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Evaporation has been one of the most classic desalination processes on the Earth. When we try to use the power of water flow itself, the evaporation process can perform even better. Here, we report a hydrodynamic solar-driven interfacial evaporation process which water evaporation rate can achieve 6.58 kg·m-2·h-1 (over 100 times higher than natural evaporation). A waterwheel-structure solar interfacial evaporator was designed and assembled by printed filter papers. The evaporator can both rapidly distribute solution on the evaporation interface and be hydraulically driven to rotate continuously to improve the evaporation rate by water flow. The hydrodynamic solar-driven interfacial evaporation process successfully overcomes the problem of slow diffusion of water vapor, but also realizes the day-and-night operation of process and the self-cleaning of salt fouling. Apart from the application in solar desalination, the developed evaporator has great potentials in vapor production and salt recovery for industrial use.

RESUMEN

Solar-driven interfacial water evaporation (SIWE) has emerged as a promising avenue for cost-effective freshwater production from seawater or wastewater. However, the simultaneous evaporation of volatile organic compounds (VOCs) presents a limitation for the widespread implementation of this technique. Thus, developing dual-functional evaporators capable of both desalining seawater and degrading VOCs is challenging. Herein, we fabricated an iron-based metal-organic framework MIL-88A/carbon nanotubes (CNTs) poly(vinyl alcohol) hydrogel (MCH) evaporator via the conventional freezing method for solar-driven seawater desalination and simultaneous photo-Fenton VOC degradation. Because of the superior photothermal conversion capability of CNTs, reduced thermal conductivity and water evaporation enthalpy within the hydrogel, and the photo-Fenton activity of rod-shaped MIL-88A, the MCH evaporator exhibits a higher evaporation rate of 2.26 kg m-2 h-1 under 1 sun illumination with simultaneous VOC degradation. The higher hydrophilicity and vertical channels in the MCH evaporator enable its self-salt cleaning ability, facilitating consistent seawater desalination, even in high salt concentrations up to 10 wt %. The synergistic effects of localized heating from CNTs and hydrogen peroxide activation through reactive sites of MIL-88A allow the MCH evaporator to degrade more than 93% of the added phenol during evaporation. This work presents a sustainable and efficient approach for solar-driven seawater desalination, offering simultaneous VOC degradation.

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Utilizing inexhaustible solar energy for water purification represents a green and sustainable solution to water scarcity. However, the developments of efficient, inexpensive, convenient and reliable photothermal materials remain a major challenge. Herein, a facile and versatile preparation strategy of sodium alginate (SA)-CuS composite coating with superior adhesion and stability has been proposed toward high-efficiency solar-driven interfacial evaporation. The fabrication process can be quickly completed in aqueous solution with cheap reagents. The SA-CuS coating can be firmly adhered on different substrates, which can withstand rinsing treatment, iterative freeze-thaw cycles as well as high and low pH environments. The SA-CuS coating can convert various substrates into photothermal materials with broad light absorption for desirable solar evaporation because of high CuS loading and rough surface. As a proof of concept, a wood evaporator covered with the SA-CuS coating can achieve a water evaporation rate of ∼2.2 kg m-2 h- 1 under one sun illumination, which is superior to most reported wood-based solar evaporators.

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Efficient seawater desalination is an effective way to solve the shortages of fresh water and energy but with limitations of the low fresh water production rate and high cost. Here, a hollow carbon fiber (HCF) wrapped by regular reduced graphene oxide (rGO) wave-like folds (rGO@HCF) is prepared on account of the differences in thermal shrinkage performance between graphene oxide (GO) and willow catkins fiber. Under one sun irradiation (1 kW m-2), the dry and wet surface temperature of the resulting evaporator reached up to 119.1 °C and 61.7 °C, respectively, and the water steam production rate reached 3.42 kg m-2 h-1. Also, for the outdoor experiment, the rGO@HCF exhibits good evaporator performance which reach up 27.8 kg m-2 day-1. Additionally, rGO@HCF also shows good seawater desalination performance and excellent durability for longtime work. DSC results indicate that the evaporation enthalpy of bulk water and adsorbed water decreased from 2503.92 to 1020.54 J g-1. The excellent evaporating performance is mainly attributed to the regular wave-like microstructure surface of the HCF, which can enhance the light absorption, reduced the vaporization enthalpy of the adsorption water. The findings not only introduce a novel approach for agricultural utilization, but also establish a crucial theoretical foundation for the design of regular wave-like microstructures.

RESUMEN

Recent advances in solar-driven interfacial evaporation (SDIE) have led to high evaporation rates that open promising avenues for practical utilization in freshwater production and industrial application for pollutant and nutrient concentration, and resource recovery. Breakthroughs in overcoming the theoretical limitation of 2D interfacial evaporation have allowed for developing systems with high evaporation rates. This study presents a comprehensive review of various evaporator designs that have achieved pure evaporation rates beyond 4 kg m-2 h-1, including structural and material designs allowing for rapid evaporation, passive 3D designs, and systems coupled with alternative energy sources of wind and joule heating. The operational mechanisms for each design are outlined together with discussion on the current benefits and areas for improvement. The overarching challenges encountered by SDIE concerning the feasibility of direct integration into contemporary practical settings are assessed, and issues relating to sustaining elevated evaporation rates under diverse environmental conditions are addressed.

RESUMEN

Photothermal conversion materials are critical in the development of solar-driven interfacial evaporation techniques; however, achieving a high energy conversion efficiency remains challenging owing to the high cost and instability of light-absorbing materials, in addition to the difficulties of simultaneously improving light absorption while suppressing heat loss. A black silicon (Si) powder with a porous structure was prepared by chemical etching of a low-cost commercial micron-sized Al-Si alloy, and a flexible Janus black Si photothermal conversion membrane was constructed. The partially broken spherical particles and porous structure obtained after etching enhanced the refraction of light from the Si powder, imparting the prepared membrane with an average light absorption rate of 95.95% over the solar spectrum. Evaporation from the membrane increased the intermediate water content and reduced the equivalent evaporation enthalpy. The thermal conduction loss was inhibited through a one-dimensional water transport structure, and the membrane achieved a water evaporation rate of 2.17 kg m-2 h-1 and a photothermal efficiency of 94.95% under 1 sun illumination. Benefiting from the broadband absorption and high photothermal efficiency of black Si powder, surface modification of hydrophobic polydimethylsiloxane, and directional salt-out structure design, the evaporation rate of the Janus black Si membrane-based system in a 10% NaCl solution was maintained >2.10 kg m-2 h-1 after 7 days of continuous evaporation cycles. The removal rate of metal ions from simulated seawater and from practical wastewater containing complex heavy metals reached >99.9%, indicating the promising potential of black Si membrane for application in solar-driven interfacial water purification.

RESUMEN

Recently, the solar-driven interfacial evaporation desalination has attracted more and more attentions due to the advantages of low cost, zero energy consumption, and high water purification rate, etc. One of the bottlenecks of this emerging technique lies in a lack of simple and low-cost ways to construct three-dimensional (3D) hierarchical microstructures for photothermal membranes. To this end, a two-step strategy is carried out by combining surface functionalization with substrate engineering. Firstly, a silane coupling agent 3-aminopropyltriethoxysilane (APTES) is grafted onto an ideal photothermal material of Ti3C2Tx MXene, to improve the nanochannel sizes and hydrophilicity, which are attributed to enlarged interspaces of MXene and introduced hydrophilic group e.g., -NH2 and -OH, respectively. Secondly, a low-cost and robust nonwoven fiber (NWF) substrate, which has a 3D micron-sized mesh structure with interlaced fiber stacks, is employed as the skeleton to load enough APTES-grafted MXene by a simple soaking method. Benefited from above design, the Ti3C2Tx-APTES/NWF composite membrane with a 3D hierarchical structure shows enhanced light scattering and utilization, water transport and vapor escape. A remarkable evaporation rate of 1.457 kg m-2 h-1 and an evaporation efficiency of 91.48 % are attained for a large-area (5 × 5 cm2) evaporator, and the evaporation rate is further increased to 1.672 kg m-2 h-1 for a small-area (2 × 2 cm2) device. The rejection rates of salt ions and heavy metal ions are higher than 99 % and 99.99 %, respectively, and the removal rates of organic dye molecules are nearly to 100 %. Besides, the composite photothermal membrane exhibits great stabilities in harsh conditions such as high salinities, long cycling, large light intensities, strong acid/alkali environments, and mechanical bending. Most importantly, the photothermal membrane shows a considerable cost-effectiveness of 89.4 g h-1/$. Hence, this study might promote the commercialization of solar-driven interfacial evaporation desalination by collaboratively considering surface modification and substrate engineering for MXene.

RESUMEN

Solar-driven interfacial evaporation (SDIE) is a highly promising approach to achieve sustainable desalination and tackle the global freshwater crisis. Despite advancements in this field, achieving balanced thermal localization and salt resistance remains a challenge. Herein, the study presents a 3D hierarchical porous ceramic platform for SDIE applications. The utilized alumina foam ceramics (AFCs) exhibit remarkable corrosion resistance and chemical stability, ensuring a prolonged operational lifespan in seawater or brines. The millimeter-scale air-filled pores in AFCs prevent thermal losses through conduction with bulk water, resulting in heat-localized interfaces. The hydrophilic nature of macroporous AFC skeletons facilitates rapid water replenishment on the evaporating surface for effective salt-resistant desalination. Benefiting from its self-radiation adsorption and side-assisted evaporation capabilities, the AFC-based evaporators exhibit high indoor evaporation rates of 2.99 and 3.54 kg m-2 h-1 under one-sided and three-sided illumination under 1.0 sun, respectively. The AFC-based evaporator maintains a high evaporation rate of ≈2.77 kg m-2 h-1 throughout the 21-day long-term test. Furthermore, it achieves a daily water productivity of ≈10.44 kg m-2 in outdoor operations. This work demonstrates the potential of 3D hierarchical porous ceramics in addressing the trade-off between heat localization and salt resistance, and contributes to the development of durable solar steam generators.

RESUMEN

Solar interfacial evaporation technology has the advantages of environmentally conscious and sustainable benefits. Recent research on light absorption, water transportation, and thermal management has improved the evaporation performance of solar interfacial evaporators. However, many studies on photothermal materials and structures only aim to improve performance, neglecting explanations for heat and mass transfer coupling or providing evidence for performance enhancement. Numerical simulation can simulate the diffusion paths and heat and water transfer processes to understand the thermal and mass transfer mechanism, thereby better achieving the design of efficient solar interfacial evaporators. Therefore, this review summarizes the latest exciting findings and tremendous advances in numerical simulation for solar interfacial evaporation. First, it presents a macroscopic summary of the application of simulation in temperature distribution, salt concentration distribution, and vapor flux distribution during evaporation. Second, the utilization of simulation in the microscopic is summed up, specifically focusing on the movement of water molecules and the mechanisms of light responses during evaporation. Finally, all simulation methods have the goal of validating the physical processes in solar interfacial evaporation. It is hoped that the use of numerical simulation can provide theoretical guidance and technical support for the application of solar-driven interfacial evaporation technology.

RESUMEN

Solar-driven interfacial evaporation (SIE) is very promising to solve the issue of fresh water shortage, however, poor salt resistance severely hinders long-term stable SIE and fresh water collection. Here, we report design of superhydrophilic solar evaporators for long-term stable desalination, fresh water collection and salt collection by vertical salt deposition. The evaporators are prepared by sequentially deposition of silicone nanofilaments, polypyrrole and Au nanoparticles on a polyester fabric composed of microfibers. The evaporators feature excellent photothermal effect and ultrafast water transport, due to their unique micro-/nanostructure and superhydrophilicity. As a result, during SIE the salt gradually deposits vertically rather than occupies larger area on the evaporators. Consequently, long-term stable SIE with high evaporation rates of 2.4-2.1 kg m-2 h-1 for 3.5-20 wt % brine in continuous 10 h is achieved under 1 sun illumination. Meanwhile, the loosely deposited salt can be easily collected, realizing zero brine discharge. Moreover, scalable preparation of the evaporator is achieved, which exhibits efficient collection of high quality fresh water (10.08 kg m-2 in 8 h) via SIE desalination under weak natural sunlight (0.46~0.66 sun). This strategy sheds a new light on the design of high-performance solar evaporators and their real-world fresh water collection.

RESUMEN

Solar-driven interfacial evaporation (SDIE) is a green and sustainable technique for desalination. Hydrogel composite evaporators have been widely used for SDIE, but it is still challenging for the hydrogel evaporators to achieve uniform distribution of the light absorbing nanomaterials and at the same time possess satisfactory evaporation rate, durability and environmental applicability. We developed a 3D hydrogel evaporator with an asymmetric structure for high-efficiency SDIE. Natural kapok fibers, an important lignocellulosic plant fiber with a hollow structure, are decorated with MXene nanosheets for construction of one-dimensional photothermal conversion network. The top composite hydrogel serves as the light-absorption layer where MXene-modified kapok fibers are evenly dispersed in PVA hydrogel, while the bottom PVA hydrogel with an oriented structure acts as water delivery path. The evaporator exhibits a high solar evaporation rate and efficiency (2.49 kg·m-2·h-1 and 91.5 %, respectively) under one sun irradiation (1 kW·m-2). Even in a high salinity brine, emulsion and corrosive solutions, the evaporator can work normally with a slightly decreased evaporation rate. The 3D hydrogel evaporator with long-term stability and durability shows promising applications in purification of seawater and different waste water.

Asunto(s)

RESUMEN

Solar-driven interfacial evaporation is a potential water purification solution. Here, a novel regenerable hydrogel interfacial evaporator is designed with tunable water production. Such an evaporator is fabricated by readily mixing hydroxypropyl chitosan (HPCS) and dibenzaldehyde-functional poly(ethylene glycol) (DF-PEG) at ambient conditions. Dynamic Schiff base bonds bestow on the HPCS/DF-PEG hydrogel (HDH) evaporator self-adaptivity and pH responsiveness. The as-prepared HDH is enabled to spontaneously change shape to adapt to different molds, endowing the evaporator with adjustable evaporation area. The water production performance of the intelligent evaporator is first evaluated using tunable evaporation index (TEI, the tunable evaporated water mass per hour), which can be altered from 0 kg h-1 to 3.21 kg h-1 under one sun. Besides, the large-scale evaporator can be expediently fabricated by virtue of the self-adaptivity. Benefiting from the pH responsiveness, the HDH evaporator is successfully regenerated with the removal of organic dye by the liquefaction-dialysis-regeneration operations. Meanwhile, the re-created evaporator maintains the self-adaptive characteristic and almost constant water evaporation rate compared to that of the initial evaporator. Therefore, this distinctive concept provides a facile strategy to develop smart and recyclable solar-driven interfacial evaporators for flexible water purification.

RESUMEN

As a promising solution to address the global challenge of freshwater scarcity, solar-powered interfacial steam generation has undergone notable advancements. This study introduces a novel solar-driven interfacial evaporation membrane (ZnIn2S4@SiO2/ACSA, ZSAS) comprising a ZnIn2S4@SiO2 composite and a black sodium alginate aerogel infused with activated carbon. The ZSAS membrane demonstrates exceptional light absorption and thermal insulation, leading to elevated surface temperatures and reduced heat dissipation into the bulk water. Furthermore, the incorporation of AC reinforces the mechanical properties of the ZSAS membrane and enhances the water purification performance. These collective features result in an impressive evaporation rate of 1.485 kg m-2 h-1 and a high photothermal conversion efficiency of 91.2% under 1 sun irradiation for the optimal ZSAS membrane. Moreover, the optimal ZSAS membrane can effectively remove salts, heavy metal ions, and organic pollutants, benefitting from its superior evaporation separation effect and the photocatalytic properties of the ZnIn2S4@SiO2 composite.

Asunto(s)

RESUMEN

Solar-driven clean water production is challenged by VOCs (volatile organic compounds), which pose health risks in distilled water. Herein, we developed a Cu/W18O49@Graphene photothermal-photocatalytic material addressing VOCs contamination. Plasmonic coupling between Cu and W18O49 enhances light absorption, and 1-2 layers of graphene encapsulation protects oxygen vacancies within W18O49 while facilitating hot electron extraction, effectively mitigating their ultrafast relaxation. Density functional theory calculations revealed enhanced VOCs adsorption on graphene. These synergies address oxygen vacancy decay in W18O49 and provide more active sites for gas-liquid-solid triphase photocatalytic reactions. Integrated with a three-dimensional floating evaporator substrate, the optimized Cu/W18O49@Graphene material achieved an effective water evaporation rate of 1.41 kg m-2 h-1 (efficiency of 88.6%), exceptional stability (>120 h), and remarkable 99% phenol removal under 1 sun irradiation (1 kW m-2). This work provides a promising solution to mitigate VOCs contamination in solar-driven water evaporation.

RESUMEN

Solar-driven interfacial evaporation for water purification is limited by the structural design of the solar evaporator and, more importantly, by the inability to separate the water from volatile organic compounds (VOCs) present in the water source. Here, we report a three-dimensional (3D) bifunctional evaporator based on N-doped carbon (CoNC/CF), which enables the separation of fresh water from VOCs by activating PMS during the evaporation process with a VOC removal rate of 99%. There is abundant van der Waals interaction between peroxymonosulfate (PMS) and CoNC/CF, and pyrrolic N is confirmed as the active site for binding phenol, thus contributing to the separation of phenol from water. With the advantageous features of sufficient light absorption, adequate water storage capacity, and spontaneous internal convection flow on its top surface, the 3D evaporator achieves a high evaporation rate under one sun (1 kW/m2) at 3.16 kg/m2/h. More notably, through careful structural design, additional energy from the environment and water can be utilized. With such a high evaporation rate and satisfactory purification performance, this work is expected to provide a promising platform for wastewater treatment.

Asunto(s)

RESUMEN

Solar-driven interfacial evaporation is an eco-friendly solution for tackling the impending water scarcity the world is facing in our century. In this work, a solar-driven interfacial evaporator was prepared from cigarette butts loaded with petroleum coke powder (Filter-PetCoke), a by-product of the oil refinery processes, for the improvement of the absorption of the incident solar light. A comparison between a flat 2D and a 3D evaporator with a surface composed of orderly patterned protrusions of 2.1 cm was carried out to assess the influence of the evaporator configuration on the evaporation performance. The 3D evaporator (3D Filter-PetCoke) achieved by far the best performance (evaporation rate: 1.97 ± 0.08 kg m-2 h-1 and solar conversion efficiency: 93.2 ± 5.4%) among the prepared samples (3D Filter-PetCoke, 3D Filter, 2D Filter-PetCoke, and 2D Filter). In addition, this configuration seems to be adaptable for real and more massive operation because of the geometry of the evaporator. The high efficiency was ascribed to the good heat generation of the petroleum coke and the excellent heat management of the 3D structure of the evaporator. Moreover, this evaporator was resistant to multiple repeated usages without significant efficiency loss and capable of producing drinking water from seawater and Escherichia coli (E. coli)-contaminated water. The findings in this work indicate that this evaporator is pertinent to real situations to supply safe freshwater very efficiently from chemically/biologically contaminated water.

RESUMEN

Solar-driven interfacial evaporation (SDIE) with excellent photothermal conversion efficiency is emerging as one of the frontier technologies for freshwater production. In this work, novel carbonized conjugate microporous polymers (CCMPs) hollow microspheres-based composite hydrogel membranes (CCMPsHM-CHM) for efficient SDIE are reported. The precursor, CMPs hollow microspheres (CMPsHM), is synthesized by an in situ Sonogashira-Hagihara cross-coupling reaction using a hard template method. The as-synthesized CCMPsHM-CHM exhibit significantly excellent properties, i.e., 3D hierarchical architecture (from micropore to macropore), superior solar light absorption (more than 89%), better thermal insulation (thermal conductivity as low as 0.32-0.42 W m-1K-1 in the wet state), superhydrophilic wettability with a water contact angle (WCA) of 0°, superior solar efficiency (up to 89-91%), a high evaporation rate of 1.48-1.51 kg m-2 h-1 under 1 sun irradiation, and excellent stability which maintains an evaporation rate of more than 80% after 10 cycles and over 83% evaporation efficiency in highly concentrated brine. In this case, the removal rate of metal ions in seawater is more than 99%, which is much lower than the ion concentration standard for drinking water set by the World Health Organization (WHO) and the United States Environmental Protection Agency (USEPA). Taking advantage of its simple and scalable manufacture, our CCMPsHM-CHM may have great potential as advanced membranes for various applications for efficient SDIE in different environments.

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Solar-driven interfacial evaporation is one of the most promising desalination technologies. However, few studies have effectively combined energy storage with evaporation processes. Here, a novel multifunctional interfacial evaporator, calcium alginate hydrogel/bismuth oxychloride/carbon black (HBiC), is designed, which integrates the characteristics of interfacial evaporation and direct photoelectric conversion. Under illumination, the Bi nanoparticles which were produced by photoetching of BiOCl and its reaction heat are simultaneously used for the heating of water molecules. Meanwhile, part of the solar energy is converted into chemical energy through the photocorrosion reaction and stored in HBiC. At night, Bi NPs undergo autooxidation reaction and an electric current is generated during this process (like a metal-air battery), in which the maximum current density is more than 15 µA cm-2. This scientific design cleverly combines desalination with power generation and provides a new development direction for energy collection and storage.

RESUMEN

With the exponentially rapid development of solar-driven interfacial evaporation, evaporators with both high evaporation efficiency and recyclability are highly desirable to alleviate resource waste and environmental problems but remain challenging. Here, a monolithic evaporator was developed based on a dynamic disulfide vitrimer (a covalently cross-linked polymer network with associative exchangeable covalent bonds). Two types of solar absorbers, carbon nanotubes and oligoanilines, were simultaneously introduced to enhance the optical absorption. A high evaporation efficiency of 89.2% was achieved at 1 sun (1 kW m-2). When the evaporator was applied to solar desalination, it shows self-cleaning performance with long-term stability. Drinkable water with low ion concentrations satisfying the drinkable water levels of the World Health Organization and a high output (8.66 kg m-2, 8 h per day) was obtained, revealing great potential for practical seawater desalination. Moreover, a high-performance film material was obtained from the used evaporator via simple hot-pressing, indicating excellent fully closed-loop recyclability of the evaporator. This work provides a promising platform for high-efficiency and recyclable solar-driven interfacial evaporators.

RESUMEN

Solar-driven interfacial evaporation is an ideal technology for seawater desalination, and the corresponding system is mainly composed of a solar evaporator and a condensing collector. The traditional scheme focuses on the evaporation efficiency of the evaporator. Still, it ignores the influence of condensing collection scheme on the overall efficiency, which is one of the obstacles to the practical use of solar seawater desalination. Here, we reported a new solar-driven interfacial evaporation seawater desalination system by studying the influence of the condensation architecture, i.e., vapor flow by a fan and an air pump, sidewall material, transparent cover shape and material, evaporation level, and transparent cover heating, on the apparent collection efficiency of the system. The apparent collection efficiency was up to over 90% after optimization. This study is expected to promote the practical application of solar evaporation desalination technology.