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.

Solar-Driven Water Treatment: New Technologies, Challenges, and Futures

In this review, the new solar water treatment technologies, including solar water desalination in two direct and indirect methods, are comprehensively presented. Recent advances and applications of five major solar desalination technologies include solar-powered humidification–dehumidification, multi-stage flash desalination, multi-effect desalination, RO, and solar stills. Each technology’s productivity, energy consumption, and water production costs are presented. Also, common methods of solar water disinfection have been reviewed as one of the common and low-cost methods of water treatment, especially in areas with no access to drinking water. However, although desalination technologies have many social, economic, and public health benefits, they are energy-intensive and negatively affect the environment. In addition, the disposal of brine from the desalination processes is one of the most challenging and costly issues. In this regard, the environmental effects of desalination technologies are presented and discussed. Among direct solar water desalination technologies, solar still technology is a low-cost, low-tech, and low-investment method suitable for remote areas, especially in developing countries with low financial support and access to skilled workers. Indirect solar-driven water desalination technologies, including thermal and membrane technologies, are more reliable and technically more mature. Recently, RO technology has received particular attention thanks to its lower energy demand, lower cost, and available solutions to increase membrane durability. Disposal of brines can account for much of the water cost and potentially negatively affect the environment. Therefore, in addition to efforts to improve the efficiency and reduce the cost of solar technologies and water treatment processes, future research studies should consider developing new solutions to this issue.

High-efficient solar-driven hydrogen production by full-spectrum synergistic photo-thermo-catalytic methanol steam reforming with in-situ photoreduced Pt-CuO_(x) catalyst

Synergy between the intrinsic photon and thermal effects from full-spectrum sunlight for H_(2) production is considered to be central to further improve solar-driven H_(2) production.To that end,the photo-thermocatalyst that demonstrates both photoelectronic and photothermal conversion capabilities have drawn much attention recently.Here,we propose a novel synergistic full-spectrum photo-thermo-catalysis technique for high-efficient H_(2) production by solar-driven methanol steam reforming(MSR),along with the Pt-Cu Oxphoto-thermo-catalyst featuring Pt-Cu/Cu_(2)O/CuO heterojunctions by Pt-mediated in-situ photoreduction of Cu O.The results show that the H_(2) production performance rises superlinearly with increasing light intensity.The optimal H_(2) production rate of 1.6 mol g^(-1) h^(-1) with the corresponding solar-to-hydrogen conversion efficiency of 7%and the CO selectivity of 5%is achieved under 15×sun full-spectrum irradiance(1×sun=1 k W m^(-2))at 180°C,which is much more efficient than the previously-reported Cu-based thermo-catalysts for MSR normally operating at 250~350°C.These attractive performances result from the optimized reaction kinetics in terms of intensified intermediate adsorption and accelerated carrier transfer by long-wave photothermal effect,and reduced activation barrier by short-wave photoelectronic effect,due to the broadened full-spectrum absorbability of catalyst.This work has brought us into the innovative technology of full-spectrum synergistic photothermo-catalysis,which is envisioned to expand the application fields of high-efficient solar fuel production.

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.

A bifunctional wood membrane modified by MoS_(2)/covalent organic framework heterojunctions for effective solar-driven water evaporation and contaminant degradation

Interfacial solar evaporation technology is considered one of the most promising strategies for alleviating the scarcity of freshwater resources.However,solar-driven evaporation technology cannot eliminate the pollutants in the residual wastewater.To solve this problem,we have prepared a two-in-one solar-driven evaporation/photocatalysis system by decorating MoS_(2)/covalent organic framework(COF)heterojunctions on wood(MoS_(2)/COF-wood).Thanks to the unique porous structure of wood,it provides a strong guarantee for water transport and vapor release during the evaporation process.The introduction of MoS_(2) and COFs can promote the breaking of hydrogen bonds between water molecules,which leads to a significant decrease in the enthalpy of evaporation,achieving a water evaporation rate as high as 2.17 kg m^(-2)h^(-1)under 1 sun irradiation.Meanwhile,the resulting MoS_(2)/COF-wood exhibits good salt resistance and reusability.In addition,the heterojunctions formed between COFs and MoS_(2) can effectively inhibit charge carrier complexation and improve the photocatalytic degradation ability of pollutants(over 99%).This study highlights the construction strategy of bifunctional wood-based materials for freshwater production and wastewater remediation.

Recent advances in heterogeneous catalysis of solar-driven carbon dioxide conversion

Solar-driven carbon dioxide(CO_(2))conversion including photocatalytic(PC),photoelectrochemical(PEC),photovoltaic plus electrochemical(PV/EC)systems,offers a renewable and scalable way to produce fuels and high-value chemicals for environment and energy sustainability.This review summarizes the basic fundament and the recent advances in the field of solar-driven CO_(2)conversion.Expanding the visible-light absorption is an important strategy to improve solar energy conversion efficiency.The separation and migration of photogenerated charges carriers to surface sites and the surface catalytic processes also determine the photocatalytic performance.Surface engineering including co-catalyst loading,defect engineering,morphology control,surface modification,surface phase junction,and Z-scheme photocatalytic system construction,have become fundamental strategies to obtain high-efficiency photocatalysts.Similar to photocatalysis,these strategies have been applied to improve the conversion efficiency and Faradaic efficiency of typical PEC systems.In PV/EC systems,the electrode surface structure and morphology,electrolyte effects,and mass transport conditions affect the activity and selectivity of electrochemical CO_(2)reduction.Finally,the challenges and prospects are addressed for the development of solar-driven CO_(2)conversion system with high energy conversion efficiency,high product selectivity and stability.

Antibacterial evaporator based on reduced graphene oxide/polypyrrole aerogel for solar-driven desalination

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.

Biosynthetic CdS-Thiobacillus thioparus hybrid for solar-driven carbon dioxide fixation

Synergistically combining biological whole-cell bacteria with man-made semiconductor materials innovates the way for sustainable solar-driven CO_(2)fixation,showing great promise to break through the bottleneck in traditional chemical photocatalyst systems.However,most of the biohybrids require uneconomical organic nutrients and anaerobic conditions for the successful cultivation of the bacteria to sustain the CO_(2)fixation,which severely limits their economic viability and applicability for practical application.Herein,we present an inorganic-biological hybrid system composed of obligate autotrophic bacteria Thiobacillus thioparus(T.thioparus)and CdS nanoparticles(NPs)biologically precipitated on the bacterial surface,which can achieve efficient CO_(2)fixation based entirely on cost-effective inorganic salts and without the restriction of anaerobic conditions.The optimized interface between CdS NPs and T.thioparus formed by biological precipitation plays an essential role for T.thioparus efficiently receiving photogenerated electrons from CdS NPs and thus changing the autotrophic way from chemoautotroph to photoautotroph.As a result,the CdS-T.thioparus biohybrid realizes the solar-driven CO_(2)fixation to produce multi-carbon glutamate synthase and biomass under visible-light irradiation with CO_(2)as the only carbon source.This work provides significant inspiration for the further exploration of the solar-driven self-replicating biocatalytic system to achieve CO_(2)fixation and conversion.

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。

基于太阳能驱动界面蒸发设计的碳基光热材料研究进展

太阳能驱动界面蒸发(solar-driven interfacial evaporation, SDIE)能够利用太阳能将液态水高效转换为蒸汽,为发展生态友好和具有成本效益的淡水生产技术提供基础。其中光热材料是实现能量转换的关键平台,产生的热量可以直接用来加热蒸发。近年来,人们在提高太阳能水蒸发效率方面做了大量的工作,许多创新光热材料被用于实现可控和高效的太阳能-热能转换,以应对从微观尺度到分子水平的能源-水关系挑战。在此基础上,以碳基光热材料为基础,综述了SDIE技术中最新研究进展,重点介绍了石墨烯、碳纳米管、天然植物碳材料以及碳基复合材料等目前应用较为广泛的光热材料在SDIE领域的设计、合成和应用概况,并总结了蒸发水收集速率相关的研究成果,以期为设计低成本、高效光吸收、化学稳定、可重复使用和宽谱吸收的SDIE装置,实现离网脱盐提供参考;最后,对未来碳基材料在SDIE结合人工智能、发电、灭菌及全天候运行等领域的发展前景进行了展望,以期实现环保高效、多用途的水处理净化技术。

聚吡咯修饰的羧甲基纤维素/磺化共轭微孔聚合物复合气凝胶光热转换净水性能研究

淡水资源作为生命赖以生存的物质基础面临严重挑战,利用高效的太阳能驱动界面蒸发(SSG)是解决目前水资源短缺的重要手段,一种新型的多孔材料共轭微孔聚合物(CMPs)在水处理技术中具有重要作用。以CMC/SCMP为前躯体在其表面喷涂聚吡咯制备了一种新型太阳能蒸发器(CMC/SCMP-PPy),喷涂聚吡咯增强了光吸收性能,光吸收率可达91%,实现了光热转化能力。该气凝胶在1 kW/m^(2)太阳条件下表现出良好的光热转换性能,蒸发效率可达85.57%。多孔结构和亲水特性使其具有优异的水传输能力,稳定的化结构使其具有优异的耐盐性以防止盐晶体沉积堵塞材料孔道,使其实现了光热转化能力。这项研究进一步优化了CMPs在废水的净化,实现了清洁能源的利用,为开发新型光热材料提供了新的思路。

甘蔗生物质炭在界面太阳能海水淡化中的应用

太阳能驱动的界面水蒸发作为环保、高效、可持续的海水淡化技术,在近年来受到广泛关注。快速的水运输、高效的光热转换是实现持续、稳定蒸发的关键。多级孔道的生物质衍生蒸发器在太阳能水蒸发应用中展示出高效、环保、可持续的应用潜力。以废弃的甘蔗节为原料,利用冷冻干燥和高温碳化工艺制备了具有天然多级孔道结构的生物质基蒸发器,并研究了材料的光吸收、水运输和蒸发性能以及不同风速下对流空气对蒸发器的蒸发性能和热损失的改善作用。结果表明:具有发达的多级孔道结构的生物质基蒸发器展示出了高达92.8%的太阳光吸收率。在一倍太阳光强下展示出1.55 kg/(m^(2)·h)的蒸发速率和77.6%的光热转换效率。此外,在风速2 m/s的条件下,蒸发器的蒸发速率展示出了高达2.27 kg/(m^(2)·h)的蒸发速率和91.6%的光热转换效率,显示了对流效应对淡水产出速率的增强和对热损失的抑制作用。

计及电解槽自保温的风光制氢系统研究

提出了一种计及电解槽自保温的风光制氢系统,使用储热罐回收利用电解制氢工作状态的余热,当电解槽需要待机时进行放热保温。新系统降低了电解水制氢设备待机工况下的电耗,减少了电解槽热损失,该系统可为我国电解水制氢生产提供一定参考。

Structure development of carbon-based solar-driven water evaporation systems

Pressing need goes ahead for accessing freshwater in insufficient supply countries and regions,which will become a restrictive factor for human development and production.In recent years,solar-driven water evaporation(SDWE)systems have attracted increasing attention for their specialty in no consume conventional energy,pollution-free,and the high purity of fresh water.In particular,carbon-based photothermal conversion materials are preferred light-absorbing material for SDWE systems because of their wide range of spectrum absorption and high photothermal conversion efficiency based on superconjugate effect.Until now,many carbon-based SDWE systems have been reported,and various structures emerged and were designed to enhance light absorption,optimize heat management,and improve the efficient water transport path.In this review,we attempt to give a comprehensive summary and discussions of structure progress of the carbon-based SDWE systems and their working mechanisms,including carbon nanoparticles systems,single-layer photothermal membrane systems,bi-layer structural photothermal systems,porous carbon-based materials systems,and three dimensional(3D)systems.In these systems,the latest 3D systems can expand the light path by allowing light to be reflected multiple times in the microcavity to increase the light absorption rate,and its large heat exchange area can prompt more water to evaporate,which makes them the promising application foreground.We hope our review can spark the probing of underlying principles and inspiring design strategies of these carbonbased SDWE systems,and further guide device optimizations,eventually promoting in extensive practical applications in the future.

多层结构聚丙烯酰胺水凝胶太阳能蒸发器的制备及性能

优化设计太阳能蒸发器的结构并提高光热转换效率是改善其蒸发性能的有效途径。本工作基于原位自由基聚合反应,设计了一种多层结构的聚丙烯酰胺(PAM)复合水凝胶太阳能蒸发器并研究了其性能。该水凝胶由底部PAM/纳米纤维素(PAM/CNF)水运输层、中部PAM/碳纳米管/氮化钛(PAM/CNTs/TiN)光热转换层以及顶部“孤岛”状PAM/空心MXene微球(PAM/HSMX)构成的粗糙表面层组成。这种设计构建的PAM/CNF-PAM/CNTs/TiN-PAM/HSMX多层结构水凝胶太阳能蒸发器(ML-SVG)不仅能够提高光热转换效率,减少热量的损耗,而且促进了水分的运输,从而赋予ML-SVG优良的蒸发性能。ML-SVG在2kW·m^(-2)太阳光照射下的蒸发速率达到2.2kg·m^(-2)·h^(-1),同时具有优良的循环使用性能,高效的污水净化和盐水淡化性能。

MIL-96(Al)及其复合吸附剂的合成及水吸附性能研究

通过溶剂热合成法制备了铝基金属有机骨架材料MIL-96(Al),并通过浸渍法合成了复合吸附剂MIL-96(Al)-L。通过扫描电子显微镜(SEM)讨论了所制备吸附剂的形貌。在不同工况的吸附实验中,MIL-96(Al)具有稳定的平衡吸附量,吸湿盐LiCl的加入增强了复合吸附剂的吸水性能。在吸附速率方面,MIL-96(Al)及其复合吸附剂表现出优异的性能。在不同温度和湿度条件下,MIL-96(Al)的吸附速率相对稳定,最高可达0.172 g/(g·h),而在相同条件下,MIL-96(Al)-L3的吸附速率最高可达MIL-96(Al)的3.7倍。MIL-96(Al)及其复合吸附剂在110℃下,可在30 min内完成脱附。其循环稳定性也通过循环再生实验得到证实。结果表明,MIL-96(Al)-L复合吸附剂是一种可实际应用于干旱地区的太阳能空气取水吸附剂。

Engineering oxygen vacancy on rutile TiO_2 for efficient electron-hole separation and high solar-driven photocatalytic hydrogen evolution

Oxygen vacancy（VO） plays a vital role in semiconductor photocatalysis. Rutile TiO2 nanomaterials with controllable contents of VO（0–2.18%） are fabricated via an insitu solid-state chemical reduction strategy, with color from white to black. The bandgap of the resultant rutile TiO2 is reduced from 3.0 to 2.56 e V, indicating the enhanced visible light absorption. The resultant rutile TiO2 with optimal contents of VO（2.07%） exhibits a high solar-driven photocatalytic hydrogen production rate of 734 μmol h-1, which is about four times as high as that of the pristine one（185 μmol h-1）. The presence of VOelevates the apparent Fermi level of rutile TiO2 and promotes the efficient electronhole separation obviously, which favor the escape of photogenerated electrons and prolong the life-time（7.6×103 ns） of photogenerated charge carriers, confirmed by scanning Kelvin probe microscopy, surface photovoltage spectroscopy and transient-state fluorescence. VO-mediated efficient photogenerated electron-hole separation strategy may provide new insight for fabricating other high-performance semiconductor oxide photocatalysts.

废旧棉制备再生纤维素气凝胶实现盐晶收集及高效海水淡化

从回收再利用废旧棉布出发,结合边缘结晶效应,制备了集太阳能蒸发与盐收集于一体的气凝胶蒸发器。以碳纳米管为光热材料,通过对气凝胶的亲疏水区域复合以及形状设计,实现了边缘结晶。研究了蒸发器的水传输行为、区域化温度差异以及不同浓度的盐溶液对蒸发速率的影响,并在3.5%NaCl溶液中实现了1.93 kg/(m^(2)·h)的蒸发速率、高达91.5%的蒸发效率以及高达99.5%的离子去除率。

Solar-driven high-efficiency remediation of wastewater containing small dye molecules

Remediation of wastewater containing dye molecules is necessary to alleviate the significant threat that poses to human health and the environment.Current treatment technologies are seriously limited by their low efficiency for removing small dye molecules or/and inferior regenerability.Herein,we report a bio-inspired,solar-driven,regenerable separation device capable of separating small dye molecules from the wastewater with high efficiency.The device is composed of porous super-hydrophilic ceramic and carbon nanotubes(CNTs).In comparison with previously reported systems,the resultant device not only achieved a highly promising separation efficiency of>99%for dye-containing wastewater,even for small dye molecules(<1.25 nm),but also demonstrated excellent separation stability and strong resistance to acid/alkali.Moreover,the device demonstrated impressive regenerability on simple calcination and re-coating of the CNT layer after it was blocked.This novel separation device shows potential for application in many fields,such as dye separation,wastewater purification and desalination.

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.