查看更多>>摘要：Electrocatalytic CO2 reduction reaction(eCO2RR)presents a promising approach for harnessing renew-able energy and converting greenhouse gas(CO2)into high value-added CO products.N-doped single atom(SA)and atomic-level metal nanocluster(MN)tandem catalysts with rich defects for eCO2RR are reported,which achieved a maximum CO Faraday efficiency(FEco)of 97.7％(-0.7 V vs.RHE)in the H-type cell and maintained over 95％FEco at potentials from-0.18 to-0.73 V vs.RHE in the flow cell.Furthermore,the catalyst in the flow cell demonstrated a remarkably low onset potential of-0.14 V vs.RHE and the current density was approximately three times that of the H-type cell.Interestingly,XPS analysis indicates that carbon substrates containing defects have more pyridine-N content.DFT calcula-tions and in-situ attenuated total reflection Fourier transform infrared support this finding by showing that the Ni-(N-C2)3 active sites with defect favors preferentially convert CO2-to-CO.
查看更多>>摘要：Cell-to-cell variations(CtCV)compromise the electrochemical performance of battery packs,yet the evo-lutional mechanism and quantitative impacts of CtCV on the pack's fast-charging performance remain unexplored.This knowledge gap is vital for the proliferation of electric vehicles.This study underlies the relationship between CtCV and charging performance by assessing the pack's charge speed,final elec-tric quantity,and temperature consistency.Cell variations and pack status are depicted using 2D param-eter diagrams,and an mPnS configured pack model is built upon a decomposed electrode cell model.Variations in three single electric parameters,i.e.,capacity(Q),electric quantity(E),and internal resis-tance(R),and their dual interactions,i.e.,E-Q and R-Q,are analyzed carefully.The results indicate that Q variations predominantly affect the final electric quantity of the pack,while R variations impact the charge speed most.With incremental variances in cell parameters,the pack's fast-charging capability first declines linearly and then deteriorates sharply as variations intensify.This research elucidates the correlations between pack charging capabilities and cell variations,providing essential insights for opti-mizing cell sorting and assembly,battery management design,and charging protocol development for battery packs.
查看更多>>摘要：Electrocatalysis plays a crucial role in the field of clean energy conversion and provides essential support for the development of eco-friendly technology.There is a pressing need for electrocatalysts in renewable energy systems that exhibit exceptional activity,selectivity,stability,and economic viability.The utiliza-tion of metal oxides as electrocatalysts for the process of water splitting has made substantial progress in both theoretical and practical aspects and has emerged as a widely explored field of research.Tungsten oxides(WOx)have attracted much attention and are regarded as a highly promising electrocatalytic material due to their exceptional electrocatalytic activity,cost-effectiveness,and ability to withstand extreme conditions.This review introduces the fundamental mechanism of WOx-based electrocatalysts for the hydrogen evolution reaction and the oxygen evolution reaction,providing a comprehensive over-view of recent research advancements in their modification.Factors contributing to the catalytic activity and stability of WOx are explored,highlighting their potential for industrial applications.The aim herein is to provide guidelines for the design and fabrication of WOx-based electrocatalysts,thereby facilitating further research on their mechanistic properties and stability improvements in water splitting.
查看更多>>摘要：The electrocatalytic nitrate reduction reaction(NO3RR)powered by renewable energy offers a promising approach for simultaneously reutilization of nitrate and synthesizing high-value products.Nevertheless,theoretical understanding of reaction mechanism was relative illusive,which is indispensable to ration-ally design of efficient catalysts.Besides,tuning the reaction microenvironment along with the scale-up device development is essential to promote the industrial deployment of electrocatalytic nitrate conver-sion,while relative research was overlooked.In this regard,recent advances in ammonia synthesis are firstly summarized,including the identification of active sites,exploration of the underlying reaction mechanisms,electrolyzer design and technical-economic analysis.Furthermore,electrocatalytic C-N coupling based on NO3RR to produce higher-value products such as urea and amino acids are also reviewed,to extend the application potential and economic feasibility.Finally,we highlight the existing challenges and the demand of future research for NO3RR.This review anticipates to provide insights into synthesis of high-value products via NO3RR,bridging the gap from laboratory research to industrial fabrication.
查看更多>>摘要：The lithium-sulfur reaction can contribute to the chemical electrical energy conversion capacity due to the multi-level ion/electron transfer process.However,the appearance of soluble intermediate products prevents efficient electron transfer,making it impossible to achieve stable cycling and capacity contribu-tion.Restricted catalysis provides a solution for inhibiting the shuttle of soluble lithium polysulfides.Herein,MXene aerogel with optimized channel utilization is designed as S host according to the polysul-fide control strategy of localization,adsorption,and catalysis.With the help of the results of oriented channels,the polysulfide conversion process is optimized,providing a comprehensive scheme for inhibit-ing the shuttle effect.Lithium sulfur catalytic batteries have achieved high capacity and stable cycling.This system provides a comprehensive solution for lithium sulfur reaction catalysis and a new perspec-tive for the functional application of MXene based lithium sulfur batteries.
查看更多>>摘要：Lead halide perovskite scintillators have recently received extensive research attention owing to their short fluorescence lifetimes,low detection limits,and ease of fabrication compared to traditional scintil-lators.The nontoxic cerium-doped lead-free perovskites with intrinsically efficient and short lifetime d-f transitions are a prospective replacement for the toxic Pb2+.Here,we demonstrated Ce-doped cesium lanthanide chloride perovskites(Cs3LnCl6,Ln=Gd,Y,Lu)synthesized through a facile solution method for the first time.These perovskites exhibit blue-violet emission,which arises from Ce 5d → 4f transi-tions.Among three types of Cs3LnCl6 perovskites,Ce:Cs3LuCl6 exhibited high photoluminescence quantum yield(PLQY)of 82％and a short excited-state lifetime of approximately 34 ns.When utilized as X-ray scintillators,Ce:Cs3LuCl6 crystals display a high light yield of 8120 photons per MeV and a low detection limit of 36.8 nGy air s-1.Importantly,the figure of merit(FoM),representing the ratio of light yield to decay time,reaches 239,which is the highest reported value for lead-free perovskite scin-tillators up to now.Additionally,the fabrication of perovskite/PMMA films was undertaken for practical demonstrations in X-ray imaging,resulting in the attainment of a resolution of up to 8.38 lp/mm.We anticipate that this work will inspire the utilization of Ce-doped Cs3LnCl6 perovskites in ultrafast scintillation applications such as high-energy physics,nuclear reaction monitoring,and dynamic X-ray imaging.
查看更多>>摘要：The development of aqueous zinc-ion batteries(AZIBs)marks a significant advancement in the field of sustainable and environmentally friendly energy storage.To address the challenges faced by single-phase vanadium-based oxides,such as poor conductivity and dissolution in electrolytes,this study intro-duces vacuum S/N doping to fabricate V2O3/VO2@S/N-C nanofibers,improving the cycling stability and enhancing the capacity.The V2O3/VO2@S/N-C electrode exhibits exceptional cyclic stability,retaining a capacity of 133.3 mA h g-1 after 30,000 cycles at a high current density of 100 A g-1 and a capacity retention of 81.8％after 150,000 cycles at 200 A g-1.Characterizations using ex-situ X-ray diffraction and ex-situ X-ray photoelectron spectroscopy reveal co-intercalation of H+and Zn2+in the V2O3/VO2@S/N-C electrode.Due to the presence of S22_,more phases changed to V10O24·12H2O,making the V2O3/VO2@S/N-C electrode better reversible.By elucidating the zinc storage mechanism and demonstrating the stable performance of the doped electrode,this work contributes valuable insights into the optimization of the electrode materials for future energy storage solutions.
Yujun ShengFarah HazmatulhaqAbdullah Al MahmudMostafa S.Sayed...
93-99页
查看更多>>摘要：Bimetallic nanocrystals have attracted considerable attention because of their complicated systems,which are far superior to those of their individual constituents.A TiO2-confined PtMnP bimetallic catalyst(PtMnP@TiO2)was prepared using an ultrasonic-assisted coincident strategy,which demonstrated exceptional catalytic activity in the universal hydrogen evolution reaction(HER).Owing to the bimetallic synergistic effect and TiO2 confinement,PtMnP@TiOx showed ultrasmall metal nanoparticles(NPs),a higher active Pt0 content,adequate activation at the porous surface,and abundant acid sites.Simulations were performed to visualize the strain properties of Mn and Pt during the bending process and demonstrate the high activity of Pt.The Pt-Mn bimetallic catalysts were enriched with Pt NPs,con-voyed by electron transfer from Mn to Pt.Briefly,PtMnP@TiO2 showed robust evolution reaction activi-ties(an overpotential of 220 mV at a current density of 10 mA cm-2 and a Tafel slope of 186 mV dec-1)and the ability to contrast stated catalysts without ultrasonication-plasma.This protocol revealed that the geometrical and electronic effects of Pt and P surrounding the Mn species in PtMnP@TiO2 were crucial for increasing the catalytic activity(99％)and durability(over 20 cycles),which were far superior to those of other reported catalysts.
查看更多>>摘要：Na3V2(PO4)2F3(NVPF)is shown to be an attractive cathode material for sodium storage due to its high theoretical capacity and suitable working voltage.However,its low electronic conductivity and poor cycling stability have to be addressed in order for enhanced high-rate performance and cycle life.Herein,we have prepared a 3D reduced graphene oxide(rGO)host-supported NVPF nanocuboids.We dis-cover that polyvinyl alcohol(PVA)serves as an important structural directing agent that bridges between NVPF and rGO through the hydrogen bonding,and thus regulates the formation of the 3D rGO framework with NVPF nanocuboids embedded inside(NVPF@C@rGO).With such a unique construction,NVPF@C@rGO exhibits excellent cycling stability and rate performance for sodium storage,showing high reversible capacities of 121 mAh/g and 113 mAh/g at 1C and 10C,respectively,and 103 mAh/g after 700 cycles at 50C with 98.3％retention.Even at an extremely high current of 100C,it also delivers a reversible capacity of 64 mAh/g,surpassing the performance of many recently reported NVPF-based electrodes.Cyclic voltammetry(CV)and galvanostatic intermittent titration technique(GITT)data confirm the much better kinetic properties of NVPF@C@rGO electrode than the control samples of NVPF@rGO and pure NVPF.In-situ XRD results reveal that the 3D rGO housing can effectively suppress the lattice variation of NVPF,with a maximum volume change of only 1.84％during cycling.Moreover,the in-situ tempera-ture sensing reveals the more stable working temperature of NVPF@C@rGO compared to phase-pure NVPF,suggesting a higher temperature safety of the electrode.Using NVPF@C@rGO as the positive elec-trode and commercial hard carbon as the negative electrode,a sodium-ion full battery has been assem-bled with about 110 mAh/g at 1C for 300 cycles,corresponding to an energy density of 291 Wh kg-1.The construction of 3D rGO housing as a conductive support offers an effective strategy for high-rate,long cycle life and high safety sodium-ion battery cathodes.
查看更多>>摘要：The confined ionic liquid(IL)in solid polymer composite electrolytes(SCPEs)can improve the perfor-mance of lithium metal batteries.However,the impact/role and working mechanism of confined IL in SCPEs remain ambiguous.Herein,IL was immobilized on SiO2(SiO2@IL-C)and then used to prepare the confined SCPEs together with LiTFSI and PEO to study the impacts of confined-IL on the properties and performance of electrolytes and reveal the Li+transport mechanism.The results show that,compared to the IL-unconfined SCPE,the IL-confined ones exhibit better performance of electrolytes and cells,such as higher ionic conductivity,higher tLi+,and wider electrochemical windows,as well as more stable cycle performance,due to the increased dissociation degree of lithium salt and enlarged polymer amorphous-ness.The finite-element/molecular-dynamics simulations suggest that the IL confined on the SiO2 pro-vided an additional Li+transport pathway(Li+→ SiO2@IL-C)that can accelerate ion transfer and alleviate lithium dendrites,leading to ultrastable stripping/plating cycling over 1900 h for the Li/SCPEs/Li symmetric cells.This study demonstrates that IL-confinement is an effective strategy for the intelligent approach of high-performance lithium metal batteries.
NETL
NSTL
万方数据