Solar-driven Seawater Desalination Research Articles

Fabrication of Micro/Nanostructured Copper Fibers by Vibration Cutting for Felt-Based Freshwater Purification

Freshwater purification from wasted water and seawater is crucial in addressing the global problem of water scarcity. Porous fiber felt with a micro/nanostructure emerges as an efficient approach for water purification; however, its production usually relies on chemical postprocessing to create micro/nano structures on the fiber surface, which might pollute the environment. This study proposed an ecofriendly method to produce micro/nanostructured copper fiber felt without chemical treatment. First, a new transverse-feeding vibration cutting is proposed to fabricate micro/nanostructured fibers with controllable structure characteristics. Through the sintering of the structured fibers without postprocessing, the fiber felt can be produced in an ecofriendly way and exhibit special wettability and excellent photothermal properties. Felt-based freshwater purification, including oil–water separation and solar-driven seawater desalination, can be realized effectively. Results show an oil–water separation efficiency of > 90% and a high evaporation rate of water of > 1.08 kg m−2 h−1 at 73 mW cm−2 are achieved, demonstrating the application prospect of the produced fiber felt.

High-efficiency electrospun PVDF@MXene composite membrane with covalent bonding and well-dispersed internal materials for solar-driven seawater desalination

Environmentally friendly and efficient solar-driven interfacial evaporation (SDIE) has been increasingly applied to seawater desalination, and the easy-to-operate electrospinning technology has attracted more and more attention. However, photothermal materials such as MXene are often combined with polymers suitable for spinning through ordinary blending. The inherent difficult dispersion of it may lead to the instability of spinning and decrease the performance of evaporators, further hindering their production and application. To address these challenges, this work designs a covalent bonding PVDF@MXene composite as the spinning raw material. Using the electrospinning technology, the high-efficiency membrane-based evaporator with well-dispersed internal materials and strong homogeneity is successfully fabricated. The membrane performance is optimal when the MXene content is 25 %, achieving an evaporation rate of 1.88 kg·m−2·h−1 and an efficiency of 94.06 % under one sun. Besides, it exhibits remarkable salt resistance, maintaining an evaporation rate of 1.81 kg·m−2·h−1 even at the salinity of up to 20 wt%. More importantly, the membrane can be immersed in oxidative reagents for 24 h without degradation or reduced performance, demonstrating its good environmental stability. Overall, this research not only provides a rational idea for addressing the dispersion issue of MXene, but also presents a potential solution to deal with the global freshwater shortage emergency.

Photo-Fenton-Active MIL-88A/CNT-Based PVA Hydrogel for Solar-Driven Water Evaporation and Simultaneous Volatile Organic Compound Removal.

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.

Enhanced hydrophilicity and stability of carbon-based aerogel with assembling of halloysite nanotubes and silica fibers for efficient solar seawater evaporation and desalination

Solar vapor generation has emerged as a sustainable technique for seawater evaporation and desalination. Integrating high hydrophilicity, strong light absorbance, good salt resistance, fast water transfer and good structural stability simultaneously in one evaporator at low cost for achieving cost-effective evaporation and long-term utilization is highly desirable but still challenging. Herein, an eco-friendly and low-cost aerogel (CSH) with natural chitosan, halloysite nanotubes and silica fibers was prepared by freeze-casting, which was then carbonized to construct a robust aerogel (cCSH) as evaporator. The cellular structure of cCSH aerogel with microchannels enables fast water transfer and rapid salt dissolution, the carbonized chitosan favors enhanced light absorption, the halloysite assembled on the walls endows the aerogel with excellent hydrophilicity, and the silica fibers penetrating the multilayer guarantee good structural stability. As expected, the prepared evaporator (cCSH200) exhibits remarkable evaporation rates of 2.49/7.20 kg·m−2·h−1 under one/four sun, respectively, exceeding most biomacromolecule-derived aerogels. Besides, it displays outstanding salt resistance, wastewater purification ability and long-term cycle stability. Outdoor test further substantiates the admirable evaporation performance, long-term durability and enormous application prospect of the cCSH200. This work affords a low-cost tactic for the development of efficient evaporator for solar-driven seawater desalination and wastewater treatment.

Ultra-high solar steam generation based on regulated water management strategy in 3D biomass hydrogels inspired by the “binding effect” of cell walls

Facing the global challenge of water scarcity, solar-driven seawater desalination has been emerged as a green, non-polluting and sustainable technology, but the practical application of existing solar evaporators was hindered by their low evaporation efficiency and poor mechanical property. Inspired by the binding effect of cell walls, a novel and high-efficiency three-dimensional (3D) evaporator (CDs/CF/CS-LF) was constructed, in which loofah (LF) served as a natural 3D skeleton to support the hydrogel evaporator, resisted deformation, and created an efficient dual water supply mode with the chitosan (CS) hydrogel ensuring that the evaporator maintains high evaporation rate even under high salt environment. Additionally, the cellulose nanofibers (CF) filler enhanced the mechanical property of the hydrogel, ensuring shape stability under pressure impact, and carbon dots (CDs) facilitated the aggregation and cross-linking of chitosan chains through hydrogen bonds, further improving the mechanical property of the evaporator, while also enhancing the photothermal conversion capability of the 3D-CDs/CF/CS-LF evaporator as a photothermal material. The experimental results indicated that the 3D-CDs/CF/CS-LF evaporator could achieve an ultra-high solar vapor production rate of 8.08 kg m−2 h−1 under 1 sunlight intensity in 3.5 wt% NaCl solution. Outdoor seawater desalination experiments demonstrated the utility of 3D-CDs/CF/CS-LF evaporator for practical applications. This work provided a new approach for the improvement of CS-based evaporators and demonstrated their potential application in seawater desalination and purification.

Superwetting PVA/cellulose aerogel with asymmetric structure for oil/water separation and solar-driven seawater desalination

Extracting clean water from oily wastewater and seawater is one of the effective strategies to alleviate the freshwater crisis. However, achieving both high separation efficiency and excellent salt resistance remain challenges for materials. Herein, a novel methyltrichlorosilane-modified polyvinyl alcohol/cellulose aerogel (MPCA) was prepared by freeze drying, chemical cross-linking, and chemical vapor deposition (CVD) methods. The superwetting MPCA presented an asymmetric structure, in which the small dense pores at the top surface facilitated the efficient separation of water-in-oil (W/O) emulsions and the large pores on the bottom surface were beneficial for brine exchange. The as-prepared superwetting aerogel was suitable for the separation of various W/O emulsions with excellent separation flux (631.9–2368.7 L·m−2·h−1) and outstanding separation efficiency (99.5 %). In addition, MPCA achieved a high evaporation efficiency of 1.39 kg·m−2·h−1 and a satisfactory energy conversion efficiency of 89.7 %. Moreover, the unique asymmetric structure endowed the evaporator excellent salt resistance and could self-dissolve the accumulated salt in 20 min. The as-prepared MPCA could achieve efficient W/O emulsion separation as well as produce freshwater in seawater, providing a new strategy for oily waste seawater purification.

Biodegradable hydrogel with excellent portability, stability and anti-pollution performance in solar-driven seawater desalination

Solar-driven interfacial evaporation technology holds great potential for efficiently utilizing solar energy to convert untapped water sources into clean water. This study developed a cellulose nanofiber (CNF)/polyvinyl alcohol (PVA)/multi-walled carbon nanotubes (MWCNTs) hydrogel-based evaporator (PCC) using low-cost wood pulp cellulose as the raw material. The experimental results revealed that the PCC hydrogel evaporator achieved a water evaporation rate of 1.61 kg·m−2·h−1 under 1 sun irradiation (solar intensity of 1 kW·m−2). Assisted by the three-dimensional interconnected hydrophilic network, the hydrogel exhibited excellent water supply capabilities, with water transport dominating within the hydrogel, enabling continuous steam generation from seawater. And the water layer formed by the super-hydrophilic pore wall structure was also beneficial to activating water, promoting the diffusion of high-concentration salt water, and enhancing the underwater oil repellent ability. After multiple compression-recovery performance tests, the PCC maintained stable evaporation performance, which greatly enhanced portability during use. In addition, the application of PCC evaporators in the fields of seawater desalination, wastewater treatment, and agricultural irrigation had shown excellent results, confirming the potential application value of this evaporator. Combined with its environmental friendliness, cost-effectiveness, and other advantages, it had broad development prospects.

Construction of magnetic and photothermal wood membrane with asymmetric wettabilities and wind drift resistance for solar-driven seawater desalination and purification

To generate clean freshwater controllably and efficiently, Fe3O4/CNT nanomaterials and hydrophobic PVDF were introduced to delignified wood with man-made-cutting structure (D-Wood) in simple brushing method for constructing the magnetic and photothermal wood evaporator with asymmetric wettabilities and wind drift resistance. Such method could endow wood with various shapes design, outstanding magnetically sensitivity, remarkable photothermal conversion efficiency (129.08 %), high evaporation rate (1.92 kg·m−2·h−1), good dye degradability (97.23 %), and excellent wind resistance (6.6 m/s). The superhydrophilic and underwater superoleophobic bottom of Fe3O4/CNT/PVDF@D-Wood evaporator accelerated the bulk seawater transport during its evaporation procedure, but prevented the oil pollutants blocking the microchannels of evaporator during the long periods of flotation at sea. Meantime, its hydrophobic top could effectively reduce the downward diffusion of heat, and improve the salt tolerance. After 10 cycles of acid-base, ultrasound treatments and evaporating experiments, Fe3O4/CNT/PVDF@D-Wood evaporator still exhibited excellent evaporation rate and conversion efficiency, displaying remarkable repeatability and long-term durability. In weak magnetic field (3 V), its furthest response displacement and time were 5 cm and 41 s, respectively. After prolonged evaporation procedure, the magnetic responsivity of Fe3O4/CNT/PVDF@D-Wood evaporator could be in almost constant level, which offers a promising biomass product for seawater desalination and polluted-water purification.

A multi-layer fabric for high-efficiency solar-driven seawater desalination

Fiber-based photothermal materials for seawater desalination usage have garnered significant attention owing to their outstanding properties. However, traditional monolayer fabrics are prone to possess inherent inefficiencies such as high thermal dissipation and salt crystallization within the evaporation zone, especially reducing the evaporation efficiency during the long-term seawater desalination. Herein, a novel three-layered three-dimensional (3D) spacer carbon/polyester cotton spacer woven fabric (SWF) evaporator is designed. This SWF material was delineated into three distinct layers: an upper evaporate layer, a foundational water absorption layer, and a central water dedicated to water transition, thermal insulation, and salt crystallization. The rational three-layered 3D architecture guarantees the swift aqueous transition within SWF evaporator, simultaneously curtailing thermal losses from the top layer. The evaporation rate of 3D SWF, with 6 mm interval space, registered at 1.6721 kg · m−2·h−1 under a solar intensity of 1 kW · m−2. Furthermore, under conditions with a solar power of 1 kW · m−2 and a wind velocity of 2 m · s−1, the evaporation efficiency of liquid water from SWF, with a central layer height of 12 mm, culminated at 3.9742 kg · m−2·h−1, which validated its adeptness for the seawater desalination applications. The results of our research are helping to provide for efficient and stable methods of wastewater treatment, desalination, and drinking water collection.

A coal-based multifunctional membrane for solar-driven seawater desalination and power generation

Water evaporation systems driven by solar energy delivers great potential for seawater desalination and sustainable energy generation, which is of great significance to relieve the worldwide shortage of fresh-water and energy. However, the achievement of well-designed materials and configuration for water evaporation systems remains a great challenge, hindering the realization of high evaporation rates and stable energy output. Herein, conductive coal-based nanocarbon material was creatively fabricated to assemble a novel multifunctional membrane based evaporation system for simultaneous solar thermal desalination of seawater and power generation. The coal-based multifunctional membrane (CBMM) possesses a permanently asymmetric wetting structure, which can ensure high photothermal evaporation efficiency and stable energy output. The constructed device unit demonstrate a long and stable operation in seawater under one sun irradiance for 100 h, achieving a high evaporation rate of 1.81 kg m−2 h−1 and a large voltage output of 410 mV. Especially, multiple units of the devices can be easily connected in series or parallel to power small electronic devices. This work provides a cost-effective and large scale method for the fabrication of coal-based nanomaterials and the creative application in high-perforamnce water evaporation systems for seawater desalination and sustainable energy generation.

Waste Tea-Derived Theabrownins for Solar-Driven Steam Generation.

Solar-driven seawater desalination has been considered an effective and sustainable solution to mitigate the global freshwater crisis. However, the substantial cost associated with photothermal materials for evaporator fabrication still hinders large-scale manufacturing for practical applications. Herein, we successfully obtained high yields of theabrownins (TB), which were oxidation polymerization products of polyphenols from waste and inferior tea leaves using a liquid-state fermentation strategy. Subsequently, a series of photothermal complexes were prepared based on the metal-phenolic networks assembled from TB and metal ions (Fe(III), Cu(II), Ni(II), and Zn(II)). Also, the screened TB@Fe(III) complexes were directly coated on a hydrophilic poly(vinylidene fluoride) (PVDF) membrane to construct the solar evaporation device (TB@Fe(III)@PVDF), which not only demonstrated superior light absorption property and notable hydrophilicity but also achieved a high water evaporation rate of 1.59 kg m-2 h-1 and a steam generation efficiency of 90% under 1 sun irradiation. More importantly, its long-term stability and exceptionally low production cost enabled an important step toward the possibility of large-scale practical applications. We believe that this study holds the potential to pave the way for the development of sustainable and cost-effective photothermal materials, offering new avenues for utilization of agriculture resource waste and solar-driven water remediation.

Intensifying heat using AgCu core-shell-based black titania with highly efficient photothermal conversion performance for solar-driven seawater desalination

A novel photoreceiver composed of black titania (BT) matrix with biochar for efficient steam production was investigated to measure the desalination efficiency under the illumination of one sun (1 kW m−2). The density of localized hotspots on the surface of the photothermal system is enhanced by the incorporation of AgCu core-shell that promotes photothermal activity and improves the degradation of methyl orange (MO) dye. Assemblages of AgCu nanoparticles on the surface of BT generated a strong stochastic plasmonic coupling and therefore broad-band absorption for much better solar energy consumption. The nanocomposite exhibited an excellent vaporization flux of 1.4 kg m−2 h−1 with high efficiency reaching 95.7 % under the illumination of one sun. AgCu@BT/BC exhibited an excellent surface temperature of 41 °C after only 5 min compared to other prepared photothermal systems. Furthermore, the prepared composites revealed superb degradation of MO dye under UV–vis light with a percentage of 96 %. The band gap energy of white titania decreased from 3.2 eV to 1.86 eV in the case of AgCu@BT/BC nanocomposite. Moreover, the crystalline AgCu@BT/BC demonstrates outstanding photocatalytic performance because of boosted charge migration, reduced electron-hole pair recombination rate, and identifiable shift to the red region.

Double-layered hydrogels based on phase change material and pen ink for continuous and efficient solar-driven seawater desalination

A novel double-layered hydrogel based on the polyacrylamide matrix, pen ink, and phase-change microcapsules was developed to construct a hydrogel-based evaporator for efficient and continuous seawater desalination. The n-eicosane (core)@crystalline TiO2 (shell) phase-change microcapsules were fabricated through interfacial polycondensation, and the resulting phase-change microcapsules obtained a considerably high latent-heat capacity of 187 J·g−1. The upper layer of the hydrogel exhibits a high solar absorptivity of over 90 % due to the introduction of pen ink as a solar absorber, which helps the hydrogel-based evaporator to gain an excellent photothermal energy conversion capability. A high evaporation efficiency of 93.89 % was obtained for the developed hydrogel-based evaporator along with a high evaporation rate of 1.85 kg·m−2·h−1 under one-sun illumination. The phase-change microcapsules dispersed in the lower layer of the hydrogel can act as a latent heat-storage unit to store a great quantity of photothermal energy through melting phase change by the phase change material core. This imparts a consecutive evaporation capability to the developed hydrogel-based evaporator. As a result, its water production was increased by 11 % under 50-min one-sun illumination and 50-min non-illumination.

Super-hydrophilic LaCoO3/g-C3N4 nanocomposite coated beauty sponge for solar-driven seawater desalination with simultaneous volatile organic compound removal.

Interfacial solar steam generation (ISSG) is emerging as a promising, environment-friendly solution for fulfilling freshwater and energy demands. However, a critical challenge for ISSG lies in the presence of harmful volatile organic compounds (VOCs) in the feedwater which are co-evaporated with water, leading to more enriched concentration in condensed water. Herein, lanthanum cobaltate-graphitic carbon nitride (LaCoO3/g-C3N4, LCO/g-CN) nanocomposite decorated beauty sponge (LCO/g-CN@BS) is proposed as an efficient photothermal/photocatalytic material for solar-driven seawater desalination and simultaneous VOC degradation. The hydrophobic surface of the beauty sponge after LCO/g-CN coating becomes super-hydrophilic, ensuring sufficient water supply and our LCO/g-CN@BS delivers an evaporation rate of 1.94 kg m-2 h-1 under 1 sun irradiation. This LCO/g-CN@BS shows excellent seawater desalination capacity with a self-cleaning ability when employed for saltwater purification for a salt (NaCl) concentration as high as 15 wt%. Moreover, fast photocarrier transfer between LCO and g-CN leads to enhanced photocatalytic degradation of over 90% of phenol simultaneously, which is about 60% for only an LCO-based beauty sponge. This work presents a promising approach to combining novel nanocomposites with microporous structures for efficient solar desalination, offering simultaneous VOC degradation.

Research Advances in Wood Composites in Applications of Industrial Wastewater Purification and Solar-Driven Seawater Desalination.

In recent years, the ecosystem has been seriously affected by sewage discharge and oil spill accidents. A series of issues (such as the continuous pollution of the ecological environment and the imminent exhaustion of freshwater resources) are becoming more and more unmanageable, resulting in a crisis of water quality and quantity. Therefore, studies on industrial wastewater purification and solar-driven seawater desalination based on wood composites have been widely considered as an important development direction. This paper comprehensively analyzes and summarizes the applications of wood composites in the fields of solar-driven seawater desalination and polluted water purification. In particular, the present situation of industrial wastewater containing heavy metal ions, microorganisms, aromatic dyes and oil stains and related problems of solar-driven seawater desalination are comprehensively analyzed and summarized. Generally, functional nanomaterials are loaded into the wood cell wall, from which lignin and hemicellulose are selectively removed. Alternatively, functional groups are modified on the basis of the molecular structure of the wood microchannels. Due to its three-dimensional (3D) pore structure and low thermal conductivity, wood is an ideal substrate material for industrial wastewater purification and solar-driven seawater desalination. Based on the study of objective conditions such as the preparation process, modification method and selection of photothermal conversion materials, the performances of the wood composites in filtration, adsorption and seawater desalination are analyzed in detail. In addition, this work points out the problems and possible solutions in applying wood composites to industrial wastewater purification and solar-driven seawater desalination.

Carbon nanotubes@polydopamine/nickel foam with a wavy shape applied for efficient solar-driven seawater desalination

Solar-powered water evaporation has been recognized as a potential water purification regeneration technology to alleviate the issue of global water shortage. Interfacial solar steam generation (ISSG) with a high rate of evaporation and high photo-thermal conversion efficiency is very desirable. Herein, a scalable, high-efficiency and surface tunable ISSG was developed by carbon nanotubes (CNTs) loaded on polydopamine (PDA) modified nickel foam (NF) with a honeycomb three-dimensional (3D) network structure. The surface of CNTs@PDA/NF (CPNF) solar evaporator was designed as the 3D wave-like for further improved water evaporation. The as-prepared solar steam generator has an evaporation rate of 1.61 kg m−2 h−1, and photo-thermal conversion efficiency of 91.0 % at 1.0 solar irradiance. Moreover, it displays efficient purification ability for heavy metal ions in seawater and lake water, and the concentration of Na+, Mg2+, K+ and Ca2+ in the desalinated condensate is in line with the World Health Organization's drinking water standards. Additionally, the dye-contaminated wastewater can also be purified and treated to be drinking water. Furthermore, it has a good salt self-melting function. In sum, this work provides some new insights for designing innovative solar evaporators with outstanding photothermal conversion capability.

Fully waste-based solar evaporator in interfacial solar-driven seawater desalination

The scarcity of freshwater resources and the increasing demand for sustainable water treatment technologies have prompted the development of interfacial solar-driven seawater desalination (ISSD). However, designing stable solar evaporators to alleviate freshwater scarcity and reduce environmental stress remains a significant challenge. This study presents a solar evaporator from waste materials to address these challenges. The device comprises a photothermal membrane (CLPM) made from cattail leaf-based fibers (CLF) and cattail leaf-based carbon (CLC) with a simple crosslinking method using sodium alginate and CaCl2, a waste humidifier filter (WHF), and discarded packaging foam. The CLPM exhibits approximately 96 % solar absorption, achieving an evaporation rate of 1.38 kg m–2 h–1 when treating groundwater and 1.22 kg m–2 h–1 when desalinating a 3.5 wt % NaCl solution. The desalination performance of CLPM can be stable for 6 h due to the sufficient water provided by the WHF with vertical water conductivity channels. The desalination performance of CLPM can be restored by washing off the accumulated salts in a 3.5 wt % NaCl solution or by self-cleaning overnight, as verified by indoor and outdoor cycling experiments. 1 m2 of CLPM can produce approximately 5.3 kg of freshwater during the daytime, sufficient to meet two adults' daily water consumption needs. This waste-derived solar evaporator promotes the efficient utilization of waste materials and offers a sustainable solution to address freshwater scarcity while reducing environmental impact.

The solar-driven redox seawater desalination based on the stable and environmentally friendly WO3/BiVO4 photoanode

Nowadays, stable photoelectrochemical seawater desalination is a challenge. In this work, an environmentally friendly WO3/BiVO4 photoanode is reported to achieve stable solar-driven redox desalination. The WO3/BiVO4 photoanode was prepared by the hydrothermal method and drop-casting and the cathode is the activated carbon coated on graphite paper. Within the desalination system, the I−/I3− redox species are recycled between anode/cathode chambers. In the short-circuit state, with illumination as the driving force, the salt removal rate of 65.03 μg/(cm2·min) is obtained without the electric consumption. During the desalination process, the energy output process can be implemented with a salt removal rate of 29.8 μg/(cm2·min) with constant current discharge. Importantly, the solar desalination system based on WO3/BiVO4 photoanode is quite stable. Within the five cycles, the variation of the salt removal rate is within 3.32 μg/(cm2·min). As the practical application, the seawater is desalted to the freshwater standard using the current system, in which the conductivity decreases to 0.96 mS/cm from 53 mS/cm. This work provides a feasible approach to developing stable and efficient solar-driven seawater desalination for long-term usage.

Salt-resistance holocellulose-based solar steam evaporator for desalination brine water

Interfacial solar-powered water evaporation is a cost-effective and sustainable approach using solar energy for seawater desalination. Nevertheless, salt accumulation during solar desalination generally restricts the widespread application of solar vapor generation. Herein, taking merits of the excellent hydrophilicity and inherent porosity of holocellulose (HC), An excellent salt-resistant solar steam evaporator for long-term interfacial solar water desalination was fabricated by decorating polypyrrole (PPy) on the surface of HC. Due to the broadband light absorbance of PPy and the superhydrophilic HC substrate, the PPy-HC evaporator exhibited a high evaporation rate of 1.45 kg m−2 h−1 and conversion efficiency of 93.4 % in a 5 wt% NaCl solution under one sun illumination. Importantly, the evaporator presented superior salt-resistance and stability during long-term cycling test in high salinity brine. This work reveals the key role of superhydrophilicity and water transportation capability in high salt solution solar-driven desalination. Thus, this work provides an effective approach to address the issue of salt accumulation of the traditional evaporator, demonstrating its great potential for real-world solar-driven seawater desalination.

A solar-driven seawater desalination and electricity generation integrating system based on carbon black-decorated magnetic phase-change composites

We have developed a novel type of solar-driven interfacial evaporation and electricity generation integrating system based on the modified carbon black (MCB)-decorated magnetic phase-change composites (MCB-MPCC) for continuous seawater desalination and clean electric power generation under intermittent solar illumination. In this system, MCB-MPCC acts as not only a solar absorber but also a hydrovoltaic functional coating. MCB-MPCC was fabricated through encapsulating n-docosane as a phase change material (PCM) in a SiO2/Fe3O4 composite shell through emulsion-templated interfacial polycondensation, followed by coating a polydopamine layer and surface-depositing MCB nanoparticles. Owing to the introduction of a PCM core, the resultant MCB-MPCC obtained a high latent heat capacity of over 145 J g−1 for consecutive seawater evaporation under intermittent solar illumination. Moreover, the surface-decorated MCB nanoparticles contribute to superior sunlight absorptivity and good wettability of MCB-MPCC, promoting a high evaporation rate of 2.67 kg m−2 h−1 for the MCB-MPCC-based evaporator under one-sun illumination along with excellent salt resistance. Meanwhile, the developed system achieved a stable output voltage of 0.43 V and output current of 10.05 μA under one-sun illumination, and the generated electric power could be stored by a commercial capacitor to provide a power supply for lightening an LED lamp.