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1.
Solar-driven steam generation, whereby solar energy is harvested to purify water directly, is emerging as a promising approach to mitigate the worldwide water crisis. The scalable application of conventional 3D evaporators is hindered by their complex spatial geometries. A 2.5D structure is a spatial extension of a 2D structure with an addition of a third vertical dimension, achieving both the feasibility of 2D structure and the performance of 3D structure simultaneously. Here, an interconnected open-pore 2.5D Cu/CuO foam-based photothermal evaporator capable of achieving a high evaporation rate of 4.1 kg m−2 h−1 under one sun illumination by exposing one end of the planar structure to air is demonstrated. The micro-sized open-pore structure of Cu/CuO foam allows it to trap incident sunlight, and the densely distributed blade-like CuO nanostructures effectively scatter sunlight inside pores simultaneously. The inherent hydrophilicity of CuO and capillarity forces from the porous structure of Cu foam continuously supply sufficient water. Moreover, the doubled working sides of Cu/CuO foam enlarge the exposure area enabling efficient vapor diffusion. The feasible fabrication process and the combined structural features of Cu/CuO foam offer new insight into the future development of solar-driven evaporators in large-scale applications with practical durability.  相似文献   

2.
Solar steam generation is achieved by localized heating system using various floating photothermal materials. However, the steam generation efficiency is hindered by the difficulty in obtaining a photothermal material with ultrathin structure yet sufficient solar spectrum absorption capability. Herein, for the first time, an ultrathin 2D porous photothermal film based on MoS2 nanosheets and single‐walled nanotube (SWNT) films is prepared. The as‐prepared SWNT–MoS2 film exhibits an absorption of more than 82% over the whole solar spectrum range even with an ultrathin thickness of ≈120 nm. Moreover, the SWNT–MoS2 film floating on the water surface can generate a sharp temperature gradient due to the localized heat confinement effect. Meanwhile, the ultrathin and porous structure effectively facilitates the fast water vapor escaping, consequently an impressively high evaporation efficiency of 91.5% is achieved. Additionally, the superior mechanical strength of the SWNT–MoS2 film enables the film to be reused for atleast 20 solar illumination cycles and maintains stable water productivity as well as high salt rejection performance. This rational designed hybrid architecture provides a novel strategy for constructing 2D‐based nanomaterials for solar energy harvesting, chemical separation, and related technologies.  相似文献   

3.
A three-plasmon hybrid, in which core–shell Au@Cu2−xS hybrids are bonded with ultrathin Ti3C2Tx MXene, is prepared for high-efficiency photothermal conversion and membrane-based solar water evaporation for the first time. The MXene/Au nanorod@Cu2−xS hybrids display excellent photothermal conversion efficiency under irradiation of an 808 laser, causing by the three-plasmon-induced synergistic plasmonic absorption and heating effects as well as the multichannel charge transfer between the components. Then, Au nanosphere@Cu2−xS and Au nanorod@Cu2−xS hybrids are mixed and combined with MXene to serve as the membrane material, which shows excellent light absorption ranging from ultraviolet to near-infrared region. By transferring the membrane materials on a hydrophilic cotton piece, the as-prepared photothermal membrane displays a high evaporation rate of 2.023 kg m−2 h−1 and light-to-heat conversion efficiency of 96.1% under 1-sun irradiation due to the synergistic photothermal conversion and over 96% of solar light absorption efficiency. Furthermore, a home-made solar evaporation device enabling automatic inflow of untreated water and outflow of evaporated water is designed based on the principles of liquid pressure and connectors. The seawater desalination and sewage treatment experiments performed on the device and membrane indicate the great potential in solar-light-driven water purification and drinkable water generation.  相似文献   

4.
Photothermal conversion, heat localization and water supply are the keys to achieving efficient solar-driven interfacial evaporation. However, effective coupling between the three aspects at the air/liquid interface remains challenging. Herein, Au@Ag-Pd trimetallic nanostructure/polystyrene (PS) microsphere Janus structures are designed as the solar absorber and thermal insulator. The Janus structures deposited on a water supply layer act as a 2D interfacial solar evaporator. The PS microsphere localizes heat at micrometer scale and enhances plasmonic absorption of the Au@Ag-Pd nanocrystals supported on the microsphere. Meanwhile, the Janus structures divide the surface of water supply layer into multiple regions with sub-micrometer depths, lowering the evaporation enthalpy. Owing to the synergic effects of these components, the evaporator realizes a solar-to-vapor conversion efficiency of 99.1% and an evaporation rate of 3.04 kg m−2 h−1 in pure water under 1 sun illumination. The efficient solar-driven evaporation can last for over 40 h. Furthermore, the solar evaporator shows high-performance seawater desalination with salt removal ratios of near 100%. This study brings new insights for controlling evaporation thermodynamics and kinetics. The Janus nano-micro structure design can be extended to other systems for various solar-thermal applications.  相似文献   

5.
Superhydrophobic photothermal materials with the micro-nano structure are considered to be promising icephobic surfaces. Unfortunately, converting micro-nano hierarchical structure concepts into genuine synthetic materials has proven to be exceedingly expensive and difficult, partially because their sophisticated structures need construction at several length scales. Herein, a facile strategy of employing ice crystals to construct sophisticated hierarchical micro-nanostructured anti-icing composites with photothermal, self-healable, and self-cleaning properties is presented. The composites are covered with interconnected microscale pores replicated from ice crystals, which facilitates the construction of the hydrophobic or superhydrophobic properties based on the Cassie–Baxter model, endowing the coating with self-cleaning ability. Besides, by adding solar-to-heat conversation nanomaterials, the coating can implement in situ solar anti-/deicing. The abundant micropores caused by ice templates can further improve the photothermal conversion capability through multiple reflections of light. Importantly, the coating is endowed with the self-healing capability to repair hydrophobicity under sunlight. Additionally, it is demonstrated that the self-cleaning and self-healing abilities are mutually reinforcing, synergistically improving anti-/deicing performances. Overall, the presented ice-templated coating shows great potential and broad impacts owing to its inexpensive component materials, simplicity, eco-friendliness, and high energy efficiency.  相似文献   

6.
An aqueous, protein‐enabled (biomimetic), layer‐by‐layer titania deposition process is developed, for the first time, to convert aligned‐nanochannel templates into high‐aspect‐ratio, aligned nanotube arrays with thin (34 nm) walls composed of co‐continuous networks of pores and titania nanocrystals (15 nm ave. size). Alumina templates with aligned open nanochannels are exposed in an alternating fashion to aqueous protamine‐bearing and titania precursor‐bearing (Ti(IV) bis‐ammonium‐lactato‐dihydroxide, TiBALDH) solutions. The ability of protamine to bind to alumina and titania, and to induce the formation of a Ti–O‐bearing coating upon exposure to the TiBALDH precursor, enables the layer‐by‐layer deposition of a conformal protamine/Ti–O‐bearing coating on the nanochannel surfaces within the porous alumina template. Subsequent protamine pyrolysis yields coatings composed of co‐continuous networks of pores and titania nanoparticles. Selective dissolution of the underlying alumina template through the porous coating then yields freestanding, aligned, porous‐wall titania nanotube arrays. The interconnected pores within the nanotube walls allow enhanced loading of functional molecules (such as a Ru‐based N719 dye), whereas the interconnected titania nanoparticles enable the high‐aspect‐ratio, aligned nanotube arrays to be used as electrodes (as demonstrated for dye‐sensitized solar cells with power conversion efficiencies of 5.2 ± 0.4%).  相似文献   

7.
An aqueous, protein‐enabled (biomimetic), layer‐by‐layer titania deposition process is developed, for the first time, to convert aligned‐nanochannel templates into high‐aspect‐ratio, aligned nanotube arrays with thin (34 nm) walls composed of co‐continuous networks of pores and titania nanocrystals (15 nm ave. size). Alumina templates with aligned open nanochannels are exposed in an alternating fashion to aqueous protamine‐bearing and titania precursor‐bearing (Ti(IV) bis‐ammonium‐lactato‐dihydroxide, TiBALDH) solutions. The ability of protamine to bind to alumina and titania, and to induce the formation of a Ti–O‐bearing coating upon exposure to the TiBALDH precursor, enables the layer‐by‐layer deposition of a conformal protamine/Ti–O‐bearing coating on the nanochannel surfaces within the porous alumina template. Subsequent protamine pyrolysis yields coatings composed of co‐continuous networks of pores and titania nanoparticles. Selective dissolution of the underlying alumina template through the porous coating then yields freestanding, aligned, porous‐wall titania nanotube arrays. The interconnected pores within the nanotube walls allow enhanced loading of functional molecules (such as a Ru‐based N719 dye), whereas the interconnected titania nanoparticles enable the high‐aspect‐ratio, aligned nanotube arrays to be used as electrodes (as demonstrated for dye‐sensitized solar cells with power conversion efficiencies of 5.2 ± 0.4%).  相似文献   

8.
Safe and clean freshwater harvesting from (organic-containing) saline or wastewater holds great potential for mitigating water scarcity and pollution, but remains challenging. Herein, a floating photothermal/catalytic-integrated interfacial micro-evaporator (g-C3N4@PANI/PS) is reported as a proof-of-concept multifunctional scavenger evaporator system (MSES) to achieve both solar-driven complete desalination and organic degradation. The spherical porous lightweight polystyrene core, incorporated with a black surface functional layer (g-C3N4@PANI), enables the hybrid micro-evaporator to naturally float and thereby collectively self-assemble under surface tension for interfacial evaporation, which achieves preeminent self-cleaning for complete salt/solute separation and efficient organic photodegradation under rotation. Remarkably, the floating micro-evaporator achieves a high solar-vapor conversion efficiency of ≈90% with high interfacial energy localization and provides abundant active photocatalytic sites on the interface, which is further enhanced by interfacial photothermal cooperation. High photo-driven degradation efficiencies of 99% for nonvolatile organic compounds (non-VOC) bisphenol A and 95% for VOC phenol in wastewater are achieved. An outdoor comprehensive solar water treatment test toward organic-containing high-salinity sewage verifies the feasibility of MSES for sustainable freshwater harvesting (1.3 kg m−2 h−1), downstream salt recovery, and organic degradation. This strategy may inspire an integrated solution of water scarcity, clean energy, and environmental pollution toward carbon neutrality.  相似文献   

9.
Recently, owing to the great structural tunability, excellent photothermal property, and strong photobleaching resistance, organic-small-molecule photothermal materials are proposed as promising solar absorbent materials. Herein, through fusing two strong electron-withdrawing units dibenzo[f,h]quinoxaline and anthraquinone units, a rigid planar acceptor dibenzo[a,c]naphtho[2,3-h]phenazine-8,13-dione (PDN) with stronger electron-withdrawing ability is obtained and used to construct donor–acceptor-type organic-small-molecule solar-energy-absorbing material, 2,17-bis(diphenylamino)dibenzo[a,c]naphtho[2,3-h]phenazine-8,13-dione (DDPA-PDN). The new compound exhibits a strong intramolecular charge transfer character and conjugates rigid plane skeleton, endowing it with a broadband optical absorption from 300 to 850 nm in the solid state, favorable photothermal properties, high photothermal conversion ability, and good photobleaching resistance. Under laser irradiation at 655 nm, the solid photothermal conversion efficiency of the resulting DDPA-PDN molecule reaches 56.23%. Additionally, DDPA-PDN-loaded cellulose papers equipped with abundant microchannels for water flow are integrated with thermoelectric devices, thus achieving an evaporation rate and voltage as high as 1.07 kg m−2 h−1 and 83 mV under 1 kW m−2 solar irradiation, respectively. This study demonstrates the application of photothermal organic-small-molecules in water evaporation and power generation, therefore offering a valuable prospect of their utilization in solar energy harvesting.  相似文献   

10.
Conversion of solar energy into heat for water evaporation is of great significance to provide clean and sustainable technology for water purification by using inexhaustible sunlight. In this field, one of the challenges comes from the design of high-performance photothermal materials powerful in light harvesting, light-to-heat conversion, and water activation. Herein, it is demonstrated that rationalization of the ionic covalent organic framework (iCOF) can simultaneously satisfy these multiple requirements and a new iCOF STTP is constructed through the Schiff base chemistry in a rapid microwave-assisted solvothermal route by using a hydrophilic dye molecule safranineT as the ionic building block. The integrated dye-related ionic moieties greatly strengthen the light absorbance (>97%) throughout the entire solar spectrum from UV–vis to the infrared region. The framework ionic moieties provide strong polarization to reduce the exciton dissociation energy for enhanced photothermal effect, and in addition, promote sufficient water activation to decrease the water evaporation enthalpy. As an outcome, the STTP driven solar water evaporator affords a fast water evaporation rate of 3.55 kg h−1 m−2 and high solar-to-vapor efficiency of 95.8%. This study highlights the potential of designing iCOF materials for photothermal applications.  相似文献   

11.
Solar-driven evaporation process brings exciting opportunities to recover clean water and resources in a sustainable way from diverse sources like seawater and wastewater. Separation membranes, as a vital material in many environmental and energy applications, can contribute significantly to this process owing to their structural features. However, the unique roles of membranes in solar evaporator construction and process design are seldom recognized and not summarized yet from scientific principles and application demands, which forms the motivation of this review. Herein, the roles of membranes in different processes based on solar-driven evaporation are focused and the design principles of membrane materials and devices to meet the requirements of these applications are discussed. Fabrication strategies for photothermal membranes are introduced primarily, followed by a discussion on how to design membrane materials, devices, and processes to pursue optimal performance and realize advanced functions accompanied by evaporation. Furthermore, the future of this field is forecast with both challenges and opportunities.  相似文献   

12.
Interfacial solar steam generation offers a promising and cost-effective way for saline water desalination. However, salt accumulation and deposition on photothermal materials during saline and brine evaporation is detrimental to the stability and sustainability of solar evaporation. Although several antisalt strategies are developed, it is difficult to simultaneously achieve high evaporation rates ( > 2.0 kg m−2 h−1) and energy efficiencies. In this study, a self-rotating photothermal evaporator with dual evaporation zones (i.e., high-temperature and low-temperature evaporation zones) is developed. This photothermal evaporator is sensitive to weight imbalance ( < 15 mg) thus is able to quickly respond to salt accumulation by rotation to refresh the evaporation surface, while the dual evaporation zones optimize the energy nexus during solar evaporation, simultaneously realizing excellent salt-resistant performance and high evaporation rate (2.6 kg m−2 h−1), which can significantly contribute to the real-world application of solar steam generation technology.  相似文献   

13.
Solar steam generation (SSG) through hydrogel-based evaporators has shown great promise for freshwater production. However, developing hydrogel-based evaporators with stable SSG performance in high-salinity brines remains challenging. Herein, phase-separated polyzwitterionic hydrogel-based evaporators are presented with sponge-like structures comprising interconnected pores for stable SSG performance, which are fabricated by photopolymerization of sulfobetaine methacrylate (SBMA) in water-dimethyl sulfoxide (DMSO) mixed solvents. It is shown that driven by competitive adsorption, the structures of the resulting poly(sulfobetaine methacrylate) (PSBMA) hydrogels can be readily tuned by the volume ratio of DMSO to achieve phase separation. The optimized phase-separated PSBMA hydrogels, combining the unique anti-polyelectrolyte effects of polyzwitterionic hydrogels, demonstrate a rapid water transport capability in brines. After introducing photothermal polypyrrole particles on the surface of the phase-separated PSBMA hydrogel evaporators, a stable water evaporation rate of ≈2.024 kg m−2 h−1 and high solar-to-vapor efficiency of ≈97.5% in a 3.5 wt.% brine are obtained under simulated solar light irradiation (1.0 kW m−2). Surprisingly, the evaporation rates remain stable even under high-intensity solar irradiation (2.0 kW m−2). It is anticipated that the polyzwitterionic hydrogel evaporators with sponge-like porous structures will contribute to developing SSG technology for high-salinity seawater applications.  相似文献   

14.
Improving interfacial solar evaporation performance is crucial for the practical application of this technology in solar-driven seawater desalination. Lowering evaporation enthalpy is one of the most promising and effective strategies to significantly improve solar evaporation rate. In this study, a new pathway to lower vaporization enthalpy by introducing heterogeneous interactions between hydrophilic hybrid materials and water molecules is developed. 2D MoN1.2 nanosheets are synthesized and integrated with rGO nanosheets to form stacked MoN1.2-rGO heterostructures with massive junction interfaces for interfacial solar evaporation. Molecular dynamics simulation confirms that atomic thick 2D MoN1.2 and rGO in the MoN1.2-rGO heterostructures simultaneously interact with water molecules, while the interactions are remarkably different. These heterogeneous interactions cause an imbalanced water state, which easily breaks the hydrogen bonds between water molecules, leading to dramatically lowered vaporization enthalpy and improved solar evaporation rate (2.6 kg m−2 h−1). This study provides a promising strategy for designing 2D-2D heterostructures to regulate evaporation enthalpy to improve solar evaporate rate for clean water production.  相似文献   

15.
As an eco-friendly means, solar water purification has attracted substantial research interest regarding material design, system engineering, and energy management. However, the low water yield and relatively high cost essentially restrict its practical potential. Here, a hydrogel-based ultrathin membrane (HUM) is developed to synergistically coordinate facilitated vapor transfer and environmental energy harvesting for solar-driven membrane distillation. The evaporation front is directly exposed to an airflow, which fundamentally eliminates the temperature polarization induced energy consumption. As such, the humidity of the output flow is significantly increased, and thus the vapor collection ratio rises to over 80% to achieve a high water yield of 2.4 kg m–2 h–1 under one sun without any energy recycling and cooling accessories. The HUM with a raw material cost of $0.36 m–2 offers a competitive potential cost of freshwater production of about $0.3–1.0 m–3. This work demonstrates a promising membrane distillation strategy based on sustainable energy toward both decentralized water purification and large-scale water treatment.  相似文献   

16.
Solar steam generation technologies have gained increasing attention due to their great potential for clean water generation with low energy consumption. The rational design of a light absorber that can maximize solar energy utilization is therefore of great importance. Here, the synthesis of Ni@C@SiO2 core–shell nanoparticles as promising light absorbers for steam generation by taking advantage of the plasmonic excitation of Ni nanoparticles, the broadband absorption of carbon, and the protective function and hydrophilic property of silica is reported. The nanoparticle-based evaporator shows an excellent photothermal efficiency of 91.2%, with an evaporation rate of 1.67 kg m−2 h−1. The performance can be further enhanced by incorporating the nanoparticles into a polyvinyl alcohol hydrogel to make a composite film. In addition, utilizing the magnetic property of the core–shell particles allows the creation of surface texture in the film by applying an external magnetic field, which helps increase surface roughness and further boost the evaporation rate to as high as 2.25 kg m−2 h−1.  相似文献   

17.
The emerging solar desalination by interfacial evaporation shows great potential for alleviating the global freshwater crisis. However, salt deposition on the whole evaporation surface during steam generation leads to a deterioration in the evaporation rate and long-term stability. Herein, it is demonstrated that a hydrogel-based 3D structure can serve as an efficient and stable solar evaporator by salt localized crystallization for high-salinity brine desalination. Under the function of micron-grade brine transport management and edge-preferential crystallization promoted by this novel design, this 3D hydrogel evaporator exhibits a superior salt-resistant property without salt deposition on the photothermal surface even in 20 wt% brine for continuous 24-h illumination. Moreover, by virtue of the synergistic effect of the promising 3D structure and excellent water transport of hydrogel, the proposed evaporator possesses an excellent evaporation performance achieving 2.07 kg m−2 h−1 on average in a high-salinity brine (from 10 to 25 wt% NaCl) under 1 sun irradiation, among the best values reported in the literature. With stable and efficient evaporation performance out of high-salinity brine, this design holds great potential for its applications in sustainable solar desalination.  相似文献   

18.
Solar‐enabled evaporation for seawater desalination is an attractive, renewable, and environment‐friendly technique, and tremendous progress has been achieved by developing various photothermal membranes. However, traditional photothermal membranes directly float on water, resulting in some limitations such as unavoidable heat‐loss to bulk water and severe salt accumulation. To solve these problems, a hydrophilic, polymer nanorod‐coated photothermal fabric is designed and fabricated, and then an indirect‐contact evaporation system by hanging the fabric is demonstrated. The two ends of the fabric are designed to be in contact with seawater to guide water flow through capillary suction. Both arc‐shaped top/bottom surfaces of the hanging fabrics are exposed to air, which can prevent heat dissipation to bulk seawater and facilitate the double‐surface evaporation upon sunlight irradiation. Our design leads to an efficient evaporation rate of 1.94 kg m?2 h?1 and high solar efficiency of 89.9% upon irradiation with sunlight (1.0 kW m?2). Importantly, the highly concentrated brine can drip from the bottom of the arc‐shaped fabric, without the appearance of solid‐salt accumulation. This indirect‐contact evaporation system establishes a new path to continuously and economically produce watersteam from seawater for fresh‐water and concentrated brine for the chlor‐alkali industry.  相似文献   

19.
Solar-driven vapor generation offers an affordable and sustainable approach to solve global freshwater scarcity. Creating interfacial solar evaporators capable of increasing water production rates matching human water requirements is highly desirable but challenging due to the slow water transportation dynamics and unavoidable oil-fouling. Herein, a bio-inspired lotus-petiole-mimetic microstructured graphene/poly(N-acryloyl glycinamide) solar evaporator with integrated hydrophilic and hydrophobic microregions is developed. Through accurate control of the supramolecular interactions, the optimized solar evaporator incorporating unique structural features and wettability shows high light harvesting, enhanced water activation, and reduced energy demand for water vaporization, enabling a groundbreaking comprehensive performance along evaporation rate up to 3.4 kg m−2 h−1 and energy conversion efficiency of ≈93% under one sun irradiation (1 kW m−2). Molecular dynamics simulations reveal that the abundant hydrogen bonding sites of the polymeric networks can thermodynamically modulate the escape behavior of water molecules. Notably, neither decrease in evaporation rate nor fouling on solar evaporators is observed during the prolonged purification process toward nano/submicrometer emulsions, oily brines, actual seawater, and domestic wastewater. This study provides distinctive insights into water evaporation behaviors at a molecular level and pioneers a rational strategy to design high-yield freshwater-generation systems for wastewater containing complex contaminants.  相似文献   

20.
The development of mutually reinforcing solar-driven interfacial evaporation (SDIE) and integrated functional materials/systems to achieve efficient production of freshwater and energy/matters simultaneously under extremely high solar utilization is in high demand. Herein, an integrated SDIE reaction system (reduced graphene oxide (rGO)-palladium (Pd) catalytic evaporator, rGO-Pd) is first reported, where SDIE and the integrated catalytic reaction are mutually reinforced. The apparent utilization of solar to thermal energy by the integrated SDIE reaction system is a combination of evaporative utilization and catalytic utilization. The reaction heat released by the rGO-Pd catalytic evaporator enhances its anti-salt water production performance to a record of 12.7 L m−2 h−1, surpassing the reported performance of other integrated SDIE reaction systems. In the rGO-Pd catalytic evaporator, the synergetic effect of photothermal and rapid mass transfer significantly increases the catalytic activity (turnover frequency) of Pd catalysts up to a record 125.07 min−1, which is about 3.75 times of the condition without light. This integrated SDIE reaction system can effectively and simultaneously produce freshwater, salt, and catalyzed chemicals after evaporating water to dryness. This study paves the way for SDIE's high-performance applications in future integrated water, energy, and environmental systems.  相似文献   

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