Harnessing overlapped temperature-salinity gradient in solar-driven interfacial seawater evaporation for efficient steam and electricity generation

Solar-driven interfacial water evaporation(SIWE)offers a superb way to leverage concentrated solar heat to minimize energy dissipation during seawater desalination.It also engenders overlapped temperaturesalinity gradient(TSG)between water-air interface and adjacent seawater,affording opportunities of harnessing electricity.However,the efficiency of conventional SIWE technologies is limited by significant challenges,including salt passivation to hinder evaporation and difficulties in exploiting overlapped TSG simultaneously.Herein,we report self-sustaining hybrid SIWE for not only sustainable seawater desalination but also efficient electricity generation from TSG.It enables spontaneous circulation of salt flux upon seawater evaporation,inducing a self-cleaning evaporative interface without salt passivation for stable steam generation.Meanwhile,this design enables spatial separation and simultaneous utilization of overlapped TSG to enhance electricity generation.These benefits render a remarkable efficiency of90.8%in solar energy utilization,manifesting in co-generation of solar steam at a fast rate of 2.01 kg m^(-2)-h^(-1)and electricity power of 1.91 W m^(-2)with high voltage.Directly interfacing the hybrid SIWE with seawater electrolyzer constructs a system for water-electricity-hydrogen co-generation without external electricity supply.It produces hydrogen at a rapid rate of 1.29 L h^(-1)m^(-2)and freshwater with 22 times lower Na+concentration than the World Health Organization(WHO)threshold.

Micro–Nano Water Film Enabled High‑Performance Interfacial Solar Evaporation

Interfacial solar evaporation holds great promise to address the freshwater shortage.However,most interfacial solar evaporators are always filled with water throughout the evaporation process,thus bringing unavoidable heat loss.Herein,we propose a novel interfacial evaporation structure based on the micro–nano water film,which demonstrates significantly improved evaporation performance,as experimentally verified by polypyrrole-and polydopamine-coated polydimethylsiloxane sponge.The 2D evaporator based on the as-prepared sponge realizes an enhanced evaporation rate of 2.18 kg m^(−2)h^(−1)under 1 sun by fine-tuning the interfacial micro–nano water film.Then,a homemade device with an enhanced condensation function is engineered for outdoor clean water production.Throughout a continuous test for 40 days,this device demonstrates a high water production rate(WPR)of 15.9–19.4 kg kW^(−1)h^(−1)m^(−2).Based on the outdoor outcomes,we further establish a multi-objective model to assess the global WPR.It is predicted that a 1 m^(2)device can produce at most 7.8 kg of clean water per day,which could meet the daily drinking water needs of 3 people.Finally,this technology could greatly alleviate the current water and energy crisis through further large-scale applications.

Self-Healing Hydrophilic Porous Photothermal Membranes for Durable and Highly Efficient Solar-Driven Interfacial Water Evaporation

It is highly desirable to develop a solar-driven interfacial water evaporatorwith a self-healing ability and high-efficiency water evaporation performance for water distillation and desalination;however,this process is considerably challenging.Herein,by exploiting the advantages of a self-healing hydrophilic polymer,a self-healing hydrophilic porous photothermal(SHPP)membrane was fabricated by curing a mixture of the polymer,carbon black,and NaCl,followed by removal of the NaCl from water.Since the SHPP membrane could serve as a photothermal layer and water transportation channel simultaneously,a solar-driven interfacial evaporator could be fabricated readily by assembling the SHPP membrane with polyethylene foam.We have shown that the SHPP membrane-based evaporator exhibited a water evaporation rate of 1.68 kg m^(−2) h^(−1) and an energy efficiency of 97.3%.These values are superior to those obtained using solar-driven interfacial evaporators with self-healing capability.Notably,by hydrogen bonds reformation between the fracture surfaces,the SHPP membrane could regain its structural integrity after breaking,making the SHPPmembrane-based evaporator the first to heal entirely and repeatedly from physical damage to sustain itswater evaporation capacity.Therefore,the potential of using SHPP membranes to develop stable,long-last ing,andhigh-efficiency solar-driven interfacial water evaporators is highlighted.

Janus membrane with enhanced interfacial activation for solar evaporation

Low solar spectrum coverage,high evaporation enthalpy,and undesired salt deposition severely limited the solar-driven interfacial evaporation technology for further sewage purification and seawater desalination.To overcome these problems,we designed an amphiphilic Janus-structured polyaniline(PANI)/ZrC/cellulose acetate(CA)(J-PZCA) membrane.Firstly,the interfacial interaction between PANI and ZrC enhances the photoabsorption and photothermal conversion efficiency.Secondly,low thermal conductivity reduces the heat lost at the interface.Most importantly,ZrC could facilitate interfacial activation,which weakens the intermolecular forces of water by affecting the hydrogen bond.Under 1 solar irradiation(1 sun),the composite membrane exhibits a high evaporation rate of 1.31 kg m^(-2)h^(-1) and an excellent efficiency of 79.4%.In addition,the sewage purification and seawater desalination experiments reveal a remarkable purification capability of J-PZCA membrane.Especially for the treatment of high-concentration salt solution,it realizes a long-term stable evaporation performance due to the excellent salt deposition resistance.Therefore,the J-PZCA membrane constructed in this study provides a new perspective for the design of efficient interfacial evaporation devices.

Fabrication of stable MWCNT bucky paper for solar-driven interfacial evaporation by coupling c-ray irradiation with borate crosslinking

Herein,we report a facile solution process for preparing multi-walled carbon nanotube(MWCNT)bucky paper for solar-driven interfacial water evaporation.This process involves vacuum filtrating a dispersion of MWCNTs that was modified by polyvinyl alcohol(PVA)under c-ray irradiation on a cellulose acetate microporous membrane,followed by borate crosslinking.Fourier transform infrared spectroscopy,Raman spectroscopy,and thermogravimetry confirmed the success of PVA grafting onto MWCNTs and borate crosslinking between modified MWCNT nanoyarns.The as-prepared crosslinked MWCNT bucky papers(BBP membranes)were used as a solar absorber,by placing them on a paper-wrapped floating platform,for interfacial water evaporation under simulated solar irradiation.The BBP membranes showed good water tolerance and mechanical stability,with an evaporation rate of 0.79 kg m^(-2)h^(-1)and an evaporation efficiency of 56%under 1 sun illumination in deionized water.Additionally,the BBP membranes achieved an evaporation rate of 0.76 kg m^(-2)h^(-1)in both NaCl solution(3.5 wt%)and sulfuric acid solution(1 mol L-1),demonstrating their impressive applicability for water reclamation from brine and acidic conditions.An evaporation rate of 0.70 kg m-2 h-1(very close to that from deionized water)was obtained from the solar evaporation of saturated NaCl solution,and the BBP membrane exhibited unexpected stability without the inference of salt accumulation on the membrane surface during long-term continuous solar evaporation.

Synergistic Interfacial and Doping Engineering of Heterostructured NiCo(OH)_(x)-Co_(y)W as an Efficient Alkaline Hydrogen Evolution Electrocatalyst

To achieve high efficiency of water electrolysis to produce hydrogen(H_(2)),developing non-noble metal-based catalysts with consid-erable performance have been considered as a crucial strategy,which is correlated with both the interphase properties and multi-metal synergistic effects.Herein,as a proof of concept,a delicate NiCo(OH)_(x)-CoyW catalyst with a bush-like heterostructure was realized via gas-template-assisted electrodeposition,followed by an electrochemical etching-growth process,which ensured a high active area and fast gas release kinetics for a superior hydrogen evolution reaction,with an overpotential of 21 and 139 mV at 10 and 500 mA cm^(−2),respectively.Physical and electrochemical analyses demonstrated that the synergistic effect of the NiCo(OH)_(x)-Co_(y)W heteroge-neous interface resulted in favorable electron redistribution and faster electron transfer efficiency.The amorphous NiCo(OH)_(x) strengthened the water dissociation step,and metal phase of CoW provided sufficient sites for moderate H immediate adsorption/H_(2) desorption.In addition,NiCo(OH)_(x)-CoyW exhibited desirable urea oxidation reaction activity for matching H_(2) generation with a low voltage of 1.51 V at 50 mA cm^(−2).More importantly,the synthesis and testing of the NiCo(OH)_(x)-CoyW catalyst in this study were all solar-powered,sug-gesting a promising environmentally friendly process for practical applications.

Nano-enabled solar driven-interfacial evaporation:Advanced design and opportunities

Solar-driven interfacial evaporation(SDIE)is emerging as a promising pathway to solving the worldwide water shortage and water pollution.Nanomaterials(e.g.,plasmonic metals,inorganic/organic semiconductors,and carbon nanomaterials)and related nanochemistry have attracted increasing attention for the solar-to-vapor process in terms of broadband absorption,electronic structure adjustment,and surface/interface chemistry manipulation.Furthermore,the assembly of nanomaterials can contribute to the mass transfer,heat management,and enthalpy regulation of water during solar evaporation.To date,numerous nano-enabled materials and structures have been developed to improve the solar absorption,heat management(i.e.,heat confinement and heat transfer),and water management(i.e.,activation,evaporation,and replenishment).In this review,we focus on a systematical summary about the composition and structure engineering of nanomaterials in SDIE,including size and morphology effects,nanostructure optimizations,and structure-property relationship decoupling.This review also surveys recent advances in nanochemistry(e.g.,preparation chemistry and structural chemistry)deployed to conceptual design of nanomaterials.Finally,the key challenges and future perspectives of nanomaterials for solar evaporation are overviewed.This review aims at providing guidance for the design and construction of nanomaterials for high-efficiency SDIE on the basis of the aspects of materials science and chemical engineering.

仿生太阳能驱动界面蒸发器的进展与挑战

太阳能驱动界面蒸发(SDIE)作为一种高效、可持续的水资源获取方法,近年来受到了广泛的关注。基于仿生原理设计的太阳能驱动界面蒸发器在提高能源转换效率、降低盐结晶和抗污染等方面展现了巨大的潜力,在解决淡水资源紧缺和能源短缺等问题上发挥重要作用。该文梳理了近年来的仿生学在SDIE领域的应用,对比了仿生太阳能驱动界面蒸发器的结构、性能和仿生机理,探讨了不同类型仿生太阳能驱动界面蒸发器的优缺点,分析了仿生太阳能驱动界面蒸发器所面临的共性问题,并提出了未来的研究挑战。

Polymer Modified Banana Pseudo Stem-based Interfacial Solar-driven Evaporation System

Interfacial solar-driven evaporation technique is an environmental friendly and cost-effective advanced approach for water purification using solar energy.Free energy sources are effectively utilized using the structural design of evaporators and functional materials.In this work,we have fabricated a solar-driven interfacial evaporation device with Banana Pseudo Stem(BPS)and a photothermal layer made up of PVA PDMS Carbon(PPC)is attached to it.High evaporation rate of 2.03 kg m^(−2) h^(−1) is achieved by the system under 1 sun illumination.Heat localization on interfacial surface,reflectance of photothermal layer,presence of micro-fluidic channels in BPS were studied using IR imaging,UV-DRS and SEM characterization techniques,respectively.Effective localization of interfacial temperature around 53℃ and very low reflectance of photothermal layer substantiates high photothermal conversion efficiency of the device.The complete purification of water containing high concentration of Rhodamine-B dye using BPS is a novel and simple approach for water purification.This is an eco-friendly,cost-efficient novel approach in fabrication of interfacial solar-driven evaporation system with high evaporation rate for purification of water containing high concentration of organic dye.

具有板式基底结构的界面蒸发系统性能模拟

针对具有板式基底结构的太阳能界面蒸发系统建立三维数学模型,利用Ansys Fluent软件求解该系统的蒸发过程,研究板缝宽度及料液质量分数对界面蒸发过程的影响.结果表明:蒸发速率随板缝宽度和料液质量分数的增大而减小;当基底输水量小于蒸发需求时,蒸发界面出现干涸现象,干涸现象出现后蒸发速率显著降低;当板缝宽度为0.5 mm时,与最大蒸发速率对应的料液质量分数为3.5%~5.0%;当料液质量分数为3.5%时,与最大蒸发速率对应的板缝宽度为0.5~0.6 mm;系统能量利用率变化规律与蒸发速率基本一致.蒸发过程中蒸发量与料液供给量的匹配是影响板式基底结构的太阳能界面蒸发系统性能的重要因素.

改性玉米芯制备太阳能界面蒸发体及其性能分析

针对天然生物质材料应用于海水淡化领域,蒸发效率较低、材料容易降解等问题,采用多巴胺对天然玉米芯进行改性处理,以改性玉米芯为基底,在其表面包覆炭黑-纤维素薄膜,制备了一种集光热转换、输水、隔热于一体的太阳能界面蒸发体。对改性玉米芯蒸发体的光学吸收性能、输水性能、接触角进行表征,并搭建了室内蒸发试验和户外蒸发试验系统,测试了改性玉米芯的蒸发性能,与天然玉米芯相比,改性玉米芯蒸发体的蒸发速率相对未改性的提升了约10.4%。对改性玉米芯蒸发体进行了30次循环试验,蒸发体均保持稳定的蒸发速率,整个循环测试中蒸发速率波动不超过1%。并且,长期工作后,蒸发体表面没有盐分沉积,没有出现材料软化、降解现象。改性玉米芯蒸发体在海水环境中能够保持良好、稳定的蒸发性能,且能够有效降低海水中的Na^(+)、K^(+)、Mg^(2+)、Ca^(2+)等离子浓度,达到世界卫生组织所规定的饮用标准中的相应限值。改性玉米芯蒸发体的制备方法简单、成本低廉、蒸发性能稳定,为扩展生物质材料在海水淡化领域的应用提供了有效途径。

活化多孔炭用于高效太阳能界面水蒸发协同吸附有机污染物

近年来,太阳能驱动界面水蒸发(solar-driven interfacial water evaporation,SDIWE)在海水淡化和废水净化方面展现出巨大应用潜力并受到了世界各国的广泛关注。然而,如何有效地利用产生的传导热损失去除有机污染物仍然是一个挑战。本文创新性地利用传导热损失进行SDIWE-辅助吸附有机污染物以提高SDIWE系统的整体能效。具体而言,通过盐模板辅助炭化和KOH活化两种方法制备了多孔炭(porous carbon,PC)和活化PC。PC与KOH活化质量比为1∶4的样品(PC-A4)具有分层多孔结构,比表面积高达1867.71 m^(2) g^(-1),孔体积高达1.04 cm^(3) g^(-1),具有较好的全光谱吸收能力。基于此,PC-A4样品具有较高的蒸发速率和能量转换效率,通过调节水体质量可以进一步提高蒸发速率和能量效率。值得注意的是,在309 K的传导温度下PC-A4样品对罗丹明B的最大吸附量达到1610 mg g^(-1),高于相同样品在298 K传导温度下的吸附量。因此,这项工作为有效利用SDIWE系统的传导热损失和推动污水净化技术的应用发展提供了一条有前途的途径。

太阳能驱动的界面式蒸发淡化装置设计

针对多种突发状况下人员淡水的获取问题,设计了一种小型的界面蒸发式海水淡化与收集装置,该装置使用太阳能作为蒸发热源,具备独立的界面蒸发、冷却、储存与收集蒸馏水的能力。在结构上设计了过滤网状栅格和漏斗式沉淀仓,可实现水质的双重过滤;设计了漏斗状双层冷凝通道,利用海水的内/外循环实现了蒸发水汽的快速冷凝;设计了负压式集水装置,可自动高效地收集的蒸馏水,并提供密封环境实现淡化水的长期储存。相比传统淡化技术,整体结构紧凑、体积小、操作简单、成本投入少、无需耗费外部能源,在沿海小岛、作业渔船、海上求生或抢险等场景具有广泛的应用价值。

基于碳纳米管-聚乙烯醇水凝胶的太阳能驱动界面水蒸发性能研究

太阳能驱动界面水蒸发是解决偏远干旱地区淡水资源短缺问题的重要技术,由于制备成本、制造工艺、蒸发性能等因素的限制,目前该技术仍难以推广应用.本文采用碳纳米管-聚乙烯醇(CNT-PVA)为太阳能吸收器,在1倍标准太阳强度(1 kW·m^(-2))下实现了1.43 kg·m^(-2)·h^(-1)的蒸发速率和92.4%的光热蒸发效率.由于CNT-PVA水凝胶对太阳能光谱良好的吸收性能和较低的散热损失,稳态蒸发阶段其表面温度达到40℃,高于本体水域温度,证实了CNT-PVA水凝胶的局域加热能力.同时,水凝胶丰富的内部孔隙可为蒸发前缘持续不断地输运水分,并为产生的蒸汽提供逃逸通道.良好的蒸发性能、较低的制备成本、简单的制造工艺等优势使得CNT-PVA水凝胶在太阳能驱动界面水蒸发技术的应用中展现出较大潜力.

石墨烯基复合水凝胶的制备及其在海水脱盐净化中的应用

利用一步化学还原法将二硫化钼(MoS_(2))纳米花嵌入石墨烯中,制得一种多孔的光热复合水凝胶,即二硫化钼夹层石墨烯水凝胶,其与人工蒸腾装置相结合用于构筑太阳能驱动的界面水蒸发体系。通过扫描电镜、透射电镜、X射线粉末衍射仪、紫外可见-近红外分光光度计及红外热像仪测试材料的形貌和理化性能,并将复合水凝胶置于模拟太阳光下进行水蒸发及脱盐试验。结果表明:MoS_(2)能稳定分散在石墨烯纳米片中,且二者的结合有助于增强材料的光热性能。结合人工蒸腾装置的特殊热定位和快速补水优势,该光热体系能够实现水的快速蒸发,在3.6 kW/m^(2)光照下水蒸发速率(15.6 kg·m^(2)/h)约为自然蒸发的33倍,并且复合水凝胶具有良好的稳定性和高效的脱盐效果,具有清洁水生产的应用前景。

基于不同类型溶液蒸气压特性的太阳能界面蒸发实验研究

太阳能界面蒸发可实现高效太阳能海水淡化和蒸发式污水处理,但目前的研究大多局限于纯水或NaCl溶液。实际脱盐或废水处理中溶质会与此不同,导致溶液蒸气压变化并影响蒸发性能。本文首先分析了溶液表面蒸气压曲线类型,将其分为上凸型、下凹型和直线型。针对这几种蒸气压曲线进一步选取[EMIM][OTf]、[EMIM][Ac]和NaCl水溶液作为代表溶液,在不同辐照强度和浓度下进行了实验研究,并与纯水的蒸发作对比。实验结果表明:低浓度下[EMIM][OTf]水溶液展现出了良好的蒸发性能,主要原因是由于其蒸气压处于上凸区间;当溶液浓度升高或辐照强度提升时,[EMIM][OTf]溶液的蒸发速率提升较NaCl水溶液小,主要原因在于蒸发过程的浓度极化导致气液界面处的[EMIM][OTf]浓度升高,蒸气压相差较小;不同工况下[EMIM][Ac]水溶液的蒸发速率均较慢,纯水的蒸发速率最快,体现了蒸气压对蒸发性能的关键影响,原因是低蒸气压导致高蒸发温度,并带来更多的能量损失。

界面光热转换水蒸发系统用纤维材料的研究进展

为缓解化石能源日益匮乏以及淡水资源短缺等问题,促进纤维材料在水资源利用方面的开发和应用,对以纤维材料为主要原料的界面光热转换水蒸发系统的最新研究进展进行综述。首先介绍了界面光热转换水蒸发技术的主要原理、发展历程和应用领域;然后分别分析了界面光热转换水蒸发系统中的光热转换材料和辅助材料,并以不同的功能作为切入点,详细阐述了纤维材料功能多样化、轻质、低成本和便于加工等特性,展示了其作为界面光热转换水蒸发系统主要原料的优异性能;最后针对在界面光热转换水蒸发系统中使用纤维材料所面临的挑战以及如何提升系统的实用性进行展望,希望能够推动纤维材料在界面光热转换技术中的广泛应用。

Scalable carbon black deposited fabric/hydrogel composites for affordable solar-driven water purification

Interfacial solar-driven evaporators have presented great potential for water purification owing to their low energy consumption and high steam generation efficiency. However, their further applications are hindered by the high costs and complicated fabrication processes. Here, a scalable bilayer interfacial evaporator was constructed via an affordable technique, in which carbon black deposited nonwoven fabric(CB@NF) was employed as the upper photothermal layer, as well as PVA/starch hybrid hydrogel for selffloating and water transport. Under simulated one sun irradiation, CB@NF layer displayed excellent photothermal conversion performance, whose temperature could increase 30.4 ℃ within 15 min. Moreover,the introduction of starch into PVA endowed the hybrid hydrogels with considerable water-absorption capability on the premise of ensuring mechanical properties. The resultant CB@NF/PVA/starch composites achieved superior interfacial adhesion performance with interfacial toughness at about 200 J m.Combining with good evaporation performance, salt-rejection property and high purification efficiency on pollutants, this evaporation system would become a promising candidate to alleviate water shortage.

PDA@PPHF太阳能驱动界面蒸发性能及水质净化研究

将聚多巴胺(PDA)负载在聚丙烯中空纤维(PPHF)膜上制备PDA@PPHF复合材料,研究了其在太阳能驱动下的界面蒸发性能及水处理性能。结果表明,在1个太阳光强下,PDA@PPHF复合材料的水蒸发效率达到80.84%,是纯水自然蒸发效率的4.2倍。此外,PDA@PPHF复合材料在1 kW/m^(2)太阳能驱动下进行了海水除盐和重金属以及染料废水净化,展现出良好的净水效果。实验结果表明,其有潜力应用于海水淡化、废水净化等领域,缓解水资源短缺问题。

太阳能界面蒸发的应用综述

太阳能界面蒸发是利用特定结构将能量局限在光吸收层,使水分在结构表面完成蒸发。由于太阳能界面蒸发器装置结构简单、占地空间小、能量利用率高,且对运行环境要求低,受到研究者的广泛关注。目前,研究者们从光吸收体材料、热量管理、蒸发器结构等方面切入,对太阳能界面蒸发方法进行了丰富研究,然而太阳能界面蒸发方法在应用方面的研究相对较少。太阳能界面蒸汽生成方法,由于其独特优势,不仅可以应用于海水淡化领域,在其他众多领域都具有应用潜力。从水资源管理、能源供给、医疗等方面对太阳能界面蒸发方法的应用领域进行梳理,并讨论了太阳能界面蒸发的潜在应用方向。这对于丰富太阳能界面蒸发的研究范畴,推动太阳能界面蒸发在应用层面的发展,探索太阳能界面蒸发在多领域的联合应用具有重要意义。