Solar steam generation(SSG)is a potential technology for freshwater production,which is expected to address the global water shortage problem.Some noble metals with good photothermal conversion performance have receiv...Solar steam generation(SSG)is a potential technology for freshwater production,which is expected to address the global water shortage problem.Some noble metals with good photothermal conversion performance have received wide concerns in SSG,while high cost limits their practical applications for water purification.Herein,a self-supporting nanoporous copper(NP-Cu)film was fabricated by one-step dealloying of a specially designed Al_(98)Cu_(2)precursor with a dilute solid solution structure.In-situ and ex-situ characterizations were performed to reveal the phase and microstructure evolutions during dealloying.The NP-Cu film shows a unique three-dimensional bicontinuous ligament-channel structure with high porosity(94.8%),multi scale-channels and nanoscale ligaments(24.2±4.4nm),leading to its strong broadband absorption over the 200–2500 nm wavelength More importantly,the NP-Cu film exhibits excellent SSG performance with high evaporation rate,superior efficiency and good stability.The strong desalination ability of NP-Cu also manifests its potential applications in seawater desalination.The related mechanism has been rationalized based upon the nanoporous network,localized surface plasmon resonance effect and hydrophilicity.展开更多
Interfacial solar steam generation(ISSG)is a novel and potential solution to global freshwater crisis.Here,based on a facile sol-gel fabrication process,we demonstrate a highly scalable Janus aramid nanofiber aerogel(...Interfacial solar steam generation(ISSG)is a novel and potential solution to global freshwater crisis.Here,based on a facile sol-gel fabrication process,we demonstrate a highly scalable Janus aramid nanofiber aerogel(JANA)as a high-efficiency ISSG device.JANA performs near-perfect broadband optical absorption,rapid photothermal conversion and effective water transportation.Owning to these features,efficient desalination of salty water and purification of municipal sewage are successfully demonstrated using JANA.In addition,benefiting from the mechanical property and chemical stability of constituent aramid nanofibers,JANA not only possesses outstanding flexibility and fire-resistance properties,but its solar steaming efficiency is also free from the influences of elastic deformations and fire treatments.We envision JANA provides a promising platform for mass-production of high-efficiency ISSG devices with supplementary capabilities of convenient transportation and long-term storage,which could further promote the realistic applications of ISSG technology.展开更多
The utilization of nanoporous copper(np-Cu)as a metallic actuator has gained attention in recent years due to its cost-effectiveness in comparison to other precious metals.Despite this,the enhancement of np-Cu’s actu...The utilization of nanoporous copper(np-Cu)as a metallic actuator has gained attention in recent years due to its cost-effectiveness in comparison to other precious metals.Despite this,the enhancement of np-Cu’s actuation performance remains a challenge due to limitations in its strain amplitude and actuation rate.Additionally,np-Cu has been deemed as a promising material for solar absorption due to its localized surface plasmon resonance effect.However,practical applications such as solar steam generators(SSGs)utilizing np-Cu have yet to be documented.In this study,we present the development of hierarchically nanoporous copper(HNC)through the dealloying of a eutectic Al-Cu alloy.The hierarchical structure of the HNC features a combination of ordered flat channels and randomly distributed continuous nanopores,which work in synergy to improve actuation performance.The ordered flat channels,with a sub-micron scale,facilitate rapid mass transport of electrolyte ions,while the nano-sized continuous pores,due to their large specific surface area,enhance the induced strain.Our results indicate that the HNC exhibits improved actuation performance,with a two times increase in both strain amplitude and rate in comparison to other reported np-Cu.Additionally,the HNC,for the first time,showcases excellent solar steam generation capabilities,with an evaporation rate of 1.47 kg·m^(-2)·h^(-1) and a photothermal conversion efficiency of 92%under a light intensity of 1 kW·m^(-2),which rivals that of nanoporous gold and silver film.The enhanced actuation performance and newly discovered solar steam generation properties of the HNC are attributed to its hierarchically porous structure.展开更多
The application of solar steam generation in seawater desalination is an effective way to solve the shortage of fresh water resources.At present,many kinds of photothermal conversion materials have been developed and ...The application of solar steam generation in seawater desalination is an effective way to solve the shortage of fresh water resources.At present,many kinds of photothermal conversion materials have been developed and used as evaporators in seawater desalination.However,some evaporators need additional thermal insulation or water supply devices to achieve efficient photothermal conversion.In addition,their complex,time consuming and no scalable preparation process,high cost of raw materials and poor salt resistance hinder the practical application of these evaporator.Owing to its distinctive nanoporous structure,diatomite as fossilized single-cells algae diatoms is a promising natural silica-based material for seawater desalination.They are taken from sea and that makes true sense to use them in the sea.Herein,we report the first example of synthesis robust three-dimensional(3D)natural-diatomite composite by assembling polyaniline nanoparticles covered diatomite into the polyvinyl alcohol pre-treated melamine foam frameworks and demonstrate its application as new evaporator for seawater desalination.The porous framework does not only improve the sunlight scattering efficiency,but also offer large network of channels for water transportation.The inherent mechanism behind salt desalination process involves the absorption of water molecules on the surface of the internal silica micro-nano pores,and evaporation under the heat induced by the polyaniline absorbed sunlight.Meanwhile,the metal ions are segregated by many available pores and channels to achieve the self-desalting effect.The developed evaporator possesses the superiority of multi-stage pore structure,strong hydrophilicity,low thermal conductivity,excellent light absorption,fast water transportation and salt-resistant crystallization as well as good durability.The evaporation rate without an additional device is found to be 1.689 kg m^(-2)h^(-1)under 1-Sun irradiation,and the energy conversion efficiency is as high as 95%.This work creates a platform and develops the prospect of employing green and sustainable natural-diatomite composite evaporator for practical applications of seawater desalination.展开更多
Given the challenges brought by the shortage of freshwater resources,solar water evaporation has been regarded as one of the most promising technologies for harnessing abundant sunlight to harvest clean water from the...Given the challenges brought by the shortage of freshwater resources,solar water evaporation has been regarded as one of the most promising technologies for harnessing abundant sunlight to harvest clean water from the sea.Nanostructured metals have attracted extensive attention in solar water evaporation due to their localized surface plasmon resonance effect,but highly porous metallic films with high evaporation efficiency are challenging.Herein,a self-supporting black nanoporous silver(NP-Ag)film was fabricated by dealloying of an extremely dilute Al99Ag1 alloy.The choice of the dilute precursor guarantees the formation of the NP-Ag film with high porosity(96.5%)and low density(0.3703 g·cm^(-3),even smaller than the lightest metal lithium).The three-dimensional ligament-channel network structure and the nanoscale(14.6 nm)of ligaments enable the NP-Ag film to exhibit good hydrophilicity and broadband absorption over 200‒2,500 nm.More importantly,the solar evaporator based on the NP-Ag film shows efficient solar steam generation,including the efficiency of 92.6%,the evaporation rate of 1.42 kg·m^(-2)·h^(-1)and good cycling stability under one sun irradiation.Moreover,the NP-Ag film exhibits acceptable seawater desalination property with the ion rejection for Mg^(2+),Ca^(2+),K^(+)and Na^(+)more than 99.3%.Our findings could provide a new idea and inspiration for the design and fabrication of metal-based photothermal films in real solar evaporation applications.展开更多
The scarcity of fresh water resources has become a serious issue hindering the sustainable development of modern civilization.The interfacial solar steam generation(ISSG)system that produces heat on material surface t...The scarcity of fresh water resources has become a serious issue hindering the sustainable development of modern civilization.The interfacial solar steam generation(ISSG)system that produces heat on material surface through photothermal conversion for desalination has been demonstrated as a promising candidate for practical application.Fibrous materials with unique flexibility,durability,processability,practicability,and multifunctionality have attracted considerable attention in the ISSG field.In this review,the basics of fibrous materials,such as their classification,manufacturing methods and flexible fibrous structure,are firstly introduced.Afterward,the outstanding properties of fibrous materials on different dimensions are demonstrated,as well as the versatile morphologies and structures that allow fibrous materials to carry out different roles in ISSG.Moreover,the practicability and multifunctionality of fibrous materials are illustrated in detail by combining specific cases to show their promising potential in practical ISSG application.Finally,existing challenges and future opportunities of fibrous material-based ISSG systems are discussed.展开更多
Many efforts have been focused on enhancing the vapor generation in bi-layer solar steam generation systems for obtaining as much pure water as possible.However,the methods to enhance the vapor temperature is seldom s...Many efforts have been focused on enhancing the vapor generation in bi-layer solar steam generation systems for obtaining as much pure water as possible.However,the methods to enhance the vapor temperature is seldom studied although the high-temperature vapor has a wide use in medical sterilization and electricity generation.In this work,to probe the high-temperature vapor system,an improved macroscopic heat and mass transfer model was proposed.Then,using the finite element method to solve the model,the influences of some main factors on the evaporation efficiency and vapor temperature were discussed,including effects of the vapor transport conditions and the heat dissipation conditions.The results show that the high-temperature vapor could not be obtained by enhancing the heat-insulating property of the bi-layer systems but by applying the optimal porosity and proper absorbers.This paper is expected to provide some information for designing a bi-layered system to produce high-temperature vapor.展开更多
Interfacial solar steam generation holds great promise in water desalination thanks to its high energy efficiency by heating only the top layer of water for evaporation.While three‐dimensional(3D)evaporators have bee...Interfacial solar steam generation holds great promise in water desalination thanks to its high energy efficiency by heating only the top layer of water for evaporation.While three‐dimensional(3D)evaporators have been proven to increase the evaporation rate by harnessing the energy from the surroundings,further development is still required in terms of convenient fabrication with potential scalability.Herein,we propose to overcome this challenge by using a high internal phase emulsion(HIPE)to template the synthesis of 3D hierarchically porous evaporators.The HIPE‐templated synthesis combined with a molding process can efficiently fabricate the desired 3D shape without wasting any materials and generate a hierarchically porous internal structure for continuous water supply.Engineering the overall shape and internal pores produces a 3D evaporator that can suppress conduction heat loss and efficiently collect thermal energy from its surroundings,boosting the evaporation rate to 2.82 kg/(m2 h)under 1‐sun illumination,which is significantly higher than conventional 2D evaporators.HIPE‐templating synthesis is an easy but effective way to produce various porous polymers,promising for a wide range of applications where easy production,excellent shape control,and potential scalability are critical.展开更多
Effective utilization of abundant solar energy for desalination of seawater and purification of wastewater is one of sustainable techniques for production of clean water,helping relieve global water resource shortage....Effective utilization of abundant solar energy for desalination of seawater and purification of wastewater is one of sustainable techniques for production of clean water,helping relieve global water resource shortage.Herein,we fabricate a vertically aligned reduced graphene oxide/Ti_(3)C_(2)T_(x)MXene(A-RGO/MX)hybrid hydrogel with aligned channels as an independent solar steam generation device for highly efficient solar steam generation.The vertically aligned channels,generated by a liquid nitrogen-assisted directional-freezing process,not only rapidly transport water upward to the evaporation surface for efficient solar steam generation,but also facilitate multiple reflections of solar light inside the channels for efficient solar light absorption.The deliberate slight reduction endows the RGO with plenty of polar groups,decreasing the water vaporization enthalpy effectively and hence accelerating water evaporation efficiently.The MXene sheets,infiltrated inside the A-RGO hydrogel on the basis of Marangoni effect,enhance light absorption capacity and photothermal conversion performance.As a result,the A-RGO/MX hybrid hydrogel achieves a water evaporation rate of 2.09 kg·m^(−2)·h^(−1)with a high conversion efficiency of 93.5%under 1-sun irradiation.Additionally,this photothermal conversion hydrogel rapidly desalinates seawater and purifies wastewater to generate clean water with outstanding ion rejection rates of above 99%for most ions.展开更多
Interfacial solar steam generation(ISSG)system has attracted extensive attention as a sustainable desalination technology because of its cost efficiency and zero fossil-energy consumption.Aiming at optimizing the desa...Interfacial solar steam generation(ISSG)system has attracted extensive attention as a sustainable desalination technology because of its cost efficiency and zero fossil-energy consumption.Aiming at optimizing the desalination properties,materials and system design have been the current research focus.Recently,many novel bio-derived/bio-inspired design strategies were proposed owing to their highly efficient structures inherited from nature,which were fine-tuned over eons of evolution,as well as their low cost and ease of treatment.In this review,we are going to systematically report recent progress of various bio-derived/bio-inspired strategies in terms of optical design,wetting,thermal management,and overall system design,presenting an overview of the current challenges of bio-inspired materials in ISSG system and other application fields.This article is intended to provide a comprehensive review of recent developments about bio-derived/bio-inspired materials in ISSG system and conclude with suggestions regarding further research directions for performance enhancement through design of bio-derived/bio-inspired materials.展开更多
Capturing solar energy as heat for water treatment has become a substantial approach to obtain freshwater.To obtain higher performance,the understanding of the mechanism of how water molecules interact with the interf...Capturing solar energy as heat for water treatment has become a substantial approach to obtain freshwater.To obtain higher performance,the understanding of the mechanism of how water molecules interact with the interface is particularly fundamental,because the migration process of water molecules on the evaporation interface will directly affect the performance of the device.Herein we regulate the number of hydroxyl groups on the surface of reduced graphene oxide quantitatively,to study the effect of different wettability of interfaces on the performance of solar water generators.The water evaporation performance displays a volcanic shape as increasing wettability.Calculated by the computational chemistry method,deviation from proper wetting humidity is not conducive to the migration of water molecules from the surface.The double-edged sword effect of wettability on performances is clarified,and the surface energy density is the key to break through the limit by the finite element method.展开更多
Graphene oxide(GO)is regarded as a promising candidate to construct solar absorbers for addressing freshwater crisis,but the easy delamination of GO in water poses a critical challenge for practical solar desalination...Graphene oxide(GO)is regarded as a promising candidate to construct solar absorbers for addressing freshwater crisis,but the easy delamination of GO in water poses a critical challenge for practical solar desalination.Herein,we improve the stability of GO membranes by a self-crosslinking poly(ionic liquid)(PIL)in a mild condition,which crosslinks neighbouring GO nanosheets without blemishing the hydrophilic structure of GO.By further adding carbon nanotubes(CNTs),the sandwiched GO/CNT@PIL(GCP)membrane displays a good stability in pH=1 or 13 solution even for 270 days.The molecular dynamics simulation results indicate that the generation of water nanofluidics in nanochannels of GO nanosheets remarkably reduces the water evaporation enthalpy in GCP membrane,compared to bulk water.Consequently,the GCP membrane exhibits a high evaporation rate(1.87 kg m^(-2)h^(-1))and displays stable evaporation rates for 14 h under 1 kW m^(-2)irradiation.The GCP membrane additionally works very well when using different water sources(e.g.,dye-polluted water)or even strong acidic solution(pH=1)or basic solution(pH=13).More importantly,through bundling pluralities of GCP membrane,an efficient solar desalination device is developed to produce drinkable water from seawater.The average daily drinkable water amount in sunny day is 10.1 kg m^(-2),which meets with the daily drinkable water needs of five adults.The high evaporation rate,long-time durability and good scalability make the GCP membrane an outstanding candidate for practical solar seawater desalination.展开更多
Developing a highly efficient system for solar steam generation(SSG)using a straightforward and eco-friendly method to harvest freshwater is fascinating but challenging.Here,we stir the mixture of brewed tea and HAuCl...Developing a highly efficient system for solar steam generation(SSG)using a straightforward and eco-friendly method to harvest freshwater is fascinating but challenging.Here,we stir the mixture of brewed tea and HAuCl4 to prepare Au nanoflowers,possessing broad wavelength light absorption and excellent photothermal effects.After freeze-drying the mixture of Au nanoflowers,cellulose nanocrystals(CNCs),and aqueous polyurethane(PU)emulsion,we obtain three-dimensional(3D)porous structures(CNC-PU-Au)for SSG.The whole process does not involve any sophisticated procedure or produce detrimental byproducts.The evaporation rates are 2.24 kg·m^(−2)·h^(−1) for pure water and 2.18 kg·m^(−2)·h^(−1) for seawater using CNC-PU-Au under one sun.The solar energy conversion efficiency is up to 90.92%under one sun illumination.Besides,CNC-PU-Au shows self-driven salt resistance and durability.In outdoors application for seawater desalination,the maximum evaporation rate can maintain at 2.19 kg·m^(−2)·h^(−1) in spring and 3.42 kg·m^(−2)·h^(−1) in summer.These unique features promise the utility of CNC-PU-Au in the ecofriendly water treatment industry.展开更多
The thermal stress-induced deformation issue of receiver is crucial to the performance and reliability of a parabolic-trough(PT) concentrating solar power(CSP) system with the promising direct steam generation(DSG) te...The thermal stress-induced deformation issue of receiver is crucial to the performance and reliability of a parabolic-trough(PT) concentrating solar power(CSP) system with the promising direct steam generation(DSG) technology.The objective of the present study is to propose a new-type receiver with axially-hollow spiral deflector and optimize the geometric structure to solve the above issue.To this end,optical-flow-thermal multi-physics coupling models have been established for the preheating,boiling and superheating sections of a typical PT-DSG loop.The simulation results show that our proposed new-type receiver demonstrates outstanding comprehensive performance.It can minimize the circumferential temperature difference through the spiral deflector while lower the flow resistance cost through the axially hollow structure at the same time.As quantitatively evaluated by the temperature uniformity improvement(ε_(ΔT)) and the performance evaluation criteria(PEC),different designs are achieved based on different optimal schemes.When ε_(ΔT)is of primary importance,the optimal design with torsional ratio of 1 is achieved,with ε_(ΔT)=25.4%,25.7%,41.5% and PEC=0.486,0.878,0.596corresponding to preheating,boiling,superheating sections,respectively.When PEC is of primary importance,the optimal design with torsional ratio of 6-6.5 is achieved,with PEC=0.950,2.070,0.993 and ε_(ΔT)=18.2%,13.3 %,19.4% corresponding to preheating,boiling,superheating sections,respectively.展开更多
Wood-based bilayer solar evaporators,which possess cooperative advantages of natural wood and photothermal conversion coating including fast water transportation,low heat conduction,renewability,and high light absorba...Wood-based bilayer solar evaporators,which possess cooperative advantages of natural wood and photothermal conversion coating including fast water transportation,low heat conduction,renewability,and high light absorbability,hold great promise for water purification.However,previous studies suffer from low evaporation rates and high cost of coatings,and lack a deep understanding how the porous structures of coating layer function.Herein,a novel bilayer solar evaporator is designed through facile surface coating of wood by low-cost porous carbon from controlled carbonization of polyester waste.The porous carbon bears rich oxygen-containing groups,well-controlled micro-/meso-/macropores,and high surface areas(1164 m^(2) g^(−1)).It is proved that porous carbon improves sunlight absorption and promotes the formation of numerous water clusters to reduce water evaporation enthalpy.Owing to these combined features,the bilayer solar evaporator exhibits high evaporation rate(2.38 kg m^(−2) h^(−1)),excellent longterm stability,and good salt resistance.More importantly,a large-scale solar desalination device for outdoor experiments is developed to produce freshwater from seawater.The daily freshwater production amount(3.65 kg m^(−2))per unit area meets the daily water consumption requirement of one adult.These findings will inspire new paradigms toward developing efficient solar steaming technologies for desalination to address global freshwater shortage.展开更多
Harvesting water from the air using adsorbents and obtaining fresh water by solar-driven desorption is considered as one of the most effective ways to solve the freshwater crisis in arid and desert regions.Based on a ...Harvesting water from the air using adsorbents and obtaining fresh water by solar-driven desorption is considered as one of the most effective ways to solve the freshwater crisis in arid and desert regions.Based on a simple and low-cost photothermal hygroscopic hydrogel,a new strategy is proposed to boost solar energy efficiency by coupling solar-driven atmospheric water harvesting technology with thermoelectric power generation technology in this paper.Photothermal hygroscopic hydrogel ink PAM-CaCl_(2)is prepared by in situ polymerization using Acrylamide as monomer,Ammonium persulfate as thermal initiator and CaCl_(2)as hygroscopic component.During the day,the photothermal hygroscopic hydrogel absorbs solar energy and evaporates its own internal water to obtain fresh water.Simultaneously,the residual waste heat is utilized to power the thermoelectric panel,which produces electricity based on Seebeck effect.At night,the hydrogel harvests water molecules in the air to achieve regeneration.This hybrid system can achieve a water production rate of 0.33 kg m^(-2)h^(-1)and an additional electrical energy gain of 124 mW m^(-2)at 1 kW m^(-2)solar intensity.Theoretical model of the hybrid system is developed to understand the heat flow and thermoelectric generation process.The results provide new insights into energy and freshwater replenishment options in arid or desert areas with abundant solar energy.展开更多
Solar-thermal water evaporation has attracted increasing attention owing to the promising potential to solve the global clean water and energy crisis.But,the development of this strategy is limited by the lack of mate...Solar-thermal water evaporation has attracted increasing attention owing to the promising potential to solve the global clean water and energy crisis.But,the development of this strategy is limited by the lack of materials with high solar-thernal conversion efficiency,local heating of superficial water,easy preparation and low cost.Herein,we proposed a facile strategy to prepare a reduced graphene oxide/carbon fiber composite membrane,denoted as RGO/CF membrane.The surface of the RGO/CF membrane was highly hydrophobic,endowing the composite membrane with the self-floating ability on the water without any assistance.The light absorbance ability achieved as high as ca.98%in the wavelength range of 300-1200 nm.The steam evaporation efliciency under the illumination of3-sun was 97%,generating water steam at a rate of 4.54 kg·m^-2·h^-1.Moreover,the solar-thermal steam production rate showed high stability during successive 30 cvcle tests.展开更多
Solar-driven water evaporation is a sustainable method to purify seawater.Nevertheless,traditional volumetric water-evaporation systems suffer from the poor sunlight absorption and inefficient light-to-thermal convers...Solar-driven water evaporation is a sustainable method to purify seawater.Nevertheless,traditional volumetric water-evaporation systems suffer from the poor sunlight absorption and inefficient light-to-thermal conversion.Also,their anti-bacterial and antifouling performances are crucial for the practical application.Herein,we introduce reduced graphene oxide(RGO)with broadband absorbance across the entire solar spectrum,and polypyrrole(PPy),an antibacterial polymer with efficient solar absorption and low thermal conductivity,to develop integrated RGO/PPy aerogel as both the solar absorber and evaporator for highly efficient solar-driven steam generation.As a result,the RGO/PPy aerogel shows strong absorption and good photothermal performance,leading to an evaporation rate of 1.44 kg·m^(−2)·h^(−1)and high salt rejection(up to 99.99%)for real seawater,with photothermal conversion efficiency>90%under one sun irradiation.The result is attributed to the localized heat at the air-water interface by the RGO/PPy and its porous nature with functional groups that facilitates the water evaporation.Moreover,the RGO/PPy demonstrates excellent durability and antibacterial efficiency close to 100%for 12 h,crucial characteristics for longterm application.Our well-designed RGO/PPy aerogel with efficient water desalination performance and antibacterial property provides a straightforward approach to improve the solar-driven evaporation performance by multifunctional materials integration,and offers a viable route towards practical seawater desalination.展开更多
Janus electrospinning nanofiber membranes have attracted extensive attention in the fields such as solar-driven interfacial desalination,liquid filtration,and waterproof and breathable fabrics.However,the Janus struct...Janus electrospinning nanofiber membranes have attracted extensive attention in the fields such as solar-driven interfacial desalination,liquid filtration,and waterproof and breathable fabrics.However,the Janus structures suffer from weak interfacial bonding and vulnerability to damage,making the durability and sustainability are highly sought after in real-word applications.Herein,we fabricate the simply reconfigurable and entirely self-healing Janus evaporator by electrospinning polypropylene glycol based polyurethane(PPG@PU)and polydimethylsiloxane based polyurethane-CNTs(PDMS@PU-CNTs)with different wettability,which are both designed based on dynamic Diels–Alder(DA)bond.The interface of the Janus membrane is stitched by the covalent bonds to directly improve the interface adhesion to 22 N·m−1,constructing an integrated evaporator,and thereby achieving a stable desalination rate of 1.34 kg·m−2·h−1 under one sun.Reversible dissociation of DA networks allows the evaporators for self-healing and reconfiguration abilities,after which the photothermal performance is maintained.This is the first work for the crosslinked self-healing polymer to be directly electrospun,achieving the improved interfacial bond and reconfiguration of entire evaporators,which presented promising new design principles and materials for interfacial solar seawater desalination.展开更多
Although solar steam generation is an eco-friendly approach for desalinating seawater and purifying wastewater,there are still issues on how to improve the efficiency of solar energy utilization and accelerate the wat...Although solar steam generation is an eco-friendly approach for desalinating seawater and purifying wastewater,there are still issues on how to improve the efficiency of solar energy utilization and accelerate the water and heat transport inside the solardriven water evaporators.Herein,we design a central hollow cylindrical reduced graphene oxide(RGO)foam with vertically and radially orientated channels as a solar steam generation device for efficient water evaporation and purification.The vertically aligned porous channels accelerate upward transport of water to the top evaporation surface,while the radially aligned porous channels facilitate water transport and heat transfer along the radial directions for fully utilizing the heat accumulated inside the central cylindrical hole of the foam.The central hole of the foam plays a highly positive role in accumulating more heat for accelerating the water evaporation,the newly generated inner sidewall resulted from the central hole can gain extra thermal energy from surrounding environment in the same way as the outer sidewall of the foam due to the surface cooling effect of the water evaporation.As a result,the vertically and radially aligned RGO foam evaporator with central hollow cylinder achieves a high solar steam generation rate of 2.32 kg·m^(−2)·h^(−1)with an exceptional energy conversion efficiency of 120.9%under 1-sun irradiation,superior to the vertically aligned RGO foam without the central hole(1.83 kg·m^(−2)·h^(−1),96.9%)because of the enhanced water and heat transfer inside the porous channels,the efficient utilization of environmental energy.展开更多
基金financial support by the Key Research and Development Program of Shandong Province(2021ZLGX01)the support of Taishan Scholar Foundation of Shandong Province+1 种基金the Natural Science Foundation of Shandong Province(ZR2021QE229,ZR2022QB169)the Postdoctoral Science foundation of China(2022M710077)。
文摘Solar steam generation(SSG)is a potential technology for freshwater production,which is expected to address the global water shortage problem.Some noble metals with good photothermal conversion performance have received wide concerns in SSG,while high cost limits their practical applications for water purification.Herein,a self-supporting nanoporous copper(NP-Cu)film was fabricated by one-step dealloying of a specially designed Al_(98)Cu_(2)precursor with a dilute solid solution structure.In-situ and ex-situ characterizations were performed to reveal the phase and microstructure evolutions during dealloying.The NP-Cu film shows a unique three-dimensional bicontinuous ligament-channel structure with high porosity(94.8%),multi scale-channels and nanoscale ligaments(24.2±4.4nm),leading to its strong broadband absorption over the 200–2500 nm wavelength More importantly,the NP-Cu film exhibits excellent SSG performance with high evaporation rate,superior efficiency and good stability.The strong desalination ability of NP-Cu also manifests its potential applications in seawater desalination.The related mechanism has been rationalized based upon the nanoporous network,localized surface plasmon resonance effect and hydrophilicity.
基金jointly supported by the National Natural Science Foundation of China (no. 62105142)Natural Science Foundation of Jiangsu Province (BK20220068)+1 种基金the Center Fundamental Research Funds for the Central UniversitiesEntrepreneurship and Innovation Program of Jiangsu Province (JSSCBS20210002)。
文摘Interfacial solar steam generation(ISSG)is a novel and potential solution to global freshwater crisis.Here,based on a facile sol-gel fabrication process,we demonstrate a highly scalable Janus aramid nanofiber aerogel(JANA)as a high-efficiency ISSG device.JANA performs near-perfect broadband optical absorption,rapid photothermal conversion and effective water transportation.Owning to these features,efficient desalination of salty water and purification of municipal sewage are successfully demonstrated using JANA.In addition,benefiting from the mechanical property and chemical stability of constituent aramid nanofibers,JANA not only possesses outstanding flexibility and fire-resistance properties,but its solar steaming efficiency is also free from the influences of elastic deformations and fire treatments.We envision JANA provides a promising platform for mass-production of high-efficiency ISSG devices with supplementary capabilities of convenient transportation and long-term storage,which could further promote the realistic applications of ISSG technology.
基金support from the Key Research and Development Program of Shandong Province(No.2021ZLGX01)the National Natural Science Foundation of China(No.52001234)the Taishan Scholar Foundation of Shandong Province.
文摘The utilization of nanoporous copper(np-Cu)as a metallic actuator has gained attention in recent years due to its cost-effectiveness in comparison to other precious metals.Despite this,the enhancement of np-Cu’s actuation performance remains a challenge due to limitations in its strain amplitude and actuation rate.Additionally,np-Cu has been deemed as a promising material for solar absorption due to its localized surface plasmon resonance effect.However,practical applications such as solar steam generators(SSGs)utilizing np-Cu have yet to be documented.In this study,we present the development of hierarchically nanoporous copper(HNC)through the dealloying of a eutectic Al-Cu alloy.The hierarchical structure of the HNC features a combination of ordered flat channels and randomly distributed continuous nanopores,which work in synergy to improve actuation performance.The ordered flat channels,with a sub-micron scale,facilitate rapid mass transport of electrolyte ions,while the nano-sized continuous pores,due to their large specific surface area,enhance the induced strain.Our results indicate that the HNC exhibits improved actuation performance,with a two times increase in both strain amplitude and rate in comparison to other reported np-Cu.Additionally,the HNC,for the first time,showcases excellent solar steam generation capabilities,with an evaporation rate of 1.47 kg·m^(-2)·h^(-1) and a photothermal conversion efficiency of 92%under a light intensity of 1 kW·m^(-2),which rivals that of nanoporous gold and silver film.The enhanced actuation performance and newly discovered solar steam generation properties of the HNC are attributed to its hierarchically porous structure.
基金the Qingdao Innovation Leading Talent Program,National Natural Science Foundation of China(21805124)Natural Science Foundation of Shandong Province(ZR2018BEM020).
文摘The application of solar steam generation in seawater desalination is an effective way to solve the shortage of fresh water resources.At present,many kinds of photothermal conversion materials have been developed and used as evaporators in seawater desalination.However,some evaporators need additional thermal insulation or water supply devices to achieve efficient photothermal conversion.In addition,their complex,time consuming and no scalable preparation process,high cost of raw materials and poor salt resistance hinder the practical application of these evaporator.Owing to its distinctive nanoporous structure,diatomite as fossilized single-cells algae diatoms is a promising natural silica-based material for seawater desalination.They are taken from sea and that makes true sense to use them in the sea.Herein,we report the first example of synthesis robust three-dimensional(3D)natural-diatomite composite by assembling polyaniline nanoparticles covered diatomite into the polyvinyl alcohol pre-treated melamine foam frameworks and demonstrate its application as new evaporator for seawater desalination.The porous framework does not only improve the sunlight scattering efficiency,but also offer large network of channels for water transportation.The inherent mechanism behind salt desalination process involves the absorption of water molecules on the surface of the internal silica micro-nano pores,and evaporation under the heat induced by the polyaniline absorbed sunlight.Meanwhile,the metal ions are segregated by many available pores and channels to achieve the self-desalting effect.The developed evaporator possesses the superiority of multi-stage pore structure,strong hydrophilicity,low thermal conductivity,excellent light absorption,fast water transportation and salt-resistant crystallization as well as good durability.The evaporation rate without an additional device is found to be 1.689 kg m^(-2)h^(-1)under 1-Sun irradiation,and the energy conversion efficiency is as high as 95%.This work creates a platform and develops the prospect of employing green and sustainable natural-diatomite composite evaporator for practical applications of seawater desalination.
基金the financial support by the National Natural Science Foundation of China(No.51871133)the Taishan Scholar Foundation of Shandong Province,the Key Research and Development Program of Shandong Province(No.2021ZLGX01)the program of Jinan Science and Technology Bureau(No.2019GXRC001).
文摘Given the challenges brought by the shortage of freshwater resources,solar water evaporation has been regarded as one of the most promising technologies for harnessing abundant sunlight to harvest clean water from the sea.Nanostructured metals have attracted extensive attention in solar water evaporation due to their localized surface plasmon resonance effect,but highly porous metallic films with high evaporation efficiency are challenging.Herein,a self-supporting black nanoporous silver(NP-Ag)film was fabricated by dealloying of an extremely dilute Al99Ag1 alloy.The choice of the dilute precursor guarantees the formation of the NP-Ag film with high porosity(96.5%)and low density(0.3703 g·cm^(-3),even smaller than the lightest metal lithium).The three-dimensional ligament-channel network structure and the nanoscale(14.6 nm)of ligaments enable the NP-Ag film to exhibit good hydrophilicity and broadband absorption over 200‒2,500 nm.More importantly,the solar evaporator based on the NP-Ag film shows efficient solar steam generation,including the efficiency of 92.6%,the evaporation rate of 1.42 kg·m^(-2)·h^(-1)and good cycling stability under one sun irradiation.Moreover,the NP-Ag film exhibits acceptable seawater desalination property with the ion rejection for Mg^(2+),Ca^(2+),K^(+)and Na^(+)more than 99.3%.Our findings could provide a new idea and inspiration for the design and fabrication of metal-based photothermal films in real solar evaporation applications.
基金support from the National Natural Science Foundation of China(52173059,U21A2095)The Major Basic Research Project of the Natural Science Foundation of the Jiangsu Higher Education Institutions(21KJA540002)The Key Research and Development Program of Hubei Province(2021BAA068).
文摘The scarcity of fresh water resources has become a serious issue hindering the sustainable development of modern civilization.The interfacial solar steam generation(ISSG)system that produces heat on material surface through photothermal conversion for desalination has been demonstrated as a promising candidate for practical application.Fibrous materials with unique flexibility,durability,processability,practicability,and multifunctionality have attracted considerable attention in the ISSG field.In this review,the basics of fibrous materials,such as their classification,manufacturing methods and flexible fibrous structure,are firstly introduced.Afterward,the outstanding properties of fibrous materials on different dimensions are demonstrated,as well as the versatile morphologies and structures that allow fibrous materials to carry out different roles in ISSG.Moreover,the practicability and multifunctionality of fibrous materials are illustrated in detail by combining specific cases to show their promising potential in practical ISSG application.Finally,existing challenges and future opportunities of fibrous material-based ISSG systems are discussed.
文摘Many efforts have been focused on enhancing the vapor generation in bi-layer solar steam generation systems for obtaining as much pure water as possible.However,the methods to enhance the vapor temperature is seldom studied although the high-temperature vapor has a wide use in medical sterilization and electricity generation.In this work,to probe the high-temperature vapor system,an improved macroscopic heat and mass transfer model was proposed.Then,using the finite element method to solve the model,the influences of some main factors on the evaporation efficiency and vapor temperature were discussed,including effects of the vapor transport conditions and the heat dissipation conditions.The results show that the high-temperature vapor could not be obtained by enhancing the heat-insulating property of the bi-layer systems but by applying the optimal porosity and proper absorbers.This paper is expected to provide some information for designing a bi-layered system to produce high-temperature vapor.
基金supported by the University of California Riverside and the Korea Institute of Materials Science through the UC‐KIMS Center for Innovation Materials for Energy and EnvironmentJinxing Chen acknowledges the support of the National Natural Science Foundation of China(Grant No.51901147)the Su‐Zhou Key Laboratory of Functional Nano and Soft Materials,Collaborative Innovation Center of Suzhou Nano Science and Technology,and the 111 Project.The authors also thank Ms.Jessica Lujia Yin and Mr.Zirui Zhou for their kind assistance.
文摘Interfacial solar steam generation holds great promise in water desalination thanks to its high energy efficiency by heating only the top layer of water for evaporation.While three‐dimensional(3D)evaporators have been proven to increase the evaporation rate by harnessing the energy from the surroundings,further development is still required in terms of convenient fabrication with potential scalability.Herein,we propose to overcome this challenge by using a high internal phase emulsion(HIPE)to template the synthesis of 3D hierarchically porous evaporators.The HIPE‐templated synthesis combined with a molding process can efficiently fabricate the desired 3D shape without wasting any materials and generate a hierarchically porous internal structure for continuous water supply.Engineering the overall shape and internal pores produces a 3D evaporator that can suppress conduction heat loss and efficiently collect thermal energy from its surroundings,boosting the evaporation rate to 2.82 kg/(m2 h)under 1‐sun illumination,which is significantly higher than conventional 2D evaporators.HIPE‐templating synthesis is an easy but effective way to produce various porous polymers,promising for a wide range of applications where easy production,excellent shape control,and potential scalability are critical.
基金support from the National Natural Science Foundation of China(Nos.51773008,51533001,and U1905217)the Fundamental Research Funds for the Central Universities(No.XK1802).
文摘Effective utilization of abundant solar energy for desalination of seawater and purification of wastewater is one of sustainable techniques for production of clean water,helping relieve global water resource shortage.Herein,we fabricate a vertically aligned reduced graphene oxide/Ti_(3)C_(2)T_(x)MXene(A-RGO/MX)hybrid hydrogel with aligned channels as an independent solar steam generation device for highly efficient solar steam generation.The vertically aligned channels,generated by a liquid nitrogen-assisted directional-freezing process,not only rapidly transport water upward to the evaporation surface for efficient solar steam generation,but also facilitate multiple reflections of solar light inside the channels for efficient solar light absorption.The deliberate slight reduction endows the RGO with plenty of polar groups,decreasing the water vaporization enthalpy effectively and hence accelerating water evaporation efficiently.The MXene sheets,infiltrated inside the A-RGO hydrogel on the basis of Marangoni effect,enhance light absorption capacity and photothermal conversion performance.As a result,the A-RGO/MX hybrid hydrogel achieves a water evaporation rate of 2.09 kg·m^(−2)·h^(−1)with a high conversion efficiency of 93.5%under 1-sun irradiation.Additionally,this photothermal conversion hydrogel rapidly desalinates seawater and purifies wastewater to generate clean water with outstanding ion rejection rates of above 99%for most ions.
基金This work was financially supported by research grants from the National Natural Science Foundation of China(No.52173235)Natural Science Foundation of Chongqing(No.cstc2018jcyjAX0375)+1 种基金Fundamental Research Funds for the Central Universities(Nos.2020CDJQY-A055 and 2019CDXYDL0007)Key Innovation Project for Clinical Technology of the Second Affiliated Hospital of Army Medical University(No.2018JSLC0025).
文摘Interfacial solar steam generation(ISSG)system has attracted extensive attention as a sustainable desalination technology because of its cost efficiency and zero fossil-energy consumption.Aiming at optimizing the desalination properties,materials and system design have been the current research focus.Recently,many novel bio-derived/bio-inspired design strategies were proposed owing to their highly efficient structures inherited from nature,which were fine-tuned over eons of evolution,as well as their low cost and ease of treatment.In this review,we are going to systematically report recent progress of various bio-derived/bio-inspired strategies in terms of optical design,wetting,thermal management,and overall system design,presenting an overview of the current challenges of bio-inspired materials in ISSG system and other application fields.This article is intended to provide a comprehensive review of recent developments about bio-derived/bio-inspired materials in ISSG system and conclude with suggestions regarding further research directions for performance enhancement through design of bio-derived/bio-inspired materials.
基金funding from the National Natural Science Foundation of China(Nos.21871009 and 21527803)the Youth Science Foundation of Hubei University(No.202011303000002)China Postdoctoral Science Foundation(No.2018M641064).
文摘Capturing solar energy as heat for water treatment has become a substantial approach to obtain freshwater.To obtain higher performance,the understanding of the mechanism of how water molecules interact with the interface is particularly fundamental,because the migration process of water molecules on the evaporation interface will directly affect the performance of the device.Herein we regulate the number of hydroxyl groups on the surface of reduced graphene oxide quantitatively,to study the effect of different wettability of interfaces on the performance of solar water generators.The water evaporation performance displays a volcanic shape as increasing wettability.Calculated by the computational chemistry method,deviation from proper wetting humidity is not conducive to the migration of water molecules from the surface.The double-edged sword effect of wettability on performances is clarified,and the surface energy density is the key to break through the limit by the finite element method.
基金the financial support of the National Key R&D Program of China(No.2019YFC1806000)the Huazhong University of Science and Technology(No.3004013118)+2 种基金support from the National Natural Science Foundation of China(No.51903099)Huazhong University of Science and Technology(No.3004013134)the 100 Talents Program of the Hubei Provincial Government.Z.D.thanks the Postdoctoral Science Foundation of China(No.0106013063).
文摘Graphene oxide(GO)is regarded as a promising candidate to construct solar absorbers for addressing freshwater crisis,but the easy delamination of GO in water poses a critical challenge for practical solar desalination.Herein,we improve the stability of GO membranes by a self-crosslinking poly(ionic liquid)(PIL)in a mild condition,which crosslinks neighbouring GO nanosheets without blemishing the hydrophilic structure of GO.By further adding carbon nanotubes(CNTs),the sandwiched GO/CNT@PIL(GCP)membrane displays a good stability in pH=1 or 13 solution even for 270 days.The molecular dynamics simulation results indicate that the generation of water nanofluidics in nanochannels of GO nanosheets remarkably reduces the water evaporation enthalpy in GCP membrane,compared to bulk water.Consequently,the GCP membrane exhibits a high evaporation rate(1.87 kg m^(-2)h^(-1))and displays stable evaporation rates for 14 h under 1 kW m^(-2)irradiation.The GCP membrane additionally works very well when using different water sources(e.g.,dye-polluted water)or even strong acidic solution(pH=1)or basic solution(pH=13).More importantly,through bundling pluralities of GCP membrane,an efficient solar desalination device is developed to produce drinkable water from seawater.The average daily drinkable water amount in sunny day is 10.1 kg m^(-2),which meets with the daily drinkable water needs of five adults.The high evaporation rate,long-time durability and good scalability make the GCP membrane an outstanding candidate for practical solar seawater desalination.
基金supported by the Natural Science Foundation for Distinguished Young Scholars of Guangdong Province(No.2020B1515020011)the National Natural Science Foundation of China(Nos.22074094,21801169,and 22005195)China Postdoctoral Science Foundation(No.2020M672797).
文摘Developing a highly efficient system for solar steam generation(SSG)using a straightforward and eco-friendly method to harvest freshwater is fascinating but challenging.Here,we stir the mixture of brewed tea and HAuCl4 to prepare Au nanoflowers,possessing broad wavelength light absorption and excellent photothermal effects.After freeze-drying the mixture of Au nanoflowers,cellulose nanocrystals(CNCs),and aqueous polyurethane(PU)emulsion,we obtain three-dimensional(3D)porous structures(CNC-PU-Au)for SSG.The whole process does not involve any sophisticated procedure or produce detrimental byproducts.The evaporation rates are 2.24 kg·m^(−2)·h^(−1) for pure water and 2.18 kg·m^(−2)·h^(−1) for seawater using CNC-PU-Au under one sun.The solar energy conversion efficiency is up to 90.92%under one sun illumination.Besides,CNC-PU-Au shows self-driven salt resistance and durability.In outdoors application for seawater desalination,the maximum evaporation rate can maintain at 2.19 kg·m^(−2)·h^(−1) in spring and 3.42 kg·m^(−2)·h^(−1) in summer.These unique features promise the utility of CNC-PU-Au in the ecofriendly water treatment industry.
基金financially supported by the National Natural Science Foundation of China (52176202)the Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory (41200101)。
文摘The thermal stress-induced deformation issue of receiver is crucial to the performance and reliability of a parabolic-trough(PT) concentrating solar power(CSP) system with the promising direct steam generation(DSG) technology.The objective of the present study is to propose a new-type receiver with axially-hollow spiral deflector and optimize the geometric structure to solve the above issue.To this end,optical-flow-thermal multi-physics coupling models have been established for the preheating,boiling and superheating sections of a typical PT-DSG loop.The simulation results show that our proposed new-type receiver demonstrates outstanding comprehensive performance.It can minimize the circumferential temperature difference through the spiral deflector while lower the flow resistance cost through the axially hollow structure at the same time.As quantitatively evaluated by the temperature uniformity improvement(ε_(ΔT)) and the performance evaluation criteria(PEC),different designs are achieved based on different optimal schemes.When ε_(ΔT)is of primary importance,the optimal design with torsional ratio of 1 is achieved,with ε_(ΔT)=25.4%,25.7%,41.5% and PEC=0.486,0.878,0.596corresponding to preheating,boiling,superheating sections,respectively.When PEC is of primary importance,the optimal design with torsional ratio of 6-6.5 is achieved,with PEC=0.950,2.070,0.993 and ε_(ΔT)=18.2%,13.3 %,19.4% corresponding to preheating,boiling,superheating sections,respectively.
基金supported by the National Natural Science Foundation of China(No.51903099 and 51991353)Huazhong University of Science and Technology(No.3004013134)the 100 Talents Program of the Hubei Provincial Government,and the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(No.B21003).
文摘Wood-based bilayer solar evaporators,which possess cooperative advantages of natural wood and photothermal conversion coating including fast water transportation,low heat conduction,renewability,and high light absorbability,hold great promise for water purification.However,previous studies suffer from low evaporation rates and high cost of coatings,and lack a deep understanding how the porous structures of coating layer function.Herein,a novel bilayer solar evaporator is designed through facile surface coating of wood by low-cost porous carbon from controlled carbonization of polyester waste.The porous carbon bears rich oxygen-containing groups,well-controlled micro-/meso-/macropores,and high surface areas(1164 m^(2) g^(−1)).It is proved that porous carbon improves sunlight absorption and promotes the formation of numerous water clusters to reduce water evaporation enthalpy.Owing to these combined features,the bilayer solar evaporator exhibits high evaporation rate(2.38 kg m^(−2) h^(−1)),excellent longterm stability,and good salt resistance.More importantly,a large-scale solar desalination device for outdoor experiments is developed to produce freshwater from seawater.The daily freshwater production amount(3.65 kg m^(−2))per unit area meets the daily water consumption requirement of one adult.These findings will inspire new paradigms toward developing efficient solar steaming technologies for desalination to address global freshwater shortage.
基金the National Natural Science Foundation of China(Grant No.52171317)。
文摘Harvesting water from the air using adsorbents and obtaining fresh water by solar-driven desorption is considered as one of the most effective ways to solve the freshwater crisis in arid and desert regions.Based on a simple and low-cost photothermal hygroscopic hydrogel,a new strategy is proposed to boost solar energy efficiency by coupling solar-driven atmospheric water harvesting technology with thermoelectric power generation technology in this paper.Photothermal hygroscopic hydrogel ink PAM-CaCl_(2)is prepared by in situ polymerization using Acrylamide as monomer,Ammonium persulfate as thermal initiator and CaCl_(2)as hygroscopic component.During the day,the photothermal hygroscopic hydrogel absorbs solar energy and evaporates its own internal water to obtain fresh water.Simultaneously,the residual waste heat is utilized to power the thermoelectric panel,which produces electricity based on Seebeck effect.At night,the hydrogel harvests water molecules in the air to achieve regeneration.This hybrid system can achieve a water production rate of 0.33 kg m^(-2)h^(-1)and an additional electrical energy gain of 124 mW m^(-2)at 1 kW m^(-2)solar intensity.Theoretical model of the hybrid system is developed to understand the heat flow and thermoelectric generation process.The results provide new insights into energy and freshwater replenishment options in arid or desert areas with abundant solar energy.
基金Supported by the National Natural Science Foundation of China(No.21706191)the Program for Tianjin Innovative Research Team in Universities,China(No.TD 13-5031)the Tianin"131"Research Team of Innovative Talents,China.
文摘Solar-thermal water evaporation has attracted increasing attention owing to the promising potential to solve the global clean water and energy crisis.But,the development of this strategy is limited by the lack of materials with high solar-thernal conversion efficiency,local heating of superficial water,easy preparation and low cost.Herein,we proposed a facile strategy to prepare a reduced graphene oxide/carbon fiber composite membrane,denoted as RGO/CF membrane.The surface of the RGO/CF membrane was highly hydrophobic,endowing the composite membrane with the self-floating ability on the water without any assistance.The light absorbance ability achieved as high as ca.98%in the wavelength range of 300-1200 nm.The steam evaporation efliciency under the illumination of3-sun was 97%,generating water steam at a rate of 4.54 kg·m^-2·h^-1.Moreover,the solar-thermal steam production rate showed high stability during successive 30 cvcle tests.
基金supported by the National Key R&D Program of China(Nos.2018YFA0209500 and 2018YFA0306900)the National Natural Science Foundation of China(Nos.21872114 and 21627811).
文摘Solar-driven water evaporation is a sustainable method to purify seawater.Nevertheless,traditional volumetric water-evaporation systems suffer from the poor sunlight absorption and inefficient light-to-thermal conversion.Also,their anti-bacterial and antifouling performances are crucial for the practical application.Herein,we introduce reduced graphene oxide(RGO)with broadband absorbance across the entire solar spectrum,and polypyrrole(PPy),an antibacterial polymer with efficient solar absorption and low thermal conductivity,to develop integrated RGO/PPy aerogel as both the solar absorber and evaporator for highly efficient solar-driven steam generation.As a result,the RGO/PPy aerogel shows strong absorption and good photothermal performance,leading to an evaporation rate of 1.44 kg·m^(−2)·h^(−1)and high salt rejection(up to 99.99%)for real seawater,with photothermal conversion efficiency>90%under one sun irradiation.The result is attributed to the localized heat at the air-water interface by the RGO/PPy and its porous nature with functional groups that facilitates the water evaporation.Moreover,the RGO/PPy demonstrates excellent durability and antibacterial efficiency close to 100%for 12 h,crucial characteristics for longterm application.Our well-designed RGO/PPy aerogel with efficient water desalination performance and antibacterial property provides a straightforward approach to improve the solar-driven evaporation performance by multifunctional materials integration,and offers a viable route towards practical seawater desalination.
基金This work was partly supported by the grants(Nos.51973027 and 52003044)the National Natural Science Foundation of China,the Fundamental Research Funds for the Central Universities(No.2232020A-08)+2 种基金International Cooperation Fund of Science and Technology Commission of Shanghai Municipality(No.21130750100)Major Scientific and Technological Innovation Projects of Shandong Province(No.2021CXGC011004)This work has also been supported by the Chang Jiang Scholars Program and the Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-03-E00023)to Prof.X.H.Q.,Young Elite Scientists Sponsorship Program by CAST,State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(KF2216)and DHU Distinguished Young Professor Program to Prof.L.M.W.
文摘Janus electrospinning nanofiber membranes have attracted extensive attention in the fields such as solar-driven interfacial desalination,liquid filtration,and waterproof and breathable fabrics.However,the Janus structures suffer from weak interfacial bonding and vulnerability to damage,making the durability and sustainability are highly sought after in real-word applications.Herein,we fabricate the simply reconfigurable and entirely self-healing Janus evaporator by electrospinning polypropylene glycol based polyurethane(PPG@PU)and polydimethylsiloxane based polyurethane-CNTs(PDMS@PU-CNTs)with different wettability,which are both designed based on dynamic Diels–Alder(DA)bond.The interface of the Janus membrane is stitched by the covalent bonds to directly improve the interface adhesion to 22 N·m−1,constructing an integrated evaporator,and thereby achieving a stable desalination rate of 1.34 kg·m−2·h−1 under one sun.Reversible dissociation of DA networks allows the evaporators for self-healing and reconfiguration abilities,after which the photothermal performance is maintained.This is the first work for the crosslinked self-healing polymer to be directly electrospun,achieving the improved interfacial bond and reconfiguration of entire evaporators,which presented promising new design principles and materials for interfacial solar seawater desalination.
基金the National Natural Science Foundation of China(Nos.U1905217,52090034,and 51773008)the Fundamental Research Funds for the Central Universities(No.XK1802)is gratefully acknowledged.
文摘Although solar steam generation is an eco-friendly approach for desalinating seawater and purifying wastewater,there are still issues on how to improve the efficiency of solar energy utilization and accelerate the water and heat transport inside the solardriven water evaporators.Herein,we design a central hollow cylindrical reduced graphene oxide(RGO)foam with vertically and radially orientated channels as a solar steam generation device for efficient water evaporation and purification.The vertically aligned porous channels accelerate upward transport of water to the top evaporation surface,while the radially aligned porous channels facilitate water transport and heat transfer along the radial directions for fully utilizing the heat accumulated inside the central cylindrical hole of the foam.The central hole of the foam plays a highly positive role in accumulating more heat for accelerating the water evaporation,the newly generated inner sidewall resulted from the central hole can gain extra thermal energy from surrounding environment in the same way as the outer sidewall of the foam due to the surface cooling effect of the water evaporation.As a result,the vertically and radially aligned RGO foam evaporator with central hollow cylinder achieves a high solar steam generation rate of 2.32 kg·m^(−2)·h^(−1)with an exceptional energy conversion efficiency of 120.9%under 1-sun irradiation,superior to the vertically aligned RGO foam without the central hole(1.83 kg·m^(−2)·h^(−1),96.9%)because of the enhanced water and heat transfer inside the porous channels,the efficient utilization of environmental energy.
