查看更多>>摘要：One key step for advancing the widespread practical application of rechargeable metal-air batteries and water electrolysis fundamentally relies on the development of cost-effective multifunctional electrocata-lysts toward oxygen and hydrogen-involving reactions.The present work initiates a tofu-derived one-pot strategy for green,facile,and mass production of highly active and stable catalyst toward oxygen reduc-tion/evolution and hydrogen evolution reactions,through the preparation of Fe/Co cross-linked tofu gel and the subsequent pyrolysis.Despite the free use of additional N/P precursors or pore-forming agents,the as-prepared materials comprise highly dispersive FeCo-rich phosphides nanoparticles and porous N,P co-doped carbon network inherited from the tofu skeleton.The resultant catalysts exhibit remarkably enhanced trifunctional activities as compared to the Fe2P and Co2P counterparts,along with better long-term stabilities than the benchmark RuO2 and Pt/C catalysts.Accordingly,the as-assembled Zn-air battery delivers a large power density(174 mW cm-2)with excellent cycle stability(the gap of charge/discharge voltage@10 mA cm-2 increases by 0.01 V after 720 h of operation,vs.0.16 V of Pt/C-RuO2 based battery after 378 h).Furthermore,the as-constructed alkaline electrolyzer just requires a small voltage of 1.55 V@10 mA cm-2,which outperforms nearly all of those of biomass-derived electrocatalysts ever reported,and that of noble metal catalysts-based electrolyzers(1.72 V@10 mA cm-2 for Pt/C-RuO2),underscoring their bright future toward commercial applications in green energy conversion devices.
查看更多>>摘要：The development of multifunctional textiles is an effective strategy to improve the quality of human life.Normal single-mode heaters and strain sensors have been developed,but their low integration leads to multiple devices being installed on the garment,which greatly increases the weight of the garment and thus reduces its wearability.Here,bio-enzymatic polymerization and a simple shaking deposition method were used to prepare poly(3,4-ethylenedioxythiophene)(PEDOT)and copper(Ⅱ)sulfide(CuS)onto the surface of the elastic nylon fabrics,which endowed the fabrics with excellent dual-mode heating properties and sensitive sensing properties,and used to develop highly integrated multifunctional and smart mountaineering clothing.In electro-driven heating mode,low-voltage(6 V)and high-voltage(12 V)heating can be used for joint heat therapy and active rapid deicing,respectively.In photo-driven heating mode,low intensity(0.3 sun)and high intensity(1.5 sun)heating can be used for joint heat therapy and rapid antibacterial,respectively.In addition,the fabric has the ability of dual-mode synergistic heating,and the surface temperature of the fabric can exhibit an ultra-high temperature of 137.9 ℃ under the external stimulation of 0.3 sun and 12 V.The fabric will greatly enhance the deicing and antibacterial efficiencies under the synergistic effect.This work provides a facile strategy for the fabrication of flexible and highly integrated multifunctional electronic devices,and therefore has great potential for the design and development of all-in-one multifunctional electronic devices such as personal thermal management,soft robotics,and human-computer interaction.
查看更多>>摘要：The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteristics.To address the incompressibility of the original PEDOT:PSS aerogel without compromis-ing its high conductivity,a stable interpenetrating polymer network(IPN)was self-assembled by guiding the molecular motion within PEDOT:PSS and introducing multi-walled carbon nanotubes(MWCNTs).By combining critical surface removal,directional freeze-drying,and polydimethylsiloxane(PDMS)reinforce-ment processes,a hydrophobic PDMS@MWCNTs/PP aerogel with a highly oriented porous structure and high strength was prepared.Under the synergistic effect of MWCNTs/PEDOT:PSS electroactive scaffold,the composite aerogel exhibited a high sensitivity of up to 16.603 kPa-1 at 0-2 kPa,a fast response time of 74 ms,and excellent repeatability.Moreover,the sensor possessed hydrophobicity with a good water contact angle of 137° The sensor could serve as a wearable electronic monitoring device to achieve ac-curate and sensitive detection of human motion including large-scale human activities and tiny muscle movements.Therefore,our findings provide a new direction to fabricate high-performance piezoresistive sensors based on three-dimensional(3D)conductive polymer active scaffolds,demonstrating their great potential for flexible electronics,human-computer interaction,and a wide range of applications under special working conditions.
查看更多>>摘要：Plasma spray physical vapor deposition(PS-PVD)(Gd0.9Yb0.1)2Zr2O7(GYbZ)thermal barrier coatings(TBCs)exhibited better silicate-phobicity than coatings produced by electron beam physical vapor depo-sition.In combination with PS-PVD and ultrafast laser direct writing technology,biomimetic structured GYbZ TBCs,with a triple-scale micro/nano surface microstructure,were obtained.Laser ablating on the PS-PVD GYbZ coatingenhanced the surface roughness,improving its wear resistance without increasing the surface hardness.Furthermore,during the laser ablation processing,numerous nanoparticles were deposited in-situ in the gaps between columns of the coating,reducing the coating Young's modulus.The simulated temperature field and heat flux field demonstrated that the presence of numerous interfaces between small columns of the PS-PVD coatings is beneficial to thermal insulation.However,laser ablation decreased the coating thickness,reducing the thermal insulation by around 20％-30％as compared to its PS-PVD counterpart,suggesting that a moderate increase in the coating thickness should be considered when designing an efficient TBC system.
查看更多>>摘要：The application of amorphous high entropy ceramics as wear-resistant materials is limited due to their inherent brittleness at room temperature and strain softening during deformation.In order to overcome this limitation,we constructed amorphous/amorphous(AlCrFeNi)N/TiN nanolaminates with varying mod-ulation period thickness by introducing a second amorphous phase through reactive radio frequency(RF)magnetron sputtering,along with corresponding monolithic amorphous films.Microstructure,mechanical properties,and tribological behaviors of the films were characterized wear in detail.Fretting wear results show that the nanolaminates with an average modulation period of 6 nm exhibited a wear rate of 2.8 times lower than that of the(AlCrFeNi)N film and 8.4 times lower than that of the TiN film.Further anal-ysis usingFIB-TEM revealed that the enhanced wear resistance of(AlCrFeNi)N/TiN nanolaminates was at-tributed to the high-density heterointerfaces.These interfaces inhibited the initiation and propagation of mature shear bands and acted as barriers to stress distribution.Additionally,the oxide composite layer at the interface demonstrated a synergistic effect through a mechanically induced tribo-chemical reaction,resulting in slight plastic deformation.For the amorphous(AlCrFeNi)N film,moderate wear resistance was achieved through the formation of transfer layer at the interface.For the amorphous TiN film,the dimensional stability of the film deteriorates due to the significant strain softening that occurs during deformation.This study deepens our understanding of the friction mechanisms involved in amorphous high entropy ceramics,offering valuable insights for the design of high damage-resistant materials.
查看更多>>摘要：The Fe-Pt based intermetallic compounds exhibit good chemical stability and unique magnetic proper-ties,where Ni is an important additional element to optimize the magnetic properties or obtain the outstanding catalytic performances of the Fe-Pt based alloys.Knowledge of how Ni addition affects the order-disorder transitions of the Fe-Pt intermetallics is thus necessary;however,the related information is limited.Therefore,in this work,the phase diagrams of the Fe-Ni-Pt system were experimentally in-vestigated,and as a result,the isothermal sections of the Fe-Ni-Pt system at 600 and 900 ℃,as well as the vertical sections of Fe80Ni20-Pt80Ni20 and Fes0Pts0-Nis0Pts0 were constructed.Based on these re-sults,the influences of Ni addition on the crystal stabilities and phase transformations of the ordered Fe-Pt intermetallics have been well described.The results show that the L10-FePt and L10-NiPt phases form a ternary continuous solid solution of L10-(Fe,Ni)Pt,whereas Ni can dissolve in the L12-Fe3Pt and L12-FePt3 phases as high as 57.0 at.％and 26.0 at.％at 600 ℃,respectively.The selective occupancy of Ni atoms has been predicted,which should depend on the alloy composition.For both the L10-(Fe,Ni)Pt and L12-FePt3 phases,when Pt contents are less than their stoichiometric values,Ni atoms will preferentially occupy the Pt sublattice,forming as many nearest-neighbor Fe-Pt bonds as possible.All these results can correlate the alloy compositions,annealing temperatures and crystal structures to both magnetic and catalytic properties,thus providing a basis for optimizing the Fe-Ni-Pt alloys towards enhanced magnetic or catalytic performances.
查看更多>>摘要：Metal-organic framework[MOF,i.e.,NH2-MIL-53(Al)]modified TiO2(NMT)composite photoanodes were successfully prepared by hydrothermal synthesis and were used for the photoelectrochemical cathodic protection(PECCP)of nickel-plated magnesium alloy(Mg/Ni).Results showed that the synthesis tem-perature significantly impacted the morphology and PECCP performance of the NMT photoanodes.The NMT@150 photoanode prepared at a reaction temperature of 150 ℃ exhibited the best PECCP perfor-mance and produced.a current density of 1980 μA cm-2 under visible light irradiation,which was 19.8 times higher than that of a single TiO2 photoanode.The composite photoanode could polarize the open circuit potential of the coupled Mg/Ni electrode to-876 mV and remain relatively stable within 35 h.XPS and EPR tests showed that a Z-scheme heterojunction was formed between the NH2-MIL-53(Al)and TiO2 nanotubes,allowing the photogenerated electrons to accumulate mainly on the conduction band of NH2-MIL-53(Al).The heterojunction greatly promoted the separation and transfer of photogenerated electron-hole in the NMT composite photoanode,significantly enhancing the PECCP performance for Mg/Ni.
查看更多>>摘要：Biodegradable magnesium(Mg)alloys exhibit excellent biocompatibility,adequate mechanical properties,and osteogenic effect.They can contribute to complete recovery of damaged tissues without concerns about a second surgery and have achieved clinical applications in orthopedic and cardiovascular fields.Porous scaffolds can provide functions such as bone integration and adjustable mechanical properties,thus widely used for bone repair.Additive manufacturing(AM)offers the advantages of design freedom and high precision,enabling the reliable production of porous scaffolds with customized structures.The combination of biodegradable Mg alloys,porous scaffolds,and AM processes has created tremendous opportunities for the precision treatment of bone defects.This article reviews the current development in the additive manufacturing process and design of Mg alloy biodegradable orthopedic implants,fo-cusing on chemical compositions,structural design,surface treatment,and their effects on mechanical properties,degradation behavior,and biocompatibility.Finally,the future perspective of porous Mg alloy biodegradable orthopedic implants is proposed.
查看更多>>摘要：With the continuous advancement of industrialization,sodium-ion batteries(SIBs)need to operate in various challenging circumstances,particularly in extremely cold conditions.However,at ultra-low tem-peratures,the reduced ionic conductivity and sluggish Na+migration of commonly carbonate-based elec-trolytes will inevitably lead to a sharp decrease in the capacity of SIBs.Herein,we design a carboxylate ester-based electrolyte with excellentultra-low temperature performance by straightforward cosolvent strategy.Due to the low viscosity,melting point,and sufficient ionic conductivity of the designed elec-trolyte,the resulting Na‖Na3V2(PO4)2O2F can achieve the capacity retention of 96％(100 cycles at 0.1 C)at-40 ℃ and can also operate stably even at-50 ℃.Besides,galvanostatic intermittent titration tech-nique(GITT),ex-situ X-ray photoelectron spectroscopy(XPS),and high-resolution transmission electron microscopy(TEM)tests are employed to analyze and confirm that the carboxylate ester-based electrolyte promotes robust and uniform cathode/electrolyte interface layer formation and accelerates ion diffusion kinetics,which collectively facilitates the better low-temperature performance.In addition,the assembled hard carbon‖NVPOF full cells further prove the practicability of the carboxylate ester-based electrolyte at low-temperature,which delivers high discharge capacity of 108.4 and 73.0 mAh g-1 at-25 and-40 ℃.This work affords a new avenue for designing advanced low-temperature electrolytes for SIBs.
查看更多>>摘要：Polymer-derived ceramics(PDCs)method opens up new possibilities for the preparation of novel multi-phase ceramic nanocomposites owing to the molecular design of the precursors at the nanoscale level.In the current work,ZrC coatings incorporated with polymer-derived ceramic microspheres(CMS),SiH-fOC_CMS,were deposited to enhance the ablation resistance by supersonic atmosphere plasma spraying.Upon 10.0 MW·m-2 plasma ablation at above 3000 ℃,the linear ablation rate of ZrC-SiHfOC_CMS coat-ing was reduced to 0.20 μm·s-1,62％lower than that of the pristine ZrC coating.The improvement was ascribed to the presentence of viscous SiO2/HfO2 molten mixed phase,rather than HfSiO4,which can ef-fectively seal pinholes and cracks.Moreover,the in-situ generated crystalline SiO2 had a lower oxygen diffusion rate than amorphous SiO2,meanwhile,m-HfO2 could improve the stability of SiO2 glassy film,thus further enhancing the ablation resistance.
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