With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electro...With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electronic instruments.Therefore,the design and preparation of electromagnetic absorbing composites represent an efficient approach to mitigate the current hazards of electromagnetic radiation.However,traditional electromagnetic absorbers are difficult to satisfy the demands of actual utilization in the face of new challenges,and emerging absorbents have garnered increasing attention due to their structure and performance-based advantages.In this review,several emerging composites of Mxene-based,biochar-based,chiral,and heat-resisting are discussed in detail,including their synthetic strategy,structural superiority and regulation method,and final optimization of electromagnetic absorption ca-pacity.These insights provide a comprehensive reference for the future development of new-generation electromagnetic-wave absorption composites.Moreover,the potential development directions of these emerging absorbers have been proposed as well.展开更多
To solve the electromagnetic pollution,herein,a CoFe_(2)O_(4)/C/PANI composite was developed by a green route,which was constructed with spinel of metal oxide,graphitized carbon and conductive polymer composites.Benef...To solve the electromagnetic pollution,herein,a CoFe_(2)O_(4)/C/PANI composite was developed by a green route,which was constructed with spinel of metal oxide,graphitized carbon and conductive polymer composites.Benefiting from the designable interfaces and increased dipoles,the microwave dielectric response capability can be boosted significantly and resulted in the enhanced microwave absorbing performance.As revealed by the reflection loss curve,the minimum reflection loss(RLmin)reached-51.81 dB at 12.4 GHz under a matched thickness of 2.57 mm.At 2.5 mm,the effective absorbing band covered 8.88 GHz,suggesting the desirable wideband feature.In our case,the method of utilization of a novel green way to fabricate multiple-component EM absorber can be a promising candidate for high-performance EM absorber.展开更多
Bioderived carbon materials have garnered considerable interest in the fields of microwave absorption and shielding due to their reproducibility and environmental friendliness.In this study,KOH was evenly distributed ...Bioderived carbon materials have garnered considerable interest in the fields of microwave absorption and shielding due to their reproducibility and environmental friendliness.In this study,KOH was evenly distributed on biomass Tremella using the swelling induction method,leading to the preparation of a three-dimensional network-structured hierarchical porous carbon(HPC)through carbonization.The achieved microwave absorption intensity is robust at-47.34 dB with a thin thickness of 2.1 mm.Notably,the widest effective absorption bandwidth,reaching 7.0 GHz(11–18 GHz),is attained at a matching thickness of 2.2 mm.The exceptional broadband and reflection loss performance are attributed to the 3D porous networks,interface effects,carbon network defects,and dipole relaxation.HPC has outstanding absorption characteristics due to its excellent impedance matching and high attenuation constant.The uniform pore structures considerably optimize the impedance-matching performance of the material,while the abundance of interfaces and defects enhances the dielectric loss,thereby improving the attenuation constant.Furthermore,the impact of carbonization temperature and swelling rate on microwave absorption performance was systematically investigated.This research presents a strategy for preparing absorbing materials using biomass-derived HPC,showcasing considerable potential in the field of electromagnetic wave absorption.展开更多
The pervasive adoption of 5th generation mobile communication technology propels electromagnetic wave(EW)absorbents to achieve high-level performance.The heterointerface construction is crucial to the improvement of a...The pervasive adoption of 5th generation mobile communication technology propels electromagnetic wave(EW)absorbents to achieve high-level performance.The heterointerface construction is crucial to the improvement of absorption ability.Herein,a series of ultralight composites with rational heterointerfaces(Co/ZnO@N-doped C/layer-stacked C,MSC)is fabricated by calcination with ration-al construction of sugarcane and CoZn-zeolitic imidazolate framework(ZIF).The components and structures of as-prepared composites were investigated,and their electromagnetic parameters could be adjusted by the content of CoZn-ZIFs.All composites possess excellent EW absorption performance,especially MSC-3.The optimal minimum reflection loss and effective absorption band of MSC-3 can reach−42 dB and 7.28 GHz at the thickness of only 1.6 mm with 20wt%filler loading.This excellent performance is attributed to the syner-gistic effect of dielectric loss stemming from the multiple heterointerfaces and magnetic loss induced by magnetic single Co.The sugar-cane-derived layer-stacked carbon has formed consecutive conductive networks and has further dissipated the electromagnetic energy through multiple reflection and conduction losses.Moreover,the simulated radar cross section(RCS)technology manifests that MSC-3 possesses outstanding EW attenuation capacity under realistic far-field conditions.This study provides a strategy for building efficient ab-sorbents based on biomass.展开更多
With the rapid development of electronic technology,how to effectively eliminate electromagnetic pollu-tion has become a serious problem.Perovskite oxides have shown great potential in the field of electro-magnetic wa...With the rapid development of electronic technology,how to effectively eliminate electromagnetic pollu-tion has become a serious problem.Perovskite oxides have shown great potential in the field of electro-magnetic wave absorption due to their unique structure and excellent physicochemical properties.Herein,by rationally manipulating the A-site ion substitution strategy,the theoretically directed doping of Sr ions into La ionic sites was utilized and the layered MoS_(2) was loaded by the hydrothermal process to modify its surface.Consequently,the introduced polarization phenomenon improved the dielectric performance of the perovskite oxides,achieving a collaborative dielectric/magnetic loss mechanism.Accordingly,the prepared La0.7Sr0.3FeO3(LSFO)/MoS_(2) as coating filler in the epoxy resin coating system can obtain the minimum reflection loss of-67.09 dB at 1.9 mm and the maximum effective absorption bandwidth of 7.28 GHz at 2.3 mm.More importantly,it also exhibits excellent absorption performance for multi-band electromagnetic waves,covering a wide range of specified frequency bands.It provides inspiration for ex-ploring novel perovskite oxide-based electromagnetic wave absorbing coatings and broadens the choice of ideal candidate materials for designing highly efficient,multi-band absorbers to cope with sophisticated electromagnetic environments.展开更多
Flower-like tungsten disulfide(WS_(2))with a diameter of 5-10μm is prepared by chemical vapor deposition(CVD).Scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),Raman spectroscopy,and ultraviolet-v...Flower-like tungsten disulfide(WS_(2))with a diameter of 5-10μm is prepared by chemical vapor deposition(CVD).Scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),Raman spectroscopy,and ultraviolet-visible(UV-vis)spectroscopy are used to characterize its morphological and optical properties,and its growth mechanism is discussed.The key factors for the formation of flower-like WS_(2)are determined.Firstly,the cooling process causes the generation of nucleation dislocations,and then the"leaf"growth of flower-like WS_(2)is achieved by increasing the temperature.展开更多
In the face of the increasingly serious electromagnetic wave (EMW) pollution, a component modulation strategy is proposed in this study. By integrating ZIF-67 and FeOOH into MXene nanosheets and performing heat treatm...In the face of the increasingly serious electromagnetic wave (EMW) pollution, a component modulation strategy is proposed in this study. By integrating ZIF-67 and FeOOH into MXene nanosheets and performing heat treatment, a multiphase heterogeneous structure based on the multicomponent synergistic effect was successfully constructed. The synergistic effect of dielectric loss and magnetic loss is realized, and the rich heterogeneous interface and multi-scale structure significantly enhance the interface polarization and multiple scattering. The results show that the EMW absorption performance can be optimized by adjusting the composition of the composites. MXene@CoFe_(2)O_(4) exhibits a minimum reflection loss (RLmin) of -44.98 dB at 2.3 mm thickness and a maximum effective absorption bandwidth (EAB_(max)) of 4.64 GHz at 2.1 mm. MXene@CoFe_(2)O_(4)/CoFe composite has an RLmin of -55.14 dB at a thickness of 2.1 mm and an EAB_(max) of 5.60 GHz at a thickness of 1.9 mm. This work provides important insights into the development of wideband EMW absorbent materials.展开更多
Effective electromagnetic wave absorption is now possible thanks to the design of the dielectric-magnetic double loss mechanism and the rich heterogeneous structure.In this study,hollow carbon spheres with rich hetero...Effective electromagnetic wave absorption is now possible thanks to the design of the dielectric-magnetic double loss mechanism and the rich heterogeneous structure.In this study,hollow carbon spheres with rich heterostructures were synthesized using an easy and effective in situ growing approach.In addition to improving impedance matching,the hollow structure also reduces material density and weight.By modifying the load,this system can alter the dielectric characteristics of MXene,which in turn affects the sample’s ability to absorb electromagnetic waves.MXene and the carbon material create a thick conductive network during the whole electromagnetic wave absorption process,creating the ideal environment for conduction loss.The sample’s ability to attenuate electromagnetic waves is further improved by the interfacial polarization that the rich heterogeneous structure can produce.Co-magnetic nanoparticle nanoparticles are the main source of magnetic loss.The MXene@Co/C-100–800(MCC-100–800)exhibits excellent electromagnetic wave absorption performance under the synergy of multiple loss mechanisms,with the maximum effective absorption bandwidth(EAB_(max))reaching 7.20 GHz and the minimum reflection loss(RL_(min))being–53.99 dB at 2.10 mm.Finally,this work is guided by the coating engineering of MXene and provides new ideas for the rational design of heterostructures of nanomaterials.展开更多
Subtle microstructure design and an appropriate multicomponent strategy are essential for advanced electromagnetic absorbing(EMA)materials with a wide effective absorption bandwidth(EAB)and intense absorption.However,...Subtle microstructure design and an appropriate multicomponent strategy are essential for advanced electromagnetic absorbing(EMA)materials with a wide effective absorption bandwidth(EAB)and intense absorption.However,sophisticated environments restrict the range of applications for EMA materials.Herein,three hollow spherical bifunctional CoSx/MnS/C nanocomposites with different crystal structures were constructed via cation exchange and subsequent vulcanization.The manganese sulfide and carbon generated during vulcanization exhibit a narrow band gap and enhanced conductivity,thereby facilitating conductive loss.The presence of cobalt sulfide facilitates the improvement of magnetic loss.More importantly,there is a potential difference between different phases at the heterogeneous interface,resulting in a region of space charge,which is conducive to interfacial polarization.The 3D hollow structure and heterogeneous dielectric/magnetic interfaces benefit the predominant EMA performance by forming perfect impedance matching,interface polarization,conduction loss,and magnetic loss effects.Specifically,an optimal reflection loss(RL)of-51.31 dB at 10.72 GHz and an effective EAB of 5.92 GHz at 2.1 mm can be achieved for Co_(1-x) S/MnS/C nanocomposite.Moreover,the nanocomposites maintained promising self-anticorrosion properties in simulated seawater environments.Transition metal sulfides with superior self-anticorrosion properties provide a pathway to efficient wave-absorbing materials in complicated environments.展开更多
Tantalum pentoxide(Ta_(2)O_(5)) has attracted intensive attention due to their excellent physicochemical properties.Ta_(2)O_(5) films were synthesized via electron beam evaporation(EBE)and subsequently annealed at dif...Tantalum pentoxide(Ta_(2)O_(5)) has attracted intensive attention due to their excellent physicochemical properties.Ta_(2)O_(5) films were synthesized via electron beam evaporation(EBE)and subsequently annealed at different temperatures ranging from 300 to 900℃.X-ray diffraction(XRD)results show that amorphous Ta_(2)O_(5) thin films form from 300 to 700℃ and then a phase transition to polycrystalline β-Ta_(2)O_(5) films occurs since 900℃.The surface morphology of the Ta_(2)O_(5) films is uniform and smooth.The resulted Ta_(2)O_(5)films exhibit excellent transmittance properties for wavelengths ranging from 300 to 1100 nm.The bandgap of the Ta_(2)O_(5) films is broadened from 4.32 to 4.46 eV by annealing.The 900℃ polycrystalline film electrode has improved electrochemical stability,compared to the other amorphous counterparts.展开更多
Killing bacteria,eliminating biofilm and building soft tissue integration are very important for percutaneous implants which service in a complicated environment.In order to endow Ti implants with above abilities,mult...Killing bacteria,eliminating biofilm and building soft tissue integration are very important for percutaneous implants which service in a complicated environment.In order to endow Ti implants with above abilities,multifunctional coatings consisted of Fe_(2)O_(3)-FeOOH nanograins as an outer layer and Zn doped microporous TiO2 as an inner layer were fabricated by micro-arc oxidation,hydrothermal treatment and annealing treatment.The microstructures,physicochemical properties and photothermal response of the coatings were observed;their antibacterial efficiencies and cell response in vitro as well as biofilm elimination and soft tissue integration in vivo were evaluated.The results show that with the increased annealing temperature,coating morphologies didn’t change obviously,but lattices of β-FeOOH gradually disorganized into amorphous state and rearranged to form Fe_(2)O_(3).The coating annealed at 450℃(MA450)had nanocrystallized Fe_(2)O_(3) and β-FeOOH.With a proper NIR irradiation strategy,MA450 killed adhered bacteria efficiently and increased fibroblast behaviors via up-regulating fibrogenic-related genes in vitro;in an infected model,MA450 eliminated biofilm,reduced inflammatory response and improved biointegration with soft tissue.The good performance of MA450 was due to a synergic effect of photothermal response and released ions(Zn^(2+)and Fe^(3+)).展开更多
The blend was synthesised with bismaleimide(BMI)resin and bisphenol A-based cyanate ester(BADCy)resin.The BMI/BADCy copolymer showed excellent dielectric and thermal conductivity properties.The volume resistivity of t...The blend was synthesised with bismaleimide(BMI)resin and bisphenol A-based cyanate ester(BADCy)resin.The BMI/BADCy copolymer showed excellent dielectric and thermal conductivity properties.The volume resistivity of the copolymer was a little lower than BADCy system.The volume resistivity of blend was 7.8×10^(15)Ω·cm when the BMI content was 20 wt%,which still showed good insulation performance.The dielectric property of modified BADCy copolymer remained the good stability from 0.1 Hz to 1 MHz.Compared to pure BADCy system,the breakdown property of BMI/BADCy blend reached the maximum value of 77.9 kV/mm when the content of BMI was 20 wt%,which was still about 1.22 times.The thermal property and thermal conductivity property of the copolymer were higher than BADCy system.展开更多
Harnessing solar energy to modulate light absorption ability and carrier separation efficiency is a highly promising strategy for enhancing oxygen photoelectrocatalytic reactions;however,it poses significant challenge...Harnessing solar energy to modulate light absorption ability and carrier separation efficiency is a highly promising strategy for enhancing oxygen photoelectrocatalytic reactions;however,it poses significant challenges.In this study,inspired by the network and structural properties of natural leaves,a leaf-like topological network is engineered via a micro-nano-structure design.A MnO/Co heterojunction is anchored on the network,exhibiting strong interfacial coupling that promotes electron-hole separation,subsequently exhibiting improved photoelectrocatalytic performance.Consequently,the MnO/Co@N-C catalyst achieves an oxygen evolution reaction(OER)overpotential of 1.42 V at a current density of 10 mA cm^(−2) under illumination,which is significantly lower than the 1.52 V obtained under dark conditions.Furthermore,a Zn-air battery(ZAB)with a MnO/Co@N-C air cathode demonstrates a power density of 189 mW cm^(−2) under illumination,which is 33.1%higher than that without illumination.Remarkably,the round-trip efficiency of the MnO/Co@N-C-based ZAB increases from 55.6%to 64.1%under illumination,while its cycling stability increases by approximately 66.7%from 150 h to 250 h.Density-functional theory calculations and multiple photonic spectroscopy analyses demonstrate that the synergistic interactions between MnO and Co significantly enhance the electron transfer rate and electron-hole separation,thus promoting excellent catalytic activity.The findings of this study open a new avenue for enhancing OER/oxygen reduction reaction(ORR)bifunctional electrocatalysis and present an effective strategy for improving the efficiency of ZABs.展开更多
基金supported by the Surface Project of Local De-velopment in Science and Technology Guided by Central Govern-ment(No.2021ZYD0041)the National Natural Science Founda-tion of China(Nos.52377026 and 52301192)+3 种基金the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Special Financial of Shandong Province(Struc-tural Design of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Tal-ent Teams)the“Sanqin Scholars”Innovation Teams Project of Shaanxi Province(Clean Energy Materials and High-Performance Devices Innovation Team of Shaanxi Dongling Smelting Co.,Ltd.).
文摘With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electronic instruments.Therefore,the design and preparation of electromagnetic absorbing composites represent an efficient approach to mitigate the current hazards of electromagnetic radiation.However,traditional electromagnetic absorbers are difficult to satisfy the demands of actual utilization in the face of new challenges,and emerging absorbents have garnered increasing attention due to their structure and performance-based advantages.In this review,several emerging composites of Mxene-based,biochar-based,chiral,and heat-resisting are discussed in detail,including their synthetic strategy,structural superiority and regulation method,and final optimization of electromagnetic absorption ca-pacity.These insights provide a comprehensive reference for the future development of new-generation electromagnetic-wave absorption composites.Moreover,the potential development directions of these emerging absorbers have been proposed as well.
基金financially supported by the National Natural Science Foundation of China(Nos.51407134 and 51801001)the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)+6 种基金the China Postdoctoral Science Foundation(Nos.2016M590619 and 2016M601878)the Provincial Key Research and Development Program of Shaanxi(No.2019GY-197)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural Functional Polymer Composites)support from The Thousand Talents PlanThe World-Class University and DisciplineThe Taishan Scholar’s Advantageous and Distinctive Discipline Program of Shandong ProvinceThe World-Class Discipline Program of Shandong Province。
文摘To solve the electromagnetic pollution,herein,a CoFe_(2)O_(4)/C/PANI composite was developed by a green route,which was constructed with spinel of metal oxide,graphitized carbon and conductive polymer composites.Benefiting from the designable interfaces and increased dipoles,the microwave dielectric response capability can be boosted significantly and resulted in the enhanced microwave absorbing performance.As revealed by the reflection loss curve,the minimum reflection loss(RLmin)reached-51.81 dB at 12.4 GHz under a matched thickness of 2.57 mm.At 2.5 mm,the effective absorbing band covered 8.88 GHz,suggesting the desirable wideband feature.In our case,the method of utilization of a novel green way to fabricate multiple-component EM absorber can be a promising candidate for high-performance EM absorber.
基金the National Natural Science Foundation of China(Nos.52102036 and52301192)the Sichuan Science and Technology Program,China(No.2021JDRC0099)+3 种基金Taishan Scholars and Young Experts Program of Shandong Province,China(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution,China(Research and Innovation Team of Structural-Functional Polymer Composites)Special Financial of Shandong Province,China(Structural Design of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams)“Sanqin Scholars”Innovation Teams Project of Shaanxi Province,China(Clean Energy Materials and High-Performance Devices Innovation Team of Shaanxi Dongling Smelting Co.,Ltd.)。
文摘Bioderived carbon materials have garnered considerable interest in the fields of microwave absorption and shielding due to their reproducibility and environmental friendliness.In this study,KOH was evenly distributed on biomass Tremella using the swelling induction method,leading to the preparation of a three-dimensional network-structured hierarchical porous carbon(HPC)through carbonization.The achieved microwave absorption intensity is robust at-47.34 dB with a thin thickness of 2.1 mm.Notably,the widest effective absorption bandwidth,reaching 7.0 GHz(11–18 GHz),is attained at a matching thickness of 2.2 mm.The exceptional broadband and reflection loss performance are attributed to the 3D porous networks,interface effects,carbon network defects,and dipole relaxation.HPC has outstanding absorption characteristics due to its excellent impedance matching and high attenuation constant.The uniform pore structures considerably optimize the impedance-matching performance of the material,while the abundance of interfaces and defects enhances the dielectric loss,thereby improving the attenuation constant.Furthermore,the impact of carbonization temperature and swelling rate on microwave absorption performance was systematically investigated.This research presents a strategy for preparing absorbing materials using biomass-derived HPC,showcasing considerable potential in the field of electromagnetic wave absorption.
基金supported by the National-Natural Science Foundation of China(Nos.52302362,52377026,and 52301192)Doctorial Foundation of Henan University of Technology,China(Nos.2021BS030 and 2020BS030)+3 种基金Key Scientific and Technological Research Projects in Henan Province,China(Nos.222102240091 and 232102240038)Natural Science Foundation from the Department of Science and Technology of Henan Province,China(No.232300420309)Taishan Scholars and Young Experts Program of Shandong Province,China(No.tsqn202103057)“Sanqin Scholars”Innovation Teams Project of Shaanxi Province,China(Clean Energy Materials and High-Performance Devices Innovation Team of Shaanxi Dongling Smelting Co.,Ltd.).
文摘The pervasive adoption of 5th generation mobile communication technology propels electromagnetic wave(EW)absorbents to achieve high-level performance.The heterointerface construction is crucial to the improvement of absorption ability.Herein,a series of ultralight composites with rational heterointerfaces(Co/ZnO@N-doped C/layer-stacked C,MSC)is fabricated by calcination with ration-al construction of sugarcane and CoZn-zeolitic imidazolate framework(ZIF).The components and structures of as-prepared composites were investigated,and their electromagnetic parameters could be adjusted by the content of CoZn-ZIFs.All composites possess excellent EW absorption performance,especially MSC-3.The optimal minimum reflection loss and effective absorption band of MSC-3 can reach−42 dB and 7.28 GHz at the thickness of only 1.6 mm with 20wt%filler loading.This excellent performance is attributed to the syner-gistic effect of dielectric loss stemming from the multiple heterointerfaces and magnetic loss induced by magnetic single Co.The sugar-cane-derived layer-stacked carbon has formed consecutive conductive networks and has further dissipated the electromagnetic energy through multiple reflection and conduction losses.Moreover,the simulated radar cross section(RCS)technology manifests that MSC-3 possesses outstanding EW attenuation capacity under realistic far-field conditions.This study provides a strategy for building efficient ab-sorbents based on biomass.
基金National Natural Science Foundation of China(No.52301192)Natural Science Foundation of Shandong Province(No.ZR2019YQ24)+2 种基金Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural Functional Polymer Composites)Special Financial of Shandong Province(Structural Design of High-efficiency Electromag-netic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams).
文摘With the rapid development of electronic technology,how to effectively eliminate electromagnetic pollu-tion has become a serious problem.Perovskite oxides have shown great potential in the field of electro-magnetic wave absorption due to their unique structure and excellent physicochemical properties.Herein,by rationally manipulating the A-site ion substitution strategy,the theoretically directed doping of Sr ions into La ionic sites was utilized and the layered MoS_(2) was loaded by the hydrothermal process to modify its surface.Consequently,the introduced polarization phenomenon improved the dielectric performance of the perovskite oxides,achieving a collaborative dielectric/magnetic loss mechanism.Accordingly,the prepared La0.7Sr0.3FeO3(LSFO)/MoS_(2) as coating filler in the epoxy resin coating system can obtain the minimum reflection loss of-67.09 dB at 1.9 mm and the maximum effective absorption bandwidth of 7.28 GHz at 2.3 mm.More importantly,it also exhibits excellent absorption performance for multi-band electromagnetic waves,covering a wide range of specified frequency bands.It provides inspiration for ex-ploring novel perovskite oxide-based electromagnetic wave absorbing coatings and broadens the choice of ideal candidate materials for designing highly efficient,multi-band absorbers to cope with sophisticated electromagnetic environments.
基金Project supported by the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(Grant No.2020GXLH-Z-029)。
文摘Flower-like tungsten disulfide(WS_(2))with a diameter of 5-10μm is prepared by chemical vapor deposition(CVD).Scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),Raman spectroscopy,and ultraviolet-visible(UV-vis)spectroscopy are used to characterize its morphological and optical properties,and its growth mechanism is discussed.The key factors for the formation of flower-like WS_(2)are determined.Firstly,the cooling process causes the generation of nucleation dislocations,and then the"leaf"growth of flower-like WS_(2)is achieved by increasing the temperature.
基金supported by the National Nat-ural Science Foundation of China(No.52377026)the Tais-han Scholars Program(No.tsqn202103057)+6 种基金the Natural Sci-ence Foundation of Shandong Province(No.ZR2024ME046)the Postdoctoral Fellowship Program of CPSF(No.GZB20240327)the Shandong Postdoctoral Science Foundation(No.SDCX-ZG-202400275)the Qingdao Postdoctoral Application Research Project(No.QDBSH20240102023)the Postdoctoral Science Foundation of China(No.2024M751563)the Key Innovative Research Team of New Energy Materials and Devices(No.BBXYKYTDxjZD01)the University Natural Science Research Project of Anhui Province(No.2022AH010101).
文摘In the face of the increasingly serious electromagnetic wave (EMW) pollution, a component modulation strategy is proposed in this study. By integrating ZIF-67 and FeOOH into MXene nanosheets and performing heat treatment, a multiphase heterogeneous structure based on the multicomponent synergistic effect was successfully constructed. The synergistic effect of dielectric loss and magnetic loss is realized, and the rich heterogeneous interface and multi-scale structure significantly enhance the interface polarization and multiple scattering. The results show that the EMW absorption performance can be optimized by adjusting the composition of the composites. MXene@CoFe_(2)O_(4) exhibits a minimum reflection loss (RLmin) of -44.98 dB at 2.3 mm thickness and a maximum effective absorption bandwidth (EAB_(max)) of 4.64 GHz at 2.1 mm. MXene@CoFe_(2)O_(4)/CoFe composite has an RLmin of -55.14 dB at a thickness of 2.1 mm and an EAB_(max) of 5.60 GHz at a thickness of 1.9 mm. This work provides important insights into the development of wideband EMW absorbent materials.
基金financially supported by the National Natural Sci-ence Foundation of China(Nos.52377026 and 52301192)the Tais-han Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+1 种基金the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Inno-vation Team of Structural-Functional Polymer Composites)the Special Financial of Shandong Province(Structural Design of High-efficiency Electromagnetic Wave-absorbing Composite Mate-rials and the Construction of Shandong Provincial Talent Teams).
文摘Effective electromagnetic wave absorption is now possible thanks to the design of the dielectric-magnetic double loss mechanism and the rich heterogeneous structure.In this study,hollow carbon spheres with rich heterostructures were synthesized using an easy and effective in situ growing approach.In addition to improving impedance matching,the hollow structure also reduces material density and weight.By modifying the load,this system can alter the dielectric characteristics of MXene,which in turn affects the sample’s ability to absorb electromagnetic waves.MXene and the carbon material create a thick conductive network during the whole electromagnetic wave absorption process,creating the ideal environment for conduction loss.The sample’s ability to attenuate electromagnetic waves is further improved by the interfacial polarization that the rich heterogeneous structure can produce.Co-magnetic nanoparticle nanoparticles are the main source of magnetic loss.The MXene@Co/C-100–800(MCC-100–800)exhibits excellent electromagnetic wave absorption performance under the synergy of multiple loss mechanisms,with the maximum effective absorption bandwidth(EAB_(max))reaching 7.20 GHz and the minimum reflection loss(RL_(min))being–53.99 dB at 2.10 mm.Finally,this work is guided by the coating engineering of MXene and provides new ideas for the rational design of heterostructures of nanomaterials.
基金financially supported by the National Natu-ral Science Foundation of China(Nos.52377026 and 52301192)the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)+3 种基金the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Re-search and Innovation Team of Structural-Functional Polymer Com-posites)the Special Financial of Shandong Province(Structural De-sign of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams)the“Sanqin Scholars”Innovation Teams Project of Shaanxi Province(Clean Energy Materials and High-Performance Devices Innovation Team of Shaanxi Dongling Smelting Co.,Ltd.).
文摘Subtle microstructure design and an appropriate multicomponent strategy are essential for advanced electromagnetic absorbing(EMA)materials with a wide effective absorption bandwidth(EAB)and intense absorption.However,sophisticated environments restrict the range of applications for EMA materials.Herein,three hollow spherical bifunctional CoSx/MnS/C nanocomposites with different crystal structures were constructed via cation exchange and subsequent vulcanization.The manganese sulfide and carbon generated during vulcanization exhibit a narrow band gap and enhanced conductivity,thereby facilitating conductive loss.The presence of cobalt sulfide facilitates the improvement of magnetic loss.More importantly,there is a potential difference between different phases at the heterogeneous interface,resulting in a region of space charge,which is conducive to interfacial polarization.The 3D hollow structure and heterogeneous dielectric/magnetic interfaces benefit the predominant EMA performance by forming perfect impedance matching,interface polarization,conduction loss,and magnetic loss effects.Specifically,an optimal reflection loss(RL)of-51.31 dB at 10.72 GHz and an effective EAB of 5.92 GHz at 2.1 mm can be achieved for Co_(1-x) S/MnS/C nanocomposite.Moreover,the nanocomposites maintained promising self-anticorrosion properties in simulated seawater environments.Transition metal sulfides with superior self-anticorrosion properties provide a pathway to efficient wave-absorbing materials in complicated environments.
基金supported by the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(Grant No.2020GXLH-Z-029).
文摘Tantalum pentoxide(Ta_(2)O_(5)) has attracted intensive attention due to their excellent physicochemical properties.Ta_(2)O_(5) films were synthesized via electron beam evaporation(EBE)and subsequently annealed at different temperatures ranging from 300 to 900℃.X-ray diffraction(XRD)results show that amorphous Ta_(2)O_(5) thin films form from 300 to 700℃ and then a phase transition to polycrystalline β-Ta_(2)O_(5) films occurs since 900℃.The surface morphology of the Ta_(2)O_(5) films is uniform and smooth.The resulted Ta_(2)O_(5)films exhibit excellent transmittance properties for wavelengths ranging from 300 to 1100 nm.The bandgap of the Ta_(2)O_(5) films is broadened from 4.32 to 4.46 eV by annealing.The 900℃ polycrystalline film electrode has improved electrochemical stability,compared to the other amorphous counterparts.
基金the National Natural Science Foundation of China(Grant No.51771142,51631007,51971171,82072075)National Key Research and Development Program of China No.2016YFC1100600(sub-project.2016YFC1100604)Natural Science Foundation of Shaanxi Province(No.2020JM-024,2021JC-07,2019TD-020)for financially supporting this work.
文摘Killing bacteria,eliminating biofilm and building soft tissue integration are very important for percutaneous implants which service in a complicated environment.In order to endow Ti implants with above abilities,multifunctional coatings consisted of Fe_(2)O_(3)-FeOOH nanograins as an outer layer and Zn doped microporous TiO2 as an inner layer were fabricated by micro-arc oxidation,hydrothermal treatment and annealing treatment.The microstructures,physicochemical properties and photothermal response of the coatings were observed;their antibacterial efficiencies and cell response in vitro as well as biofilm elimination and soft tissue integration in vivo were evaluated.The results show that with the increased annealing temperature,coating morphologies didn’t change obviously,but lattices of β-FeOOH gradually disorganized into amorphous state and rearranged to form Fe_(2)O_(3).The coating annealed at 450℃(MA450)had nanocrystallized Fe_(2)O_(3) and β-FeOOH.With a proper NIR irradiation strategy,MA450 killed adhered bacteria efficiently and increased fibroblast behaviors via up-regulating fibrogenic-related genes in vitro;in an infected model,MA450 eliminated biofilm,reduced inflammatory response and improved biointegration with soft tissue.The good performance of MA450 was due to a synergic effect of photothermal response and released ions(Zn^(2+)and Fe^(3+)).
基金This work was financially supported by the NSFC(no.51407134)China Postdoctoral Science Foundation(nos.2016M590619,2016M601878)+1 种基金Natural Science Foundation of Shandong Province(no.ZR2016EEQ28)Special Scientific Research Program of Shaanxi Provincial Department of Education(no.16JK1043)。
文摘The blend was synthesised with bismaleimide(BMI)resin and bisphenol A-based cyanate ester(BADCy)resin.The BMI/BADCy copolymer showed excellent dielectric and thermal conductivity properties.The volume resistivity of the copolymer was a little lower than BADCy system.The volume resistivity of blend was 7.8×10^(15)Ω·cm when the BMI content was 20 wt%,which still showed good insulation performance.The dielectric property of modified BADCy copolymer remained the good stability from 0.1 Hz to 1 MHz.Compared to pure BADCy system,the breakdown property of BMI/BADCy blend reached the maximum value of 77.9 kV/mm when the content of BMI was 20 wt%,which was still about 1.22 times.The thermal property and thermal conductivity property of the copolymer were higher than BADCy system.
基金supported by the National Natural Science Foundation of China(Grant No.11474137)the Program for Changjiang Scholars and Innovative Research Team in University(IRT 16R35)+4 种基金the Fundamental Research Funds for the Central Universities(Grant No.LZUMMM2018017,lzujbky-2018-121)the Natural Science project of Shaanxi Province(No.2023-JC-QN-0145)the Special Scientific Research Project of Shaanxi Education Department(No.202310561)the Key Project of Baoji University of Arts and Sciences(No.209040127)supported by The Thousand Talents Plan for Yong Professionals of Shaanxi Province(No.202140019).
文摘Harnessing solar energy to modulate light absorption ability and carrier separation efficiency is a highly promising strategy for enhancing oxygen photoelectrocatalytic reactions;however,it poses significant challenges.In this study,inspired by the network and structural properties of natural leaves,a leaf-like topological network is engineered via a micro-nano-structure design.A MnO/Co heterojunction is anchored on the network,exhibiting strong interfacial coupling that promotes electron-hole separation,subsequently exhibiting improved photoelectrocatalytic performance.Consequently,the MnO/Co@N-C catalyst achieves an oxygen evolution reaction(OER)overpotential of 1.42 V at a current density of 10 mA cm^(−2) under illumination,which is significantly lower than the 1.52 V obtained under dark conditions.Furthermore,a Zn-air battery(ZAB)with a MnO/Co@N-C air cathode demonstrates a power density of 189 mW cm^(−2) under illumination,which is 33.1%higher than that without illumination.Remarkably,the round-trip efficiency of the MnO/Co@N-C-based ZAB increases from 55.6%to 64.1%under illumination,while its cycling stability increases by approximately 66.7%from 150 h to 250 h.Density-functional theory calculations and multiple photonic spectroscopy analyses demonstrate that the synergistic interactions between MnO and Co significantly enhance the electron transfer rate and electron-hole separation,thus promoting excellent catalytic activity.The findings of this study open a new avenue for enhancing OER/oxygen reduction reaction(ORR)bifunctional electrocatalysis and present an effective strategy for improving the efficiency of ZABs.
