查看更多>>摘要：The conversion of intermittent renewable elec-trical energy to chemical energy is of great importance,which can not only mitigate current energy and environ-mental crisis but also contribute to the ongoing carbon neutrality national strategy.Electrocatalysis is serving as a low-carbon conversion technology that enables green and efficient energy conversion mainly through hydrogen evo-lution reaction(HER),carbon dioxide reduction reaction(CO2RR),and nitrogen reduction reaction(NRR).The core of electrocatalysis is the design and construction of low-cost,high-activity and high-stability electrocatalyst to drive reaction thermodynamics and kinetics.The employment of polyoxometalates(POMs)as platforms or precursors to construct different types of electrocatalysts has been widely reported.Herein,we systematically summarized the recent advances in POM-derived nanostructures for electrocataly-sis application.The strategies for precursor design and electrocatalyst synthesis were briefly introduced.The mor-phology control,phase control,composite modulation,and heterostructure engineering in POM-derived nanostructures were presented in detail.The structure-activity relationship of POM-derived nanostructures is fully discussed for HER,CO2RR,and NRR applications.Finally,the current chal-lenges and future outlooks of POM-derived nanostructures are summarized to provide insights toward high-efficiency electrocatalysts for energy conversion technologies.
查看更多>>摘要：Aqueous zinc-ion batteries(AZIBs)as green battery systems have attracted widespread attention in large-scale electrochemical energy storage devices,owing to their high safety,abundant Zn materials,high theoretical specific capacity and low redox potential.Nevertheless,there are some thorny issues in AZIBs that hinder their practical application,such as low intrinsic electron con-ductivity,slow ion migration kinetics,zinc dendrites and side reactions.MXene-based materials with superior con-ductivity,large polar surface and abundant active sites can simultaneously serve as cathode materials,electrolyte additive and protection layer of anode to regulate redox reactions of AZIBs.Although various materials have been used to improve electrochemical performances of AZIBs,there is a lack of in-depth discussion on the regulation mechanism of MXene-based materials for AZIBs.In this review,we elaborate the research progress of MXene-based materials in AZIBs,including their application in cathode materials and inhibition of zinc dendrites.Finally,the future prospects and development directions of MXene-based materials that may improve performance of AZIBs are prospected.
查看更多>>摘要：Reasonable design and applications of gra-phene-based materials are supposed to be promising ways to tackle many fundamental problems emerging in lithium batteries,including suppression of electrode/electrolyte side reactions,stabilization of electrode architecture,and improvement of conductive component.Therefore,exten-sive fundamental research on this aspect has been per-formed so far.However,when it comes to large-scale industrial applications,the utilization of graphene-based materials progresses at a very slow pace.Namely,there presents a severe technological decoupling between aca-demic research and industrial application,and there is an urgent need to link them.Herein,in order to address cur-rent issues of graphene-based materials used in lithium batteries,we present their latest advancements with state-of-the-art technologies.Potential applications of graphene-based materials in practical lithium batteries are high-lighted and predicted to bridge the gap between the aca-demic progress and industrial manufacture,thereby paving the way for accelerating the development of graphene-based material as well as lithium battery industry.
查看更多>>摘要：Recently,metal selenides have obtained wide-spread attention as electrode materials for alkali(Li+/Na+/K+)batteries due to their promising theoretical capacity and mechanism.Nevertheless,metal selenides,similar to metal oxides and sulfides,also suffer from severe volume explosion during repeated charge/discharge processes,which results in the structure collapse and the following pulverization of electrode materials.Hence,it leads to poor cycle stability and influencing their further application.In order to solve these issues,some special strategies,including elemental doping,coupling with carbon materi-als,synthesis of the bimetal selenides with heterostructure,etc.,have been gradually applied to design novel electrode materials with outstanding electrochemical performance.Herein,the recent research progress on metal selenides as anodes for alkali ion batteries is summarized,including the regulation of crystal structure,synthesis strategies,modi-fication methods,and electrochemical mechanisms and kinetics.Besides,the challenges of metal selenides and the perspective for future electrode material design are pro-posed.It is hoped to pave a way for the development of metal selenide electrode materials for the potential appli-cations for alkali metal ion(Li+/Na+/K+)batteries.
查看更多>>摘要：As a novel structural and functional material,porous titanium and its alloys have been widely used in the aerospace,marine engineering and biomedical fields due to their high corrosion resistance,low density,good bio-compatibility and excellent mechanical properties.There-fore,in this paper,a comprehensive review of powder metallurgy(PM)(including additive manufacturing(AM)processes)for fabricating porous titanium is firstly covered in terms of their working principles,capabilities,short-comings and strengths.Simultaneously,the influencing factors of various methods on final pore structure of porous Ti are involved.Secondly,a summary of the chemical methods(CM)to obtain the porous Ti is also provided,such as dealloying method and reduction method.Finally,the tendency and direction of preparation technology as well as application of porous titanium were prospected.
查看更多>>摘要：Materials featuring topological energy bands and nontrivial surface states hold significant promise in unlocking unprecedented opportunities for innovating electrocatalytic mechanism.However,it remains a chal-lenge to realize superior topological catalysts which can carry both high catalytic activity and excellent catalytic stability.Here,we propose that a family of Ni-based binary materials hosting fantasying topological conjunct-nodal-point state and a large nontrivial energy window(NEWD)represents an ideal choice for such superior topological catalysts in hydrogen evolution reaction.The presence of conjunct-nodal-points ensures long Fermi arcs on the sur-face,thereby enabling an extremely high catalytic activity.The NEWD plays a crucial role in stabilizing the high catalytic activity against external perturbations,such as strain and electron/hole injection.The roles for conjunct-nodal-points and NEWD are substantiated by the observ-able weakening of catalytic performance during topologi-cal phase transitions,which result in the removal of the conjunct-nodal-points,NEWD and their corresponding long Fermi arcs.Our work unveils a hidden mechanism and opens a feasible route for developing superior quantum catalysts from novel topology point of view.
查看更多>>摘要：Opportunity to harmonize aspects of oxygen reduction reaction(ORR)performance and structure,and morphology,as well as composition,is urgent for the commercialization of proton exchange membrane fuel cells.Herein,we demonstrate the design and synthesis of a functionalized-supported-Pt catalyst(Pt@HNC)featuring a hollow nitrogen-modified dodecahedral carbon substrate obtained by a stress-induced-shrink tailoring route.The as-obtained Pt@HNC catalyst possesses enhanced ORR per-formance,in particular with half-wave potential,mass activity(MA)and specific activity,which greatly exceed the commercial Pt/C.The density functional theory(DFT)calculations further confirmed that the charge redistribution induced by the electronegativity differences improved the electron interaction between Pt and HNC support.The optimized electronic structure of Pt weakens the reaction energy barrier on the Pt@HNC surface and adsorption of*OH species,thus cooperatively improving the intrinsic activity toward ORR.Additionally,our work indeed pro-vides a guide for the future design of functional nanoma-terials in the field of catalysts and clean energy.
查看更多>>摘要：A stable,efficient,and economical bifunctional electrolytic catalyst would be incredibly beneficial for the development of hydrogen production by electrocatalytic water splitting.In this study,we synthesized a novel MnS-MnO heterogeneous nanocube@N,S-doped carbon(MnS-MnO@NSC).MnS-MnO nanocubes possess rich hetero-geneous interfaces and plentiful catalytic active sites to promote electrochemical reactions,while the N,S-doped carbon shell possesses excellent conductivity and catalytic properties and protects the nanocubes.MnS-MnO@NSC exhibited excellent electrochemical properties as an effective bifunctional electrocatalyst for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in KOH solution.In the HER,the overpotential was as low as 124 mV at a current density of 10 mA·cm-2,while in the OER,it was only 340 mV at 100 mA·cm-2 under the same conditions.In addition,a MnS-MnO@NSC‖MnS-MnO@NSC electrolyzer exhibited almost comparable activity and higher steadiness than those exhibited by the state-of-the-art Pt/C‖RuO2/C system for full water splitting in KOH solution.
查看更多>>摘要：The construction of highly stable and efficient electrocatalysts is desirable for seawater splitting but remains challenging due to the high concentration of Cl-in seawater.Herein,FeOOH/Ni(OH)2 heterostructure sup-ported on Ni3S2-covered nickel foam(Fe-Ni/Ni3S2/NF)was fabricated by hydrothermal and etching methods,as well as anodic oxidation process.The electronic structure of FeOOH and Ni(OH)2 could be modulated after depositing FeOOH nanoparticles on Ni(OH)2 nanosheet,which greatly boosted the catalytic activity.When the catalyst used as an electrode for oxygen evolution reaction(OER),it needed low overpotentials of 266 and 368 mV to achieve current densities of 100 and 800 mA·cm-2,respectively,in 1 mol·L-1 KOH+seawater electrolyte.It can operate continuously at 100 mA·cm-2 for 400 h without obvious decay.Particularly,in situ generated SO42-from inner Ni3S2 during electrolysis process would accumulate on the surface of active sites to form passivation layers to repel Cl-,which seemed to be responsible for superior stability.The study not only syn-thesizes an OER catalyst for highly selective and stable seawater splitting,but also gives a novel approach for industrial hydrogen production.
查看更多>>摘要：In the process of photocatalytic water cracking,the migration rate and utilization rate of photogenerated charges determine the hydrogen evolution performance of the catalyst.In this paper,a carbon isotope superconduct-ing material graphdiyne(GDY)is prepared by mechanical ball milling and introduced into the S-scheme heterojunc-tion Zn0.5Co0.5S/MoS2 inorganic system.In terms of hydrogen evolution kinetics,GDY acts as an electron bridge,not only accelerating the migration of photogen-erated carriers but also improving the utilization of pho-togenerated charges.Morphologically,the large two-dimensional layer provides more loading and anchoring points for Zn0.5Co0.5S/MoS2,which increases the number of active sites.The ternary composite catalyst 20％GDY/Zn0.5Co0.5S/Mo2S(20-GCSM)generates 69.94 μmol of hydrogen(5 h)in triethanolamine solution.It is 2.97 and 1.80 times higher than Zn0.5Co0.5S and Zn0.5Co0.5S/MoS2,respectively.After the cyclic experiment,it still has stable hydrogen evolution performance after standing for 24 h(under dark conditions).In addition,the potential mechanism of photocatalytic hydrogen evolution is demonstrated through in-situ X-ray photoelectron spectroscopy.This work provides a reference for further research in the field of introducing carbon materials into photocatalytic systems and improving the utilization of photogenerated charges.
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