The surface-enhanced Raman scattering(SERS) optical fiber probes were successfully prepared by self-assembling on polyelectrolyte multilayers. Gold nanorods(Au NRs) were used as SERS enhancement material to give excel...The surface-enhanced Raman scattering(SERS) optical fiber probes were successfully prepared by self-assembling on polyelectrolyte multilayers. Gold nanorods(Au NRs) were used as SERS enhancement material to give excellent biological affinity and stability to the SERS optical fiber probes. Au NRs were synthesized by seed growth method. The synergistic effect between AgNO_(3) and surfactant was investigated, and the highest yield was found when AgNO_(3) was 500 uL. Meanwhile, different SERS optical fiber probes were obtained by selecting silane coupling agent, polyelectrolyte multilayer and graphene oxide(GO) to treat quartz fiber. It was found that the SERS optical fiber probes obtained by the self-assembled on polyelectrolyte multilayers method performed better than those by other methods. In addition, Mapping was combined with finite element simulation to analyze the electromagnetic field distribution at the fiber end face.The electromagnetic field distribution of Au NRs was investigated, the difference of electromagnetic field intensity around the Au NRs with different arrangements was compared, the strongest signal was obtained when the Au NRs were head-to-head. Finally, sensitivity of the optimized SERS optical fiber probes could reach 10^(-9)mol/L, with excellent stability and repeatability.展开更多
Controllable design and synthesis of catalysts with the target active sites are extremely important for their applications such as for the oxygen reduction reaction(ORR)in fuel cells.However,the controllably synthesiz...Controllable design and synthesis of catalysts with the target active sites are extremely important for their applications such as for the oxygen reduction reaction(ORR)in fuel cells.However,the controllably synthesizing electrocatalysts with a single type of active site still remains a grand challenge.In this study,we developed a facile and scalable method for fabricating highly efficient ORR electrocatalysts with sole atomic Fe-N4 species as the active site.Herein,the use of cost-effective highly porous carbon as the support not only could avoid the aggregation of the atomic Fe species but also a feasible approach to reduce the catalyst cost.The obtained atomic Fe-N4 in activated carbon(aFe@AC)shows excellent ORR activity.Its half-wave potential is 59 mV more negative but 47 mV more positive than that of the commercial Pt/C in acidic and alkaline electrolytes,respectively.The full cell performance test results show that the aFe@AC sample is a promising candidate for direct methanol fuel cells.This study provides a general method to prepare catalysts with a certain type of active site and definite numbers.展开更多
Photocatalytic water splitting has increasingly attracted attention as one of the most useful methods of converting solar energy into chemical fuel.However,the undesirable reverse reaction significantly limits the enh...Photocatalytic water splitting has increasingly attracted attention as one of the most useful methods of converting solar energy into chemical fuel.However,the undesirable reverse reaction significantly limits the enhancement of efficiency.Herein,we fabricated an Au nanorods/TiO2 nanodumbbells structure photocatalyst(Au NRs/TiO2 NDs)via a facile synthetic strategy,which has spatially separated oxidation and reduction reaction zones.Owing to the unique structure,the charge separation of these photocatalysts can be significantly improved and the reverse reaction can be efficiently inhibited.The photogenerated electrons were injected from the TiO2 to the Au NRs,and a positively charged TiO2 region and negatively charged Au region were formed under UV irradiation.An enhanced hydrogen production performance was obtained compared with that seen in normal Au-TiO2 heterostructure.Under optimized conditions,the H2-production rate can reach up to 60,264μmol/g/h,about six times higher than previously reported Au/TiO2 photocatalysts.Besides this,our work also demonstrates the key factors of precise synthesis of the Au NRs/TiO2 NDs structure,which provides a new perspective and experience for the design of similar catalysts.展开更多
Magnetite (Fe3O4) nanoparticles with different sizes and shapes are synthesized by the thermal decomposition method. Two approaches, non-injection one-pot and hot-injection methods, are designed to investigate the g...Magnetite (Fe3O4) nanoparticles with different sizes and shapes are synthesized by the thermal decomposition method. Two approaches, non-injection one-pot and hot-injection methods, are designed to investigate the growth mechanism in detail. It is found that the size and shape of nanoparticles are determined by adjusting the precursor concentration and duration time, which can be well explained by the mechanism based on the LaMer model in our synthetic system. The monodisperse Fe3O4 nanoparticles have a mean diameter from 5nm to 16nm, and shape evolution from spherical to triangular and cubic. The magnetic properties are size-dependent, and Fe3O4 nanoparticles in small size about 5 nm exhibit superparamagnetie properties at room temperature and maximum saturation magnetization approaches to 78 emu/g, whereas Fe3O4 nanoparticles develop ferromagnetic properties when the diameter increases to about 16nm.展开更多
Microbial fabrication of metal nanoparticles(MNPs)has received significant attention due to the advantages of low toxicity,energy efficiency and ecological safety.Diverse groups of MNPs can be synthesized intracellula...Microbial fabrication of metal nanoparticles(MNPs)has received significant attention due to the advantages of low toxicity,energy efficiency and ecological safety.Diverse groups of MNPs can be synthesized intracellularly or extracellularly by various wild-type microorganisms,including bacteria,fungi,algae and viruses.Synthetic biology approaches,represented by genetic engineering,have been applied to overcome the shortcomings in productivity,stability,and controllability of biosynthetic MNPs.Scanning electron microscope(SEM),transmission electron microscope(TEM)and other characterization techniques assist in deciphering their unique properties.In addition,biosynthetic MNPs have been widely explored for the utilization in environmental remediation and contaminant detection.And machine learning contains a great potential for designing targeted MNPs and predicting their toxicity.This review provides a comprehensive overview of the research progress in the microbial synthesis of MNPs.An outlook on the current challenges and future prospects in the biologically controllable synthesis and engineering environmental applications of MNPs is also provided in this review.展开更多
In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterpart...In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterparts.The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications.In this context,the atomic substitution method has emerged as a favorable approach.It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting materials.In this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC materials.The effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are discussed.The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these advancements.Finally,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.展开更多
Different solvothermal reactions of ZnC2O_(4)with oxalic acid(H_(2)ox)and 1,2,4-triazole(Htrz)successfully gave a new quaternary(NJTU-Bai83,NJTU-Bai=Nanjing Tech University Bai's group)and a new quinary(NJTU-Bai84...Different solvothermal reactions of ZnC2O_(4)with oxalic acid(H_(2)ox)and 1,2,4-triazole(Htrz)successfully gave a new quaternary(NJTU-Bai83,NJTU-Bai=Nanjing Tech University Bai's group)and a new quinary(NJTU-Bai84)anionic metal-organic frameworks(MOFs),where NJTU-Bai83=(Me_(2)NH_(2))2[Zn_(3)(trz)_(2)(ox)_(3)]·2H_(2)O and NJTU-Bai84=(Me_(2)NH_(2))[Zn_(3)(trz)_(3)(ox)_(2)]·H_(2)O,respectively.With the[Zn_(2)(ox)4(trz)_(2)]secondary building unit(SBU)in NJTU-Bai83 replaced by the[Zn_(3)(ox)_(2)(trz)_(6)]and planar[Zn(ox)_(2)(trz)_(2)]ones in NJTU-Bai84,2D supramolecular building layers(SBLs)are changed from the A-layer and B-layer to another A-layer,while pillars are transformed from the tetrahedral[Zn(ox)_(2)(trz)_(2)]SBU to the irregular tetrahedral[Zn(ox)_(2)(trz)_(2)]and planar[Zn(ox)_(2)(trz)_(2)]SBUs.Thus,cdq-topological quaternary NJTU-Bai83 is tuned to(4,4,8)-c new topological quinary NJTU-Bai84.Two MOFs were well characterized by powder X-ray diffraction,thermogravimetric analysis,elemental analysis,etc.CCDC:2351819,NJTU-Bai83;2351820,NJTU-Bai84.展开更多
A series of Tb-based metal-organic frameworks(Tb-MOFs)were successfully synthesized by a solvothermal method.The size and morphology of the as-obtained Tb-MOFs can be effectively controlled via regulating the experime...A series of Tb-based metal-organic frameworks(Tb-MOFs)were successfully synthesized by a solvothermal method.The size and morphology of the as-obtained Tb-MOFs can be effectively controlled via regulating the experimental conditions such as the volume fraction of DMF and the molar ratio of Tb^(3+)to NaOH.It is found that all the samples exhibit strong green emissions under ultraviolet excitation,corresponding to^(5)D_(4)→^(7)F_(J)transitions of Tb^(3+).Interestingly,Tb-MOFs displayed an efficient and distinct luminescence quenching by Cu^(2+)in aqueous solutions.The competitive fluorescence detection experiments indicate that these Tb-MOFs sensors can be used as a high selective and sensitive sensor of Cu^(2+)detection with the detection limit of 10μmol·L^(-1),which can be used as a promising fluorescence sensor for Cu^(2+)detection in daily life.展开更多
Two-dimensional molybdenum disulfide(2D MoS_(2))is considered as a promising candidate for many applications due to its unique structure and properties.However,the controllable synthesis of large-scale and high-qualit...Two-dimensional molybdenum disulfide(2D MoS_(2))is considered as a promising candidate for many applications due to its unique structure and properties.However,the controllable synthesis of large-scale and high-quality 2D 1T-phase MoS_(2)is still a challenge.Herein,we present the scalable and controllable synthesis of 2D MoS2 from 2H to 1T@2H phase by using K_(2)SO_(4)salt as a simultaneous high-temperature sulfur source and template.The as-synthesized 1T@2H-2D MoS_(2)exhibits a high yield and can be easily assembled into freestanding electrode with high specific capacitance of 434 F/g at a scan rate of 1 mV/s in LiClO_(4)ethylene carbonate/dimethyl carbonate(EC/DMC).Moreover,various single-crystal 2D transition metal sulfides(WS_(2),PbS,MnS and Ni_(9)S_(8))and 2D S-doped carbon can be synthesized using this method.We believe that this study may provide a new sight for scalable and controllable synthesis of other 2D materials beyond 2D MoS_(2).展开更多
Isomerism is an essential and widespread phenomenon in organic chemistry but rarely observed in covalent organic frameworks(COFs),a novel class of crystalline porous organic polymers with versatile applications.Herein...Isomerism is an essential and widespread phenomenon in organic chemistry but rarely observed in covalent organic frameworks(COFs),a novel class of crystalline porous organic polymers with versatile applications.Herein,we give an account of the first example of a controllable synthesis of constitutional isomers of a COF.The two isomers exhibited marked differences in their gas/vapor adsorption behaviors and chemical stability in various solvents.Furthermore,structure transformation from one isomer to the other was realized.This work not only paves the way for rational design and synthesis of COF isomers but also provides a vivid example of structure–property relationship in crystalline porous polymers.展开更多
In this paper,CuO_(x)@Ag/CeO_(2) catalysts were synthesized by simple wet-chemical method and equal volume impregnation method.The obtained catalysts were subjected to soot temperature programmed oxidation(soot-TPO)ac...In this paper,CuO_(x)@Ag/CeO_(2) catalysts were synthesized by simple wet-chemical method and equal volume impregnation method.The obtained catalysts were subjected to soot temperature programmed oxidation(soot-TPO)activity tests and were further characterized by various techniques such as X-ray diffraction(XRD),transmission electron microscopy/high-resolution transmission electron microscopy(TEM/HR-TEM),N_(2) physisorption,X-ray photoelectron spectroscopy(XPS)and H_(2)-temperature programmed reduction(H_(2)-TPR).The results show that CuO_(x)@Ag/CeO_(2) synthesized presents well controlled core-shell structures,with nano-cube like Cu_(2)O as the core and Ag decorated polycrystalline CeO_(2) grafting layers as the shell.Such core-shell structured CuO_(x)@Ag/CeO_(2) can successfully construct a secondary oxygen delivery channel(CuO_(x)→CeO_(2)→Ag)to effectively transfer bulk oxygen of the catalyst to the soot,resulting in its excellent soot oxidation activity compared to CuO_(x)@CeO_(2).The potential benefiting effect by Ag introduction over Cu@Ag/Ce can be concluded as:(ⅰ)pumping lattice oxygen and accelerating gaseous O_(2) dissociation to generate significantly increased active surface oxygen content;(ⅱ)modulating a moderate surface oxygen vacancies concentration to maintain more highly active O_(2) species.展开更多
Transition metal oxides are found to have overwhelming applications in energy,electronics,catalytic,and bio-and micromechanical systems.A recent report emphasized the current advancements in molybdenum oxide(MoO_(x))n...Transition metal oxides are found to have overwhelming applications in energy,electronics,catalytic,and bio-and micromechanical systems.A recent report emphasized the current advancements in molybdenum oxide(MoO_(x))nanowire synthesis and the corresponding surface-functionalized nanostructured materials based on our previously reported investigations.The preparation of the nanowires and their applications were systematically summarized.MoO_(x) nanowires combined with substrates exhibited remarkable performances for high energy storage and power densities with high stability.In addition,the review concluded the future advancements of MoO_(x) nanowires.展开更多
Whitlockite(WH,Ca_(18)Mg_(2)(HPO_(4))_(2)(PO_(4))_(12))is an important inorganic phase in human bones and has positive significance for participating in the bone reconstruction process.In this paper,we report differen...Whitlockite(WH,Ca_(18)Mg_(2)(HPO_(4))_(2)(PO_(4))_(12))is an important inorganic phase in human bones and has positive significance for participating in the bone reconstruction process.In this paper,we report different doping strategies to prepare WH and WH-Ln(Eu/Tb)nanocrystals,and have successfully synthesized WH-Ln(Eu/Tb)nanoparticles(NPs)with bright red or green fluorescence based on ions exchange doping by two-step hydrothermal reaction.WH-5%Ln(Eu/Tb)NPs with the best fluorescence properties were successfully applied to live cell imaging,and WH-5%Eu NPs were implanted into the bone defect site in rabbit femoral condyles to visually observe its degradation process.The related results would help us understand WH nanocrystals and further expand their potential applications in tissue engineering and related fields.展开更多
Herein,a novel photonic coordination polymer material was constructed by aggregation-induced emission luminogen(AIEgen)containing a tripyridyl moiety used as the linking ligand.It displayed a spontaneous direct centro...Herein,a novel photonic coordination polymer material was constructed by aggregation-induced emission luminogen(AIEgen)containing a tripyridyl moiety used as the linking ligand.It displayed a spontaneous direct centrosymmetric to noncentrosymmetric phase transition in a single crystal.The two crystals,before and after the phase transition,were both controllably synthesized and characterized by single-crystal X-ray diffraction.After being exposed to air,the centrosymmetric metastable phase(1-α)transitioned to a new stable phase with a noncentrosymmetric structure(1-β).Interestingly,the 1-βstructure exhibited a strong phasematching second-harmonic generation(SHG)response,about4.5 times higher than that of KH2PO4(KDP).In order to better understand the relationship between the structure and the nonlinear optical properties,the dipole moments were calculated and discussed.Remarkably,the noncentrosymmetric phase with high thermal stability for 1-βretained and improved the initial photoluminescent properties of the AIEgen ligand after the structural phase transition from 1-α,and simultaneously produced the excellent SHG property,which are beneficial for the design and construction of excellent optical materials.展开更多
Through a controllable“reactivate””graft”synthetic route,two asymmetrical“Janus”dendronized polymers(DPs)were successfully synthesized.Dendrons were grafted to a linear polymer motherboard by a story-by-story co...Through a controllable“reactivate””graft”synthetic route,two asymmetrical“Janus”dendronized polymers(DPs)were successfully synthesized.Dendrons were grafted to a linear polymer motherboard by a story-by-story constructionmethod.Due to the heterogenetic“Janus”structure,with orderly arranged chromophore moieties,the polymers demonstrated extremely large second-order nonlinear optical(NLO)coefficients and excellent NLO thermal stability.DP-4l and DP-6l had high d33 values of 232 and 227 pm/V,respectively,which reached the highest value reported so far for linear-based polymers containing simple azo-chromophore moieties.The controllable synthesis sheds light on the structure–property relationships of NLO polymers and other dendronized-structure functional polymers.展开更多
Electrocatalysis,as the nexus for energy storage and environmental remediation,requires developing low-cost and highperforming heterogeneous catalysts.Compared with the single atom catalysts(SACs),dual-atom catalysts(...Electrocatalysis,as the nexus for energy storage and environmental remediation,requires developing low-cost and highperforming heterogeneous catalysts.Compared with the single atom catalysts(SACs),dual-atom catalysts(DACs)are attracting ever-increasing interest due to their higher metal loading,more versatile active sites and unique reactivity.However,controlled synthesis of DACs remains a great challenge,and their electrocatalytic applications are still in infancy.This review first discusses the synthesis of DACs by highlighting several synthetic strategies.Subsequently,we exemplify the unique reactivities of DACs in electrocatalytic applications including water splitting,oxygen reduction,carbon dioxide reduction and nitrogen reduction.The structure-activity relations of DACs are specifically discussed in comparison with that of SACs,on the basis of experimental and theoretical studies.Finally,the opportunities and challenges of DACs are summarized in terms of rational design,controlled synthesis,characterization,and applications.展开更多
As a direct wide bandgap semiconductor,CsPbCl_(3)has great potential applications in the eld of near-ultraviolet photodetectors,lasers and higher-order multiphoton uores-cent detectors.In this work,we synthesized CsPb...As a direct wide bandgap semiconductor,CsPbCl_(3)has great potential applications in the eld of near-ultraviolet photodetectors,lasers and higher-order multiphoton uores-cent detectors.In this work,we synthesized CsPbCl_(3)micro/nanocrystals by vapor depo-sition method with CsCl and PbCl_(2)powders as the source materials.It was con rmed that the formation of CsPbCl_(3)perovskite through the chemical reaction of CsCl with PbCl_(2)occurred in the quartz boat before the source evaporation,not in vapor or on sub-strate surface.The evaporated CsPbCl_(3)can form micro/nanocrystals on substrate surfaces under appropriate conditions.Various morphologies including irregular polyhedrons,rods and pyramids could be observed at lower temperature,while stable and uniform CsPbCl_(3)single crystal microplatelets were controllably synthesized at 450℃.Prolonging the growth time could modulate the size and density of the microcrystals,but could not change the morphology.Substrate types made little di erence to the morphology of CsPbCl_(3)crystals.The photoluminescence spectra indicated that the crystallinity and morphology of CsPbCl_(3)micro/nanocrystals have signi cant e ects on their optical properties.The work is expected to be helpful to the development of optoelectronic devices based on individual CsPbCl_(3)microcrystal.展开更多
Designing a highly active-and stable non-noble metal bifunctional oxygen catalyst for rechargeable Znair battery remains a great challenge. Herein, we develop a facile and melamine-assisted-pyrolysis(MAP)strategy for ...Designing a highly active-and stable non-noble metal bifunctional oxygen catalyst for rechargeable Znair battery remains a great challenge. Herein, we develop a facile and melamine-assisted-pyrolysis(MAP)strategy for the synthesis of core–shell Co-based electrocatalysts@N-doped carbon nanotubes(Co@CNTs)derived from metal–organic frameworks. The Co@CNTs exhibited excellent bifunctional electrocatalytic performance for both oxygen evolution and reduction. DFT calculations demonstrated that the Gibbs free energy of the rate-determining step was small enough to improve ORR activities. As a result, a Zn-air battery assembled with Co@CNTs proves a lager power density, low voltage gap between charge–discharge and excellent stability. Thus, this work offers a facile strategy to realize the synthesis of non-noble metal electrocatalyst for Zn-air battery materials with high electrochemical performance.展开更多
Doping effects of manganese (Mn) on catalytic performance and structure evolution of NiMgO catalysts for synthesis of multi-walled carbon nanotubes (MWCNTs) from methane were investigated for the first time. Addit...Doping effects of manganese (Mn) on catalytic performance and structure evolution of NiMgO catalysts for synthesis of multi-walled carbon nanotubes (MWCNTs) from methane were investigated for the first time. Addition of Mn in NiMgO catalyst can greatly improve the MWCNTs yield. Mno.2NiMgO catalyst among the tested ones gives the highest MWCNTs yield as 2244%, which is two times higher than that of the catalyst without Mn. The structure evolution, reduction behaviors and surface chemical properties of MnNiMgO catalysts with various Mn contents were studied in detail. It was found that the stable solid solution of NiMgO2 formed in NiMgO catalyst was disturbed by the addition of Mn. Instead, another solid solution of MnMg608 is formed. More amount of Ni can be reduced and dispersed on the catalyst surface to be acted as active sites. Importantly, the changes of Ni content on the surface are correlated with the Ni particle size and the outer diameter of MWCNTs, suggesting the controllable synthesis of MWCNTs over MnNiMgO catalysts.展开更多
基金Funded by National Natural Science Foundation of China (Nos.51372179, 51772224)the Open Projects Foundation of Yangtze Optical Fiber and Cable Joint Stock Limited Company (YOFC)(No.SKLD1705)。
文摘The surface-enhanced Raman scattering(SERS) optical fiber probes were successfully prepared by self-assembling on polyelectrolyte multilayers. Gold nanorods(Au NRs) were used as SERS enhancement material to give excellent biological affinity and stability to the SERS optical fiber probes. Au NRs were synthesized by seed growth method. The synergistic effect between AgNO_(3) and surfactant was investigated, and the highest yield was found when AgNO_(3) was 500 uL. Meanwhile, different SERS optical fiber probes were obtained by selecting silane coupling agent, polyelectrolyte multilayer and graphene oxide(GO) to treat quartz fiber. It was found that the SERS optical fiber probes obtained by the self-assembled on polyelectrolyte multilayers method performed better than those by other methods. In addition, Mapping was combined with finite element simulation to analyze the electromagnetic field distribution at the fiber end face.The electromagnetic field distribution of Au NRs was investigated, the difference of electromagnetic field intensity around the Au NRs with different arrangements was compared, the strongest signal was obtained when the Au NRs were head-to-head. Finally, sensitivity of the optimized SERS optical fiber probes could reach 10^(-9)mol/L, with excellent stability and repeatability.
基金The authors would like to thank the Australian Research Council(ARC DP170103317,DP200103043)for financial support during the course of this study.Prof Jun Chen would like to thank the Australian National Fabrication Facility and EMC at the University of Wollongong for facilities/equipment access.
文摘Controllable design and synthesis of catalysts with the target active sites are extremely important for their applications such as for the oxygen reduction reaction(ORR)in fuel cells.However,the controllably synthesizing electrocatalysts with a single type of active site still remains a grand challenge.In this study,we developed a facile and scalable method for fabricating highly efficient ORR electrocatalysts with sole atomic Fe-N4 species as the active site.Herein,the use of cost-effective highly porous carbon as the support not only could avoid the aggregation of the atomic Fe species but also a feasible approach to reduce the catalyst cost.The obtained atomic Fe-N4 in activated carbon(aFe@AC)shows excellent ORR activity.Its half-wave potential is 59 mV more negative but 47 mV more positive than that of the commercial Pt/C in acidic and alkaline electrolytes,respectively.The full cell performance test results show that the aFe@AC sample is a promising candidate for direct methanol fuel cells.This study provides a general method to prepare catalysts with a certain type of active site and definite numbers.
基金supported by the National Natural Science Foundation of China(21703046)the National Key R&D of China(2016YFF0203803,2016YFA0200902)~~
文摘Photocatalytic water splitting has increasingly attracted attention as one of the most useful methods of converting solar energy into chemical fuel.However,the undesirable reverse reaction significantly limits the enhancement of efficiency.Herein,we fabricated an Au nanorods/TiO2 nanodumbbells structure photocatalyst(Au NRs/TiO2 NDs)via a facile synthetic strategy,which has spatially separated oxidation and reduction reaction zones.Owing to the unique structure,the charge separation of these photocatalysts can be significantly improved and the reverse reaction can be efficiently inhibited.The photogenerated electrons were injected from the TiO2 to the Au NRs,and a positively charged TiO2 region and negatively charged Au region were formed under UV irradiation.An enhanced hydrogen production performance was obtained compared with that seen in normal Au-TiO2 heterostructure.Under optimized conditions,the H2-production rate can reach up to 60,264μmol/g/h,about six times higher than previously reported Au/TiO2 photocatalysts.Besides this,our work also demonstrates the key factors of precise synthesis of the Au NRs/TiO2 NDs structure,which provides a new perspective and experience for the design of similar catalysts.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51571135,11274214 and 61434002the Special Funds of Shanxi Scholars Program under Grant No IRT1156+1 种基金Collaborative Innovation Center for Shanxi Advanced Permanent Materials and Technologythe Special Funds of the Ministry of Education of China under Grant No 20121404130001
文摘Magnetite (Fe3O4) nanoparticles with different sizes and shapes are synthesized by the thermal decomposition method. Two approaches, non-injection one-pot and hot-injection methods, are designed to investigate the growth mechanism in detail. It is found that the size and shape of nanoparticles are determined by adjusting the precursor concentration and duration time, which can be well explained by the mechanism based on the LaMer model in our synthetic system. The monodisperse Fe3O4 nanoparticles have a mean diameter from 5nm to 16nm, and shape evolution from spherical to triangular and cubic. The magnetic properties are size-dependent, and Fe3O4 nanoparticles in small size about 5 nm exhibit superparamagnetie properties at room temperature and maximum saturation magnetization approaches to 78 emu/g, whereas Fe3O4 nanoparticles develop ferromagnetic properties when the diameter increases to about 16nm.
基金supported by National Key Research and Development Program of China(No.2020YFC1808204-01)Nanchang“Double Hundred Plan”Project(Innovative Talents-Talent Introduction)+1 种基金the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2021TS11)Heilongjiang Provincial Key Laboratory of Environmental Biotechnology and Heilongjiang Touyan Innovation Team Program。
文摘Microbial fabrication of metal nanoparticles(MNPs)has received significant attention due to the advantages of low toxicity,energy efficiency and ecological safety.Diverse groups of MNPs can be synthesized intracellularly or extracellularly by various wild-type microorganisms,including bacteria,fungi,algae and viruses.Synthetic biology approaches,represented by genetic engineering,have been applied to overcome the shortcomings in productivity,stability,and controllability of biosynthetic MNPs.Scanning electron microscope(SEM),transmission electron microscope(TEM)and other characterization techniques assist in deciphering their unique properties.In addition,biosynthetic MNPs have been widely explored for the utilization in environmental remediation and contaminant detection.And machine learning contains a great potential for designing targeted MNPs and predicting their toxicity.This review provides a comprehensive overview of the research progress in the microbial synthesis of MNPs.An outlook on the current challenges and future prospects in the biologically controllable synthesis and engineering environmental applications of MNPs is also provided in this review.
基金supported by the Teli Fellowship from Beijing Institute of Technology,the National Natural Science Foundation of China(Nos.52303366,22173109).
文摘In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterparts.The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications.In this context,the atomic substitution method has emerged as a favorable approach.It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting materials.In this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC materials.The effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are discussed.The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these advancements.Finally,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.
文摘Different solvothermal reactions of ZnC2O_(4)with oxalic acid(H_(2)ox)and 1,2,4-triazole(Htrz)successfully gave a new quaternary(NJTU-Bai83,NJTU-Bai=Nanjing Tech University Bai's group)and a new quinary(NJTU-Bai84)anionic metal-organic frameworks(MOFs),where NJTU-Bai83=(Me_(2)NH_(2))2[Zn_(3)(trz)_(2)(ox)_(3)]·2H_(2)O and NJTU-Bai84=(Me_(2)NH_(2))[Zn_(3)(trz)_(3)(ox)_(2)]·H_(2)O,respectively.With the[Zn_(2)(ox)4(trz)_(2)]secondary building unit(SBU)in NJTU-Bai83 replaced by the[Zn_(3)(ox)_(2)(trz)_(6)]and planar[Zn(ox)_(2)(trz)_(2)]ones in NJTU-Bai84,2D supramolecular building layers(SBLs)are changed from the A-layer and B-layer to another A-layer,while pillars are transformed from the tetrahedral[Zn(ox)_(2)(trz)_(2)]SBU to the irregular tetrahedral[Zn(ox)_(2)(trz)_(2)]and planar[Zn(ox)_(2)(trz)_(2)]SBUs.Thus,cdq-topological quaternary NJTU-Bai83 is tuned to(4,4,8)-c new topological quinary NJTU-Bai84.Two MOFs were well characterized by powder X-ray diffraction,thermogravimetric analysis,elemental analysis,etc.CCDC:2351819,NJTU-Bai83;2351820,NJTU-Bai84.
基金the National Key R&D Program of China(No.2017YFC0504903)the Project of Education Department of Sichuan Province(No.18ZA0408)the Opening Laboratory Project of Sichuan Normal University(No.KFSY2018022)。
文摘A series of Tb-based metal-organic frameworks(Tb-MOFs)were successfully synthesized by a solvothermal method.The size and morphology of the as-obtained Tb-MOFs can be effectively controlled via regulating the experimental conditions such as the volume fraction of DMF and the molar ratio of Tb^(3+)to NaOH.It is found that all the samples exhibit strong green emissions under ultraviolet excitation,corresponding to^(5)D_(4)→^(7)F_(J)transitions of Tb^(3+).Interestingly,Tb-MOFs displayed an efficient and distinct luminescence quenching by Cu^(2+)in aqueous solutions.The competitive fluorescence detection experiments indicate that these Tb-MOFs sensors can be used as a high selective and sensitive sensor of Cu^(2+)detection with the detection limit of 10μmol·L^(-1),which can be used as a promising fluorescence sensor for Cu^(2+)detection in daily life.
基金supported by the National Natural Science Foundation of China(Nos.51972124,51872101,51672097,51902115,and 61434001)the National Program for Support of Top-notch Young Professionals,and the program for the HUST Academic Frontier Youth Team.
文摘Two-dimensional molybdenum disulfide(2D MoS_(2))is considered as a promising candidate for many applications due to its unique structure and properties.However,the controllable synthesis of large-scale and high-quality 2D 1T-phase MoS_(2)is still a challenge.Herein,we present the scalable and controllable synthesis of 2D MoS2 from 2H to 1T@2H phase by using K_(2)SO_(4)salt as a simultaneous high-temperature sulfur source and template.The as-synthesized 1T@2H-2D MoS_(2)exhibits a high yield and can be easily assembled into freestanding electrode with high specific capacitance of 434 F/g at a scan rate of 1 mV/s in LiClO_(4)ethylene carbonate/dimethyl carbonate(EC/DMC).Moreover,various single-crystal 2D transition metal sulfides(WS_(2),PbS,MnS and Ni_(9)S_(8))and 2D S-doped carbon can be synthesized using this method.We believe that this study may provide a new sight for scalable and controllable synthesis of other 2D materials beyond 2D MoS_(2).
基金the National Science Fund for Distinguished Young Scholars of China(no.21725404)Shanghai Scientific and Technological Innovation Project(18JC1410600)the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB20000000)for financial support.
文摘Isomerism is an essential and widespread phenomenon in organic chemistry but rarely observed in covalent organic frameworks(COFs),a novel class of crystalline porous organic polymers with versatile applications.Herein,we give an account of the first example of a controllable synthesis of constitutional isomers of a COF.The two isomers exhibited marked differences in their gas/vapor adsorption behaviors and chemical stability in various solvents.Furthermore,structure transformation from one isomer to the other was realized.This work not only paves the way for rational design and synthesis of COF isomers but also provides a vivid example of structure–property relationship in crystalline porous polymers.
基金Project supported by National Key R&D Program of China(2017YFC0211102)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(20KJB610005)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20201037)Key Research and Development Program of Anhui Province(202104g01020006)the Scientific Research Fund of Nanjing Institute of Technology(YKJ2019111,YKJ2019110)。
文摘In this paper,CuO_(x)@Ag/CeO_(2) catalysts were synthesized by simple wet-chemical method and equal volume impregnation method.The obtained catalysts were subjected to soot temperature programmed oxidation(soot-TPO)activity tests and were further characterized by various techniques such as X-ray diffraction(XRD),transmission electron microscopy/high-resolution transmission electron microscopy(TEM/HR-TEM),N_(2) physisorption,X-ray photoelectron spectroscopy(XPS)and H_(2)-temperature programmed reduction(H_(2)-TPR).The results show that CuO_(x)@Ag/CeO_(2) synthesized presents well controlled core-shell structures,with nano-cube like Cu_(2)O as the core and Ag decorated polycrystalline CeO_(2) grafting layers as the shell.Such core-shell structured CuO_(x)@Ag/CeO_(2) can successfully construct a secondary oxygen delivery channel(CuO_(x)→CeO_(2)→Ag)to effectively transfer bulk oxygen of the catalyst to the soot,resulting in its excellent soot oxidation activity compared to CuO_(x)@CeO_(2).The potential benefiting effect by Ag introduction over Cu@Ag/Ce can be concluded as:(ⅰ)pumping lattice oxygen and accelerating gaseous O_(2) dissociation to generate significantly increased active surface oxygen content;(ⅱ)modulating a moderate surface oxygen vacancies concentration to maintain more highly active O_(2) species.
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.51572022 and 51872025)the National Key Research and Development Program of China(Grant No.2016 YFB0701100).
文摘Transition metal oxides are found to have overwhelming applications in energy,electronics,catalytic,and bio-and micromechanical systems.A recent report emphasized the current advancements in molybdenum oxide(MoO_(x))nanowire synthesis and the corresponding surface-functionalized nanostructured materials based on our previously reported investigations.The preparation of the nanowires and their applications were systematically summarized.MoO_(x) nanowires combined with substrates exhibited remarkable performances for high energy storage and power densities with high stability.In addition,the review concluded the future advancements of MoO_(x) nanowires.
基金supported by the National Natural Science Foundation of China(Nos.22078265,21908179,and 21838009)the Shaanxi Provincial Science Foundation(Nos.2017SF-201 and 2018JQ2052).
文摘Whitlockite(WH,Ca_(18)Mg_(2)(HPO_(4))_(2)(PO_(4))_(12))is an important inorganic phase in human bones and has positive significance for participating in the bone reconstruction process.In this paper,we report different doping strategies to prepare WH and WH-Ln(Eu/Tb)nanocrystals,and have successfully synthesized WH-Ln(Eu/Tb)nanoparticles(NPs)with bright red or green fluorescence based on ions exchange doping by two-step hydrothermal reaction.WH-5%Ln(Eu/Tb)NPs with the best fluorescence properties were successfully applied to live cell imaging,and WH-5%Eu NPs were implanted into the bone defect site in rabbit femoral condyles to visually observe its degradation process.The related results would help us understand WH nanocrystals and further expand their potential applications in tissue engineering and related fields.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China(2019D01C059)the National Natural Science Foundation of China(21671003 and 21201005)+4 种基金the High Performance Computing Center of Henan Normal University and the 111 Project(D17007)Xinjiang Program of Cultivation of Young Innovative Technical Talents(2018Q061)the“2018 Tianchi Doctoral Plan”of Xinjiang Uygur Autonomous Region of Chinathe Doctoral Scientific Research Foundation of Anhui Jianzhu University(2017QD15)Xinjiang University.We thank LetPub(www.letpub.com)for its linguistic assistance during the preparation of this manuscript。
文摘Herein,a novel photonic coordination polymer material was constructed by aggregation-induced emission luminogen(AIEgen)containing a tripyridyl moiety used as the linking ligand.It displayed a spontaneous direct centrosymmetric to noncentrosymmetric phase transition in a single crystal.The two crystals,before and after the phase transition,were both controllably synthesized and characterized by single-crystal X-ray diffraction.After being exposed to air,the centrosymmetric metastable phase(1-α)transitioned to a new stable phase with a noncentrosymmetric structure(1-β).Interestingly,the 1-βstructure exhibited a strong phasematching second-harmonic generation(SHG)response,about4.5 times higher than that of KH2PO4(KDP).In order to better understand the relationship between the structure and the nonlinear optical properties,the dipole moments were calculated and discussed.Remarkably,the noncentrosymmetric phase with high thermal stability for 1-βretained and improved the initial photoluminescent properties of the AIEgen ligand after the structural phase transition from 1-α,and simultaneously produced the excellent SHG property,which are beneficial for the design and construction of excellent optical materials.
基金This research was made possible as a result of a generous grant from NSFC Foundation(Grant Number 21734007).
文摘Through a controllable“reactivate””graft”synthetic route,two asymmetrical“Janus”dendronized polymers(DPs)were successfully synthesized.Dendrons were grafted to a linear polymer motherboard by a story-by-story constructionmethod.Due to the heterogenetic“Janus”structure,with orderly arranged chromophore moieties,the polymers demonstrated extremely large second-order nonlinear optical(NLO)coefficients and excellent NLO thermal stability.DP-4l and DP-6l had high d33 values of 232 and 227 pm/V,respectively,which reached the highest value reported so far for linear-based polymers containing simple azo-chromophore moieties.The controllable synthesis sheds light on the structure–property relationships of NLO polymers and other dendronized-structure functional polymers.
基金This work was supported by the National Basic Research Program of China (973 Project,No.2013CB932901),and the National Natural Science Foundation of China (Nos.11274066,51172047,51102050,amd U1330118).This project was sponsored by Shanghai Pujiang Program and 'Shu Guang' project of Shanghai Municipal Education Commission and Shanghai Education Development Foundation (No.09SG01).
基金supported by the National Key R&D Program of China(2019YFA0709200)the National Natural Science Foundation of China(22075162)。
文摘Electrocatalysis,as the nexus for energy storage and environmental remediation,requires developing low-cost and highperforming heterogeneous catalysts.Compared with the single atom catalysts(SACs),dual-atom catalysts(DACs)are attracting ever-increasing interest due to their higher metal loading,more versatile active sites and unique reactivity.However,controlled synthesis of DACs remains a great challenge,and their electrocatalytic applications are still in infancy.This review first discusses the synthesis of DACs by highlighting several synthetic strategies.Subsequently,we exemplify the unique reactivities of DACs in electrocatalytic applications including water splitting,oxygen reduction,carbon dioxide reduction and nitrogen reduction.The structure-activity relations of DACs are specifically discussed in comparison with that of SACs,on the basis of experimental and theoretical studies.Finally,the opportunities and challenges of DACs are summarized in terms of rational design,controlled synthesis,characterization,and applications.
基金supported by the National Natu-ral Science Foundation of China(No.11575187)the National Key Research and Development Program(No.2016YFB0700205).
文摘As a direct wide bandgap semiconductor,CsPbCl_(3)has great potential applications in the eld of near-ultraviolet photodetectors,lasers and higher-order multiphoton uores-cent detectors.In this work,we synthesized CsPbCl_(3)micro/nanocrystals by vapor depo-sition method with CsCl and PbCl_(2)powders as the source materials.It was con rmed that the formation of CsPbCl_(3)perovskite through the chemical reaction of CsCl with PbCl_(2)occurred in the quartz boat before the source evaporation,not in vapor or on sub-strate surface.The evaporated CsPbCl_(3)can form micro/nanocrystals on substrate surfaces under appropriate conditions.Various morphologies including irregular polyhedrons,rods and pyramids could be observed at lower temperature,while stable and uniform CsPbCl_(3)single crystal microplatelets were controllably synthesized at 450℃.Prolonging the growth time could modulate the size and density of the microcrystals,but could not change the morphology.Substrate types made little di erence to the morphology of CsPbCl_(3)crystals.The photoluminescence spectra indicated that the crystallinity and morphology of CsPbCl_(3)micro/nanocrystals have signi cant e ects on their optical properties.The work is expected to be helpful to the development of optoelectronic devices based on individual CsPbCl_(3)microcrystal.
基金supported by the National Natural Science Foundation of China (51403114, 21905167)Science and Technology Innovation Program of Universities of Shandong Province (2020KJA012)+3 种基金Taishan Scholars Program of Shandong Province (tsqn201909065)China Postdoctoral Science Foundation (No. 2014 M56053, 2019M650232)the Opening Fund of State Key Laboratory of Heavy Oil Processing (SKLOP202002004)Fundamental Research Funds for the Central Universities (GK202003025)。
文摘Designing a highly active-and stable non-noble metal bifunctional oxygen catalyst for rechargeable Znair battery remains a great challenge. Herein, we develop a facile and melamine-assisted-pyrolysis(MAP)strategy for the synthesis of core–shell Co-based electrocatalysts@N-doped carbon nanotubes(Co@CNTs)derived from metal–organic frameworks. The Co@CNTs exhibited excellent bifunctional electrocatalytic performance for both oxygen evolution and reduction. DFT calculations demonstrated that the Gibbs free energy of the rate-determining step was small enough to improve ORR activities. As a result, a Zn-air battery assembled with Co@CNTs proves a lager power density, low voltage gap between charge–discharge and excellent stability. Thus, this work offers a facile strategy to realize the synthesis of non-noble metal electrocatalyst for Zn-air battery materials with high electrochemical performance.
基金supported by the National Natural Science Foundation of China(20776089)the Fundamental Research Funds for the Central Universities(2014NZYQN20)
文摘Doping effects of manganese (Mn) on catalytic performance and structure evolution of NiMgO catalysts for synthesis of multi-walled carbon nanotubes (MWCNTs) from methane were investigated for the first time. Addition of Mn in NiMgO catalyst can greatly improve the MWCNTs yield. Mno.2NiMgO catalyst among the tested ones gives the highest MWCNTs yield as 2244%, which is two times higher than that of the catalyst without Mn. The structure evolution, reduction behaviors and surface chemical properties of MnNiMgO catalysts with various Mn contents were studied in detail. It was found that the stable solid solution of NiMgO2 formed in NiMgO catalyst was disturbed by the addition of Mn. Instead, another solid solution of MnMg608 is formed. More amount of Ni can be reduced and dispersed on the catalyst surface to be acted as active sites. Importantly, the changes of Ni content on the surface are correlated with the Ni particle size and the outer diameter of MWCNTs, suggesting the controllable synthesis of MWCNTs over MnNiMgO catalysts.