Highly thermal conductivity materials with excellent electromagnetic interference shielding and Joule heating performances are ideal for thermal management in the next generation of communication industry,artificial i...Highly thermal conductivity materials with excellent electromagnetic interference shielding and Joule heating performances are ideal for thermal management in the next generation of communication industry,artificial intelligence and wearable electronics.In this work,silver nanowires(AgNWs)are prepared using silver nitrate as the silver source and ethylene glycol as the solvent and reducing agent,and boron nitride(BN)is performed to prepare BN nanosheets(BNNS)with the help of isopropyl alcohol and ultrasonication-assisted peeling method,which are compounded with aramid nanofibers(ANF)prepared by chemical dissociation,respectively,and the(BNNS/ANF)-(AgNWs/ANF)thermal conductivity and electromagnetic interference shielding composite films with Janus structures are prepared by the"vacuum-assisted filtration and hot-pressing"method.Janus(BNNS/ANF)-(AgNWs/ANF)composite films exhibit"one side insulating,one side conducting"performance,the surface resistivity of the BNNS/ANF surface is 4.7×10^(13) Ω,while the conductivity of the AgNWs/ANF surface is 5,275 S/cm.And Janus(BNNS/ANF)-(AgNWs/ANF)composite film with thickness of 95 pm has a high in-plane thermal conductivity coefficient of 8.12 W/(m·K)and superior electromagnetic interference shielding effectiveness of 70 dB.The obtained composite film also has excellent tensile strength of 122.9 MPa and tensile modulus and 2.7 GPa.It also has good temperature-voltage response characteristics(high Joule heating temperature at low supply voltage(5 V,215.0℃),fast response time(10 s)),excellent electrical stability and reliability(stable and constant real-time relative resistance under up to 300 cycles and 1,500 s of tensile-bending fatigue work tests).展开更多
Flexible multifunctional polymer-based electromagnetic interference(EMI)shielding composite films have important application values in the fields of 5G communication technology,wearable electronic devices and artifici...Flexible multifunctional polymer-based electromagnetic interference(EMI)shielding composite films have important application values in the fields of 5G communication technology,wearable electronic devices and artificial intelligence.In this work,Fe_(3)O_(4)/polyamic acid(PAA)nanofiber films are prepared by in-situ polymerization and electrospinning technology,and Ti_(3)C_(2)T_(x)nanosheets are deposited on the surface of the Fe_(3)O_(4)/PAA nanofiber films via vacuum-assisted filtration.Then,Janus Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/polyimide(PI))composite films are obtained by thermal imidization.The two sides of the Janus films exhibit completely different properties.The Fe_(3)O_(4)/PI side has excellent hydrophobicity and insulation property,and the Ti_(3)C_(2)T_(x)side has hydrophilicity and terrific conductivity.When the mass fraction of Ti_(3)C_(2)T_(x)is 80 wt.%,the Janus Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/PI)composite film has excellent EMI shielding performances and mechanical properties,with EMI shielding effectiveness,tensile strength and Young’s modulus reaching 66 dB,114.5 MPa and 5.8 GPa,respectively.At the same time,electromagnetic waves show different absorption shielding effectiveness(SEA)when incident from two sides of the Janus films.When the electromagnetic waves are incident from the Fe_(3)O_(4)/PI side,the SEA of the Janus film is 58 dB,much higher than that when the electromagnetic waves are incident from the Ti_(3)C_(2)T_(x)side(39 dB).In addition,the Ti_(3)C_(2)T_(x)side of the Janus Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/PI)composite films also has excellent electrothermal and photothermal conversion performances.When the applied voltage is 4 V,the stable surface temperature reaches 108°C;when it is irradiated by simulated sunlight with power density of 200 mW/cm2,the stable surface temperature reaches 95℃.展开更多
The detection and removal of volatile organic compounds(VOCs) are of great importance to reduce the risk of indoor air quality concerns. This study reports the rational synthesis of a dual-functional Janus nanostructu...The detection and removal of volatile organic compounds(VOCs) are of great importance to reduce the risk of indoor air quality concerns. This study reports the rational synthesis of a dual-functional Janus nanostructure and its feasibility for simultaneous detection and removal of VOCs.The Janus nanostructure was synthesized via an anisotropic growth method, composed of plasmonic nanoparticles,semiconductors, and metal organic frameworks(e.g.,Au@ZnO@ZIF-8). It exhibits excellent selective detection to formaldehyde(HCHO, as a representative VOC) at room temperature over a wide range of concentrations(from 0.25 to100 ppm), even in the presence of water and toluene molecules as interferences. In addition, HCHO was also found to be partially oxidized into non-toxic formic acid simultaneously with detection. The mechanism underlying this technology was unraveled by both experimental measurements and theoretical calculations: ZnO maintains the conductivity, while ZIF-8 improves the selective gas adsorption; the plasmonic effect of Au nanorods enhances the visible-light-driven photocatalysis of ZnO at room temperature.展开更多
Background:Excessive exudate secreted from chronic wounds often leads to overhydration and infection.Although a variety of dressings are currently available in clinical applications,they frequently fail to provide mul...Background:Excessive exudate secreted from chronic wounds often leads to overhydration and infection.Although a variety of dressings are currently available in clinical applications,they frequently fail to provide multifunction to promote chronic wound healing.The dressings with a Janus structure,featuring distinct properties on each side,are potential to improve wound healing.Methods:Composite dressings with a Janus structure were fabricated,comprising freeze-dried polycaprolactone(PCL)electrospun membrane and alginate-based hydrogel.The PCL fibrous membrane provided air permeability,while the hydrogel loaded with Deferoxamine,composed of alginate and poly(N-isopropylacrylamide)(PNIPAM),exhibited hygroscopic properties.The inclusion of PNIPAM imparted thermo-responsivity.Results:The hydrogel(thickness of 2.778±0.082 mm)exhibited a robust adhesion to the fiber membrane(thickness of 0.261±0.041 mm).For ANDC(Alginate-PNIPAM hydrogel with Deferoxamine/PCL membrane)samples,the water vapor transmission rate(WVTR)was measured to be 3364.80±23.23 g∙m−2∙day−1 and the swelling ratio at 2 h was determined to be 1179±125%.The thermo-responsivity of ANDC samples manifested in an increased swelling rate,escalating from 797±189%at 37°C to 1132±147%at 4°C.The elastic modulus was assessed for lyophilized and rehydrated ANDC sample.When theωof the rheometer rotor was decreased from 10 rad/s to 0.1 rad/s,the lyophilized dressing exhibited a decrease from 2.65±0.01 MPa to 1.80±0.90 MPa,while the rehydrated dressing demonstrated an increase from 133.65±55.68 Pa to 264.23±141.71 Pa.The pro-healing properties of the dressings were evaluated using full-thickness skin defect model on SD rats,and a circular wound of diameter 10 mm healed completely by day 12.Conclusion:The dressings not only protected the wound and absorbed excess exudate,but also demonstrated nondestructive peelability upon cooling,providing a novel approach for accelerating wound healing and management.展开更多
Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion tran...Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion transference number(t^(+)) of liquid electrolyte confined in porous matrix remains challenging.Herein,we report a novel Janus MOFLi/MSLi QSEs with asymmetric porous structure to inherit the benefits of both mesoporous and microporous hosts.This Janus QSE composed of mesoporous silica and microporous MOF exhibits a neat Li^(+) conductivity of 1.5.10^(–4)S cm^(−1) with t^(+) of 0.71.A partially de-solvated structure and preference distribution of Li^(+)near the Lewis base O atoms were depicted by MD simulations.Meanwhile,the nanoporous structure enabled efficient ion flux regulation,promoting the homogenous deposition of Li^(+).When incorporated in Li||Cu cells,the MOFLi/MSLi QSEs demonstrated a high Coulombic efficiency of 98.1%,surpassing that of liquid electrolytes(96.3%).Additionally,NCM 622||Li batteries equipped with MOFLi/MSLi QSEs exhibited promising rate performance and could operate stably for over 200 cycles at 1 C.These results highlight the potential of Janus MOFLi/MSLi QSEs as promising candidates for next-generation LMBs.展开更多
Solar vapor generation is a promising sustainable technology that uses solar distillation to produce fresh water from seawater and wastewater,helping relieve global water resource shortage.Here,inspired by naturally g...Solar vapor generation is a promising sustainable technology that uses solar distillation to produce fresh water from seawater and wastewater,helping relieve global water resource shortage.Here,inspired by naturally grown integrally molded mulberry leaves with a Janus hydrophilic and hydrophobic structure,a novel,simple,and efficient integrated molding method is proposed to break through the limitations of the traditional split manufacturing strategy and realizes the integrated formation of Janus evaporator.Based on the spontaneous sedimentation characteristics of MXene in silk fibroin solution and its regulation of mesoscopic structure and hydrophilicity of silk fibroin,layered structures with different compositions and hydrophilicities were obtained in one step.Meanwhile,ethanol and glutaraldehyde were added to construct a physical crystallization-chemical crosslinking dual stabilization structure in silk fibroin.Our evaporator has the evaporation rate of 3.07 kg·m^(-2)·h^(-1) and the efficiency of 86.8%under 1 sun and maintains high evaporation performance under various extreme test conditions including vigorous washing,repeated compression,and high-intensity ultraviolet(UV)irradiation.Additionally,the evaporator performs well in practical application scenarios,its evaporation rate in the simulated Dead Sea seawater exceeds 2.13 kg·m^(-2)·h^(-1),and more than 99.9%of the salt,heavy metal ions,oil pollution,and dyes are purified.展开更多
Regulating chemical bonds to balance the adsorption and disassociation of water molecules on catalyst surfaces is crucial for overall water splitting in alkaline solution.Here we report a facile strategy for designing...Regulating chemical bonds to balance the adsorption and disassociation of water molecules on catalyst surfaces is crucial for overall water splitting in alkaline solution.Here we report a facile strategy for designing Ni2W4C-W3C Janus structures with abundant Ni-W metallic bonds on surfaces through interfacial engineering.Inserting Ni atoms into the W3C crystals in reaction progress generates a new Ni2 W4C phase,making the inert W atoms in W3C be active sites in Ni2W4C for overall water splitting.The Ni2W4CW3C/carbon nanofibers(Ni2 W4-W3C/CNFs)require overpotentials of 63 mV to reach 10 mA cm^-2 for hydrogen evolution reaction(HER)and 270 mV to reach 30 mA cm^-2 for oxygen evolution reaction(OER)in alkaline electrolyte,respectively.When utilized as both cathode and anode in alkaline solution for overall water splitting,cell voltages of 1.55 and 1.87 V are needed to reach 10 and 100 mA cm^-2,respectively.Density functional theory(DFT)results indicate that the strong interactions between Ni and W increase the local electronic states of W atoms.The Ni2W4C provides active sites for cleaving H-OH bonds,and the W3C facilitates the combination of Hads intermediates into H2 molecules.The in situ electrochemical-Raman results demonstrate that the strong absorption ability for hydroxyl and water molecules and further demonstrate that W atoms are the real active sites.展开更多
锂金属具有氧化还原电位低、理论比容量大等优点,是下一代高比能电池极具发展前景的负极.然而,锂枝晶生长和低可逆性严重阻碍了高比能锂金属电池的发展.受启发于生物细胞膜结构,本文采用涂布法在锂金属表面成功构筑了一种具有仿生离子...锂金属具有氧化还原电位低、理论比容量大等优点,是下一代高比能电池极具发展前景的负极.然而,锂枝晶生长和低可逆性严重阻碍了高比能锂金属电池的发展.受启发于生物细胞膜结构,本文采用涂布法在锂金属表面成功构筑了一种具有仿生离子通道的人工界面固体电解质层(CAL).该CAL中大量带负电荷的离子通道可以促进锂离子均匀、快速的输运,有利于稳定、均匀地进行锂沉积/剥离.此外,在循环过程中,CAL底部与锂金属发生原位转化反应,生成了一层富含亲锂性无机组分的过渡层,促进了锂离子的扩散并抑制了锂金属与电解液的连续副反应.因此,形成的具有双面神结构的人工界面固体电解质层(CAJL)使得锂金属负极可以在10 mA cm^(-2)的高电流密度和10 mAh cm^(-2)的高面积容量下长期稳定循环.更重要的是,基于CAJL功能化锂金属负极的锂硫软包电池实现了429.2 Wh kg^(-1)的高能量密度.展开更多
The development of bifunctional catalysts for solar-driven hydrogen and oxygen evolution has been regarded as a challenging but interesting research topic.As promising multi-electron-transfer catalysts,previously repo...The development of bifunctional catalysts for solar-driven hydrogen and oxygen evolution has been regarded as a challenging but interesting research topic.As promising multi-electron-transfer catalysts,previously reported polyoxometalate(POM)-based catalysts often contain only a single type of transition metal substitution for driving either hydrogen production or oxygen evolution.Herein,a viable two-step parental substitution approach has been developed to synthesize two structurally-new mixed-transition-metal-substituted polyoxometalates(mixed TMSPs),K_(6)Na_(4)[Mn_(2)Ni_(2)(H_(2)O)2(PW_(9)O_(34))2]·21H_(2)O({Mn_(2)Ni_(2)})and K10[Mn_(2)Co_(2)(H_(2)O)2(PW_(9)O_(34))2]·35H_(2)O({Mn_(2)Co_(2)}),using Na_(12)[Mn_(2)Na_(2)(PW_(9)O_(34))2]·36H_(2)O({Mn_(2)Na_(2)})as the precursor.Characterization results confirmed the nearly quantitative substitution of Na+with Ni_(2)+and Co_(2+)ions.X-ray absorption fine structure(XAFS)spectroscopy revealed that the Mn atoms are preferentially located in the internal positions of the central belt while Ni and Co atoms preferentially reside in the external,solvent-accessible positions.Benefiting from the second substitution of catalytically active transition metals,the resulting{Mn_(2)Ni_(2)}and{Mn_(2)Co_(2)}can be utilized as Janus catalysts towards H_(2) evolution and O_(2) evolution under visible light irradiation with greatly-enhanced activity compared to that of parental{Mn_(2)Na_(2)}.The introduction of mixed transition metals into POM structures not only enriches the POMs family,but also provides an effective strategy to control electronic structures and catalytic properties of POM-based catalysts at the atomic level.展开更多
Precise structural control had attracted tremendous interest in nanosynthesis due to its great importance in tailoring the physical properties of nanomaterials.Here we report the synthesis of highly ordered Cd S-Au-Ti...Precise structural control had attracted tremendous interest in nanosynthesis due to its great importance in tailoring the physical properties of nanomaterials.Here we report the synthesis of highly ordered Cd S-Au-TiO_(2) ternary Janus structure via templateprotected sequential growth and conversion method.Arising from the integration of the rectification effect of Au-CdS and AuTiO_(2) Schottky barriers,the Janus configuration of the Cd S-TiO_(2) domains,the plasmonic effect of Au nanosphere,and the Zscheme charge transportation,the Cd S-Au-TiO_(2) Janus structure showed high efficiency in the model photocatalytic degradation of methyl orange(MO)dye.Importantly,the well-defined structural order allowed the identification of the correlation between the structure and the catalytic performance.We believe that the synthetic control and the mechanism insights would help the design and synthesis of sophisticated nanostructures,and would eventually promote their applications in photocatalysis fields.展开更多
Several natural organism can change shape under external stimuli. These natural phenomena have inspired a vast amount of research on exploration and implementation of reconfigurable shape transformation. The Janus str...Several natural organism can change shape under external stimuli. These natural phenomena have inspired a vast amount of research on exploration and implementation of reconfigurable shape transformation. The Janus structure is a promising approach to achieve shape transformation based on its heterogeneous chemical or physical properties on opposite sides.However, the heterogeneity is generally realized by multi-step processing, different materials,and/or different processing parameters. Here, we present a simple and flexible method of producing p H-sensitive Janus microactuators from a single material, using the same laser printing parameters. These microactuators exhibit reversible structural deformations with large bending angles of ~31°and fast response(~0.2 s) by changing the p H value of the aqueous environment. Benefited from the high flexibility of the laser printing technique and the spatial arrangements, pillar heights, and bending directions of microactuators are readily controlled,enabling a variety of switchable ordered patterns and complex petal-like structures on flat surfaces and inside microchannels. Finally, we explore the potential applications of this method in information encryption/decryption and microtarget capturing.展开更多
Photoelectrochemical water splitting using solar energy,generating oxygen and hydrogen is one of the clean fuel production processes.Inspired by surface-dependent characteristics of Janus structures,a newly designed J...Photoelectrochemical water splitting using solar energy,generating oxygen and hydrogen is one of the clean fuel production processes.Inspired by surface-dependent characteristics of Janus structures,a newly designed Janus monolayer Silicon Phosphorous Arsenide(SiPAs)was analyzed with Density Functional Theory(DFT)methods.Hybrid exchange-correlation functional(HSE06)combined with Wannier90-based analysis for electronic and optical properties of SiPAs reveals that it can act as a photocatalyst.SiPAs show an indirect bandgap of 1.88 eV,absorbing visible light range is 350 to 500 nm.The phonon spectrum confirms dynamic stability.The exciton binding energy is computed with GW/BSE methods.The electronic band edge positions are at-5.75 and-4.43 eV,perfectly straddling the water redox potentials.Interestingly the strain application modifies the bandgap and also non-homogenously widens the absorption band.A novel range of photocatalyst designs with Group IV-V elements with great promise for water-splitting,photovoltaic,and narrow bandgap semiconductor(optoelectronics)applications may be feasible.展开更多
The development of excellent catalyst to achieve photocatalytic syngas production from CO_(2) and H_(2)O is a prospective and sustainable strategy to alleviate environment and energy crisis. In this study, a unique Ja...The development of excellent catalyst to achieve photocatalytic syngas production from CO_(2) and H_(2)O is a prospective and sustainable strategy to alleviate environment and energy crisis. In this study, a unique Janus PdZn-Co catalyst is prepared by annealed the Pd/IRMOF-3(Co, Zn) precursor. Due to the strong interaction, the electron transfers from PdZn terminal to Co terminal in the Janus structure. The electron-received Co terminal facilitates Co sites coordinate with the electrophilic C atom of CO_(2) and the electron-donated PdZn center is easier to coordinate with nucleophilic O atoms of H_(2)O or C=O bonds.The charge redistribution enhances the absorption of CO_(2) and H2O, which promotes H_(2) evolution and CO production. In addition, the carbon shell effectively suppresses the metal core agglomeration and facilitates the electron transmission from photosensitizer to metallic active sites. Meanwhile, the ratio of CO/H_(2) can be regulated(~3:1 to 2:1) by adjusting the proportion of Co and PdZn. The Janus structure and graphite carbon synergistically play a profound impact on improving the photocatalytic performance.The optimized PdZn-Co catalyst exhibits a superior photocatalytic CO production rate(20.03 μmol/h) and the H_(2) generation rate(9.90 μmol/h) with a ratio of CO/H_(2)= 2.02.展开更多
The accurate delivery of nanoparticles and organic small molecule drugs remains a serious challenge in nanoparticle-based tumor therapy.Dual-targeted therapy combining tumor cell targeting and organelle targeting is a...The accurate delivery of nanoparticles and organic small molecule drugs remains a serious challenge in nanoparticle-based tumor therapy.Dual-targeted therapy combining tumor cell targeting and organelle targeting is an effective solution.Here,an anticancer nanoformulation accurate delivery system was prepared using hyaluronic acid (HA) targeting CD44 receptors on the surface of tumor cells and IR780iodine (IR780) targeting mitochondrial for delivery.The system is based on an ultra-small Janus structured inorganic sensitizer TiO_(2-x)@NaGdF_(4) nanoparticles (TN NPs) prepared by one-step pyrolysis,further loaded with organic small molecule acoustic sensitizer IR780 and mitochondrial hexokinase Ⅱ inhibitor lonidamine (LND),followed by encapsulation of HA.Ultra-small size nanoparticles exhibit strong tissue penetration,tumor inhibition and in vivo metabolism.Under ultrasound radiation,TN NPs and IR780could produce a synergistic effect,effectively increased the efficiency of reactive oxygen species (ROS)production.Meanwhile,the released IR780 could smoothly target the mitochondria,and the ROS produced by IR780 can destroy the mitochondrial structure and disrupt the mitochondrial respiration.LND could inhibit the energy metabolism of tumor cells by reducing the activity of hexokinase Ⅱ (HK Ⅱ),which further accelerates the process of apoptosis.Furthermore,since the Janus structure allows the integration of multifunctional components into a single system,TN NPs can not only serve as an acoustic sensitizer to generate ROS,but the Gd element contained can also act as the nuclear magnetic resonance (MR)imaging contrast agent,suggesting that the nanoformulation can enable imaging-guided diagnosis and therapy.In conclusion,a new scheme to enhance sonodynamic therapy (SDT) and chemotherapy synergistically is proposed here based on ultra-small dual-targeted nanoformulation with Janus structure in the ultrasound radiation environment.展开更多
基金The authors are grateful for the support and funding from the Guangdong Basic and Applied Basic Research Foundation(No.2019B1515120093)Foundation of National Natural Science Foundation of China(Nos.U21A2093 and 51973173)Technological Base Scientific Research Projects(Highly Thermal conductivity Nonmetal Materials).
文摘Highly thermal conductivity materials with excellent electromagnetic interference shielding and Joule heating performances are ideal for thermal management in the next generation of communication industry,artificial intelligence and wearable electronics.In this work,silver nanowires(AgNWs)are prepared using silver nitrate as the silver source and ethylene glycol as the solvent and reducing agent,and boron nitride(BN)is performed to prepare BN nanosheets(BNNS)with the help of isopropyl alcohol and ultrasonication-assisted peeling method,which are compounded with aramid nanofibers(ANF)prepared by chemical dissociation,respectively,and the(BNNS/ANF)-(AgNWs/ANF)thermal conductivity and electromagnetic interference shielding composite films with Janus structures are prepared by the"vacuum-assisted filtration and hot-pressing"method.Janus(BNNS/ANF)-(AgNWs/ANF)composite films exhibit"one side insulating,one side conducting"performance,the surface resistivity of the BNNS/ANF surface is 4.7×10^(13) Ω,while the conductivity of the AgNWs/ANF surface is 5,275 S/cm.And Janus(BNNS/ANF)-(AgNWs/ANF)composite film with thickness of 95 pm has a high in-plane thermal conductivity coefficient of 8.12 W/(m·K)and superior electromagnetic interference shielding effectiveness of 70 dB.The obtained composite film also has excellent tensile strength of 122.9 MPa and tensile modulus and 2.7 GPa.It also has good temperature-voltage response characteristics(high Joule heating temperature at low supply voltage(5 V,215.0℃),fast response time(10 s)),excellent electrical stability and reliability(stable and constant real-time relative resistance under up to 300 cycles and 1,500 s of tensile-bending fatigue work tests).
基金supports from the National Natural Science Foundation of China(Nos.U21A2093 and 51903145)Fundamental Research Funds for the Central Universities(No.D5000210627)+1 种基金Y.L.Z.would like to thank the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2021107)This work is also financially supported by Polymer Electromagnetic Functional Materials Innovation Team of Shaanxi Sanqin Scholars.
文摘Flexible multifunctional polymer-based electromagnetic interference(EMI)shielding composite films have important application values in the fields of 5G communication technology,wearable electronic devices and artificial intelligence.In this work,Fe_(3)O_(4)/polyamic acid(PAA)nanofiber films are prepared by in-situ polymerization and electrospinning technology,and Ti_(3)C_(2)T_(x)nanosheets are deposited on the surface of the Fe_(3)O_(4)/PAA nanofiber films via vacuum-assisted filtration.Then,Janus Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/polyimide(PI))composite films are obtained by thermal imidization.The two sides of the Janus films exhibit completely different properties.The Fe_(3)O_(4)/PI side has excellent hydrophobicity and insulation property,and the Ti_(3)C_(2)T_(x)side has hydrophilicity and terrific conductivity.When the mass fraction of Ti_(3)C_(2)T_(x)is 80 wt.%,the Janus Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/PI)composite film has excellent EMI shielding performances and mechanical properties,with EMI shielding effectiveness,tensile strength and Young’s modulus reaching 66 dB,114.5 MPa and 5.8 GPa,respectively.At the same time,electromagnetic waves show different absorption shielding effectiveness(SEA)when incident from two sides of the Janus films.When the electromagnetic waves are incident from the Fe_(3)O_(4)/PI side,the SEA of the Janus film is 58 dB,much higher than that when the electromagnetic waves are incident from the Ti_(3)C_(2)T_(x)side(39 dB).In addition,the Ti_(3)C_(2)T_(x)side of the Janus Ti_(3)C_(2)T_(x)-(Fe_(3)O_(4)/PI)composite films also has excellent electrothermal and photothermal conversion performances.When the applied voltage is 4 V,the stable surface temperature reaches 108°C;when it is irradiated by simulated sunlight with power density of 200 mW/cm2,the stable surface temperature reaches 95℃.
基金the supports from the American Chemical Society Petroleum Research Fund(57072-DNI10)the National Science Foundation(CMMI-1727553)+2 种基金Partial support from the Virginia Commonwealth University Presidential Research Quest Fundsupports by the US Department of Energy under Awards No.DE-FG02-96ER45579and No.DE-AC02-05CH11231BET measurements(NSF I/UCR Center Grant,IIP 1464595)
文摘The detection and removal of volatile organic compounds(VOCs) are of great importance to reduce the risk of indoor air quality concerns. This study reports the rational synthesis of a dual-functional Janus nanostructure and its feasibility for simultaneous detection and removal of VOCs.The Janus nanostructure was synthesized via an anisotropic growth method, composed of plasmonic nanoparticles,semiconductors, and metal organic frameworks(e.g.,Au@ZnO@ZIF-8). It exhibits excellent selective detection to formaldehyde(HCHO, as a representative VOC) at room temperature over a wide range of concentrations(from 0.25 to100 ppm), even in the presence of water and toluene molecules as interferences. In addition, HCHO was also found to be partially oxidized into non-toxic formic acid simultaneously with detection. The mechanism underlying this technology was unraveled by both experimental measurements and theoretical calculations: ZnO maintains the conductivity, while ZIF-8 improves the selective gas adsorption; the plasmonic effect of Au nanorods enhances the visible-light-driven photocatalysis of ZnO at room temperature.
基金supported by the Shenzhen Basic Research Project,No.JCYJ20190807155805818the Foundation of Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument,No.2020B1212060077the Sun Yat-sen University Training Program of Research for Undergraduates,No.76190-51200001.
文摘Background:Excessive exudate secreted from chronic wounds often leads to overhydration and infection.Although a variety of dressings are currently available in clinical applications,they frequently fail to provide multifunction to promote chronic wound healing.The dressings with a Janus structure,featuring distinct properties on each side,are potential to improve wound healing.Methods:Composite dressings with a Janus structure were fabricated,comprising freeze-dried polycaprolactone(PCL)electrospun membrane and alginate-based hydrogel.The PCL fibrous membrane provided air permeability,while the hydrogel loaded with Deferoxamine,composed of alginate and poly(N-isopropylacrylamide)(PNIPAM),exhibited hygroscopic properties.The inclusion of PNIPAM imparted thermo-responsivity.Results:The hydrogel(thickness of 2.778±0.082 mm)exhibited a robust adhesion to the fiber membrane(thickness of 0.261±0.041 mm).For ANDC(Alginate-PNIPAM hydrogel with Deferoxamine/PCL membrane)samples,the water vapor transmission rate(WVTR)was measured to be 3364.80±23.23 g∙m−2∙day−1 and the swelling ratio at 2 h was determined to be 1179±125%.The thermo-responsivity of ANDC samples manifested in an increased swelling rate,escalating from 797±189%at 37°C to 1132±147%at 4°C.The elastic modulus was assessed for lyophilized and rehydrated ANDC sample.When theωof the rheometer rotor was decreased from 10 rad/s to 0.1 rad/s,the lyophilized dressing exhibited a decrease from 2.65±0.01 MPa to 1.80±0.90 MPa,while the rehydrated dressing demonstrated an increase from 133.65±55.68 Pa to 264.23±141.71 Pa.The pro-healing properties of the dressings were evaluated using full-thickness skin defect model on SD rats,and a circular wound of diameter 10 mm healed completely by day 12.Conclusion:The dressings not only protected the wound and absorbed excess exudate,but also demonstrated nondestructive peelability upon cooling,providing a novel approach for accelerating wound healing and management.
基金supported by National Natural Science Foundation of China(Grant No.22005266)Zhejiang Provincial Natural Science Foundation(Grant No.LR21E020003)“the Fundamental Research Funds for the Central Universities”(2021FZZX001-09).
文摘Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion transference number(t^(+)) of liquid electrolyte confined in porous matrix remains challenging.Herein,we report a novel Janus MOFLi/MSLi QSEs with asymmetric porous structure to inherit the benefits of both mesoporous and microporous hosts.This Janus QSE composed of mesoporous silica and microporous MOF exhibits a neat Li^(+) conductivity of 1.5.10^(–4)S cm^(−1) with t^(+) of 0.71.A partially de-solvated structure and preference distribution of Li^(+)near the Lewis base O atoms were depicted by MD simulations.Meanwhile,the nanoporous structure enabled efficient ion flux regulation,promoting the homogenous deposition of Li^(+).When incorporated in Li||Cu cells,the MOFLi/MSLi QSEs demonstrated a high Coulombic efficiency of 98.1%,surpassing that of liquid electrolytes(96.3%).Additionally,NCM 622||Li batteries equipped with MOFLi/MSLi QSEs exhibited promising rate performance and could operate stably for over 200 cycles at 1 C.These results highlight the potential of Janus MOFLi/MSLi QSEs as promising candidates for next-generation LMBs.
基金supported by the National Natural Science Foundation of China(Nos.51773171 and 12074322)Science and Technology Project of Xiamen City(No.3502Z20183012)+1 种基金Science and Technology Planning Project of Guangdong Province(No.2018B030331001)Shenzhen Science and Technology Plan Project(No.JCYJ20180504170208402).
文摘Solar vapor generation is a promising sustainable technology that uses solar distillation to produce fresh water from seawater and wastewater,helping relieve global water resource shortage.Here,inspired by naturally grown integrally molded mulberry leaves with a Janus hydrophilic and hydrophobic structure,a novel,simple,and efficient integrated molding method is proposed to break through the limitations of the traditional split manufacturing strategy and realizes the integrated formation of Janus evaporator.Based on the spontaneous sedimentation characteristics of MXene in silk fibroin solution and its regulation of mesoscopic structure and hydrophilicity of silk fibroin,layered structures with different compositions and hydrophilicities were obtained in one step.Meanwhile,ethanol and glutaraldehyde were added to construct a physical crystallization-chemical crosslinking dual stabilization structure in silk fibroin.Our evaporator has the evaporation rate of 3.07 kg·m^(-2)·h^(-1) and the efficiency of 86.8%under 1 sun and maintains high evaporation performance under various extreme test conditions including vigorous washing,repeated compression,and high-intensity ultraviolet(UV)irradiation.Additionally,the evaporator performs well in practical application scenarios,its evaporation rate in the simulated Dead Sea seawater exceeds 2.13 kg·m^(-2)·h^(-1),and more than 99.9%of the salt,heavy metal ions,oil pollution,and dyes are purified.
基金supported by the National Natural Science Foundation of China(51803077,51872204)the National Key Research and Development Program of China(2017YFA0204600)+4 种基金the Natural Science Foundation of Jiangsu Province(BK20180627)Postdoctoral Science Foundation of China(2018M630517,2019T120389)the Ministry of Education(MOE)and the State Administration for Foreign Expert Affairs(SAFEA),111 Project(B13025)the National First-Class Discipline Program of Light Industry Technology and Engineering(LITE2018-19)the Fundamental Research Funds for the Central Universities。
文摘Regulating chemical bonds to balance the adsorption and disassociation of water molecules on catalyst surfaces is crucial for overall water splitting in alkaline solution.Here we report a facile strategy for designing Ni2W4C-W3C Janus structures with abundant Ni-W metallic bonds on surfaces through interfacial engineering.Inserting Ni atoms into the W3C crystals in reaction progress generates a new Ni2 W4C phase,making the inert W atoms in W3C be active sites in Ni2W4C for overall water splitting.The Ni2W4CW3C/carbon nanofibers(Ni2 W4-W3C/CNFs)require overpotentials of 63 mV to reach 10 mA cm^-2 for hydrogen evolution reaction(HER)and 270 mV to reach 30 mA cm^-2 for oxygen evolution reaction(OER)in alkaline electrolyte,respectively.When utilized as both cathode and anode in alkaline solution for overall water splitting,cell voltages of 1.55 and 1.87 V are needed to reach 10 and 100 mA cm^-2,respectively.Density functional theory(DFT)results indicate that the strong interactions between Ni and W increase the local electronic states of W atoms.The Ni2W4C provides active sites for cleaving H-OH bonds,and the W3C facilitates the combination of Hads intermediates into H2 molecules.The in situ electrochemical-Raman results demonstrate that the strong absorption ability for hydroxyl and water molecules and further demonstrate that W atoms are the real active sites.
基金financially supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(T23-601/17-R)supported by the Fundamental Research Funds for the Central Universities(D5000220443)。
文摘锂金属具有氧化还原电位低、理论比容量大等优点,是下一代高比能电池极具发展前景的负极.然而,锂枝晶生长和低可逆性严重阻碍了高比能锂金属电池的发展.受启发于生物细胞膜结构,本文采用涂布法在锂金属表面成功构筑了一种具有仿生离子通道的人工界面固体电解质层(CAL).该CAL中大量带负电荷的离子通道可以促进锂离子均匀、快速的输运,有利于稳定、均匀地进行锂沉积/剥离.此外,在循环过程中,CAL底部与锂金属发生原位转化反应,生成了一层富含亲锂性无机组分的过渡层,促进了锂离子的扩散并抑制了锂金属与电解液的连续副反应.因此,形成的具有双面神结构的人工界面固体电解质层(CAJL)使得锂金属负极可以在10 mA cm^(-2)的高电流密度和10 mAh cm^(-2)的高面积容量下长期稳定循环.更重要的是,基于CAJL功能化锂金属负极的锂硫软包电池实现了429.2 Wh kg^(-1)的高能量密度.
基金supported by the National Natural Science Foundation of China(21871025,21831001,21701168)the Recruitment Program of Global Experts(Young Talents)+1 种基金BIT Excellent Young Scholars Research Fundthe National Key R&D Program of China(2020YFA0406101)。
文摘The development of bifunctional catalysts for solar-driven hydrogen and oxygen evolution has been regarded as a challenging but interesting research topic.As promising multi-electron-transfer catalysts,previously reported polyoxometalate(POM)-based catalysts often contain only a single type of transition metal substitution for driving either hydrogen production or oxygen evolution.Herein,a viable two-step parental substitution approach has been developed to synthesize two structurally-new mixed-transition-metal-substituted polyoxometalates(mixed TMSPs),K_(6)Na_(4)[Mn_(2)Ni_(2)(H_(2)O)2(PW_(9)O_(34))2]·21H_(2)O({Mn_(2)Ni_(2)})and K10[Mn_(2)Co_(2)(H_(2)O)2(PW_(9)O_(34))2]·35H_(2)O({Mn_(2)Co_(2)}),using Na_(12)[Mn_(2)Na_(2)(PW_(9)O_(34))2]·36H_(2)O({Mn_(2)Na_(2)})as the precursor.Characterization results confirmed the nearly quantitative substitution of Na+with Ni_(2)+and Co_(2+)ions.X-ray absorption fine structure(XAFS)spectroscopy revealed that the Mn atoms are preferentially located in the internal positions of the central belt while Ni and Co atoms preferentially reside in the external,solvent-accessible positions.Benefiting from the second substitution of catalytically active transition metals,the resulting{Mn_(2)Ni_(2)}and{Mn_(2)Co_(2)}can be utilized as Janus catalysts towards H_(2) evolution and O_(2) evolution under visible light irradiation with greatly-enhanced activity compared to that of parental{Mn_(2)Na_(2)}.The introduction of mixed transition metals into POM structures not only enriches the POMs family,but also provides an effective strategy to control electronic structures and catalytic properties of POM-based catalysts at the atomic level.
基金supported by Jiangsu Science and Technology Plan(BK20211258)Nanjing Tech University(39837140)Jiangsu Funding Program for Excellent Postdoctoral Talents。
文摘Precise structural control had attracted tremendous interest in nanosynthesis due to its great importance in tailoring the physical properties of nanomaterials.Here we report the synthesis of highly ordered Cd S-Au-TiO_(2) ternary Janus structure via templateprotected sequential growth and conversion method.Arising from the integration of the rectification effect of Au-CdS and AuTiO_(2) Schottky barriers,the Janus configuration of the Cd S-TiO_(2) domains,the plasmonic effect of Au nanosphere,and the Zscheme charge transportation,the Cd S-Au-TiO_(2) Janus structure showed high efficiency in the model photocatalytic degradation of methyl orange(MO)dye.Importantly,the well-defined structural order allowed the identification of the correlation between the structure and the catalytic performance.We believe that the synthetic control and the mechanism insights would help the design and synthesis of sophisticated nanostructures,and would eventually promote their applications in photocatalysis fields.
基金the Hong Kong Scholar Program (XJ2018035) for their financial supportsupported by Research Grants Council of Hong Kong (No. JLFS/E-402/18)National Natural Science Foundation of China (No. 51805509)。
文摘Several natural organism can change shape under external stimuli. These natural phenomena have inspired a vast amount of research on exploration and implementation of reconfigurable shape transformation. The Janus structure is a promising approach to achieve shape transformation based on its heterogeneous chemical or physical properties on opposite sides.However, the heterogeneity is generally realized by multi-step processing, different materials,and/or different processing parameters. Here, we present a simple and flexible method of producing p H-sensitive Janus microactuators from a single material, using the same laser printing parameters. These microactuators exhibit reversible structural deformations with large bending angles of ~31°and fast response(~0.2 s) by changing the p H value of the aqueous environment. Benefited from the high flexibility of the laser printing technique and the spatial arrangements, pillar heights, and bending directions of microactuators are readily controlled,enabling a variety of switchable ordered patterns and complex petal-like structures on flat surfaces and inside microchannels. Finally, we explore the potential applications of this method in information encryption/decryption and microtarget capturing.
基金the financial support for conducting part of the computational work,by the Australian Government through the Australian Research Council(ARC)under the centre of Excellence scheme(Project No.CE170100026)National Computational Infrastructure(NCI),a National Facility for computing resources.S K M also acknowledges the computing system resources’support from the University of Tsukuba,Japan through the International Postdoctoral Fellowship of Japan Society for the Promotion of Science(JSPS)’s KAKENHI(Grant No.JP22F32733)+1 种基金during the computational work and finalization of this studyS K M also acknowledges the support of Mr Matta Sai Aneesh,University of Queensland,Australia while preparing the graphical abstract.
文摘Photoelectrochemical water splitting using solar energy,generating oxygen and hydrogen is one of the clean fuel production processes.Inspired by surface-dependent characteristics of Janus structures,a newly designed Janus monolayer Silicon Phosphorous Arsenide(SiPAs)was analyzed with Density Functional Theory(DFT)methods.Hybrid exchange-correlation functional(HSE06)combined with Wannier90-based analysis for electronic and optical properties of SiPAs reveals that it can act as a photocatalyst.SiPAs show an indirect bandgap of 1.88 eV,absorbing visible light range is 350 to 500 nm.The phonon spectrum confirms dynamic stability.The exciton binding energy is computed with GW/BSE methods.The electronic band edge positions are at-5.75 and-4.43 eV,perfectly straddling the water redox potentials.Interestingly the strain application modifies the bandgap and also non-homogenously widens the absorption band.A novel range of photocatalyst designs with Group IV-V elements with great promise for water-splitting,photovoltaic,and narrow bandgap semiconductor(optoelectronics)applications may be feasible.
基金supported by the National Natural Science Foundation of China (No. 51872025)the National Key R&D Program of China (No. 2021YFB3802200)+4 种基金Natural Science Foundation of Guangdong Province (No. 2220XCC061)the National Defense Basic Scientific Research (No. JCKY2021110B206)Scientific and Technological Innovation Foundation of Foshan (No. BK21BE008)Zibo Key Research and Development Program (No. 2020XCCG0036)supported by USTB MatCom of Beijing Advanced Innovation Center for Materials Genome Engineering。
文摘The development of excellent catalyst to achieve photocatalytic syngas production from CO_(2) and H_(2)O is a prospective and sustainable strategy to alleviate environment and energy crisis. In this study, a unique Janus PdZn-Co catalyst is prepared by annealed the Pd/IRMOF-3(Co, Zn) precursor. Due to the strong interaction, the electron transfers from PdZn terminal to Co terminal in the Janus structure. The electron-received Co terminal facilitates Co sites coordinate with the electrophilic C atom of CO_(2) and the electron-donated PdZn center is easier to coordinate with nucleophilic O atoms of H_(2)O or C=O bonds.The charge redistribution enhances the absorption of CO_(2) and H2O, which promotes H_(2) evolution and CO production. In addition, the carbon shell effectively suppresses the metal core agglomeration and facilitates the electron transmission from photosensitizer to metallic active sites. Meanwhile, the ratio of CO/H_(2) can be regulated(~3:1 to 2:1) by adjusting the proportion of Co and PdZn. The Janus structure and graphite carbon synergistically play a profound impact on improving the photocatalytic performance.The optimized PdZn-Co catalyst exhibits a superior photocatalytic CO production rate(20.03 μmol/h) and the H_(2) generation rate(9.90 μmol/h) with a ratio of CO/H_(2)= 2.02.
基金financially supported by the National Natural Science Foundation of China (Nos. 52250077, 52272156, 51872263 and 52202175)Taishan Scholars Project (No. ts20190911)+1 种基金Shandong Natural Science Foundation (No. ZR2020ZD36)Guangdong Basic and Applied Basic Research Foundation (No. 2022A1515010461)。
文摘The accurate delivery of nanoparticles and organic small molecule drugs remains a serious challenge in nanoparticle-based tumor therapy.Dual-targeted therapy combining tumor cell targeting and organelle targeting is an effective solution.Here,an anticancer nanoformulation accurate delivery system was prepared using hyaluronic acid (HA) targeting CD44 receptors on the surface of tumor cells and IR780iodine (IR780) targeting mitochondrial for delivery.The system is based on an ultra-small Janus structured inorganic sensitizer TiO_(2-x)@NaGdF_(4) nanoparticles (TN NPs) prepared by one-step pyrolysis,further loaded with organic small molecule acoustic sensitizer IR780 and mitochondrial hexokinase Ⅱ inhibitor lonidamine (LND),followed by encapsulation of HA.Ultra-small size nanoparticles exhibit strong tissue penetration,tumor inhibition and in vivo metabolism.Under ultrasound radiation,TN NPs and IR780could produce a synergistic effect,effectively increased the efficiency of reactive oxygen species (ROS)production.Meanwhile,the released IR780 could smoothly target the mitochondria,and the ROS produced by IR780 can destroy the mitochondrial structure and disrupt the mitochondrial respiration.LND could inhibit the energy metabolism of tumor cells by reducing the activity of hexokinase Ⅱ (HK Ⅱ),which further accelerates the process of apoptosis.Furthermore,since the Janus structure allows the integration of multifunctional components into a single system,TN NPs can not only serve as an acoustic sensitizer to generate ROS,but the Gd element contained can also act as the nuclear magnetic resonance (MR)imaging contrast agent,suggesting that the nanoformulation can enable imaging-guided diagnosis and therapy.In conclusion,a new scheme to enhance sonodynamic therapy (SDT) and chemotherapy synergistically is proposed here based on ultra-small dual-targeted nanoformulation with Janus structure in the ultrasound radiation environment.
