TiO_(2)is one of the best-known environmentally friendly photocatalysts that has demonstrated the great potential to degrade a wide variety of organic foulants in water and wastewater treatment when placed under UV ra...TiO_(2)is one of the best-known environmentally friendly photocatalysts that has demonstrated the great potential to degrade a wide variety of organic foulants in water and wastewater treatment when placed under UV radiation.Currently,TiO_(2)-based photocatalytic membranes are at the forefront of photodegra-dation research and technical readiness.The membrane setup provides a high contact surface area for ef-fective filtration and degradation,without the necessary hassle of photocatalyst recovery after water and wastewater treatment.Meanwhile,TiO_(2)photocatalytic ceramic membranes have become an emerging re-search area due to the inherent chemical and mechanical stability of ceramic membranes,which enables them to outperform polymeric membranes.With the recent shift from polymeric to ceramic membranes in industrial applications,TiO_(2)photocatalytic ceramic membranes will become a key player among the next-generation ceramic membranes,as they are capable of multiple functionalities.This review provides a timely and focused investigation into the fabrication and application of such TiO_(2)photocatalytic ceramic membranes for water and wastewater treatment.The benefits of using photocatalytic ceramic membranes in filtration,such as a higher foulant removal efficiency,higher water permeability,and much improved antifouling capabilities,are highlighted and explained.Finally,the current research,technical readiness,and remaining gaps are identified,and a set of critical insights are provided using the available data to guide the developmental pathway of practical TiO_(2)photocatalytic ceramic membranes for water and wastewater treatment.展开更多
Rechargeable batteries of high energy density and overall performance are becoming a critically important technology in the rapidly changing society of the twenty-first century.While lithium-ion batteries have so far ...Rechargeable batteries of high energy density and overall performance are becoming a critically important technology in the rapidly changing society of the twenty-first century.While lithium-ion batteries have so far been the dominant choice,numerous emerging applications call for higher capacity,better safety and lower costs while maintaining sufficient cyclability.The design space for potentially better alternatives is extremely large,with numerous new chemistries and architectures being simultaneously explored.These include other insertion ions(e.g.sodium and numerous multivalent ions),conversion electrode materials(e.g.silicon,metallic anodes,halides and chalcogens)and aqueous and solid electrolytes.However,each of these potential“beyond lithium-ion”alternatives faces numerous challenges that often lead to very poor cyclability,especially at the commercial cell level,while lithium-ion batteries continue to improve in performance and decrease in cost.This review examines fundamental principles to rationalise these numerous developments,and in each case,a brief overview is given on the advantages,advances,remaining challenges preventing cell-level implementation and the state-of-the-art of the solutions to these challenges.Finally,research and development results obtained in academia are compared to emerging commercial examples,as a commentary on the current and near-future viability of these“beyond lithium-ion”alternatives.展开更多
Lithium sulfur batteries(LSBs)show great promise as next-generation batteries due to their high energy density.However,commercialization is hindered by limited cycle life,fast capacity decay and poor sulfur utilizatio...Lithium sulfur batteries(LSBs)show great promise as next-generation batteries due to their high energy density.However,commercialization is hindered by limited cycle life,fast capacity decay and poor sulfur utilization,primarily due to the intricate phase evolution during battery operation and insulating characteristics of sulfur,leading to uncontrollable sulfur and polysulfide distribution and inefficient conversion kinetics.Therefore,the incorporation of metal and covalent organic frameworks(MOFs and COFs)has been widely employed in LSBs to serve as hosts,enabling the regulation of conversion and diffusion behavior of vip species,including lithium ions,sulfur and polysulfides,within their well-defined nanosized cavities.Nevertheless,pristine frameworks often fail to meet the requisite standards,and framework functionalization offers unique opportunities to tailor desired attributes and facilitate selective host-vip interactions in LSBs.However,a thorough understanding on how to precisely customize the nano-channels with functional groups to promote such interactions remains largely unexplored.In this review,we provide a systematic discussion on how the grafting of functional groups containing various active sites can play a role in host-vip chemistry,and focus on the latest advancements in engineering functionalized MOFs and COFs as charged-species regulators to tackle the problems causing poor LSB electrochemical performance.The concepts of electrophilic and nucleophilic effects are proposed,uncovering the mechanisms of framework functionalization in LSBs and serving as guidance for future developments.展开更多
All solid-state batteries(ASSBs)are the holy grails of rechargeable batteries,where extensive searches are ongoing in the pursuit of ideal solid-state electrolytes.Nevertheless,there is still a long way off to the sat...All solid-state batteries(ASSBs)are the holy grails of rechargeable batteries,where extensive searches are ongoing in the pursuit of ideal solid-state electrolytes.Nevertheless,there is still a long way off to the satisfactorily high(enough)ionic conductivity,long-term stability and especially being able to form compatible interfaces with the solid electrodes.Herein,we have explored ionic transport behavior and high mobility in the sub-nano pore networks in the framework structures.Macroscopically,the frameworked electrolyte behaves as a solid,and however in the(sub)-nano scales,the very limited number of solvent molecules in confinement makes them completely different from that in liquid electrolyte.Differentiated from a liquid-electrolyte counterpart,the interactions between the mobile ions and surrounding molecules are subject to dramatic changes,leading to a high ionic conductivity at room temperature with a low activation energy.Li+ions in the sub-nano cages of the network structure are highly mobile and diffuse rather independently,where the rate-limiting step of ions crossing cages is driven by the local concentration gradient and the electrostatic interactions between Li^(+)ions.This new class of frameworked electrolytes(FEs)with both high ionic conductivity and desirable interface with solid electrodes are demonstrated to work with Li-ion batteries,where the ASSB with LiFePO_(4)shows a highly stable electrochemical performance of over 450 cycles at 2℃ at room temperature,with an almost negligible capacity fade of 0.03‰ each cycle.In addition,the FE shows outstanding flexibility and anti-flammability,which are among the key requirements of large-scale applications.展开更多
Lithium-ion batteries(LIBs)are undoubtedly the current working-horse in almost all portable electronic devices,electric vehicles,and even large-scale stationary energy storage.Given the problems faced by LIBs,a big qu...Lithium-ion batteries(LIBs)are undoubtedly the current working-horse in almost all portable electronic devices,electric vehicles,and even large-scale stationary energy storage.Given the problems faced by LIBs,a big question arises as to which battery(ies)would be the“Beyond LIBs”batteries.Among the front-runners,lithium-sulfur batteries(LSBs)have been extensively pursued owing to their intrinsically high energy density and extremely low cost.Despite the steady and sometimes exciting progress reported on sulfur chemistry and cell performance at laboratory scales over the past decade,one of the major bottlenecks is the poor cyclability.In this perspective,we examine the key challenges and opportunities faced by LSBs,as well as approaches at the materials,electrode/electrolyte and cell integration levels that can be taken to transform LSBs from a front-runner to a real leading champion in the pursuit of the“Beyond LIBs”.While the key new mechanistic insights are very important,we propose a set of the near-future research directions for both the liquid and solid state LSBs,where the currently on-going parallel pursuits of both liquid and solid LSBs will be converging.The“liquid current”will gradually be taken over by“solid future”in the expected LSBs commercialization in the coming decade.展开更多
基金supported by the National Research Foundation Singapore(NRF-CRP26-2021RS-0002,Advanced Porous Materials and Membranes for Liquid-Phase Hydrocarbon Separations),conducted at the National University of Singapore.
文摘TiO_(2)is one of the best-known environmentally friendly photocatalysts that has demonstrated the great potential to degrade a wide variety of organic foulants in water and wastewater treatment when placed under UV radiation.Currently,TiO_(2)-based photocatalytic membranes are at the forefront of photodegra-dation research and technical readiness.The membrane setup provides a high contact surface area for ef-fective filtration and degradation,without the necessary hassle of photocatalyst recovery after water and wastewater treatment.Meanwhile,TiO_(2)photocatalytic ceramic membranes have become an emerging re-search area due to the inherent chemical and mechanical stability of ceramic membranes,which enables them to outperform polymeric membranes.With the recent shift from polymeric to ceramic membranes in industrial applications,TiO_(2)photocatalytic ceramic membranes will become a key player among the next-generation ceramic membranes,as they are capable of multiple functionalities.This review provides a timely and focused investigation into the fabrication and application of such TiO_(2)photocatalytic ceramic membranes for water and wastewater treatment.The benefits of using photocatalytic ceramic membranes in filtration,such as a higher foulant removal efficiency,higher water permeability,and much improved antifouling capabilities,are highlighted and explained.Finally,the current research,technical readiness,and remaining gaps are identified,and a set of critical insights are provided using the available data to guide the developmental pathway of practical TiO_(2)photocatalytic ceramic membranes for water and wastewater treatment.
基金J.Wang acknowledges the support by MOE,Singapore Ministry of Education(MOE2018-T2-2-095)for research work conducted at the National University of Singapore.Z.L.Liu acknowledges the A*STAR’s Central Research Funds(CRF)Award(Project:SC25/21-111312)+1 种基金Y.Gao acknowledges financial support by ST Engineering Advanced Material Engineering Pte.Ltd.and Singapore Economic Development BoardOpen access funding provided by Shanghai Jiao Tong University
文摘Rechargeable batteries of high energy density and overall performance are becoming a critically important technology in the rapidly changing society of the twenty-first century.While lithium-ion batteries have so far been the dominant choice,numerous emerging applications call for higher capacity,better safety and lower costs while maintaining sufficient cyclability.The design space for potentially better alternatives is extremely large,with numerous new chemistries and architectures being simultaneously explored.These include other insertion ions(e.g.sodium and numerous multivalent ions),conversion electrode materials(e.g.silicon,metallic anodes,halides and chalcogens)and aqueous and solid electrolytes.However,each of these potential“beyond lithium-ion”alternatives faces numerous challenges that often lead to very poor cyclability,especially at the commercial cell level,while lithium-ion batteries continue to improve in performance and decrease in cost.This review examines fundamental principles to rationalise these numerous developments,and in each case,a brief overview is given on the advantages,advances,remaining challenges preventing cell-level implementation and the state-of-the-art of the solutions to these challenges.Finally,research and development results obtained in academia are compared to emerging commercial examples,as a commentary on the current and near-future viability of these“beyond lithium-ion”alternatives.
基金supported by the Singapore Ministry of Education,and the National Research Foundation(NRF)for research conducted at the National University of Singapore(CRP NRF-CRP26-2021-0003).
文摘Lithium sulfur batteries(LSBs)show great promise as next-generation batteries due to their high energy density.However,commercialization is hindered by limited cycle life,fast capacity decay and poor sulfur utilization,primarily due to the intricate phase evolution during battery operation and insulating characteristics of sulfur,leading to uncontrollable sulfur and polysulfide distribution and inefficient conversion kinetics.Therefore,the incorporation of metal and covalent organic frameworks(MOFs and COFs)has been widely employed in LSBs to serve as hosts,enabling the regulation of conversion and diffusion behavior of vip species,including lithium ions,sulfur and polysulfides,within their well-defined nanosized cavities.Nevertheless,pristine frameworks often fail to meet the requisite standards,and framework functionalization offers unique opportunities to tailor desired attributes and facilitate selective host-vip interactions in LSBs.However,a thorough understanding on how to precisely customize the nano-channels with functional groups to promote such interactions remains largely unexplored.In this review,we provide a systematic discussion on how the grafting of functional groups containing various active sites can play a role in host-vip chemistry,and focus on the latest advancements in engineering functionalized MOFs and COFs as charged-species regulators to tackle the problems causing poor LSB electrochemical performance.The concepts of electrophilic and nucleophilic effects are proposed,uncovering the mechanisms of framework functionalization in LSBs and serving as guidance for future developments.
基金Singapore Ministry of Education,Grant/Award Number:A-8000186-01-00National Research Foundation(NRF)Singapore,Grant/Award Numbers:CRP NRF-CRP26-2021-0003,NRFCRP24-2020-0002A*STAR SERC CRF Award。
文摘All solid-state batteries(ASSBs)are the holy grails of rechargeable batteries,where extensive searches are ongoing in the pursuit of ideal solid-state electrolytes.Nevertheless,there is still a long way off to the satisfactorily high(enough)ionic conductivity,long-term stability and especially being able to form compatible interfaces with the solid electrodes.Herein,we have explored ionic transport behavior and high mobility in the sub-nano pore networks in the framework structures.Macroscopically,the frameworked electrolyte behaves as a solid,and however in the(sub)-nano scales,the very limited number of solvent molecules in confinement makes them completely different from that in liquid electrolyte.Differentiated from a liquid-electrolyte counterpart,the interactions between the mobile ions and surrounding molecules are subject to dramatic changes,leading to a high ionic conductivity at room temperature with a low activation energy.Li+ions in the sub-nano cages of the network structure are highly mobile and diffuse rather independently,where the rate-limiting step of ions crossing cages is driven by the local concentration gradient and the electrostatic interactions between Li^(+)ions.This new class of frameworked electrolytes(FEs)with both high ionic conductivity and desirable interface with solid electrodes are demonstrated to work with Li-ion batteries,where the ASSB with LiFePO_(4)shows a highly stable electrochemical performance of over 450 cycles at 2℃ at room temperature,with an almost negligible capacity fade of 0.03‰ each cycle.In addition,the FE shows outstanding flexibility and anti-flammability,which are among the key requirements of large-scale applications.
基金Fundamental Research Funds for the Central Universities(Tongji University),MOE,Singapore Ministry of Education,Grant/Award Number:MOE2018-T2-2-095。
文摘Lithium-ion batteries(LIBs)are undoubtedly the current working-horse in almost all portable electronic devices,electric vehicles,and even large-scale stationary energy storage.Given the problems faced by LIBs,a big question arises as to which battery(ies)would be the“Beyond LIBs”batteries.Among the front-runners,lithium-sulfur batteries(LSBs)have been extensively pursued owing to their intrinsically high energy density and extremely low cost.Despite the steady and sometimes exciting progress reported on sulfur chemistry and cell performance at laboratory scales over the past decade,one of the major bottlenecks is the poor cyclability.In this perspective,we examine the key challenges and opportunities faced by LSBs,as well as approaches at the materials,electrode/electrolyte and cell integration levels that can be taken to transform LSBs from a front-runner to a real leading champion in the pursuit of the“Beyond LIBs”.While the key new mechanistic insights are very important,we propose a set of the near-future research directions for both the liquid and solid state LSBs,where the currently on-going parallel pursuits of both liquid and solid LSBs will be converging.The“liquid current”will gradually be taken over by“solid future”in the expected LSBs commercialization in the coming decade.
