A one-step ultrasonic mechanical method was used to synthesize a kind of atmospheric water harvesting material with high water harvesting performance in a wide relative humidity(RH)range,especially at low RH(RH<40%...A one-step ultrasonic mechanical method was used to synthesize a kind of atmospheric water harvesting material with high water harvesting performance in a wide relative humidity(RH)range,especially at low RH(RH<40%),namely,mesoporous silica capsule(MSC)with core-shell structure.Transmission electron microscopy(TEM),nitrogen adsorption and other characterization techniques were used to study the formation process of nano-microspheres.A new mechanism of self-adaptive concentration gradient regulation of silicon migration and recombination core-shell structure was proposed to explain the formation of a cavity in the MSC system.The core-shell design can enhance the specific surface area and pore volume while maintaining the monodispersity and mesoporous size.To study the water harvesting performance of MSC,solid silica nanoparticles(SSN)and mesoporous silica nanoparticles(MSN)were prepared.In a small atmospheric water collection test(25℃,40%RH),the water vapour adsorption and desorption kinetics of MSC,SSN,MSN and a commercial silica gel(CSG)were compared and analyzed.The results show that the MSC with mesoporous channels and core-shell structure can provide about 0.324 gwater/gadsorbent,79%higher than the CSG(0.181 gwater/gadsorbent).It is 25.1%higher than that of 0.259 gwater/gadsorbentof un-hollowed MSN and 980%higher than that of0.03 gwater/gadsorbentof un-hollowed SSN.The material has a large specific surface area and pore volume,simple preparation method and low cost,which provides a feasible idea for realising atmospheric water collection in arid and semi-arid regions.展开更多
Atmospheric water harvesting offers a powerful and promising solution to address the problem of global freshwater scarcity.In the past decade,significant progress has been achieved in utilizing hydrolytically stable m...Atmospheric water harvesting offers a powerful and promising solution to address the problem of global freshwater scarcity.In the past decade,significant progress has been achieved in utilizing hydrolytically stable metal-organic frameworks as recyclable water-sorbent materials under low relative humidity,especially in those arid areas.Recently,Yaghi's group has employed a combined crystallographic and theoretical technique to decipher the water filling mechanism in MOF-303,where the polar organic linkers rather than the inorganic units of MOF are demonstrated as the key factor.Hence,the hydrophilic strength of the water-binding pocket in MOFs can be optimized through the approach of multivariate modulations,resulting in enhanced water harvesting properties.展开更多
Harvesting water from the atmosphere is an important process to solve the extreme lack of water resources in arid regions. Adsorption-based atmospheric water harvesting(AWH) takes advantage of solar thermal energy to ...Harvesting water from the atmosphere is an important process to solve the extreme lack of water resources in arid regions. Adsorption-based atmospheric water harvesting(AWH) takes advantage of solar thermal energy to harvest water from air. This technique is particularly suitable for arid regions characterized by low humidity and an abundance of sunshine. Nonetheless, under low humidity conditions, AWH is highly dependent on water-adsorbing materials exhibiting excellent performance. In this work, a metal–organic framework(MOF), namely [Zn_(2)(bpy)(btec)(H_(2)O)_(2)]·2H_(2)O, also denoted as MWH-1, was investigated for application in water harvesting under low humidity conditions(<20%). Notably,MWH-1 displayed outstanding water and thermal stability. At temperatures of 293–333 K and low pressure, activated MWH-1a exhibited competitive water uptake(relative humidity(RH) = 5%,uptake>200 cm^(3)·cm^(-3);RH = 10%, uptake >250 cm^(3)·cm^(-3)). This ensured effective water harvesting at high temperatures during the day. In situ powder X-ray diffraction and Fourier-transform infrared analyses confirmed the sensitive water adsorption process of MWH-1a. The X-ray single-crystal study further demonstrated that single-crystal structures could be completely restored following water harvesting.MWH-1 showed good structural stability and enabled water harvesting under low humidity and high temperature conditions. Thus, it has the potential for application in round-the-clock water harvesting in extremely arid regions.展开更多
Moisture removal and water recovery from the air are vital for regulating indoor humidity and mitigating water scarcity.Most atmospheric water harvesters(AWH)focus primarily on increasing the moisture capture rate,but...Moisture removal and water recovery from the air are vital for regulating indoor humidity and mitigating water scarcity.Most atmospheric water harvesters(AWH)focus primarily on increasing the moisture capture rate,but for it to be economical and sustainable,it is essential to consider the energy required to recover and harvest the captured water.Here,a mechanically flexible,biphilic sorption-based AWH made of green,environmentally friendly material is presented.It consists of a hygroscopic chitosan polymer embedded within a flexible,hydrophobic silica xerogel that can harvest 86.3 g water/g chitosan at 97%relative humidity and 25℃reaching saturation after 30 days(i.e.2.88 g water/g chitosan/day).Roughly 88%of the sorbed moisture was recovered by mechanical squeezing(ca.0.020 MPa)within 150 s.Repeated water harvesting experiments and uniaxial compression tests demonstrate that chitosan-silica xerogel is durable for longterm operations,providing a fast,reliable,and sustainable moisture removal and water harvesting tool.展开更多
Atmospheric water harvesting based on vapor adsorption is a newly emerged and potential technology to supply portable water for arid areas.To efficiently harvest vapor from the air,sorbents are required to have consid...Atmospheric water harvesting based on vapor adsorption is a newly emerged and potential technology to supply portable water for arid areas.To efficiently harvest vapor from the air,sorbents are required to have conside-rable adsorption capacity,easy regeneration and high stability.With the advantages of porous structure,tunable pore size and tailorable hydrophilicity,metal-organic frameworks(MOFs)have demonstrated excellent performance in vapor adsorption and water generation.In this review,we first discuss the degradation mechanisms of MOFs exposed to water and summarize the structure-stability relationship;by centering on the adsorption isotherms,the connection between the structure of MOFs and the water adsorption property is illuminated;finally,some prospects are suggested in order to push forward the progress of this technology.展开更多
Atmospheric water,as one of the most abundant natural resources on Earth,has attracted huge research interest in the field of water harvesting and energy harvesting and conversion owing its environmental friendliness ...Atmospheric water,as one of the most abundant natural resources on Earth,has attracted huge research interest in the field of water harvesting and energy harvesting and conversion owing its environmental friendliness and easy access.The developments of new materials have seen advanced technologies that can extract water and energy out of this long-neglected resource,suggesting a promising and sustainable approach to address the water and energy crises over the world.Carbon-based functional materials have been considered to be indispensable materials for atmospheric water utilization due to their large surface area,excellent adsorption performance,and higher surface activity.In this review,first,we analyze the interaction between carbon-based functional materials and atmospheric water molecular.Then,technologies developed in recent years for atmospheric water utilization based on carbon-based functional materials are reviewed,mainly focusing on atmospheric water harvesting,moisture-enabled electricity generation,and moisture-responsive actuation.Finally,the remaining challenges and some tentative suggestions possibly guiding developments are proposed,which may pave a way for a bright future of carbon-based functional material in the utilization of atmospheric water.展开更多
大气集水(atmospheric water harvest,AWH)是一种从空气获取淡水的技术,对于缓解水资源危机具有潜在的应用前景.金属有机框架(metal-organic framework,MOF)是一种具有高比表面积、可调孔道结构的晶态多孔材料.MOF材料对水蒸气的逐级吸...大气集水(atmospheric water harvest,AWH)是一种从空气获取淡水的技术,对于缓解水资源危机具有潜在的应用前景.金属有机框架(metal-organic framework,MOF)是一种具有高比表面积、可调孔道结构的晶态多孔材料.MOF材料对水蒸气的逐级吸附和适中的脱附温度使得其在AWH领域具有较好的适用性.本文对近年来MOF材料在AWH领域的研究进展进行了系统综述,总结了MOF水吸附机理,梳理了用于AWH的MOF材料和装置及其集水性能.本文最后还从AWH装置产水效率、运行稳定性和MOF的可持续设计与合成等方面进行了展望,旨在为MOF材料在AWH领域的应用发展提供参考.展开更多
基金the National Natural Science Foundation of China(No.50772131)the National High-tech R&D Program of China(863 Program)(No.2011AA322100)+1 种基金the Key Project of Chinese Ministry of Education(No.106086)the Fundamental Research Funds for the Central Universities(No.2010YJ05)。
文摘A one-step ultrasonic mechanical method was used to synthesize a kind of atmospheric water harvesting material with high water harvesting performance in a wide relative humidity(RH)range,especially at low RH(RH<40%),namely,mesoporous silica capsule(MSC)with core-shell structure.Transmission electron microscopy(TEM),nitrogen adsorption and other characterization techniques were used to study the formation process of nano-microspheres.A new mechanism of self-adaptive concentration gradient regulation of silicon migration and recombination core-shell structure was proposed to explain the formation of a cavity in the MSC system.The core-shell design can enhance the specific surface area and pore volume while maintaining the monodispersity and mesoporous size.To study the water harvesting performance of MSC,solid silica nanoparticles(SSN)and mesoporous silica nanoparticles(MSN)were prepared.In a small atmospheric water collection test(25℃,40%RH),the water vapour adsorption and desorption kinetics of MSC,SSN,MSN and a commercial silica gel(CSG)were compared and analyzed.The results show that the MSC with mesoporous channels and core-shell structure can provide about 0.324 gwater/gadsorbent,79%higher than the CSG(0.181 gwater/gadsorbent).It is 25.1%higher than that of 0.259 gwater/gadsorbentof un-hollowed MSN and 980%higher than that of0.03 gwater/gadsorbentof un-hollowed SSN.The material has a large specific surface area and pore volume,simple preparation method and low cost,which provides a feasible idea for realising atmospheric water collection in arid and semi-arid regions.
基金supported by the National Natural Science Foundation of China(Grant Nos.21471118,21971199,22025106,51202127,91545205,and 91622103)National Key Research and Development Project of China(2018YFA0704000)+1 种基金Natural Science Foundation of Hubei Province(2016CFB382)Fundamental Research Funds for the Central Universities(2042017kf0227,2042019kf0205)。
文摘Atmospheric water harvesting offers a powerful and promising solution to address the problem of global freshwater scarcity.In the past decade,significant progress has been achieved in utilizing hydrolytically stable metal-organic frameworks as recyclable water-sorbent materials under low relative humidity,especially in those arid areas.Recently,Yaghi's group has employed a combined crystallographic and theoretical technique to decipher the water filling mechanism in MOF-303,where the polar organic linkers rather than the inorganic units of MOF are demonstrated as the key factor.Hence,the hydrophilic strength of the water-binding pocket in MOFs can be optimized through the approach of multivariate modulations,resulting in enhanced water harvesting properties.
基金supported by the National Natural Science Foundation of China (21908155, 21922810 and 22090062)Natural Science Foundation for Young Scientists of Shanxi Province ( 201901D211053)。
文摘Harvesting water from the atmosphere is an important process to solve the extreme lack of water resources in arid regions. Adsorption-based atmospheric water harvesting(AWH) takes advantage of solar thermal energy to harvest water from air. This technique is particularly suitable for arid regions characterized by low humidity and an abundance of sunshine. Nonetheless, under low humidity conditions, AWH is highly dependent on water-adsorbing materials exhibiting excellent performance. In this work, a metal–organic framework(MOF), namely [Zn_(2)(bpy)(btec)(H_(2)O)_(2)]·2H_(2)O, also denoted as MWH-1, was investigated for application in water harvesting under low humidity conditions(<20%). Notably,MWH-1 displayed outstanding water and thermal stability. At temperatures of 293–333 K and low pressure, activated MWH-1a exhibited competitive water uptake(relative humidity(RH) = 5%,uptake>200 cm^(3)·cm^(-3);RH = 10%, uptake >250 cm^(3)·cm^(-3)). This ensured effective water harvesting at high temperatures during the day. In situ powder X-ray diffraction and Fourier-transform infrared analyses confirmed the sensitive water adsorption process of MWH-1a. The X-ray single-crystal study further demonstrated that single-crystal structures could be completely restored following water harvesting.MWH-1 showed good structural stability and enabled water harvesting under low humidity and high temperature conditions. Thus, it has the potential for application in round-the-clock water harvesting in extremely arid regions.
基金Innovation and Technology Commission,Grant/Award Number:ITS/022/15Research Grants Council,University Grants Committee,Grant/Award Number:E-HKUST601/17+2 种基金The European Union-Hong Kong Research and Innovation Cooperation Co-funding Mechanism,Grant/Award Number:E-HKUST601/17The European Union's Horizon 2020,Grant/Award Number:BIORIMAthe Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone,Grant/Award Number:HZQB-KCZYB-2020083。
文摘Moisture removal and water recovery from the air are vital for regulating indoor humidity and mitigating water scarcity.Most atmospheric water harvesters(AWH)focus primarily on increasing the moisture capture rate,but for it to be economical and sustainable,it is essential to consider the energy required to recover and harvest the captured water.Here,a mechanically flexible,biphilic sorption-based AWH made of green,environmentally friendly material is presented.It consists of a hygroscopic chitosan polymer embedded within a flexible,hydrophobic silica xerogel that can harvest 86.3 g water/g chitosan at 97%relative humidity and 25℃reaching saturation after 30 days(i.e.2.88 g water/g chitosan/day).Roughly 88%of the sorbed moisture was recovered by mechanical squeezing(ca.0.020 MPa)within 150 s.Repeated water harvesting experiments and uniaxial compression tests demonstrate that chitosan-silica xerogel is durable for longterm operations,providing a fast,reliable,and sustainable moisture removal and water harvesting tool.
文摘Atmospheric water harvesting based on vapor adsorption is a newly emerged and potential technology to supply portable water for arid areas.To efficiently harvest vapor from the air,sorbents are required to have conside-rable adsorption capacity,easy regeneration and high stability.With the advantages of porous structure,tunable pore size and tailorable hydrophilicity,metal-organic frameworks(MOFs)have demonstrated excellent performance in vapor adsorption and water generation.In this review,we first discuss the degradation mechanisms of MOFs exposed to water and summarize the structure-stability relationship;by centering on the adsorption isotherms,the connection between the structure of MOFs and the water adsorption property is illuminated;finally,some prospects are suggested in order to push forward the progress of this technology.
基金supported by the National Natural Science Foundation of China(Nos.52022051,22035005,22075165,52090032,and 52073159)Tsinghua-Foshan Innovation Special Fund(No.2020THFS0501).
文摘Atmospheric water,as one of the most abundant natural resources on Earth,has attracted huge research interest in the field of water harvesting and energy harvesting and conversion owing its environmental friendliness and easy access.The developments of new materials have seen advanced technologies that can extract water and energy out of this long-neglected resource,suggesting a promising and sustainable approach to address the water and energy crises over the world.Carbon-based functional materials have been considered to be indispensable materials for atmospheric water utilization due to their large surface area,excellent adsorption performance,and higher surface activity.In this review,first,we analyze the interaction between carbon-based functional materials and atmospheric water molecular.Then,technologies developed in recent years for atmospheric water utilization based on carbon-based functional materials are reviewed,mainly focusing on atmospheric water harvesting,moisture-enabled electricity generation,and moisture-responsive actuation.Finally,the remaining challenges and some tentative suggestions possibly guiding developments are proposed,which may pave a way for a bright future of carbon-based functional material in the utilization of atmospheric water.
文摘大气集水(atmospheric water harvest,AWH)是一种从空气获取淡水的技术,对于缓解水资源危机具有潜在的应用前景.金属有机框架(metal-organic framework,MOF)是一种具有高比表面积、可调孔道结构的晶态多孔材料.MOF材料对水蒸气的逐级吸附和适中的脱附温度使得其在AWH领域具有较好的适用性.本文对近年来MOF材料在AWH领域的研究进展进行了系统综述,总结了MOF水吸附机理,梳理了用于AWH的MOF材料和装置及其集水性能.本文最后还从AWH装置产水效率、运行稳定性和MOF的可持续设计与合成等方面进行了展望,旨在为MOF材料在AWH领域的应用发展提供参考.
