查看更多>>摘要：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-Al2O3,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 Al2O3 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 Al2O3 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.
查看更多>>摘要：Dendrites growth,chemical corrosion,and hydrogen evolution reaction(HER)on zinc anodes are the main barriers for the development of aqueous zinc-ion batteries(AZIBs).Constructing interfacial protec-tive layer is an effective way to alleviate the side reactions on the anodes.Herein,Cu/Ti3C2Cl2 MXene(CMX)with high zincophilic and hydrophobic property is prepared by the lewis molten salts etching method,and the CMX interface protection layer is constructed by a simple spin coating.The CMX coat-ing layer can provide abundant nucleation sites and uniformize the charge distribution through the zin-cophilic Ti3C2Cl2 MXene matrix,leading to homogenous Zn deposition.In addition,the hydrophobic coat-ing contained anti-corrosive Cu nanoparticles can prevent the Zn anode from the electrolyte,beneficial for suppressing the chemical corrosion and HER.Therefore,the stable and reversible Zn plating/stripping is achieved for the Zn anode coated by the CMX,which exhibits the lifespan of over 1400 h at 0.5 mA cm-2,and even can steadily run for 700 h with 65 mV at 10 mA cm-2.Furthermore,CMX@Zn shows a high coulombic efficiency of over 100％for 3800 cycles,which indicates that the CMX@Zn electrode has excellent stability and reversibility of Zn stripping/plating.The full batteries assembled with ZnCoMnO/C(ZCM)cathodes also exhibits higher capacity(450.6 mAh g-1 at 0.1 A g-1)and cycle stability(capacity retention of 70％after 1500 cycles).This work enhanced the lifespan of AZIBs and broaden the research of multifunctional coating layer to other secondary batteries based on metal anodes.
查看更多>>摘要：Effective bulk phase and surface charge separation is critical for charge utilization during the photo-catalytic energy conversion process.In this work,the ternary Ni2P-NiS/twinned Mn0.5Cd0.5S(T-MCS)nanohybrids were successfully constructed via combining Ni2P-NiS with T-MCS solid solution for visible light photocatalytic H2 evolution.T-MCS is composed of zinc blende Mn0.5Cd0.5S(ZB-MCS)and wurtzite Mn0.5Cd0.5S(WZ-MCS)and those two alternatively arranged crystal phases endow T-MCS with excellent bulk phase charge separation performance for the slight energy level difference between ZB-MCS and WZ-MCS.S-scheme carriers transfer route between NiS and T-MCS can accelerate the interfacial charge separation and retain the active electrons and holes,meanwhile,co-catalyst Ni2P as electron receiver and proton reduction center can further optimize the H2 evolution reaction kinetics based on the surface Schottky barrier effect.The above-formed homo-heterojunctions can establish multiple charge transfer channels in the bulk phase of T-MCS and interface of T-MCS and Ni2P-NiS.Under the synergistic effect of twinned homojunction,S-scheme heterojunction,and Schottky barrier,the ternary Ni2P-NiS/T-MCS com-posite manifested an H2 production rate of 122.5 mmol h-1 g-1,which was 1.33,1.24,and 2.58 times higher than those of the NiS/T-MCS(92.4 mmol h-1 g-1),Ni2P/T-MCS(98.4 mmol h-1 g-1),and T-MCS(47.5 mmol h-1 g-1),respectively.This work demonstrates a promising strategy to develop efficient sul-fides photocatalyst toward targeted solar-driven H2 evolution through homo-heterojunction engineering.
查看更多>>摘要：In this work,we proposed a novel Cu/θ dual nanoparticles strategy to tailor the austenite characteris-tics of a medium Mn steel via a tempering-annealing process to optimize the mechanical properties.We explored the effects of Cu-rich particles and cementite precipitated in the tempering process on the austenite reversion during the subsequent annealing process.Both experiments and numerical simula-tions verified that the austenite inherited from cementite had a finer size and a higher Mn enrichment compared with the austenite originating from the tempered martensite matrix.In addition,quantitative evaluations revealed that the pinning effect exerted by the Cu-rich particles could significantly hinder the α/γ interface migration and the recrystallized grain growth,thereby further refining the final mi-crostructure.With contributions from the effects of dual nanoprecipitates on the austenite reversion,the heterogeneous austenite grains inherited from varying nucleation sites ensured the sustained and gradual deformation-induced martensite and twinning formation.Therefore,the Cu-added steels subjected to a tempering-annealing process achieved synergetic enhancement of the tensile strength from 1055 MPa to 1250 MPa and elongation from 33％to 45％.This strategy may provide new guidance for the development and alloy design of high-performance medium Mn steels.
查看更多>>摘要：Due to the thermal depolarization effect,adequate piezoelectric performance with high operating tem-perature is regarded to be challenging to accomplish concurrently in piezoceramics for applications in specific piezoelectric devices.In this work,we synthesized(0.8-x)BiFeO3-xPbTiO3-0.2Ba(Zr025Ti0.75)O3(abbreviated as BFO-xPT-BZT)ternary solid solutions with 0.15 ≤ x ≤ 0.30 by conventional solid-state reaction method.The MPB composition with a coexisting state of rhombohedral-tetragonal phases ex-hibits enhanced electromechanical properties,including Curie temperature of 380 ℃,large-signal equiv-alent piezoelectric coefficient d*33 of 395 pm V-1,small-signal piezoelectric coefficient d33 of 302 pC N-1,and electromechanical coupling factor kp of 50.2％,which is comparable to commercial PZT-5A ceramics,indicating potential in high-temperature applications.Furthermore,in-situ X-ray diffraction(XRD)and piezoelectric force microscopic(PFM)techniques demonstrate that multiphase coexistence and complex nanodomains promote piezoelectric response via synergism.The x=0.24 composition exhibits the high-est in-situ d33 of 577 pC N-1 and good temperature stability in 30-280 ℃,indicating that BZT-modified BFO-PT ceramics are promising candidates for high-temperature piezoelectric devices.
查看更多>>摘要：Recently,S-scheme heterojunctions have gained considerable attention in the field of photocatalytic en-vironmental remediation as their potential to achieve efficient spatial charge separation coupled with strong redox capacities.Herein,this review provides an overview of the current state-of-the-art in the development of S-scheme-based photocatalysts for the purification of environmental contaminants.The review first covers the fundamentals of heterogeneous photocatalysis for environmental purification.Sub-sequently,an introduction to the background,mechanism,design principles,and characterization tech-niques of S-scheme heterojunctions is presented.Then,the review presents a comparison and summary of using various S-scheme photocatalysts for the removal of several target pollutants,such as bacteria,heavy metals,nitrogen oxides,antibiotics,and phenols.Additionally,the modification strategies of S-scheme heterojunction photocatalysts are also provided.Finally,a brief discussion of the challenges and prospects associated with S-scheme photocatalytic systems is demonstrated.
查看更多>>摘要：MXene-contained paper is a good choice to design ultrathin and flexible electromagnetic interference(EMI)shielding materials.However,the deficiencies in strength and stability of MXene-contained paper impede its practical applications.Herein,a composite paper was proposed to address the problems,in which a filter paper was modified with a three-layer structured surface via a facile layer-by-layer coat-ing procedure.Specifically,the TEMPO-oxidized cellulose nanofibers(TOCN)/cationic starch(CS)/MXene gel layer and TOCN/MXene nacre structure layer ensured the good EMI shielding and mechanical per-formances of the composite paper,while the uppermost TOCN/CS hydrogel film layer mainly protected MXene.The composite paper achieved an EMI SE of 40.3 dB at a thickness of merely 0.1894 mm(SE/t value of ca.212.8 dB mm-1,SSE/t values of ca.13216 dB cm2 g-1)and the total MXene dosage was 20 g m-2.Its tensile strength could be up to 11.7 MPa while the original filter paper was 6.4 MPa.Four pieces of this composite papers could be easily packed together to attain an EMI SE of nearly 70 dB.Importantly,the hydrogel film layer efficiently protected the MXene and maintained the EMI shielding performance of the composite paper when immersed in different liquids including water,HC1(1 M)and ethanol,due to the dense and compact structure of hydrogel film layer.This work provides a practical way to develop ultrathin,flexible and durable EMI shielding materials.
查看更多>>摘要：Bacterial biofilms,especially those caused by multidrug-resistant bacteria,have emerged as one of the greatest dangers to global public health.The acceleration of antimicrobial resistance to conventional an-tibiotics and the severe lack of new drugs necessitates the development of novel agents for biofilm erad-ication.Photodynamic therapy(PDT)is a promising non-antibiotic method for treating bacterial infec-tions.However,its application in biofilm eradication is hampered by the hypoxic microenvironment of biofilms and the physical protection of extracellular polymeric substances.In this study,we develop a composite nanoplatform with oxygen(O2)self-supplying and heat-sensitizing capabilities to improve the PDT efficacy against biofilms.CaO2/ICG@PDA nanoparticles(CIP NPs)are fabricated by combining calcium peroxide(CaO2)with the photosensitizer indocyanine green(ICG)via electrostatic interactions,followed by coating with polydopamine(PDA).The CIP NPs can gradually generate O2 in response to the acidic microenvironment of the biofilm,thereby alleviating its hypoxic state.Under near-infrared(NIR)irradia-tion,the nanoplatform converts O2 into a significant amount of singlet oxygen(1O2)and heat to eradicate biofilm.The generated heat enhances the release of O2,accelerates the generation of 1O2 in PDT,increases cell membrane permeability,and increases bacterial sensitivity to 1O2.This nanoplatform significantly improves the efficacy of PDT in eradicating biofilm-dwelling bacteria without fostering drug resistance.Experiments on biofilm eradication demonstrate that this nanoplatform can eradicate over 99.9999％of methicillin-resistant Staphylococcus aureus(MRSA)biofilms under 5-min NIR irradiation.Notably,these integrated advantages enable the system to promote the healing of MRSA biofilm-infected wounds with negligible toxicity in vivo,indicating great promise for overcoming the obstacles associated with bacterial biofilm eradication.
Dehua LiuDongjiang WuYunsong Wang Zhuo ChenChangrong Ge...
220-234页
查看更多>>摘要：Recently,rapid and cost-effective additive manufacturing solutions for lightweight aluminum alloys with excellent high-temperature mechanical properties have been increasingly in demand.In this study,we combined laser-arc hybrid additive manufacturing with solution and artificial aging treatments to achieve Al-Zn-Mg-Cu alloy with favorable high-temperature strength via microstructure control.Hydrogen pores became the major defect in the as-deposited and heat-treated specimens.The continuous distribution of eutectics with hard-brittle characteristics at the grain boundaries was destructed following heat treat-ment.High-density η'precipitates were uniformly dispersed in the heat-treated Al-Zn-Mg-Cu alloy,whereas appeared coarsened and dissolved at 473 K,owing to the rapid diffusion of Zn and Mg.The average 0.2％yield strength(318±16 MPa)and ultimate tensile strength(362±20 MPa)at 473 K af-ter heat treatment were enhanced by approximately 58％and 51％,respectively,compared to those of the as-deposited specimen.In addition,the η'precipitates contributed to lattice distortions and strain fields,which prevented dislocation motion and increased slip deformation resistance at high temper-atures.The as-deposited specimen exhibited intergranular fracture at 473 K,with cracks preferring to propagate along the aggregated eutectics.However,crack propagation proceeded in the sections with more pores in the heat-treated specimen.Our approach may provide a valid option for achieving alu-minum alloys with excellent high-temperature mechanical properties.
查看更多>>摘要：In this study,a two-step method was used to synthesize highly luminescent AgGaS/ZnS/ZnS quantum dots(QDs).In the first step,an inner ZnS shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AgGaS core and the outer ZnS shell,thereby facilitating the formation of a thick outer shell.After the two-step shelling process,the synthesized AgGaS/ZnS/ZnS QDs showed an excellent photoluminescence quantum yield(PLQY)of 96.4％with a peak wavelength of 508 nm,repre-senting the highest PLQY reported thus far for AgGaS QDs.Furthermore,the effect of halogen ions in Zn precursors on the shelling process was investigated.It was proposed that the capacity of halogen ions to coordinate with the QDs influenced the balance between Zn cation diffusion and ZnS shelling reaction.Specifically,the ZnS shelling reaction was dominant when ZnCl2 was employed,while Zn cation diffusion was the dominant process under the I--rich environment.This work provides insights into the interfacial restructuring during the ZnS shelling and offers a clear map for the tailored synthesis of core/shell QDs.
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