(v)-TiO_(2) exhibits superior catalytic properties,where oxygen vacancies modulate the electronic structure,enhancing electron enrichment and charge transfer;phosphorus doping tailors the d-band center of the catalyst,strengthening Ti-S interactions between the{101}facets and LiPSs.As a result,Li-S coin cells modified with P-O_(v)-TiO_(2) achieve a high specific capacity of 895 mAh g^(−1) at 5 C and exhibit a minimal decay rate of 0.14%per cycle over 200 cycles.Furthermore,Li-S pouch cells deliver a high capacity of 1004 mAh g^(−1) at 0.1 C under lean electrolyte conditions.This study elucidates the mechanisms of charge states on specific crystal planes and deepens our understanding of dual-defect engineering in Li-S electrochemistry,offering a promising approach for developing efficient and cost-effective catalysts for Li-S battery applications.
文摘ASEAN’s major power balancing strategy refers to the balancing strategy adopted by ASEAN and its member states to seek national and regional security and development by maintaining multi-faceted friendship and impartiality with surrounding major powers.The evolution of this strategy is a process of dynamic adjustment,with ASEAN and its members being the implementing subjects,major powers the objects.
基金Advanced Research Center for Chemical Building Blocks,ARC CBBC,which is co-foundedco-financed by the Dutch Research Council(NWO)and the Netherlands Ministry of Economic Affairs and Climate Policy.
文摘Photocatalysis is a promising technology for purification of indoor air by oxidation of volatile organic compounds.This study provides a comprehensive analysis of the adsorption and photo-oxidation of surface-adsorbed acetone on three SrTiO_(3)morphologies:cubes(for which exclusively{100}facets are exposed),{110}-truncated cubes,and{100}-truncated rhombic dodecahedrons,respectively,all prepared by hydrothermal synthesis.In situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy shows that cubic crystals contain a high quantity of surface-OH groups,enabling significant quantities of adsorbed acetone in the form ofη^(1)-enolate when exposed to gas phase acetone.Contrary,{110}facets exhibit fewer surface-OH groups,resulting in relatively small quantities of adsorbedη^(1)-acetone,without observable quantities of enolate.Interestingly,acetate and formate signatures appear in the spectra of cubic,surfaceη^(1)-enolate containing,SrTiO_(3)upon illumination,while besides acetate and formate,the formation of(surface)formaldehyde was observed on truncated cubes,and dodecahedrons,by conversion of adsorbedη^(1)-acetone.Time-Resolved Photoluminescence studies demonstrate that the lifetimes of photogenerated charge carriers vary with crystal morphology.The shortest carrier lifetime(τ_(1)=33±0.1 ps)was observed in{110}-truncated cube SrTiO_(3),likely due to a relatively strong built-in electric field promoting electron transport to{100}facets and hole transport to{110}facets.The second lifetime(τ_(2)=259±1 ps)was also the shortest for this morphology,possibly due to a higher amount of surface trap states.Our results demonstrate that SrTiO_(3)crystal morphology can be tuned to optimize performance in photocatalytic oxidation.
基金supported by National Natural Science Fund for Excellent Young Scholars(22222813)the National Natural Science Foundation of China(22078338)+2 种基金the National Key Research and Development Program of China(2023YFA1506803)the Postdoctoral Fellowship Program of CPSF(GZC20232700)the“Special Research Assistant Project”of the Chinese Academy of Sciences.
文摘Nanostructured ceria has attracted much attention in the field of redox catalysts due to the numerous active sites with excellent redox ability.Based on the acidic medium etching strategy,we constructed the strong binding centers(hydroxyl sites and strong acid sites)on the surfaces of nanostructured ceria,which regulate the adsorption process of KA-Oil(the mixture of cyclohexanol and cyclohexanone)and to promote high KA-Oil selectivity in cyclohexane oxidation.The three CeO_(2)(nanocube,nanorod and nanopolyhedron)with different exposed crystal planes were treated by acid etching to change the surface sites and catalytic properties.The transition behavior of surface sites during etching was revealed,abundant strong binding centers were proved to be constructed successfully.And especially for the nanorod treated by acid(Acid@CeO_(2)-NR)with the strongest response for sulfuric acid etching,the strong adsorption of cyclohexanone by strong binding centers was confirmed based on the in-situ DRIFTs.The sulfuric acid etching strategy to enhance the selective oxidation of cyclohexane based on the construction of strong binding centers was proved to be feasible and effective,Acid@CeO_(2)-NR with strongest etching response achieved the dramatic promotion of KA-Oil selectivity from 64.1%to 92.3%.
基金supported by the National Natural Science Foundation of China(Nos.52100087,52170079,U20A20322)Science and Technology Development Program of Jilin Province,China(Nos.20220508100RC,20230402035GH).
文摘Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks,but limited work has been explored for achieving modulation of crystal facets and metal doping in a single system.MIL-68(In)was promising for photocatalytic applications due to its low toxicity and excellent photoresponsivity.However,its catalytic activity was constrained by severe carrier recombination and a lack of active sites.Herein,increased(001)facet ratio and active sites exposure were simultaneously realized by cobalt doping in MIL-68(In)through a one-pot solvothermal strategy.Optimized MIL-68(In/Co)-2.5 exhibited remarkable catalytic performance in comparison with pristine MIL-68(In)and other MIL-68(In/Co).The reaction kinetic constant and degradation efficiency of MIL-68(In/Co)were approximately twice and 17%higher than the pristine MIL-68(In)in 36 min reaction,respectively.Density functional theory calculations revealed that Co dopant could modulate the orientation of MIL-68(In)facets,facilitate the exchange of electrons and reduce the adsorption energy of peroxymonosulfate(PMS).This work provides a novel pathway for improvement of In-based MOFs in PMS/vis system,it also promotes the profound comprehension of the correlation between crystal facet regulation and catalytic activation in the PMS/vis system.
基金supported by the National Key R&D Program of China(No.2023YFB3809500)the Fundamental Research Funds for the Central Universities(No.2024CDJXY003)+1 种基金the Venture&Innovation Support Program for Chongqing Overseas Returnees(cx2023087)The Chongqing Technology Innovation and Application Development Project(No.2024TIAD-KPX0003).
文摘Micro-sized anatase TiO_(2) displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg^(2+)in anatase TiO_(2) lattice.Herein,we report that nanosized anatase TiO_(2) exposed(001)facet doubles the capacity compared to the micro-sized sample ascribed to the interfacial Mg^(2+)ion storage.First-principles calculations reveal that the diffusion energy barrier of Mg^(2+)on the(001)facet is significantly lower than those in the bulk phase and on(100)facet,and the adsorption energy of Mg^(2+)on the(001)facet is also considerably lower than that on(100)facet,which guarantees superior interfacial Mg^(2+)storage of(001)facet.Moreover,anatase TiO_(2) exposed(001)facet displays a significantly higher capacity of 312.9 mAh g^(−1) in Mg-Li dual-salt electrolyte compared to 234.3 mAh g^(−1) in Li salt electrolyte.The adsorption energies of Mg^(2+)on(001)facet are much lower than the adsorption energies of Li+on(001)facet,implying that the Mg^(2+)ion interfacial storage is more favorable.These results highlight that controlling the crystal facet of the nanocrystals effectively enhances the interfacial storage of multivalent ions.This work offers valuable guidance for the rational design of high-capacity storage systems.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFB1506400)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB43000000)+3 种基金the CAS Project for Young Scientists in Basic Research(YSBR-090)the National Natural Science Foundation of China(Contract Nos.U20A20206,51972300,62274155,and 62304219)support from the Youth Innovation Promotion Association,the Chi-nese Academy of Sciences(No.2020114)Beijing Natural Sci-ence Foundation(Grant No.JQ24029).
文摘Developing high-performance narrow-bandgap (NBG) perovskite solar cells based on tin-lead (Sn-Pb) perovskite is critical for the advancement of all-perovskite tandem solar cells. However, the limitations of the device current density and efficiency are magnified by the issues concerning poor carrier transport caused by a substantial number of defects in thick NBG films. This problem is further exacerbated by the quality of film crystallization, which is associated with the rapid and uncontrolled crystallization of Sn-rich perovskite chemistry using the antisolvent approach. We regulate the crystallization of Sn-contained perovskite with a mild gas-quench approach to fabricate a highly crystal-oriented and well-arranged NBG perovskite absorber. This strategy effectively boosts electron transport and light absorption of the NBG perovskite. Consequently, the average power conversion efficiency (PCE) of the NBG perovskite solar cells increases from 19.50% to 21.18%, with the best device achieving an excellent PCE of 21.84%. Furthermore, when combined with a wide-bandgap perovskite subcell to form an all-perovskite tandem solar cell, a PCE of 25.23% is achieved. After being stored in the glovebox for 1000 h, the unencapsulated device maintains over 90% of its initial PCE, demonstrating long-term stability and durability. This work presents a promising approach for developing high-efficiency NBG perovskite solar cells.
文摘Photocatalytic ozonation holds promise for advanced water purification,yet its development has been hindered by a limited understanding of ozone activation mechanisms and its related photogenerated electron transfer dynamics.Herein,we employed in-situ DRIFTS and Raman spectroscopy to elucidate the distinct adsorption and activation behaviors of ozone(O_(3))on the{001}and{110}crystal facets of Bi_(2)O_(2)CO_(3)(BOC)nanosheets.BOC-{001}demonstrates superior photocatalytic ozonation performance,with 85%phenol mineralization and excellent durability,significantly outperforming the 53%mineralization rate of BOC-{110}.This enhanced activity is attributed to non-dissociative ozone adsorption and favorable adsorption energy over{001}facet,which facilitate the one-electron O_(3) reduction pathway.Furthermore,crystal facet engineering strengthens the built-in electric field,promoting exciton dissociation and the generation of localized charge carriers.The synergistic effects of optimized electron availability and ozone adsorption significantly boost the production of reactive oxygen species.These findings provide a deeper understanding of the critical roles of O_(3) adsorption and electron transfer in radical generation,which could provide some guidance for the strategic development of highly effective photocatalytic ozonation catalysts.
文摘The electrochemical CO_(2)reduction(ECR)to hydrocarbon products is an attractive pathway to decrease CO_(2)emission and advance a carbon-neutral process.Among the products of ECR,methane(CH_(4))stands out due to its high calorific value,serving as the main component of natural gas.However,the development of ECR catalysts capable of producing CH_(4)with both high activity and stability remains critically urgent.This review summarizes and explores the research progress and future application strategies for ECR toward CH_(4)production.Combining experiments,in-situ characterizations,and theoretical calculations,this review examines mechanism of CH_(4)formation in ECR.It then clarifies key factors affecting Cu-based catalysts for CH_(4)production,including facet dependence,size effects,and valence states.Next,this review details emerging strategies such as sub-nanoscale catalysts,Cu/oxides interface engineering,and Cu surface modification.Finally,future directions highlight in-situ characterization,reactor design,and high-throughput screening,guiding industrial CH_(4)production.
基金supported by the National Natural Science Foundation of China(No.22176151)。
文摘Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and non-toxicity.However,its inadequate catalytic activity results in difficulty in effectively degrading pollutants in the catalytic degradation system that it constitutes.Thus,we constructed a photochemical system composed of hematite with{001}facet of high activity facet and low-cost and non-toxic oxalic acid(OA)for the removal of various types of pollutants.The removal rate for the degradation of metronidazole,tetracycline hydrochloride,Rhodamine B,and hexavalent chromium by hematite nanoplate with the exposed{001}facet activating OA under visible light irradiation was 4.75,2.25,2.33,and 2.74 times than that by the exposed{110}facet,respectively.Density functional theory(DFT)calculation proved that the OA molecule was more easily adsorbed on the{001}facet of hematite than that on the{110}facet,which would favor the formation of the more Fe(Ⅲ)-OA complex and reactive species.In addition,the reactive site of metronidazole for the attraction of radicals was identified on the basis of the DFT calculation on the molecular occupied orbitals,and the possible degradation pathway for metronidazole included carbon chain fracture,hydroxyethyl-cleavage,denitrogenation,and hydroxylation.Thus,this finding may offer a valuable direction in designing an efficient iron-based catalyst based on facet engineering for the improved activity of Fenton-like systems such as OA activation.
基金supported by the National Natural Science Foundation of China(No.52173251)the China National Funds for Distinguished Young Scientists(No.51925104)+1 种基金NSFC-Guangdong Province Joint Program(Key program No.U21A2084)the Cen-tral Guidance on Local Science and Technology Development Fund of Hebei Province(No.226Z1303G).
文摘Photocatalysis has been a research hotspot in recent years,and the design and modification of photocat-alysts have been the key points.Common methods for designing photocatalysts,including constructing heterojunctions and homojunctions,have been developed on the basis of heterojunctions.In this study,two homojunctions of manganese dioxide(MnO_(2)),including a high-index crystal plane homojunction and a general homojunction,are prepared using a stepwise hydrothermal method.Using a capping agent,the high-index crystal surface of the MnO_(2)is exposed.It is found that the electron transport efficiency be-tween the two components of the homojunction with high-index planes is higher and the adsorption capacity of the oxygen is stronger,which leads to higher photocatalytic efficiency.In addition,the newly designed high-index homojunction is used for the treatment of bacterial infections,and it kills Staphy-lococcus aureus(S.aureus)and Escherichia coli(E.coli)at rates of 99.95%±0.04%and 99.31%±0.25%,respectively.It also has excellent therapeutic effects on mouse wounds,which implies superb practical application value.This work provides a new strategy for the improved design of homojunctions and the application of photocatalytic materials.
基金financially supported by Guangdong Major Project of Basic and Applied Basic Research(No.2021B0301030002)the National Natural Science Foundation of China(No.52025023)the Key R&D Program of Guangdong Province(No.2020B010189001).
文摘Depending on the production process,copper(Cu)foils can be classified into two types,i.e.,rolled copper(r-Cu)foils and electrolytic copper(e-Cu)foils.Owing to their high electrical conductivity and ductility at low cost,e-Cu foils are employed extensively in modern industries and account for more than 98%of the Cu foil market share.However,industrial e-Cu foils have never been single-crystallized due to their high density of grain boundaries,various grain orientations and vast impurities originating from the electrochemical deposition process.Here,we report a methodology of transforming industrial e-Cu foils into single crystals by facet copy from a single-crystal template.Different facets of both low and high indices are successfully produced,and the thickness of the single crystal can reach 500μm.Crystallographic characterizations directly recognized the single-crystal copy process,confirming the complete assimilation impact from the template.The obtained single-crystal e-Cu foils exhibit remarkably improved ductility(elongation-to-fracture of 105%vs.25%),fatigue performance(the average numbers of cycles to failure of 1600 vs.200)and electrical property(electrical conductivity of 102.6%of the international annealed copper standard(IACS)vs.98.5%)than original ones.This work opens up a new avenue for the preparation of single-crystal e-Cu foils and may expand their applications in high-speed,flexible,and wearable devices.
基金supported by the National Natural Science Foundation of China (52374311)the National Natural Science Foundation of Shaanxi (2022KXJ-146)+3 种基金the Fundamental Research Funds for the Central Universities (D5000230091)Open project of Shaanxi Laboratory of Aerospace Power (2022ZY2-JCYJ-01-09)full-depth-sea battery project (No.2020-XXXX-XX-246-00)the Youth Innovation Team of Shaanxi Universities。
文摘The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode active materials(CAMs)are considered a promising alternative to commercially available cathodes such as layered and polyanion oxide cathodes,primarily due to their notable safety and high energy density,particularly in their single-crystal type.Nevertheless,the industrial application of the LNMO CAMs is severely inhibited due to the interfacial deterioration and corrosion under proton-rich and high-voltage conditions.This study successfully designed and synthesized two typical types of crystal facets-exposed single-crystal LNMO CAMs.By tracking the electrochemical deterioration and chemical corrosion evolution,this study elucidates the surface degradation mechanisms and intrinsic instability of the LNMO,contingent upon their crystal facets.The(111)facet,due to its elevated surface energy,is found to be more susceptible to external attack compared to the(100)and(110)facets.Our study highlights the electrochemical corrosion stability of crystal plane engineering for spinel LNMO CAMs.
基金This work was supported by the National Science Fund for Distinguished Young Scholars(52125309)the National Natural Science Foundation of China(51991343,51920105002,and 52102179)+4 种基金Guangdong Basic and Applied Basic Research Foundation(2023A1515011752)Guangdong Innovative and Entrepreneurial Research Team Program(2017ZT07C341)Shenzhen Basic Research Project(JCYJ20200109144616617,JCYJ20220818101014029)Shuimu Tsinghua Scholar Program(2022SM092)China Postdoctoral Science Foundation(2021M691715)。
文摘Non-layered two-dimensional(2D)materials have sparked much interest recently due to their atomic thickness,large surface area,thickness-and facet-dependent properties.Currently,these materials are mainly grown from wet-chemistry methods but suffer from small size,low quality,and multi-facets,which is a major challenge hindering their facet-dependent property studies and applications.Here,we report the facet-engineered growth(FEG)of non-layered 2D manganese chalcogenides(MnX,X=S,Se,Te)based on the chemical vapor deposition method.The as-grown samples exhibit large-area surfaces of single facet,high-crystallinity,and ordered domain orientation.As a proof-of-concept,we show the facet-dependent electrocatalytic property of non-layered 2D MnSe,proving they are ideal candidates for fundamental research.Furthermore,we elucidate the underlying mechanism of FEG during the vapor growth process by the interfacial energy derived nucleation models.The method developed in this work provides new opportunities for regulating and designing the structure of 2D materials.
基金supported by the National Natural Science Foundation of China(Nos.21806141,22021003,and 21976163)。
文摘The nanoscale zinc oxide(n-ZnO)was used in food packages due to its superior antibac terial activity,resulting in potential intake of n-ZnO through the digestive system,wherein n-ZnO interacted with saliva.In recent,facet engineering,a technique for controlling the exposed facets,was applied to n-ZnO,whereas risk of n-ZnO with specific exposed facets in saliva was ignored.ZnO nanoflakes(ZnO-0001)and nanoneedles(ZnO-1010)with the pri mary exposed facets of{0001}and{1010}respectively were prepared in this study,investigat ing stability and toxicity of ZnO-0001 and ZnO-1010 in synthetic saliva.Both ZnO-0001 and ZnO-1010 partially transformed into amorphous Zn_(3)(PO_(4))_(2)within 1 hr in the saliva even containing orgnaic components,forming a ZnO-Zn_(3)(PO_(4))_(2)core-shell structure.Neverthe less,ZnO-1010 relative to ZnO-0001 would likely transform into Zn_(3)(PO_(4))_(2),being attributed to superior dissolution of{1010}facet due to its lower vacancy formation energy(1.15 eV than{0001}facet(3.90 eV)).The toxicity of n-ZnO to Caco-2 cells was also dependent on the primary exposed facet;ZnO-0001 caused cell toxicity through oxidative stress,whereas ZnO-1010 resulted in lower cells viability than ZnO-0001 through oxidative stress and mem brane damage.Density functional theory calculations illustrated that·O_(2)^(-)was formed and released on{1010}facet,yet O_(2)^(2-)instead of·O_(2)^(-)was generated on{0001}facet,leading to low oxidative stress from ZnO-0001.All findings demonstrated that stability and toxicity of n-ZnO were dependent on the primary exposed facet,improving our understanding o health risk of nanomaterials.
