Cobalt nickel bimetallic oxides(NiCo_(2)O_(4))have received numerous attentions in terms of their controllable morphology,high temperature,corrosion resistance and strong electromagnetic wave(EMW)absorption capability...Cobalt nickel bimetallic oxides(NiCo_(2)O_(4))have received numerous attentions in terms of their controllable morphology,high temperature,corrosion resistance and strong electromagnetic wave(EMW)absorption capability.However,broadening the absorption bandwidth is still a huge challenge for NiCo_(2)O_(4)-based absorbers.Herein,the unique NiCo_(2)O_(4)@C core-shell microcubes with hollow structures were fabricated via a facile sacrificial template strategy.The concentration of oxygen vacancies and morphologies of the three-dimensional(3D)cubic hollow core-shell NiCo_(2)O_(4)@C framework were effectively optimized by adjusting the calcination temperature.The specially designed 3D framework structure facilitated the multiple reflections of incident electromagnetic waves and provided rich interfaces between multiple components,generating significant interfacial polarization losses.Dipole polarizations induced by oxygen vacancies could further enhance the attenuation ability for the incident EM waves.The optimized NiCo_(2)O_(4)@C hollow microcubes exhibit superior EMW absorption capability with minimum RL(RLmin)of-84.45 dB at 8.4 GHz for the thickness of 3.0 mm.Moreover,ultrabroad effective absorption bandwidth(EAB)as large as 12.48 GHz(5.52-18 GHz)is obtained.This work is believed to illuminate the path to synthesis of high-performance cobalt nickel bimetallic oxides for EMW absorbers with excellent EMW absorption capability,especially in broadening effective absorption bandwidth.展开更多
MXene,a transition metal carbide/nitride,has been prominent as an ideal electrochemical active material for supercapacitors.However,the low MXene load limits its practical applications.As environmental concerns and su...MXene,a transition metal carbide/nitride,has been prominent as an ideal electrochemical active material for supercapacitors.However,the low MXene load limits its practical applications.As environmental concerns and sustainable development become more widely recognized,it is necessary to explore a greener and cleaner technology to recycle textile by-products such as cotton.The present study proposes an effective 3D fabrication method that uses MXene to fabricate waste denim felt into ultralight and flexible supercapacitors through needling and carbonization.The 3D structure provided more sites for loading MXene onto Z-directional fiber bundles,resulting in more efficient ion exchange between the electrolyte and electrodes.Furthermore,the carbonization process removed the specific adverse groups in MXenes,further improving the specific capacitance,energy density,power density and electrical conductivity of supercapacitors.The electrodes achieve a maximum specific capacitance of 1748.5 mF cm-2 and demonstrate remarkable cycling stability maintaining more than 94%after 15,000 galvanostatic charge/discharge cycles.Besides,the obtained supercapacitors present a maximum specific capacitance of 577.5 mF cm^(-2),energy density of 80.2μWh cm^(-2)and power density of 3 mW cm^(-2),respectively.The resulting supercapacitors can be used to develop smart wearable power devices such as smartwatches,laying the foundation for a novel strategy of utilizing waste cotton in a high-quality manner.展开更多
With the innovation of microelectronics technology, the heat dissipation problem inside the device will face a severe test. In this work, cellulose aerogel(CA) with highly enhanced thermal conductivity(TC) in vertical...With the innovation of microelectronics technology, the heat dissipation problem inside the device will face a severe test. In this work, cellulose aerogel(CA) with highly enhanced thermal conductivity(TC) in vertical planes was successfully obtained by constructing a vertically aligned silicon carbide nanowires(SiC NWs)/boron nitride(BN) network via the ice template-assisted strategy. The unique network structure of SiC NWs connected to BN ensures that the TC of the composite in the vertical direction reaches 2.21 W m^(-1) K^(-1) at a low hybrid filler loading of 16.69 wt%, which was increased by 890% compared to pure epoxy(EP). In addition, relying on unique porous network structure of CA, EP-based composite also showed higher TC than other comparative samples in the horizontal direction. Meanwhile, the composite exhibits good electrically insulating with a volume electrical resistivity about 2.35 × 10^(11) Ω cm and displays excellent electromagnetic wave absorption performance with a minimum reflection loss of-21.5 dB and a wide effective absorption bandwidth(<-10 dB) from 8.8 to 11.6 GHz. Therefore, this work provides a new strategy for manufacturing polymer-based composites with excellent multifunctional performances in microelectronic packaging applications.展开更多
While the rechargeable aqueous zinc-ion batteries(AZIBs)have been recognized as one of the most viable batteries for scale-up application,the instability on Zn anode–electrolyte interface bottleneck the further devel...While the rechargeable aqueous zinc-ion batteries(AZIBs)have been recognized as one of the most viable batteries for scale-up application,the instability on Zn anode–electrolyte interface bottleneck the further development dramatically.Herein,we utilize the amino acid glycine(Gly)as an electrolyte additive to stabilize the Zn anode–electrolyte interface.The unique interfacial chemistry is facilitated by the synergistic“anchor-capture”effect of polar groups in Gly molecule,manifested by simultaneously coupling the amino to anchor on the surface of Zn anode and the carboxyl to capture Zn^(2+)in the local region.As such,this robust anode–electrolyte interface inhibits the disordered migration of Zn^(2+),and effectively suppresses both side reactions and dendrite growth.The reversibility of Zn anode achieves a significant improvement with an average Coulombic efficiency of 99.22%at 1 mA cm^(−2)and 0.5 mAh cm^(−2)over 500 cycles.Even at a high Zn utilization rate(depth of discharge,DODZn)of 68%,a steady cycle life up to 200 h is obtained for ultrathin Zn foils(20μm).The superior rate capability and long-term cycle stability of Zn–MnO_(2)full cells further prove the effectiveness of Gly in stabilizing Zn anode.This work sheds light on additive designing from the specific roles of polar groups for AZIBs.展开更多
Magnesium metal anode holds great potentials toward future high energy and safe rechargeable magnesium battery technology due to its divalent redox and dendrite-free nature. Electrolytes based on Lewis acid chemistry ...Magnesium metal anode holds great potentials toward future high energy and safe rechargeable magnesium battery technology due to its divalent redox and dendrite-free nature. Electrolytes based on Lewis acid chemistry enable the reversible Mg plating/stripping,while they fail to match most cathode materials toward highvoltage magnesium batteries. Herein,reversible Mg plating/stripping is achieved in conventional carbonate electrolytes enabled by the cooperative solvation/surface engineering. Strongly electronegative Cl from the MgCl_(2) additive of electrolyte impairs the Mg…O = C interaction to reduce the Mg^(2+) desolvation barrier for accelerated redox kinetics,while the Mg^(2+)-conducting polymer coating on the Mg surface ensures the facile Mg^(2+) migration and the e ective isolation of electrolytes. As a result,reversible plating and stripping of Mg is demonstrated with a low overpotential of 0.7 V up to 2000 cycles. Moreover,benefitting from the wide electrochemical window of carbonate electrolytes,high-voltage(> 2.0 V) rechargeable magnesium batteries are achieved through assembling the electrode couple of Mg metal anode and Prussian blue-based cathodes. The present work provides a cooperative engineering strategy to promote the application of magnesium anode in carbonate electrolytes toward high energy rechargeable batteries.展开更多
The search for wearable electronics has been attracted great efforts,there is an ever-growing demand for all-solid-state flexible energy storage devices.However,it is a challenge to obtain both positive and negative e...The search for wearable electronics has been attracted great efforts,there is an ever-growing demand for all-solid-state flexible energy storage devices.However,it is a challenge to obtain both positive and negative electrodes with excellent mechanical strength and match positive and negative charges to achieve high energy densities and operate voltages to satisfy practical application requirements.Here,flexible MXene(Ti_(3)C_(2)Tx)/cellulose nanofiber(CNF)composite film negative electrodes(MCNF)were fabricated with a vacuum filtration method,as well as positive electrodes(CP)by combining polyaniline(PANI)with carbon cloth(CC)using an in-situ polymerization method.Both positive and negative free-standing electrodes exhibited excellent electrochemical behavior and bendable/foldable flexibility.As a result,the all-pseudocapacitance asymmetric device of MCNF//CP assembled with charge-matched between anode and cathode achieves an extended voltage window of 1.5 V,high energy density of 30.6 Wh·kg^(−1)(1211 W·kg^(−1)),86%capacitance retention after 5000 cycles,the device maintains excellent bendability,simultaneously.This work will pave the way for the development of all-pseudocapacitive asymmetric supercapacitors(ASC)with simultaneously preeminent mechanical properties,high energy density,wide operating voltage window.展开更多
The Ni-Nb_(2)O_(5)nanocatalysts have been prepared by the solgel method,and the catalytic hydrodeoxygenation(HDO)performance of anisole as model compound is studied.The results show that Nb exists as amorphous Nb_(2)O...The Ni-Nb_(2)O_(5)nanocatalysts have been prepared by the solgel method,and the catalytic hydrodeoxygenation(HDO)performance of anisole as model compound is studied.The results show that Nb exists as amorphous Nb_(2)O_(5)species,which can promote Ni dispersion.The addition of Nb_(2)O_(5)increases the acidity of the catalyst.However,when the content of niobium is high,there is an inactive Nb-Ni-O mixed phase.The size and morphology of Ni grains in catalysts are different due to the difference of Nb/Ni molar ratio.The Ni_(0.9)Nb_(0.1)sample has the largest surface area of 170.8 m^(2)·g^(-1)among the catalysts prepared in different Nb/Ni molar ratios,which is mainly composed of spherical nanoparticles and crack pores.The HDO of anisole follows the reaction route of the hydrogenation HYD route.The Ni_(0.9)Nb_(0.1)catalyst displayed a higher HDO performance for anisole than Ni catalyst.The selectivity to cyclohexane over the Ni_(0.9)Nb_(0.1)sample is about 10 times that of Ni catalyst at 220℃and 3 MPa H_(2).The selectivity of cyclohexane is increased with the increase of reaction temperature.The anisole is almost completely transformed into cyclohexane at 240℃,3 MPa H_(2)and 4 h.展开更多
Solid-state sodium metal batteries utilizing inorganic solid electrolytes(SEs)hold immense potentials such as intrinsical safety,high energy density,and environmental sustainability.However,the interfacial inhomogenei...Solid-state sodium metal batteries utilizing inorganic solid electrolytes(SEs)hold immense potentials such as intrinsical safety,high energy density,and environmental sustainability.However,the interfacial inhomogeneity/instability at the anode-SE interface usually triggers the penetration of sodium dendrites into the electrolyte,leading to short circuit and battery failure.Herein,confronting with the original nonuniform and high-resistance solid electrolyte interphase(SEI)at the Na-Na_(3)Zr_(2)Si_(2)PO_(12)interface,an oxygen-regulated SEI innovative approach is proposed to enhance the cycling stability of anode-SEs interface,through a spontaneous reaction between the metallic sodium(containing trace amounts of oxygen)and the Na_(3)Zr_(2)Si_(2)POi_(2)SE.The oxygen-regulated spontaneous SEI is thin,uniform,and kinetically stable to facilitate homogenous interfacial Na^+transportation,Benefitting from the optimized SEI,the assembled symmetric cell exhibits an ultra-stable sodium plating/stripping cycle for over 6600 h under a practical capacity of 3 mAh cm^(-2).Qua si-sol id-state batteries with Na_(3)V_(2)(PO_(4))_(3)cathode deliver excellent cyclability over 500 cycles at a rate of 0.5 C(1 C=117 mA cm^(-2))with a high capacity retention of95.4%.This oxygen-regulated SEI strategy may offer a potential avenue for the future development of high-energy-density solid-state metal batteries.展开更多
Erratum to Nano Research 2023,16(7):10493–10499 https://doi.org/10.1007/s12274-023-5727-6 The article“Advancing pressure sensors performance through a flexible MXene embedded interlocking structure in a microlens ar...Erratum to Nano Research 2023,16(7):10493–10499 https://doi.org/10.1007/s12274-023-5727-6 The article“Advancing pressure sensors performance through a flexible MXene embedded interlocking structure in a microlens array”,written by Tong Li,Zhenzong Xu,Ben Bin Xu,Zhanhu Guo,Yunhong Jiang,Xuehua Zhang,Maryam Bayati,Terence Xiaoteng Liu,and Yan-Hua Liu,was originally published electronically on the publisher’s internet portal on May 20,2023 without open access due to an unfortunate oversight during the conversion process.The publisher apologizes this mistake.The article is forthwith distributed under a Creative Commons Attribution 4.0 International License,which permits use,sharing,adaptation,distribution and reproduction in any medium or format,as long as you give appropriate credit to the original author(s)and the source,provide a link to the Creative Commons licence,and indicate if changes were made.展开更多
Although many material designs or strategic methods have been proposed for treating oil spills and oily wastewater,the complex oily state,dealing with the harsh operating conditions of oil–water separation(such as th...Although many material designs or strategic methods have been proposed for treating oil spills and oily wastewater,the complex oily state,dealing with the harsh operating conditions of oil–water separation(such as the recovery of viscous spilled crude oil,bacteria-containing oily wastewater,and removal of spilled oil under fire),and the autorecycling of oil and absorption materials remain a great challenge.This work proposed an ingenious design strategy of“several birds with one stone”to prepare p H/thermoresponsive flame-retardant/photothermal bactericidal P-Fe_(3)O_(4)-polydopamine(PDA)@melamine–formaldehyde(MF)foams.This design makes the foams remarkably effective in the recovery of spilled viscous crude oil as well as in the separation of bacteria-containing oily emulsions,particularly for instant fire extinguishing by magnetically controlled oil absorption as well as for fire alarms.The photothermal effect and p H response induce a change in the surface wettability of the foams,facilitating excellent autoadsorption/desorption of the spilled oil.The photothermal bactericidal activity and fouling resistance of the foam are beneficial to the separation of bacteria-containing oily wastewater.Outstanding flame-retardant properties and maneuverable magnetic control enable the foam to rapidly recover the spilled oil in a large range of fires,extinguish fires instantly,and facilitate early fire warning.The proposed strategy is expected to inspire further research on treating oil spills under complex conditions.展开更多
Piezoresistive composite elastomers have shown great potentials for wearable and flexible electronic applications due to their high sensitivity,excellent frequency response,and easy signal detection.A composition memb...Piezoresistive composite elastomers have shown great potentials for wearable and flexible electronic applications due to their high sensitivity,excellent frequency response,and easy signal detection.A composition membrane sensor with an interlocked structure has been developed and demonstrated outstanding pressure sensitivity,fast response time,and low temperature drift features.Compared with a flexible MXene-based flat sensor(Ti_(3)C_(2)),the interlocked sensor exhibits a significantly improved pressure sensitivity of two magnitudes higher(21.04 kPa^(-1)),a fast reaction speed of 31 ms,and an excellent cycle life of 5000 test runs.The viability of sensor in responding to various external stimuli with high deformation capacity has been confirmed by calculating the force distribution of a polydimethylsiloxane(PDMS)film model with a microlens structure using the solid mechanics module in COMSOL.Unlike conventional process,we utilized three-dimensional(3D)laser-direct writing lithography equipment to directly transform high-precision 3D data into a micro-nano structure morphology through variable exposure doses,which reduces the hot melting step.Moreover,the flexible pressure device is capable of detecting and distinguishing signals ranging from finger movements to human pulses,even for speech recognition.This simple,convenient,and large-format lithographic method offers new opportunities for developing novel human-computer interaction devices.展开更多
An active bacterial anti-adhesion strategy based on directional transportation of bacterial droplets driven by a triboelectric nanogenerator(TENG)has not been reported to date,although passive defense approaches can p...An active bacterial anti-adhesion strategy based on directional transportation of bacterial droplets driven by a triboelectric nanogenerator(TENG)has not been reported to date,although passive defense approaches can prevent bacterial adhesion by regulating superwetting surfaces combined with incorporated antibacterial substances.Here a triboelectric nanogenerator driving droplet system(TNDDS)was built to drive directional transportation of bacterial droplets to be eliminated,which comprises TENG with periodical frictional Kapton film and aluminum foils and a superhydrophobic driving platform(SDP)with paralleled driving electrodes.The current generated by the TENG triboelectricity is transmitted to the paralleled driving electrodes to form an electric field driving the directional transportation of charged droplets.The critical value of the driven droplet volume on SDP is closely related to the distributed electrodes’distance and width,and the driving distance of droplets is related to the number of electrodes.More crucially,TNDDS can actively drive the charged droplets of prepared triangular silver nanoprisms(Ag NPs)forward and back to mix with and remove a tiny bacterial droplet on an open SDP or in a tiny semi-enclosed channel.Bacteria could be killed by releasing Ag+and effectively removed by TNDDS by regulating the motion direction.Generally,this approach offers a promising application for removing bacteria from material surfaces driven by TENG and opens a new avenue for bacterial anti-adhesion.展开更多
Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregation...Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregations of metal and serious loss of nitrogen species constituting the M-N_(x) active sites are frequently observed in the commonly used pyrolysis procedure.Herein,single-atomic nickel(Ni)-based sheet-like electrocatalysts with abundant Ni-N_(4) active sites were created by using a novel ammonium chloride(NH_(4)Cl)-assited pyrolysis method.Spherical aberration correction electron microscopy and X-ray absorption fine structure analysis clearly revealed that Ni species are atomically dispersed and anchored by N in Ni-N_(4) structure.The addition of NH_(4)Cl optimized the mesopore size to 7-10 nm and increased the concentrations of pyridinic N(3.54 wt%)and Ni-N_(4)(3.33 wt%)species.The synergistic catalytic effect derived from Ni-N_(4) active sites and pyridinic N species achieved an outstanding CO_(2) RR performance,presenting a high CO Faradaic efficiency(FE_(CO))up to 98% and a large CO partial current density of 8.5 mA cm^(-2) at a low potential of-0.62 V vs.RHE.Particularly,the FE_(CO) maintains above 80% within a large potential range from -0.43 to -0.73 V vs.RHE.This work provides a practical and feasible approach to building highly active single-atomic catalysts for CO_(2) conversion systems.展开更多
Three-dimensional holey nitrogen-doped carbon matrixes decorated with molybdenum dioxide(MoO_(2))nanoparticles have been successfully synthesized via a NaCl-assisted template strategy.The obtained MoO_(2)/C composites...Three-dimensional holey nitrogen-doped carbon matrixes decorated with molybdenum dioxide(MoO_(2))nanoparticles have been successfully synthesized via a NaCl-assisted template strategy.The obtained MoO_(2)/C composites offered multi-advantages,including higher specific surface area,more active sites,more ions/electrons transmission channels,and shorter transmission path due to the synergistic effect of the uniformly distributed MoO_(2) nanoparticles and porous carbon structure.Especially,the oxygen vacancies were introduced into the prepared composites and enhanced the Li^(+)intercalation/deintercalation process during electrochemical cycling by the Coulomb force.The existence of the local built-in electric field was proved by experimental data,differential charge density distribution,and density of states calculation.The uniquely designed structure and introduced oxygen vacancy defects endowed the MoO_(2)/C composites with excellent electrochemical properties.In view of the synergistic effect of the uniquely designed morphology and introduced oxygen vacancy defects,the MoO_(2)/C composites exhibited superior electrochemical performance of a high capacity of 918.2 mAh g^(-1) at 0.1 A g^(-1) after 130 cycles,562.1 mAh g^(-1) at 1.0 A g^(-1) after 1000 cycles,and a capacity of 181.25 mAh g^(-1) even at 20.0 A g^(-1).This strategy highlights the path to promote the commercial application of MoO_(2)-based and other transition metal oxide electrodes for energy storage devices.展开更多
A visible light-active photoelectrocatalyst,ZnFe-layered double oxide(LDO)/cobalt(II,III)oxide(Co_(3)O_(4))composites were obtained by calcining the Co loaded ZnFe-layered double hydroxide(LDH)prepared by a hydrotherm...A visible light-active photoelectrocatalyst,ZnFe-layered double oxide(LDO)/cobalt(II,III)oxide(Co_(3)O_(4))composites were obtained by calcining the Co loaded ZnFe-layered double hydroxide(LDH)prepared by a hydrothermal and microwave hydrothermal method.The morphological studies revealed that the ZnFe-LDO/Co_(3)O_(4) composites exhibited a flower-like structure comprising Co_(3)O_(4) nanowires and ZnFe-LDO nanosheets.Further,when the mass ratio of Co(NO_(3))_(2)·6H_(2)O/LDH was 1:1.8 and the calcination temperature was 550℃,the ZnFe-LDO/Co_(3)O_(4) composite exhibited 93.3%degradation efficiency for methylene blue(MB)at the applied voltage of 1.0 V under visible light after 3 h.Furthermore,the Mott-Schottky model experiments showed that the formation of a p-n heterojunction between ZnFe-LDO and Co_(3)O_(4) could effectively inhibit the recombination of electrons and holes in the photoelectrocatalytic process.Meanwhile,free radical scavenging experiments showed that the active radicals of⋅OH played an important role in the degradation of MB.Therefore,the photoelectrocatalytic effect of ZnFe-LDO/Co_(3)O_(4) provides a simple and effective strategy for the removal of organic pollutants.展开更多
The microscopic morphology of electromagnetic wave absorbers influences the multiple reflections of electromagnetic waves and impedance matching,determining the absorption properties.Herein,the urchin-shaped bimetalli...The microscopic morphology of electromagnetic wave absorbers influences the multiple reflections of electromagnetic waves and impedance matching,determining the absorption properties.Herein,the urchin-shaped bimetallic nickel-cobalt oxide/carbon(NiCo_(2)O_(4)/C)composites are prepared via a hy-drothermal route,whose absorption properties are investigated by different morphologies regulated by changing calcination temperature.A minimum reflection loss(RL_(min))of-75.26 dB is achieved at a match-ing thickness of 1.5 mm,and the effective absorption bandwidth(EAB)of 8.96 GHz is achieved at 2 mm.Multi-advantages of the synthesized NiCo_(2)O_(4)/C composites contribute to satisfactory absorption proper-ties.First,the interweaving of the needle-like structures increases the opportunities for scattering and multiple reflections of incident electromagnetic waves,and builds up a conductive network to facilitate the enhancement of conductive losses.Second,the carbon component in the NiCo_(2)O_(4)/C composites en-hances the interfacial polarization and reduces the density of the absorber.Besides,generous oxygen va-cancy defects are introduced into the NiCo_(2)O_(4)/C composites,which induces defect polarization and dipole polarization.In summary,the ternary coordination of components,defects and morphology led to out-standing electromagnetic wave absorption,which lightened the path for improving the electromagnetic wave absorption property and enriching the family of NiCo_(2)O_(4) absorbers with excellent performance.展开更多
钠金属二次电池由于丰富的地壳钠资源储备、金属钠负极高的理论容量等优势受到广泛的关注,已成为后锂离子电池时代的重要技术之一.然而,金属钠负极在充放电循环过程中存在枝晶生长、体积变化等严重问题,严重制约了钠金属电池技术的发展...钠金属二次电池由于丰富的地壳钠资源储备、金属钠负极高的理论容量等优势受到广泛的关注,已成为后锂离子电池时代的重要技术之一.然而,金属钠负极在充放电循环过程中存在枝晶生长、体积变化等严重问题,严重制约了钠金属电池技术的发展.基于以上问题,本文提出在金属钠负极体相内引入NaSICON型固态钠离子导体,构建具有离子/电子混合传输能力的金属钠基复合负极.一方面,通过钠离子传导相和金属电子导电相之间的紧密接触构建了快速的离子/电子通道和丰富的电化学反应界面,有利于实现稳定可逆的钠沉积/剥离;另一方面,紧密堆积的复合结构保护了金属钠免受液态有机电解质的腐蚀和副反应的发生.得益于上述独特的结构设计,复合负极表现出高度可逆和稳定的钠的沉积/剥离行为.在碳酸酯类电解液中,对称电池在1 m A cm^(-2)的电流密度、5 m Ah cm^(-2)的高充放电容量下实现了高于700 h的超长寿命,以及高达8 m A cm^(-2)电流密度的出色倍率性能.在搭配Na_(3)V_(2)(PO_(4))_(3)/C正极时,全电池展现出优异的循环稳定性(容量衰减单次平均仅0.012%)以及低的充放电极化.展开更多
Rational construction of hierarchical multi-component materials with abundant heterostructure is evolving as a promising strategy to achieve excellent metal-organic frameworks(MOFs)based electromagnetic wave(EMW)absor...Rational construction of hierarchical multi-component materials with abundant heterostructure is evolving as a promising strategy to achieve excellent metal-organic frameworks(MOFs)based electromagnetic wave(EMW)absorbers.Herein,hierarchical heterostructure WS_(2)/CoS_(2)@carbonized cotton fiber(CCF)was fabricated using the ZIF-67 MOFs nanosheets anchored cotton fiber(ZIF-67@CF)as a precursor through the tungsten etching,sulfurization,and carbonization process.Apart from the synergetic effect of dielectric-magnetic dual-loss mechanism,the hierarchical heterostructure and multicomponent of WS_(2)/CoS_(2)@CCF also display improved impedance matching.Furthermore,numerous W-S-Co bands and heterojunction interfaces of heterogeneous WS_(2)/CoS_(2)are beneficial to promoting additional interfacial/dipole polarization loss and conductive loss,thereby enhancing the EMW attenuation performance.Based on the percolation theory,a good balance between impedance matching and EMW absorption capacity was achieved for the WS_(2)/CoS_(2)@CCF/paraffin composite with 20 wt.%filler loading,exhibiting strong EMW absorption capability with a minimum reflection loss(RLmin)value of−51.26 dB at 17.36 GHz with 2 mm thickness and a maximum effective absorption bandwidth(EABmax)as wide as 6.72 GHz.Our research will provide new guidance for designing high-efficient MOFs derived EMW absorbers.展开更多
Structural optimization of ionomers is an effective strategy for achieving high-performance proton ex-change membranes(PEMs)under low relative humidity(RH)conditions.In this study,sulfonimide group and trifluoromethan...Structural optimization of ionomers is an effective strategy for achieving high-performance proton ex-change membranes(PEMs)under low relative humidity(RH)conditions.In this study,sulfonimide group and trifluoromethanesulfonate acid(TFSA)ionic liquids were introduced to the perfluorosulfonic acid(PFSA)side chain,resulting in polymer membranes with varying chain lengths(i.e.,PFC_(2)-TF-SI,PFC_(4)-TF-SI,and PFC_(5)-TF-SI).This dual proton-conducting structure extended the length of the hydrophilic side chain and enhanced the hydrophobic-hydrophilic phase separation,aiding in the formation of proton transport channels.Notably,the proton conductivity of PFC_(5)-TF-SI and PFC_(2)-TF-SI membranes reached 7.1 and 10.6 mS/cm at 30%RH and 80°C,respectively,which were approximately 29.1%and 92.7%higher than that of the pristine PFC_(5)-SA membrane(5.5 mS/cm).Furthermore,the maximum power density of the PFC_(5)-TF-SI and PFC_(2)-TF-SI membranes from the built single fuel cell achieved 649 and 763 mW/cm 2 at 30%RH and 80°C,respectively,which were higher than that of the pristine PFC_(5)-SA membrane(567 mW/cm 2)by about 14.5%and 34.6%,respectively.Thus,this study provides a strategy for PEM design under low RH conditions.展开更多
In order to maintain the optimal operating temperature of the battery surface and meet the demand for thermal storage technology,battery thermal management system based on phase change materials has attracted increasi...In order to maintain the optimal operating temperature of the battery surface and meet the demand for thermal storage technology,battery thermal management system based on phase change materials has attracted increasing interest.In this work,a kind of core-shell structured microcapsule was synthesized by an in-situ polymerization,where paraffin was used as the core,while methanol was applied to mod-ify the melamine-formaldehyde shell to reduce toxicity and improve thermal stability.Moreover,three different types of heat conductive fillers with the same content of 10 wt.%,i.e.,nano-Al_(2)O_(3),nano-ZnO and carbon nanotubes were added,generating composites.The microcapsules were uniform,and were not affected by the thermal fillers,which were evenly dispersed around.The composite sample with carbon nanotubes(10 wt.%)showed the highest thermal conductivity of 0.50 W/(m K)and latent heat of 139.64 J/g.Furthermore,according to the leakage testing and battery charge/discharge experiments,compared with Al_(2)O_(3)and ZnO,the addition of carbon nanotubes remarkably enhances the heat storage ability as latent heat from 126.98 J/g for the prepared sample with Al_(2)O_(3)and 125.86 J/g for the one with ZnO,then to 139.64 J/g,as well as dissipation performance as a cooling effect by decreasing the sur-face temperature of battery from 2%to 12%of microcapsule,composite sample with carbon nanotubes presents a broad application prospect in battery thermal management system and energy storage field.展开更多
基金This work was supported by Natural Science Foundation of Shandong Province(ZR2022ME089)National Natural Science Foundation of China(52207249)Yantai Basic Research Project(2022JCYJ04).
文摘Cobalt nickel bimetallic oxides(NiCo_(2)O_(4))have received numerous attentions in terms of their controllable morphology,high temperature,corrosion resistance and strong electromagnetic wave(EMW)absorption capability.However,broadening the absorption bandwidth is still a huge challenge for NiCo_(2)O_(4)-based absorbers.Herein,the unique NiCo_(2)O_(4)@C core-shell microcubes with hollow structures were fabricated via a facile sacrificial template strategy.The concentration of oxygen vacancies and morphologies of the three-dimensional(3D)cubic hollow core-shell NiCo_(2)O_(4)@C framework were effectively optimized by adjusting the calcination temperature.The specially designed 3D framework structure facilitated the multiple reflections of incident electromagnetic waves and provided rich interfaces between multiple components,generating significant interfacial polarization losses.Dipole polarizations induced by oxygen vacancies could further enhance the attenuation ability for the incident EM waves.The optimized NiCo_(2)O_(4)@C hollow microcubes exhibit superior EMW absorption capability with minimum RL(RLmin)of-84.45 dB at 8.4 GHz for the thickness of 3.0 mm.Moreover,ultrabroad effective absorption bandwidth(EAB)as large as 12.48 GHz(5.52-18 GHz)is obtained.This work is believed to illuminate the path to synthesis of high-performance cobalt nickel bimetallic oxides for EMW absorbers with excellent EMW absorption capability,especially in broadening effective absorption bandwidth.
基金The authors acknowledge the financial support from the National Natural Science Foundation of China(Nos.52073224,32201491)the Textile Vision Basic Research Program of China(No.J202110)+3 种基金the Scientific Research Project of Shaanxi Provincial Education Department,China(No.22JC035)the Advanced Manufacturing Technology Program of Xi’an Science and Technology Bureau,China(No.21XJZZ0019)the Research Fund for the Doctoral Program of Xi’an Polytechnic University(No.BS202053)the Youth Innovation Team of Shaanxi Universities and Institute of Flexible electronics and Intelligent Textile.
文摘MXene,a transition metal carbide/nitride,has been prominent as an ideal electrochemical active material for supercapacitors.However,the low MXene load limits its practical applications.As environmental concerns and sustainable development become more widely recognized,it is necessary to explore a greener and cleaner technology to recycle textile by-products such as cotton.The present study proposes an effective 3D fabrication method that uses MXene to fabricate waste denim felt into ultralight and flexible supercapacitors through needling and carbonization.The 3D structure provided more sites for loading MXene onto Z-directional fiber bundles,resulting in more efficient ion exchange between the electrolyte and electrodes.Furthermore,the carbonization process removed the specific adverse groups in MXenes,further improving the specific capacitance,energy density,power density and electrical conductivity of supercapacitors.The electrodes achieve a maximum specific capacitance of 1748.5 mF cm-2 and demonstrate remarkable cycling stability maintaining more than 94%after 15,000 galvanostatic charge/discharge cycles.Besides,the obtained supercapacitors present a maximum specific capacitance of 577.5 mF cm^(-2),energy density of 80.2μWh cm^(-2)and power density of 3 mW cm^(-2),respectively.The resulting supercapacitors can be used to develop smart wearable power devices such as smartwatches,laying the foundation for a novel strategy of utilizing waste cotton in a high-quality manner.
基金financial support from National Natural Science Foundation of China(21704096,51703217)the China Postdoctoral Science Foundation(Grant No.2019M662526)financial support from Taif University Researchers Supporting Project Number(TURSP-2020/135),Taif University,Taif,Saudi Arabia。
文摘With the innovation of microelectronics technology, the heat dissipation problem inside the device will face a severe test. In this work, cellulose aerogel(CA) with highly enhanced thermal conductivity(TC) in vertical planes was successfully obtained by constructing a vertically aligned silicon carbide nanowires(SiC NWs)/boron nitride(BN) network via the ice template-assisted strategy. The unique network structure of SiC NWs connected to BN ensures that the TC of the composite in the vertical direction reaches 2.21 W m^(-1) K^(-1) at a low hybrid filler loading of 16.69 wt%, which was increased by 890% compared to pure epoxy(EP). In addition, relying on unique porous network structure of CA, EP-based composite also showed higher TC than other comparative samples in the horizontal direction. Meanwhile, the composite exhibits good electrically insulating with a volume electrical resistivity about 2.35 × 10^(11) Ω cm and displays excellent electromagnetic wave absorption performance with a minimum reflection loss of-21.5 dB and a wide effective absorption bandwidth(<-10 dB) from 8.8 to 11.6 GHz. Therefore, this work provides a new strategy for manufacturing polymer-based composites with excellent multifunctional performances in microelectronic packaging applications.
基金supported by National Key R&D Program(2022YFB2502000)Zhejiang Provincial Natural Science Foundation of China(LZ23B030003)+1 种基金the Fundamental Research Funds for the Central Universities(2021FZZX001-09)the National Natural Science Foundation of China(52175551).
文摘While the rechargeable aqueous zinc-ion batteries(AZIBs)have been recognized as one of the most viable batteries for scale-up application,the instability on Zn anode–electrolyte interface bottleneck the further development dramatically.Herein,we utilize the amino acid glycine(Gly)as an electrolyte additive to stabilize the Zn anode–electrolyte interface.The unique interfacial chemistry is facilitated by the synergistic“anchor-capture”effect of polar groups in Gly molecule,manifested by simultaneously coupling the amino to anchor on the surface of Zn anode and the carboxyl to capture Zn^(2+)in the local region.As such,this robust anode–electrolyte interface inhibits the disordered migration of Zn^(2+),and effectively suppresses both side reactions and dendrite growth.The reversibility of Zn anode achieves a significant improvement with an average Coulombic efficiency of 99.22%at 1 mA cm^(−2)and 0.5 mAh cm^(−2)over 500 cycles.Even at a high Zn utilization rate(depth of discharge,DODZn)of 68%,a steady cycle life up to 200 h is obtained for ultrathin Zn foils(20μm).The superior rate capability and long-term cycle stability of Zn–MnO_(2)full cells further prove the effectiveness of Gly in stabilizing Zn anode.This work sheds light on additive designing from the specific roles of polar groups for AZIBs.
基金supported by National Key Research and Development Program (2019YFE0111200)the National Natural Science Foundation of China (51722105)+1 种基金Zhejiang Provincial Natural Science Foundation of China (LR18B030001)the Fundamental Research Funds for the Central Universities and the Fundamental Research Funds for the Central Universities。
文摘Magnesium metal anode holds great potentials toward future high energy and safe rechargeable magnesium battery technology due to its divalent redox and dendrite-free nature. Electrolytes based on Lewis acid chemistry enable the reversible Mg plating/stripping,while they fail to match most cathode materials toward highvoltage magnesium batteries. Herein,reversible Mg plating/stripping is achieved in conventional carbonate electrolytes enabled by the cooperative solvation/surface engineering. Strongly electronegative Cl from the MgCl_(2) additive of electrolyte impairs the Mg…O = C interaction to reduce the Mg^(2+) desolvation barrier for accelerated redox kinetics,while the Mg^(2+)-conducting polymer coating on the Mg surface ensures the facile Mg^(2+) migration and the e ective isolation of electrolytes. As a result,reversible plating and stripping of Mg is demonstrated with a low overpotential of 0.7 V up to 2000 cycles. Moreover,benefitting from the wide electrochemical window of carbonate electrolytes,high-voltage(> 2.0 V) rechargeable magnesium batteries are achieved through assembling the electrode couple of Mg metal anode and Prussian blue-based cathodes. The present work provides a cooperative engineering strategy to promote the application of magnesium anode in carbonate electrolytes toward high energy rechargeable batteries.
基金the National Natural Science Foundation of China(No.32201491)Major projects of Natural Science Foundation of Jiangsu(No.18KJA220002)China Postdoctoral Science Foundation:Special Program(No.2017T100313).
文摘The search for wearable electronics has been attracted great efforts,there is an ever-growing demand for all-solid-state flexible energy storage devices.However,it is a challenge to obtain both positive and negative electrodes with excellent mechanical strength and match positive and negative charges to achieve high energy densities and operate voltages to satisfy practical application requirements.Here,flexible MXene(Ti_(3)C_(2)Tx)/cellulose nanofiber(CNF)composite film negative electrodes(MCNF)were fabricated with a vacuum filtration method,as well as positive electrodes(CP)by combining polyaniline(PANI)with carbon cloth(CC)using an in-situ polymerization method.Both positive and negative free-standing electrodes exhibited excellent electrochemical behavior and bendable/foldable flexibility.As a result,the all-pseudocapacitance asymmetric device of MCNF//CP assembled with charge-matched between anode and cathode achieves an extended voltage window of 1.5 V,high energy density of 30.6 Wh·kg^(−1)(1211 W·kg^(−1)),86%capacitance retention after 5000 cycles,the device maintains excellent bendability,simultaneously.This work will pave the way for the development of all-pseudocapacitive asymmetric supercapacitors(ASC)with simultaneously preeminent mechanical properties,high energy density,wide operating voltage window.
基金Major Science and Technology Project of Yunnan Province(202102AE090042)National Natural Science Foundation of China(21766016)+1 种基金the Science and Technology Talent and Platform Program of Yunnan Provincial Science and Technology Department(202005AF150037)the financial support of Taif University Researchers Supporting Project(TURSP-2020/27),Taif University,Taif,Saudi Arabia。
文摘The Ni-Nb_(2)O_(5)nanocatalysts have been prepared by the solgel method,and the catalytic hydrodeoxygenation(HDO)performance of anisole as model compound is studied.The results show that Nb exists as amorphous Nb_(2)O_(5)species,which can promote Ni dispersion.The addition of Nb_(2)O_(5)increases the acidity of the catalyst.However,when the content of niobium is high,there is an inactive Nb-Ni-O mixed phase.The size and morphology of Ni grains in catalysts are different due to the difference of Nb/Ni molar ratio.The Ni_(0.9)Nb_(0.1)sample has the largest surface area of 170.8 m^(2)·g^(-1)among the catalysts prepared in different Nb/Ni molar ratios,which is mainly composed of spherical nanoparticles and crack pores.The HDO of anisole follows the reaction route of the hydrogenation HYD route.The Ni_(0.9)Nb_(0.1)catalyst displayed a higher HDO performance for anisole than Ni catalyst.The selectivity to cyclohexane over the Ni_(0.9)Nb_(0.1)sample is about 10 times that of Ni catalyst at 220℃and 3 MPa H_(2).The selectivity of cyclohexane is increased with the increase of reaction temperature.The anisole is almost completely transformed into cyclohexane at 240℃,3 MPa H_(2)and 4 h.
基金Zhejiang Provincial Natural Science Foundation of China(LZ23B030003)the National Key R&D Program(2022YFB2502000)+1 种基金the National Key R&D Program(2022YFB2502000)the Fundamental Research Funds for the Central Universities(2021FZZX001-09)。
文摘Solid-state sodium metal batteries utilizing inorganic solid electrolytes(SEs)hold immense potentials such as intrinsical safety,high energy density,and environmental sustainability.However,the interfacial inhomogeneity/instability at the anode-SE interface usually triggers the penetration of sodium dendrites into the electrolyte,leading to short circuit and battery failure.Herein,confronting with the original nonuniform and high-resistance solid electrolyte interphase(SEI)at the Na-Na_(3)Zr_(2)Si_(2)PO_(12)interface,an oxygen-regulated SEI innovative approach is proposed to enhance the cycling stability of anode-SEs interface,through a spontaneous reaction between the metallic sodium(containing trace amounts of oxygen)and the Na_(3)Zr_(2)Si_(2)POi_(2)SE.The oxygen-regulated spontaneous SEI is thin,uniform,and kinetically stable to facilitate homogenous interfacial Na^+transportation,Benefitting from the optimized SEI,the assembled symmetric cell exhibits an ultra-stable sodium plating/stripping cycle for over 6600 h under a practical capacity of 3 mAh cm^(-2).Qua si-sol id-state batteries with Na_(3)V_(2)(PO_(4))_(3)cathode deliver excellent cyclability over 500 cycles at a rate of 0.5 C(1 C=117 mA cm^(-2))with a high capacity retention of95.4%.This oxygen-regulated SEI strategy may offer a potential avenue for the future development of high-energy-density solid-state metal batteries.
文摘Erratum to Nano Research 2023,16(7):10493–10499 https://doi.org/10.1007/s12274-023-5727-6 The article“Advancing pressure sensors performance through a flexible MXene embedded interlocking structure in a microlens array”,written by Tong Li,Zhenzong Xu,Ben Bin Xu,Zhanhu Guo,Yunhong Jiang,Xuehua Zhang,Maryam Bayati,Terence Xiaoteng Liu,and Yan-Hua Liu,was originally published electronically on the publisher’s internet portal on May 20,2023 without open access due to an unfortunate oversight during the conversion process.The publisher apologizes this mistake.The article is forthwith distributed under a Creative Commons Attribution 4.0 International License,which permits use,sharing,adaptation,distribution and reproduction in any medium or format,as long as you give appropriate credit to the original author(s)and the source,provide a link to the Creative Commons licence,and indicate if changes were made.
基金financially supported by the National Natural Science Foundation of China(No.22078077)the National Science Foundation of Guangdong Province(No.2021A1515010078)financial support of Taif University Researchers Supporting Project(No.TURSP-2020/14),Taif University,Taif,Saudi Arabia。
文摘Although many material designs or strategic methods have been proposed for treating oil spills and oily wastewater,the complex oily state,dealing with the harsh operating conditions of oil–water separation(such as the recovery of viscous spilled crude oil,bacteria-containing oily wastewater,and removal of spilled oil under fire),and the autorecycling of oil and absorption materials remain a great challenge.This work proposed an ingenious design strategy of“several birds with one stone”to prepare p H/thermoresponsive flame-retardant/photothermal bactericidal P-Fe_(3)O_(4)-polydopamine(PDA)@melamine–formaldehyde(MF)foams.This design makes the foams remarkably effective in the recovery of spilled viscous crude oil as well as in the separation of bacteria-containing oily emulsions,particularly for instant fire extinguishing by magnetically controlled oil absorption as well as for fire alarms.The photothermal effect and p H response induce a change in the surface wettability of the foams,facilitating excellent autoadsorption/desorption of the spilled oil.The photothermal bactericidal activity and fouling resistance of the foam are beneficial to the separation of bacteria-containing oily wastewater.Outstanding flame-retardant properties and maneuverable magnetic control enable the foam to rapidly recover the spilled oil in a large range of fires,extinguish fires instantly,and facilitate early fire warning.The proposed strategy is expected to inspire further research on treating oil spills under complex conditions.
基金This work was supported by the National Natural Science Foundation of China(No.61974100)the National Science Foundation of the Jiangsu Higher Education Institutions of China(No.20KJA480002)+2 种基金This project was also funded by the Collaborative Innovation Center of Suzhou Nano Science and Technology,and by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)X.H.Z.acknowledges the support from the NSERC-Alberta Innovated Advanced Program.B.B.X.and Y.H.J.are grateful for the support from the Engineering and Physical Sciences Research Council(EPSRC,UK)(Nos.EP/N007921 and EP/X02041X)Y.H.J.also acknowledges the support from the Leverhulme Trust(No.RPG-2022-177).
文摘Piezoresistive composite elastomers have shown great potentials for wearable and flexible electronic applications due to their high sensitivity,excellent frequency response,and easy signal detection.A composition membrane sensor with an interlocked structure has been developed and demonstrated outstanding pressure sensitivity,fast response time,and low temperature drift features.Compared with a flexible MXene-based flat sensor(Ti_(3)C_(2)),the interlocked sensor exhibits a significantly improved pressure sensitivity of two magnitudes higher(21.04 kPa^(-1)),a fast reaction speed of 31 ms,and an excellent cycle life of 5000 test runs.The viability of sensor in responding to various external stimuli with high deformation capacity has been confirmed by calculating the force distribution of a polydimethylsiloxane(PDMS)film model with a microlens structure using the solid mechanics module in COMSOL.Unlike conventional process,we utilized three-dimensional(3D)laser-direct writing lithography equipment to directly transform high-precision 3D data into a micro-nano structure morphology through variable exposure doses,which reduces the hot melting step.Moreover,the flexible pressure device is capable of detecting and distinguishing signals ranging from finger movements to human pulses,even for speech recognition.This simple,convenient,and large-format lithographic method offers new opportunities for developing novel human-computer interaction devices.
基金This work was supported by the National Natural Science Foundation of China(No.22078077).
文摘An active bacterial anti-adhesion strategy based on directional transportation of bacterial droplets driven by a triboelectric nanogenerator(TENG)has not been reported to date,although passive defense approaches can prevent bacterial adhesion by regulating superwetting surfaces combined with incorporated antibacterial substances.Here a triboelectric nanogenerator driving droplet system(TNDDS)was built to drive directional transportation of bacterial droplets to be eliminated,which comprises TENG with periodical frictional Kapton film and aluminum foils and a superhydrophobic driving platform(SDP)with paralleled driving electrodes.The current generated by the TENG triboelectricity is transmitted to the paralleled driving electrodes to form an electric field driving the directional transportation of charged droplets.The critical value of the driven droplet volume on SDP is closely related to the distributed electrodes’distance and width,and the driving distance of droplets is related to the number of electrodes.More crucially,TNDDS can actively drive the charged droplets of prepared triangular silver nanoprisms(Ag NPs)forward and back to mix with and remove a tiny bacterial droplet on an open SDP or in a tiny semi-enclosed channel.Bacteria could be killed by releasing Ag+and effectively removed by TNDDS by regulating the motion direction.Generally,this approach offers a promising application for removing bacteria from material surfaces driven by TENG and opens a new avenue for bacterial anti-adhesion.
基金financially supported by the National Natural Science Foundation of China(Nos.21571159 and U1704256)the Natural Science Foundation of Henan Province,China(No.212300410299)the Doctoral Research Fund of Zhengzhou University of Light Industry(No.2018BSJJ024).
文摘Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregations of metal and serious loss of nitrogen species constituting the M-N_(x) active sites are frequently observed in the commonly used pyrolysis procedure.Herein,single-atomic nickel(Ni)-based sheet-like electrocatalysts with abundant Ni-N_(4) active sites were created by using a novel ammonium chloride(NH_(4)Cl)-assited pyrolysis method.Spherical aberration correction electron microscopy and X-ray absorption fine structure analysis clearly revealed that Ni species are atomically dispersed and anchored by N in Ni-N_(4) structure.The addition of NH_(4)Cl optimized the mesopore size to 7-10 nm and increased the concentrations of pyridinic N(3.54 wt%)and Ni-N_(4)(3.33 wt%)species.The synergistic catalytic effect derived from Ni-N_(4) active sites and pyridinic N species achieved an outstanding CO_(2) RR performance,presenting a high CO Faradaic efficiency(FE_(CO))up to 98% and a large CO partial current density of 8.5 mA cm^(-2) at a low potential of-0.62 V vs.RHE.Particularly,the FE_(CO) maintains above 80% within a large potential range from -0.43 to -0.73 V vs.RHE.This work provides a practical and feasible approach to building highly active single-atomic catalysts for CO_(2) conversion systems.
基金financially supported by the National Natural Science Foundation of China(No.52207249)the research program of Top Talent Project of Yantai University(No.1115/2220001)+1 种基金the Yantai Basic Research Project(No.2022JCYJ04)the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing(No.AMGM2021F11).
文摘Three-dimensional holey nitrogen-doped carbon matrixes decorated with molybdenum dioxide(MoO_(2))nanoparticles have been successfully synthesized via a NaCl-assisted template strategy.The obtained MoO_(2)/C composites offered multi-advantages,including higher specific surface area,more active sites,more ions/electrons transmission channels,and shorter transmission path due to the synergistic effect of the uniformly distributed MoO_(2) nanoparticles and porous carbon structure.Especially,the oxygen vacancies were introduced into the prepared composites and enhanced the Li^(+)intercalation/deintercalation process during electrochemical cycling by the Coulomb force.The existence of the local built-in electric field was proved by experimental data,differential charge density distribution,and density of states calculation.The uniquely designed structure and introduced oxygen vacancy defects endowed the MoO_(2)/C composites with excellent electrochemical properties.In view of the synergistic effect of the uniquely designed morphology and introduced oxygen vacancy defects,the MoO_(2)/C composites exhibited superior electrochemical performance of a high capacity of 918.2 mAh g^(-1) at 0.1 A g^(-1) after 130 cycles,562.1 mAh g^(-1) at 1.0 A g^(-1) after 1000 cycles,and a capacity of 181.25 mAh g^(-1) even at 20.0 A g^(-1).This strategy highlights the path to promote the commercial application of MoO_(2)-based and other transition metal oxide electrodes for energy storage devices.
文摘A visible light-active photoelectrocatalyst,ZnFe-layered double oxide(LDO)/cobalt(II,III)oxide(Co_(3)O_(4))composites were obtained by calcining the Co loaded ZnFe-layered double hydroxide(LDH)prepared by a hydrothermal and microwave hydrothermal method.The morphological studies revealed that the ZnFe-LDO/Co_(3)O_(4) composites exhibited a flower-like structure comprising Co_(3)O_(4) nanowires and ZnFe-LDO nanosheets.Further,when the mass ratio of Co(NO_(3))_(2)·6H_(2)O/LDH was 1:1.8 and the calcination temperature was 550℃,the ZnFe-LDO/Co_(3)O_(4) composite exhibited 93.3%degradation efficiency for methylene blue(MB)at the applied voltage of 1.0 V under visible light after 3 h.Furthermore,the Mott-Schottky model experiments showed that the formation of a p-n heterojunction between ZnFe-LDO and Co_(3)O_(4) could effectively inhibit the recombination of electrons and holes in the photoelectrocatalytic process.Meanwhile,free radical scavenging experiments showed that the active radicals of⋅OH played an important role in the degradation of MB.Therefore,the photoelectrocatalytic effect of ZnFe-LDO/Co_(3)O_(4) provides a simple and effective strategy for the removal of organic pollutants.
基金financially supported by the National Natu-ral Science Foundation of China(No.52207249)the Natural Sci-ence Foundation of Shandong Province(No.ZR2022ME089)+2 种基金the research program of Top Talent Project of Yantai University(No.1115/2220001)the Yantai Basic Research Project(No.2022JCYJ04)the Science Fund of Shandong Laboratory of Advanced Ma-terials and Green Manufacturing(No.AMGM2021F11).The au-thors would like to thank the Deanship of Scientific Research at Umm Al-Qura University for supporting this work by Grant Code:22UQU4320141DSR72.
文摘The microscopic morphology of electromagnetic wave absorbers influences the multiple reflections of electromagnetic waves and impedance matching,determining the absorption properties.Herein,the urchin-shaped bimetallic nickel-cobalt oxide/carbon(NiCo_(2)O_(4)/C)composites are prepared via a hy-drothermal route,whose absorption properties are investigated by different morphologies regulated by changing calcination temperature.A minimum reflection loss(RL_(min))of-75.26 dB is achieved at a match-ing thickness of 1.5 mm,and the effective absorption bandwidth(EAB)of 8.96 GHz is achieved at 2 mm.Multi-advantages of the synthesized NiCo_(2)O_(4)/C composites contribute to satisfactory absorption proper-ties.First,the interweaving of the needle-like structures increases the opportunities for scattering and multiple reflections of incident electromagnetic waves,and builds up a conductive network to facilitate the enhancement of conductive losses.Second,the carbon component in the NiCo_(2)O_(4)/C composites en-hances the interfacial polarization and reduces the density of the absorber.Besides,generous oxygen va-cancy defects are introduced into the NiCo_(2)O_(4)/C composites,which induces defect polarization and dipole polarization.In summary,the ternary coordination of components,defects and morphology led to out-standing electromagnetic wave absorption,which lightened the path for improving the electromagnetic wave absorption property and enriching the family of NiCo_(2)O_(4) absorbers with excellent performance.
基金supported by the National Natural Science Foundation of China(51722105)National Key Research and Development Program(2016YFB0901600)+1 种基金Zhejiang Provincial Natural Science Foundation(LR18B030001)Ten Thousand Talent Program of Zhejiang Province。
文摘钠金属二次电池由于丰富的地壳钠资源储备、金属钠负极高的理论容量等优势受到广泛的关注,已成为后锂离子电池时代的重要技术之一.然而,金属钠负极在充放电循环过程中存在枝晶生长、体积变化等严重问题,严重制约了钠金属电池技术的发展.基于以上问题,本文提出在金属钠负极体相内引入NaSICON型固态钠离子导体,构建具有离子/电子混合传输能力的金属钠基复合负极.一方面,通过钠离子传导相和金属电子导电相之间的紧密接触构建了快速的离子/电子通道和丰富的电化学反应界面,有利于实现稳定可逆的钠沉积/剥离;另一方面,紧密堆积的复合结构保护了金属钠免受液态有机电解质的腐蚀和副反应的发生.得益于上述独特的结构设计,复合负极表现出高度可逆和稳定的钠的沉积/剥离行为.在碳酸酯类电解液中,对称电池在1 m A cm^(-2)的电流密度、5 m Ah cm^(-2)的高充放电容量下实现了高于700 h的超长寿命,以及高达8 m A cm^(-2)电流密度的出色倍率性能.在搭配Na_(3)V_(2)(PO_(4))_(3)/C正极时,全电池展现出优异的循环稳定性(容量衰减单次平均仅0.012%)以及低的充放电极化.
基金the National Natural Science Foundation of China(Nos.51803191 and 12072325)the National Key R&D Program of China(No.2019YFA0706802)+2 种基金the 111 project(No.D18023)Key Scientific and Technological Project of Henan Province(No.202102210038)the Deanship of Scientific Research at Umm Al-Qura University(No.22UQU4331100DSR01).
文摘Rational construction of hierarchical multi-component materials with abundant heterostructure is evolving as a promising strategy to achieve excellent metal-organic frameworks(MOFs)based electromagnetic wave(EMW)absorbers.Herein,hierarchical heterostructure WS_(2)/CoS_(2)@carbonized cotton fiber(CCF)was fabricated using the ZIF-67 MOFs nanosheets anchored cotton fiber(ZIF-67@CF)as a precursor through the tungsten etching,sulfurization,and carbonization process.Apart from the synergetic effect of dielectric-magnetic dual-loss mechanism,the hierarchical heterostructure and multicomponent of WS_(2)/CoS_(2)@CCF also display improved impedance matching.Furthermore,numerous W-S-Co bands and heterojunction interfaces of heterogeneous WS_(2)/CoS_(2)are beneficial to promoting additional interfacial/dipole polarization loss and conductive loss,thereby enhancing the EMW attenuation performance.Based on the percolation theory,a good balance between impedance matching and EMW absorption capacity was achieved for the WS_(2)/CoS_(2)@CCF/paraffin composite with 20 wt.%filler loading,exhibiting strong EMW absorption capability with a minimum reflection loss(RLmin)value of−51.26 dB at 17.36 GHz with 2 mm thickness and a maximum effective absorption bandwidth(EABmax)as wide as 6.72 GHz.Our research will provide new guidance for designing high-efficient MOFs derived EMW absorbers.
基金This work was financially supported by the National Key Re-search and Development Program of China(No.2022YFB4003500)the National Natural Science Foundation of China(No.T2241003)+2 种基金the Key R&D Project of Hubei Province,China(No.2021AAA006)the National Natural Science Foundation of China(No.52202009)The researchers would like to acknowledge Deanship of Scientific Research,Taif University for funding this work.HA is thankful to the Deanship of Scientific Research at Najran University for funding this work,under the Research Groups Funding program grant code(NU/RG/SERC/12/10).
文摘Structural optimization of ionomers is an effective strategy for achieving high-performance proton ex-change membranes(PEMs)under low relative humidity(RH)conditions.In this study,sulfonimide group and trifluoromethanesulfonate acid(TFSA)ionic liquids were introduced to the perfluorosulfonic acid(PFSA)side chain,resulting in polymer membranes with varying chain lengths(i.e.,PFC_(2)-TF-SI,PFC_(4)-TF-SI,and PFC_(5)-TF-SI).This dual proton-conducting structure extended the length of the hydrophilic side chain and enhanced the hydrophobic-hydrophilic phase separation,aiding in the formation of proton transport channels.Notably,the proton conductivity of PFC_(5)-TF-SI and PFC_(2)-TF-SI membranes reached 7.1 and 10.6 mS/cm at 30%RH and 80°C,respectively,which were approximately 29.1%and 92.7%higher than that of the pristine PFC_(5)-SA membrane(5.5 mS/cm).Furthermore,the maximum power density of the PFC_(5)-TF-SI and PFC_(2)-TF-SI membranes from the built single fuel cell achieved 649 and 763 mW/cm 2 at 30%RH and 80°C,respectively,which were higher than that of the pristine PFC_(5)-SA membrane(567 mW/cm 2)by about 14.5%and 34.6%,respectively.Thus,this study provides a strategy for PEM design under low RH conditions.
基金supported by the National Natural Science Foundation of China(Nos.12202410 and 51906238)the China Postdoctoral Science Foundation(No.2023M733935)+4 种基金the Natural Science Foundation of Hunan Province(No.2023JJ40726)the Research Project Supported by the Shanxi Scholarship Council of China(No.2022-139)the Natural Science Foundation of Shanxi Province(Nos.20210302123017 and 2023recipient Changcheng Liu)the Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(No.20220012)the Changsha Municipal Natural Science Foundation(No.kq2208277).
文摘In order to maintain the optimal operating temperature of the battery surface and meet the demand for thermal storage technology,battery thermal management system based on phase change materials has attracted increasing interest.In this work,a kind of core-shell structured microcapsule was synthesized by an in-situ polymerization,where paraffin was used as the core,while methanol was applied to mod-ify the melamine-formaldehyde shell to reduce toxicity and improve thermal stability.Moreover,three different types of heat conductive fillers with the same content of 10 wt.%,i.e.,nano-Al_(2)O_(3),nano-ZnO and carbon nanotubes were added,generating composites.The microcapsules were uniform,and were not affected by the thermal fillers,which were evenly dispersed around.The composite sample with carbon nanotubes(10 wt.%)showed the highest thermal conductivity of 0.50 W/(m K)and latent heat of 139.64 J/g.Furthermore,according to the leakage testing and battery charge/discharge experiments,compared with Al_(2)O_(3)and ZnO,the addition of carbon nanotubes remarkably enhances the heat storage ability as latent heat from 126.98 J/g for the prepared sample with Al_(2)O_(3)and 125.86 J/g for the one with ZnO,then to 139.64 J/g,as well as dissipation performance as a cooling effect by decreasing the sur-face temperature of battery from 2%to 12%of microcapsule,composite sample with carbon nanotubes presents a broad application prospect in battery thermal management system and energy storage field.
