Scalable Core–Sheath Yarn for Boosting Solar Interfacial Desalination Through Engineering Controllable Water Supply

Tailoring water supply to achieve confined heating has proven to be an effective strategy for boosting solar interfacial evaporation rates.However,because of salt clogging during desalination,a critical point of constriction occurs when controlling the water rate for confined heating.In this study,we demonstrate a facile and scalable weaving technique for fabricating core-sheath photothermal yarns that facilitate controlled water supply for stable and efficient interracial solar desalination.The core-sheath yarn comprises modal fibers as the core and carbon fibers as the sheaths.Because of the core-sheath design,remarkable liquid pumping can be enabled in the carbon fiber bundle of the dispersed superhydrophilic modal fibers.Our woven fabrics absorb a high proportion(92%)of the electromagnetic radiation in the solar spectrum because of the weaving structure and the carbon fiber sheath.Under one-sun(1 kW·m^(-2))illumination,our woven fabric device can achieve the highest evaporation rate(of 2.12kg·m^(-2)·h^(-1) with energy conversion efficiency:93.7%)by regulating the number of core-sheath yarns.Practical application tests demonstrate that our device can maintain high and stable desalination performance in a 5 wt%NaCl solution.

Synergistic realization of high efficiency solar desalination and carbon dioxide reduction

Methods of seawater desalination and carbon dioxide(CO_(2))reduction using clean and renewable energy have attracted much attention withing the reducing fresh water and growing CO_(2)concentration.Here,we propose a synergistic method for solardriven desalination and CO_(2)reduction at the surface of sea using a three-dimensional titanium oxide-gold semiconductor/metal(TiO_(2)-Au NW/NPs(NW:nanowire,NP:nanoparticle))photothermal conversion membrane that can efficiently harvest a broad solar spectrum(200 to 2500 nm,94%)to undertake the conversion of light-to-heat and light-to-electricity.The TiO_(2)-Au NW/NPs membrane demonstrated a high solar vapor conversion efficiency of~90%,CO_(2)reduction yields of 0.066μmol·cm^(-2)CH_(4)and 0.015μmol·cm^(-2)CO within 5 h.In addition,the membrane efficiently evaporated seawater with different salt concentrations to produce drinking water which meet World Health Organization(WHO)and US Environmental Protection Agency(EPA)standards.This work provides an integrated solution for solar desalination and CO_(2)reduction at the surface of sea to reduce the harm to marine life caused by ocean acidification while producing pure water.

Graphene oxide film for efficient solar desalination under one sun with a confined 2D water path

Subject Code:A04With the support by the National Natural Science Foundation of China and the State Key Program for Basic Research of China,the research team led by Prof.Zhu Jia(朱嘉)at the National Laboratory of Solid State Microstructures,College of Engineering and Applied Sciences,Nanjing University,improved the efficiency of solar desalination using graphene oxide film through suppressing the conduction loss。

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.

Simultaneous Solar-driven Steam and Electricity Generation by Cost-effective,Easy Scale-up MnO 2-based Flexible Membranes

Harvesting solar energy in an effective manner for steam and electricity generation is a promising technique to simultaneously cope with the energy and water crises.However,the construction of efficient and easy scale-up photothermal materials for steam and electricity cogeneration remains challenging.Herein,we report a facile and cost-effective strategy to prepare MnO_(2)-decorated cotton cloth(MCx).The wide adsorption spectrum and excellent photothermal conversion ability of the in situ-formed MnO_(2)nanoparticles make the MCx to be advanced photothermal materials.Consequently,the hybrid device integrated with MCx as the photothermal layer and the thermoelectric(TE)module for electricity power conversion exhibits an extremely high evaporation rate of 2.24 kg m^(−2)h^(−1)under 1 kW m^(−2)irradiation,which is ranked among the most powerful solar evaporators.More importantly,during solar evaporation,the hybrid device produces an open-circuit voltage of 0.3 V and a power output of 1.6 W m^(−2)under 3 Sun irradiation,and outperforms most of the previously reported solar-driven electricity generation devices.Therefore,the integrated device with synergistic solar-thermal utilization opens up a green way toward simultaneous solar vapor and electric power generation in remote and resource-constrained areas.

Self-Floating Efficient Solar Steam Generators Constructed Using Super-Hydrophilic N,O Dual-Doped Carbon Foams from Waste Polyester

Solar evaporation is recognized as a prospective technique to produce freshwater from non-drinkable water using inexhaustible solar energy.However,it remains a challenge to fabricate low-cost solar evaporators with obviously reduced water evaporation enthalpy to achieve high evaporation rates.Herein,N,O dual-doped carbon foam(NCF)is fabricated from the lowtemperature carbonization of poly(ethylene terephthalate)(PET)waste by melamine/molten salts at 340℃.During carbonization,melamine reacts with carboxylic acids of PET degradation products to yield a crosslinking network,and then molten salts catalyze the decarboxylation and dehydration to construct a stable framework.Owing to rich N,O-containing groups,3D interconnected pores,super-hydrophilicity,and ultra-low thermal conductivity(0.0599 W m^(−1) K^(−1)),NCF not only achieves high light absorbance(ca.99%)and solar-to-thermal conversion,but also promotes the formation of water cluster to reduce water evaporation enthalpy by ca.37%.Consequently,NCF exhibits a high evaporation rate(2.4 kg m^(−2) h^(−1)),surpassing the-state-of-the-art solar evaporators,and presents good antiacid/basic abilities,long-term salt-resistance,and self-cleaning ability.Importantly,a large-scale NCF-based outdoor solar desalination device is developed to produce freshwater.The daily freshwater production amount per unit area(6.3 kg)meets the two adults’daily water consumption.The trash-to-treasure strategy will give impetus to the development of low-cost,advanced solar evaporators from waste plastics for addressing the global freshwater shortage.

Tea stain-inspired solar energy harvesting polyphenolic nanocoatings with tunable absorption spectra

Discovery and development of new sustainable photothermal materials with tunable light absorption spectra play a key role in solar energy harvesting and conversion.One possible solution to this quest is to check nature as a source of matters or inspiration.Inspired by the formation of tea stains,a unique class of dark stain materials generated by the interfacial reaction between tea polyphenols and metal substance,we reported the facile preparation and screening of a series of photothermal nanocoating layers via the metal ion(i.e.C u(ll)>Fe(lll),Ni(ll),Zn(ll))promoted in situ polymerization of typical phenolic moieties of tea polyphenols(i.e.,catechol and pyrogallol).It was found that those resulting metal-polyphenolic nanocoatings showed various promising features,such as high blackness and strong adhesion,excellent and tunable light absorption properties,good hydrophilicity and long-term stability.We further fabricated the photothermal composite devices by/n s/'fty formation of meta卜polyphenolic nanocoatings on pristine silks for solar desalination,which demonstrated promising durable evaporation behaviors with excellent evaporation rates and steam generation efficiencies.We believe that this work could provide more opportunities towards new types of bio-inspired and sustainable photothermal nanomaterials for solar energy harvesting applications such as water desalination.

Three-dimensional porous photo-thermal fiber felt with salt-resistant property for high efficient solar distillation

The urgent need for fresh water resource is a public issue facing the world.Solar distillation for seawater desalination is a promising freshwater production method.Interfacial solar evaporation systems based on 2 D photo-thermal membranes have been widely studied,but salt pollution is one of the main challenges for solar distillation.In order to solve this problem,a hydrophilic three-dimensional(3 D)porous photo-thermal fiber felt(PFF)was obtained by one-step method,through a simple polydopamine(PDA)coating method with hydrophobic graphite felt as a substrate.The PFF had a good evaporation rate of 1.48 kg m^(-2)h^(-1)and its corresponding light-vapor conversion efficiency reached 87.4%.In addition,the PFF exhibited an excellent salt-resistant ability when applied to photo-thermal evaporation of highsalinity seawater with 10 wt%NaCl,owing to its intrinsic 3 D macroporous structure for the migration circulation of salt ions.The development of the PFF offers a new route for the exploration of salt-re sistant photo-thermal materials and is promising for the practical application of solar distillation.

Stretchable and Superhydrophilic Polyaniline/Halloysite Decorated Nanofiber Composite Evaporator for High Efficiency Seawater Desalination

Here,authors report on composition of a stretchable,mechanically durable and superhydrophilic polyaniline(PANI)/hal-loysite nanotubes(HNTs)decorated PU nanofiber(PANI/HNTs@PU).The polymer nanofibers are placed as the core and PANI/HNTs makes the shell section.The PANI/HNTs creates a membrane with outstanding light absorption and photo-thermal conversion performance.The strong solar absorption capability and superhydrophilicity of the PANI/HNTs@PU remain almost unchanged during stretching,abrasion,and ultrasonic washing tests,exhibiting superior surface stability and durability.When the PANI/HNTs@PU is used for the interfacial evaporation,the evaporation rate and efficiency reach as high as 1.61 kg m^(-2) h^(-1) and 94.7%,respectively.No salt precipitation is observed on the solar absorber surface even under a high salinity or during the long term or cyclic evaporation test.Furthermore,the excellent interfacial evaporation function is maintained when the nanofiber composite is mechanically stretched.The PANI/HNTs@PU based evaporation device shows promising applications in high performance solar desalination.

Preparation and properties of substrate PVA-GO composite membrane for solar photothermal conversion

Solar thermal desalination(STD)is a promising and sustainable technology for extracting clean water resources.Whereas recent studies to improve STD performance primarily focus on interfacial solar evaporation,a non-traditional bottom heating method was designed in this study.Herein,we prepared the polyvinyl alcohol/graphene oxide(PVA-GO)composite membrane and adhered to the bottom of a beaker using crystallized PVA.The GO was loaded on a non-woven fabric and different concentrations of PVA were compared for their effect on the evaporation efficiency.The results showed that the addition of PVA increased the evaporation rate.The surface characteristic of GO membrane without PVA was a fibrous filamentous structure as observed by SEM,whereby the fibers were clearly visible.When the PVA concentration reached 6%,the non-woven fiber was completely wrapped by PVA.Under the action of a fixed light intensity,the photothermal conversion rates of GO,2%PVA-GO,4%PVA-GO and 6%PVA-GO membrane device could reach 39.93%,42.61%,45.10%and 47.00%,respectively,and the evaporation rates were 0.83,0.88,0.94 and 0.98 kg$m-2$h-1,respectively.In addition,the PVA-GO composite membrane showed an excellent stability,which has significance for industrial application.

受水车启发的、在饱和盐水中也能实现高效和稳定的太阳能淡化的旋转蒸发器

太阳能海水淡化是解决全球淡水短缺的最有前景方法之一.然而,传统的蒸发体在高盐度海水中遭遇了盐累积带来的蒸发速率下降甚至失效的瓶颈.受古代水车的启发,本文开发了一种自适应旋转蒸发器,其可以在任意浓度的盐水中实现长期高效的太阳能海水淡化.这种蒸发器是一种双硫化物负载的滚筒式生物质炭.借助了木材天然的水传输通道和分层结构,蒸发器具有杰出的水供应和热定位能力.实验和数值模拟表明,归因于其低密度及独特的亲疏水特性,这个蒸发器能够在盐结晶产生的重心偏移下周期性转动以实现自动盐移除.这使得这个蒸发体甚至可以在饱和盐水(26.47%)中,24 h内保持2.8 kg m^(-2)h^(-1)的高蒸发速率,这是过去一直无法实现的.因此,这项概念验证工作展示了一种不受浓度和运行时间限制的、自旋转诱导脱盐的蒸发器.

仿生微/纳米疏水多孔膜负载亲水海绵用于高效太阳能蒸汽转化

利用光热材料吸收太阳能产生局域化的热效应实现太阳能蒸汽转化是一项环境友好型海水淡化和废水净化的技术.本文受自然界中叶片蒸腾作用的启发,设计了一种新型仿生叶片结构,以实现高效的太阳能蒸汽转化.这种新型仿生叶片结构由三个部分组成:(1)亲水性聚乙烯醇(PVA)海绵层(相当于叶子中的叶肉组织层),具有高孔隙率和低导热性;(2)聚吡咯(PPy)层(相当于叶子中的叶绿素层)负载于PVA海绵表面以吸收太阳能;(3)微/纳米尺度的多孔疏水表面层(相当于叶片中的气孔层).其中,亲水海绵的PVA聚合物网络提供了高效水传输通道的同时实现了内部水蒸发焓的降低;PPy层吸收太阳能并转化为内能加热气液蒸汽界面的水,实现热局部化,大大减小了热损耗;疏水性多孔表面层的边缘效应,为水蒸气提供了高效逃逸通道.基于仿生叶片结构的太阳能蒸汽转化装置在一倍太阳光强(1 kW m^(−2))下蒸发率高达3.09 kg m^(−2) h^(−1).在室外自然光照条件下成功地对盐水和海水进行了脱盐和净化,平均净水速率为1.4 L m^(−2) h^(−1).这种基于仿生叶片结构的太阳能蒸汽转化装置提供了一种极具潜力的高效水净化方法,有助于利用可持续能源缓解全球水危机.

Renewable biomass reinvigorates sustainable water-energy nexus

The water-energy nexus has garnered worldwide interest.Current dual-functional research aimed at coproducing freshwater and electricity faces significant challenges,including sub-optimal capacities("1+1<2"),poor inter-functional coordination,high carbon footprints,and large costs.Mainstream water-toelectricity conversions are often compromised owing to functionality separation and erratic gradients.Herein,we present a sustainable strategy based on renewable biomass that addresses these issues by jointly achieving competitive solar-evaporative desalination and robust clean electricity generation.Using hydrothermally activated basswood,our solar desalination exceeded the 100% efficiency bottleneck even under reduced solar illumination.Through simple size-tuning,we achieved a high evaporation rate of 3.56 kg h^(-1)m^(-2)and an efficiency of 149.1%,representing 128%-251% of recent values without sophisticated surface engineering.By incorporating an electron-ion nexus with interfacial Faradaic electron circulation and co-ion-predominated micro-tunnel hydrodynamic flow,we leveraged free energy from evaporation to generate long-term electricity(0.38 W m^(-3)for over 14 d),approximately 322% of peer performance levels.This inter-functional nexus strengthened dual functionalities and validated general engineering practices.Our presented strategy holds significant promise for global human–society–environment sustainability.