Near-infrared light activated persistent luminescence nanoparticles via upconversion

Persistent luminescence nanoparticles (PLNPs) and upconversion nanoparticles (UCNPs) are two special optical imaging nanoprobes.In this study,efficient upconverted persistent luminescence (UCPL) is realized by combining their unique features into polymethyl methacrylate,forming a film composed of both PLNPs and UCNPs.The red persistent luminescence (～640 nm) of the PLNPs (CaS∶Eu,Tm,Ce) can be activated by upconverted green emission of UCNPs (β-NaYF4∶Yb,Er@NaYF4) excited by near-infrared light (NIR).Using this strategy,both the unique optical properties of PLNPs and UCNPs can be optimally synergized,thus generating efficient upconversion,photoluminescence,and UCPL simultaneously.The UCPL system has potential applications in in vivo bioimaging by simply monitoring the biocompatible low power density of NIR-light-excited persistent luminescence.Due to its simplicity,we anticipate that this method for the preparation of UCPL composite can be easily adjusted using other available upconversion and persistent phosphor pairs for a number of biophotonic and photonic applications.     

Cyanobacteria-based near-infrared light-excited self-supplying oxygen system for enhanced photodynamic therapy of hypoxic tumors

Tumor hypoxia has been considered to induce tumor cell resistance to radiotherapy and anticancer chemotherapy,as well as predisposing for increased tumor metastases.Therefore,strategies for the eradication of the hypoxic tumor are highly desirable.Photodynamic therapy(PDT)is a new technique that can be used to treat tumors using laser irradiation to photochemically activate a photosensitizer.Compared to traditional radiotherapy and chemotherapy,photodynamic therapy has many advantages,such as good selectivity,low toxicity,and less trauma and resistance.However,PDT is oxygen-dependent,and the lack of oxygen in hypoxic tumors renders photodynamic therapy ineffective.Cyanobacteria,the earliest photosynthetic oxygen-generating organisms,can utilize water as an electron donor to reduce CO₂ into organic carbon compounds along with continuously releasing oxygen under sunlight.Inspired by this,herein,cyanobacteria were used as a living carrier of photosensitizer conjugated upconversion nanoparticles(UCNP)to construct a self-supplying oxygen PDT system.Improvement in the PDT efficiency for hypoxic tumors can be achieved as a result of in situ oxygen production by cyanobacteria under near-infrared(NIR)light using UCNP as a light harvesting antenna.A successful demonstration of this concept would be of great significance and could open the door to a new generation of carrier systems in the field of hypoxia-targeted drug transport platforms.     

Freestanding nanosheets of 1T-2H hybrid MoS2 as electrodes for efficient sodium storage

Molybdenum disulfide(MoS₂) is a promising electrode material for sodium-ion batteries as it offers a large capacity through a distinct conversion reaction.However,the electrochemical potential of MoS₂ is often restrained by the poor conductivity as the dominant 2 H phase is a semiconductor while the metallic1 T phase is thermodynamically unstable.In this work,we report a hybrid design and material preparation of freestanding nanosheets of MoS₂ composed of both 1 T and 2 H phases based on mild hydrothermal reaction.The introduction of the metallic 1 T-MoS₂ phase into 2 H-MoS₂ and their intimate hybridization enable a significant improvement in electronic conductivity,while the freestanding architecture avoids possible electrochemical aggregation.When used as electrodes for sodium storage,such a hybrid MoS₂ affords a high capacity of~500 mA h g^-1 at 0.5 A g^-1 after 300 cycles,and retains capacity of~200 mA h g^-1 at a high current rate of 4 A g^-1,thus demonstrating their potential in high-performance battery applications.     

Multidimensional thermally-induced transformation of nest-structured complex Au-Fe nanoalloys towards equilibrium

Bimetallic nanoparticles are often superior candidates for a wide range of technological and biomedical applications owing to their enhanced catalytic,optical,and magnetic properties,which are often better than their monometallic counterparts.Most of their properties strongly depend on their chemical composition,crystallographic structure,and phase distribution.However,little is known of how their crystal structure,on the nanoscale,transforms over time at elevated temperatures,even though this knowledge is highly relevant in case nanoparticles are used in,e.g.,high-temperature catalysis.Au-Fe is a promising bimetallic system where the low-cost and magnetic Fe is combined with catalytically active and plasmonic Au.Here,we report on the in s/fi;temporal evolution of the crystalline ordering in Au-Fe nanoparticles,obtained from a modern laser ablation in liquids synthesis.Our in-depth analysis,complemented by dedicated atomistic simulations,includes a detailed structural characterization by X-ray diffraction and transmission electron microscopy as well as atom probe tomography to reveal elemental distributions down to a single atom resolution.We show that the Au-Fe nanoparticles initially exhibit highly complex internal nested nanostructures with a wide range of compositions,phase distributions,and size-depended microstrains.The elevated temperature induces a diffusion-controlled recrystallization and phase merging,resulting in the formation of a single face-centered-cubic ultrastructure in contact with a body-centered cubic phase,which demonstrates the metastability of these structures.Uncovering these unique nanostructures with nested features could be highly attractive from a fundamental viewpoint as they could give further insights into the nanoparticle formation mechanism under non-equilibrium conditions.Furthermore,the in situ evaluation of the crystal structure changes upon heating is potentially relevant for high-temperature process utilization of bimetallic nanoparticles,e.g.,during catalysis.     

Di-defects synergy boost electrocatalysis hydrogen evolution over two-dimensional heterojunctions

Electronic modulation on the inert basal plane of transition-metal dichalcogenides(TMDs)through vacancy defect excitation,although extremely challenging,is urgent for understanding the factors that impact the hydrogen evolution reaction(HER)catalytic activity.Here,ultrathin WS2 nanosheets with precise quantitative single atomic S-vacancy on the inert basal plane were flexible prepared through hydrogen peroxide etching strategy.The as-synthesized single atomic S-vacancy defect WS2(SVD-WS2)nanoflake with the activated basal plane exhibited an impressive overpotential of 137 mV at a current density of 10 mA·cm^-2 and a Tafel slope of 53.9 mV dec^-1.Furthermore,anchoring on the defect graphene matrix,the assembled two-dimensional(2D)stacking heterojunction exhibits further enhanced HER catalytic activity(an overpotential of 108 mV vs.10 mA·cm^-2 and a Tafel slope of 48.3 mV·dec^-1)and stability(?10%decline after 9,000 cycles),which attributed to the electronic structure modulation from the synergetic interactions between SVD-WS₂ and defect graphene.Our finding provides a smart defects introduce strategy to trigger high-efficiency hydrogen evolution over WS₂ nanosheets and a general 2D heterojunctions fabricated inspiration based on strong interaction interface.     

Green synthesis of Au@WSe2 hybrid nanostructures with the enhanced peroxidase-like activity for sensitive colorimetric detection of glucose

We report a colorimetric method for glucose detection based on Au nanoparticle-decorated WSe₂(Au@WSe₂)hybrid nanostructures.These hybrid structures are easily synthesized by simply stirring HAuCl₄ precursor with WSe₂ nanosheets in aqueous solution.Owing to strong synergistic catalytic effects of Au nanoparticles and WSe₂ nanosheets,the Au@WSe₂ hybrid nanostructures exhibit enhanced peroxidase-like activity(about 2-fold higher compared to WSe₂ nanosheets alone)for 3,3',5,5'-tetramethylbenzidine oxidation by H₂O₂.Based on the highly catalytical property,the colorimetric method for glucose detection is established by coupling glucose oxidase(GOx).The detection limit of glucose is 3.66 pM.Moreover,the proposed colorimetric method is applicable to glucose detection in serum samples and is promising for applications in biomedical fields.     

One-step Synthesis of Shape-controllable Gold Nanoparticles and Their Application in Surface-enhanced Raman Scattering

Gold nanoparticles（NPs） of various shapes were synthesized by a one-step method at ambient temperature in the presence of NaCI.2-mercaptosuccinic acid（MSA） was used as both reducing agent and stabilizing agent.The shapes of gold NPs were controllable by simply tuning S/Au ratio（S is from MSA molecule,and S/Au ratio is controlled by tuning the volume of added MSA solution）,and triangle,polygonal and spherical nanoparticles were obtained.This result suggested a new way to consider the effects of MSA on the growth of nanoparticles,which showed that MSA is a strong capping agent and facilitates more uniform growth of nanoparticles in every dimension.And other important factors on nanoparticles growth including NaCI and temperature were discussed.Furthermore,a typical probe molecule,4-aminothiophenol（4-ATP） was used to test the surface-enhanced Raman scattering（SERS） activity of these gold NPs and the results indicated good Raman activity on these substrates.And the enhancement factor（EF） at 1078 cm^-1（a₁） was estimated to be as large as 6.3×10⁴ and 5.5×10⁴ for triangular plates and truncated particles,respectively.     

Cerium oxide nanoparticles-mediated cascade catalytic chemo-photo tumor combination therapy

ROS-based tumor therapy based on nanocatalytic medicine has recently been proposed for its tumor-specificity.However,a safe and highly efficient strategy towards getting high enough ROS to kill the hypoxic cancer cells is still a great challenge.Herein,we report a simple pH/H_{)20_(2}-activatable,O₂-evolving,and ROS regulating doxorubicin(DOX)and indocyanine green(ICG)co-loading PEGylated polyaniline(PANI)coated CeOx@polyacrylic acid(PAA)nanoclusters for highly selective and optimized cancer combination treatment.It can selectively and greatly enhance intracellular O₂ and ROS levels in tumor region,which depends on two-step catalytic properties of nanoceria(Ce⁴⁺/Ce³⁺=3.46,neutral surface charge,mostly localize into the cytoplasm,pH 7.4-6.5,catalase-like catalytic agents convert to Ce⁴⁺/Ce³⁺=0.58,negative surface charge,mostly localize into the lysosomes,pH 5-4,oxidase-like catalytic agents,triggered by near infrared(NIA)laser irradiation).Furthermore,the protective effect of polyethylene glycol(PEG),PANI,and PAA ensure that the nanoceria can only play the role of catalase under the irradiation of NIR light arrived at the tumor area.Moreover,loading of nanoceria and ICG onto PANI greatly enhanced photo thermal effect of nanoparticles.(NPs),which is useful for killing cancer cells by relieving hypoxia and promoting cross-membrane drug delivery.to further enhance photodynamic therapy and chemotherapy efficiency.The chemo-photo combination therapies fantastically inhibited tumor growth and prevented tumor recurrence in vivo,suggesting a smart nanotheranostic system to achieve more precise and effective therapies in O₂-deprived tumor tissue.     

Continuous dimethyl carbonate synthesis from CO2 and methanol over BixCe1-xOδ monoliths:Effect of bismuth doping on population of oxygen vacancies,activity,and reaction pathway

We evaluated bismuth doped cerium oxide catalysts for the continuous synthesis of dimethyl carbonate(DMC)from methanol and carbon dioxide in the absence of a dehydrating agent.Bi_xCe_1-xO_δnanocomposites of various compositions(x=0.06-0.24)were coated on a ceramic honeycomb and their structural and catalytic properties were examined.The incorporation of Bi species into the CeO₂ lattice facilitated controlling of the surface population of oxygen vacancies,which is shown to play a crucial role in the mechanism of this reaction and is an important parameter for the design of ceria-based catalysts.The DMC production rate of the Bi_xCe_1-xO_δ catalysts was found to be strongly enhanced with increasing Ov concentration.The concentration of oxygen vacancies exhibited a maximum for Bi_0.12Ce_0.88O_δ,which afforded the highest DMC production rate.Long-term tests showed stable activity and selectivity of this catalyst over 45 h on-stream at 140°C and a gas-hourly space velocity of 2,880 mL·g_cat^-1·h^-1.In-situ modulation excitation diffuse reflection Fourier transform infrared spectroscopy and first-principle calculations indicate that the DMC synthesis occurs through reaction of a bidentate carbonate intermediate with the activated methoxy(-OCH₃)species.The activation of C0₂ to form the bidentate carbonate intermediate on the oxygen vacancy sites is identified as highest energy barrier in the reaction pathway and thus is likely the rate-determining step.     

Investigation of weak interlayer coupling in 2D layered GeS2 from theory to experiment

Interlayer coupling as a unique feature for two-dimensional(2D)materials may influence their thickness-dependent physical properties,especially the bandgap due to quantum confinement effect.Widely-studied 2D materials usually possess strong interlayer coupling such as most of transition metal dichalcogenides(TMDs),PtS₂ and so on.However,2D materials with weak interlayer coupling are rarely referred that mainly focus on ReS₂,as well as its counterpart ReSe₂.Here we report a new member of weak interlayer coupling 2D materials,germanium disulfide(GeS₂).The interlayer interaction in GeS₂ is investigated from theory to experiment.By density functional theory calculations,we find that this extraordinarily weak interlayer coupling in GeS₂ originates from the weak hybridization of interlayer S atoms.Thickness-dependent Raman spectra of GeS₂ flakes exhibit that the Raman peaks remain unchanged when increasing the thickness;and a small first-order temperature coefficient of-0.00857 cm^-1·K^-1 is obtained from the temperature-dependent Raman spectra.These experimental results further confirm the weak interlayer coupling in GeS₂.     

Ionic Liquids Assisted Synthesis of ZnO Nanostructures:Controlled Size,Morphology and Antibacterial Properties

Systematic analysis about the exploitation of imidazolium based ionic liquids（ILs）,[BMIM]BF₄[IL1],[EMIM]BF₄ [IL2]and[BMIM]PF₆[IL3]as the morphological template on the basic sol-gel method adopted synthesis of nanostructured zinc oxide（ZnO） is presented.X-ray diffraction（XRD）,particle size analysis（PSA） and scanning electron microscopy（SEM） have been employed for the characterization of structure and morphology of the synthesized ZnO particles.Well-defined capsule like shaped morphology with lower nanosize is observed for the ZnO nanoparticles with IL1 than those with IL2 and IL3.This confirms that IL1 served as an effective templating material due to their unique properties.Especially the effective aggregation of ZnO particles with a self-organized frame of IL1 was the essential factor to produce the lower nanosized ZnO with capsule shaped structure.The synthesized ZnO samples with IL2 and IL3 fabricated the flake like shaped and rod like shaped morphologies in the range of nanoscale.The formed ZnO nanoparticles with IL2 exhibit higher nanosize than the ZnO nanoparticles produced by IL1,owing to shorter length of alkyl group in its cation which restricts steric effect and permits the nanoparticles to grow longer.Even though IL3 produced the discrete ZnO nanorods,the hydrophobic nature of IL3 created the higher nanosize than the ZnO nanoparticles formed by other two ionic liquids.Antibacterial properties of the synthesized ZnO nanostructures were investigated against Staphylococcus aureus（gram positive） and Escherichia coli（gram negative） bacteria by Agar diffusion test method.Microbial experiments indicate that the synthesized ZnO samples show a wide spectrum of antimicrobial activities and performed better against S.aureus than E.coli with the same concentration of ZnO.     

Facile synthesis of C3N4-supported metal catalysts for efficient CO2 photoreduction

Facile synthesis of photocatalysts with highly dispersed metal centers is a high-priority target yet still a significant challenge.In this work,a series of Co-C₃N₄ photocatalysts with different Co contents atomically dispersed on g-CaN4 have been prepared via one-step thermal treatment of cobalt-based metal-organic frameworks(MOFs)and urea in the air.Thanks to the highly dispersed and rich exposed Co sites,as well as good charge separation efficiency and abundant mesopores,the optimal 25-Co-C₃N₄,in the absence of noble metal catalysts/sensitizers,exhibits excellent performance for photocatalytic C0₂ reduction to CO under visible.light irradiation,with a high CO evolution rate of 394.4μmol·g^-1·h^-1,over 80 times higher than that of pure g-C₃N₄(4.9μmol·g^-1·h^-1).In:addition,by this facile synthesis strategy,the atomically dispersed Fe and Mn anchoring on g-C₃N₄(Fe-C₃N₄ and Mn-C₃N₄)have been also obtained,indicating the reliability and universality of this strategy in synthesizing photocatalysts with highly dispersed metal centers.This work paves a new way to develop cost-effective photocatalysts for photocatalytic C0₂ reduction.     

2D interspace confined growth of ultrathin MoS2-intercalated graphite hetero-layers for high-rate Li/K storage

Herein,a two-dimensional(2D)interspace-confined synthetic strategy is developed for producing MoS₂intercalated graphite(G-MoS₂)hetero-layers composite through sulfuring the pre-synthesized stage-1 MoCI5-graphite intercalation compound(M0 CI5-GIC).The in situ grown MoS₂nanosheets(3-7 layers)are evenly encapsulated in graphite layers with intimate interface thus forming layer-by-layer MoS₂-intercalated graphite composite.In this structure,the unique merits of MoS₂and graphite components are integrated,such as high capacity contribution of MoS₂and the flexibility of graphite layers.Besides,the tight interfacial interaction between hetero-layers optimizes the potential of conductive graphite layers as matrix for MoS₂.As a result,the G-MoS₂exhibits a high reversible Li+storage of 344 mAh·g^-1even at 10 A·g^-1and a capacity of 539.9 mAh·g^-1after 1,500 cycles at 5 A·g^-1.As for potassium ion battery,G-MoS₂delivers a reversible capacity of 377.0 mAh·g^-1at 0.1 A·g^-1and 141.2 mAh·g^-1even at 2 A·g^-1.Detailed experiments and density functional theory calculation demonstrate the existence of hetero-layers enhances the diffusion rates of Li⁺and K⁺.This graphite interspace-confined synthetic methodology would provide new ideas for preparing function-integrated materials in energy storage and conversion,catalysis or other fields.     

Metal-organic layers as reusable solid fluorination reagents and heterogeneous catalysts for aromatic fluorination

Reusable solid fluorination reagents and heterogeneous catalysts are ideally suited for late-stage fluorination with fast and clean conversion and simplified work-up.Here we report Pd-functionalized two-dimensional metal-organic layers(MOLs)as solid reagents and heterogeneous catalysts to efficiently fluorinate a broad scope of aromatic compounds.Site isolation in the MOLs provides a unique opportunity to stabilize highly active F-containing species for the chemical conversion.A terpyridine(TPY)-based ligand on the MOL,together with a 2-chloro-1,10-phenanthroline(phenCl)as a co-ligand,chelates Pd^Ⅱtoform a reactive center.After treatment with Selectfluor/H₂0,an(N-fluoroxy)-(2-chloro)-phenanthrolinium[N-(FO)-phenCl⁺]moiety is produced from the co-ligand on the Pd center.This active species serves as a stochiometric solid fluorination reagent,which shows different regioselectivities and reactivities as compared to homogeneous catalysts that involves Pd^Ⅲ/Ⅳ-F intermediates in catalytic cycles.The MOLs can also be used as heterogeneous catalysts for fluorination using Selectfluor.This work highlights opportunities in using MOLs to stabilize unique active sites for late-stage fluorination.     

Combining in-situ TEM observations and theoretical calculation for revealing the thermal stability of CeO2 nanoflowers

The thermal stability of Ce₂ nanomaterials can directly impact both the uniformity of the supported catalysts and the catalytic behavior of Ce₂ itself.However,knowledge about the thermal stability of Ce₂ is still deficient.Here,we conduct in-situ transmission electron microscopy experiments and theoretical calculations to elucidate the thermal stability of Ce₂ nanomaterials under different environments.A sinter(<700℃)and a structural decomposition(>700℃)are observed within Ce₂ nanoflowers under O₂.The sinter firstly occurs among the nanoflowers’monomers and then the sintered nanoparticles structurally decompose to tiny nanoparticles from the strain interface.Under a vacuum environment,the Ce₂ nanoflowers firstly undergo a transition from cubic fluorite Ce₂ to hexagonal Ce₂O₃,accompanied by the oxygen release.The Ce₂O₃ nanoparticles further atomically sublimate from the edges to the center under high temperatures.Theoretical calculation results reveal a considerably lower energy barrier for the structural decomposition under O₂ and for the sublimation under vacuum.This work provides a perspective on the structural design and performance optimization of Ce₂-based catalysts.     

Study on mechanism of low-temperature oxidation of n-hexanal catalysed by 2D ultrathin Co3O4 nanosheets

Achieving high catalytic performance with lower possible cost and higher energetic efficiency is critical for catalytic oxidation of volatile organic compounds(VOCs).However,traditional thermocatalysts generally undergo low catalytic activity and fewer active sites.Herein,this paper synthesizes nearly all-surface-atomic,ultrathin two-dimensional(2D)Co₃O₄ nanosheets to address these problems through offering a numerous active sites and high electron mobility.The 2D Co₃O₄ nanosheets(1.70 nm)exhibit catalyzation to the total oxidation of n-hexanal at the lower temperature of r90%=202℃,and at the space velocity of 5.0×10⁴ h^-1.It is over 1.2 and 6 times higher catalytic activity than that of 2D CoO nanosheets(1.71 nm)and bulk Co₃O₄ counterpart,respectively.Transient absorption spectroscopy analysis shows that the oxygen vacancy defect traps electrons,thereby preventing the recombination with holes,increasing the lifetime of electrons,and making electron-holes reach a nondynamic equilibrium.The longer the electron lifetime is,the easier the oxygen vacancy defects capture electrons.Furthermore,the defects combine with oxygen to form active oxygen components.Compared with the lattice oxygen involved in the reaction of bulk Co₃O₄,the nanosheets change the catalytic reaction path,which effectively reduces the activation energy barrier from 34.07 to 27.15 kJ/mol.The changed surface disorder,the numerous coordinatively-unsaturated Co atoms and the high ratio of O_ads/O_lat on the surface of 2D Co₃O₄ nanosheets are responsible for the catalytic performance.     

Boosted photoreduction of diluted CO2 through oxygen vacancy engineering in NiO nanoplatelets

Converting carbon dioxide(CO₂)to diverse value-added products through photocatalysis can validly alleviate the critical issues of greenhouse effect and energy shortages simultaneously.In particular,based on practical considerations,exploring novel catalysts to achieve efficient photoreduction of diluted CO₂ is necessary and urgent.However,this process is extremely challenging owing to the disturbance of competitive adsorption at low CO₂ concentration.Herein,we delicately synthesize oxygen vacancy-laden NiO nanoplatelets(r-NiO)via calcination under Ar protection to reduce diluted CO₂ through visible light irradiation(>400 nm)assisted by a Ru-based photosensitizer.Benefitting from the strongly CO₂ adsorption energy of oxygen vacancies,which was confirmed by density functional calculations,the r-NiO catalysts exhibit higher activity and selectivity(6.28×10³μmol·h^?1·g^?1;82.11%)for diluted CO₂-to-CO conversion than that of the normal NiO(3.94×10³μmol·h^?1·g^?1;65.26%).Besides,the presence of oxygen vacancies can also promote the separation of electron-hole pairs.Our research demonstrates that oxygen vacancies could act as promising candidates for photocatalytic CO₂ reduction,offering fundamental guidance for the actual photoreduction of diluted CO₂ in the future.     

Improving the intrinsic electronic conductivity of NiMo04 anodes by phosphorous doping for high lithium storage

Heteroatom doping is one of the most promising strategies toward regulating intrinsically sluggish electronic conductivity and kinetic reaction of transition metal oxides for enhancing their lithium storage.Herein,we designed phosphorus-doped NiMo0₄ nanorods(P-NiMo0₄)by using a facile hydrothermal method and subsequent low-temperature phosphorization treatment.Phosphorus doping played an indispensable role in significantly improving electronic conductivity and the Li+diffusion kinetics of NiMo0₄ materials.Experimental investigation and density functional theory calculation demonstrated that phosphorus doping can expand the interplanar spacing and alter electronic structures of NiMo0₄ nanorods.Meanwhile,the introduced phosphorus dopant can generate some oxygen vacancies on the surface of NiMo0₄,which can accelerate Li+diffusion kinetics and provide more active site for lithium storage.As excepted,P-NiMo0₄ electrode delivered a high specific capacity(1,130 mA·g^-1 at 100 mA·g^-1 after 100 cycles),outstanding cycling durability(945 mA·g^-1 at 500 mA·g^-1 over 200 cycles),and impressive rate performance(640 mA·g^-1at 2,000mA·g^-1)for lithium ion batteries(LIBs).This work could provide a potential strategy for improving intrinsic conductivity of transition metal oxides as high-performance anodes for LIBs.     

Microstructure and Mechanical Properties of Al2O3/ZrO2 Directionally Solidified Eutectic Ceramic Prepared by Laser 3D Printing

Directionally solidified eutectic ceramics such as（Al）₂O₃/ZrO₂ are promising structural materials for applications in harsh environment with an ultrahigh temperature. In this work, through adopting assistant heating laser 3D printing,（Al）₂O₃/ZrO₂eutectic samples were manufactured with suppressing the formation of cracks. The dependence of the average rod spacing（λav） on the scanning rate（V） follows a relation with λav V0.5= 1 μm1.5s–0.5. Typical eutectic microstructures, so-called complex regular, were analyzed with respect to its evolution with modulating the growth conditions. Formation mechanism of the solidification defect, shrinkage porosity, was discussed and the defect is found to be significantly suppressed by optimizing the solidification parameters. The maximum hardness and fracture toughness are measured to be 16.7 GPa and 4.5 MPa m1/2, respectively. The interplay between the propagation of cracks and the （Al）₂O₃/ZrO₂ interface is discussed.     

Phase and structure modulating of bimetallic Cu/In nanoparticles realizes efficient electrosynthesis of syngas with wide CO/H2 ratios

Syngas(CO+H₂)is the incredibly important feedstock for producing synthetic fuels and various value-added chemicals.CO₂ electrochemical reduction to syngas is an environmental-friendly and sustainable approach,but still challenging to produce tunable syngas with a wide ratio of CO+H₂.Herein,by modulating the structure and phase,we have successfully obtained a series of copper-indium(Cu-ln)catalysts,which are efficient for producing syngas with tunable CO+H₂ ratios.A series of Culn bimetallic catalysts with different structures from hollow sphere to two-layer hollow sphere and different phases from CuO to CU₂O are developed.We find that the CO and H2 are the only gaseous products,in which the CCD/H₂ ratios can be readily tuned from 1.2±0.1 to 9.0±1.5 by simply controlling the thermal annealing temperature.It also exhibits high durability during a 10-h test.The unique performance is attributed to the modulated In enrichment on the Cu surfaces during the CO₂ reduction reaction,which causes the differences in binding energies for key reaction intermediates,thus resulting in the tunable composition of syngas.The present work emphasizes a simple yet efficient phase and structure modulating strategy for designing potential electrocatalysts for producing syngas with widely tunable CO+H₂ ratios.