Ni-based Plasmonic/Magnetic Nanostructures as Efficient Light Absorbers for Steam Generation

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.     

Nature-Inspired Structure-Engineered TiN/TiO2 Nanotubes Array Toward Solar Desalination Synergy with Photothermal-Enhanced Degradation and Thermoelectric Generation

Solar-driven interfacial evaporation systems are considered as promising technology to alleviate the water scarcity crisis, yet lack of innovative evaporators obstructs further improvement of energy utilization efficiency. Herein, inspired by mangrove, the structure-engineered design is utilized to synthesis multi-level reflection TiN/TiO₂@carbon cloth (CC) nanotubes array. The hollowed TiO₂ nanorods can promote expeditious water transport, while the TiN/TiO₂ array can act as localized surface plasmon resonance (LSPR)-enhanced multi-level reflection structure for solar energy harvesting. The enhanced light absorption capability of the bionic nanostructure is confirmed by finite-difference time-domain (FDTD) simulations. Therefore, the TiN/TiO₂@CC-3 exhibits high evaporation rate of 2.02 kg m⁻² h⁻¹ under 1 solar illumination, which is comparable or better than most of fabric-based evaporators. When applied in wide acid–base (pH 1–13) and salinity range (8–100 ‰) over 15 days, the TiN/TiO₂@CC-3 displays outstanding durability. Furthermore, to expand application scope of the elaborate nanostructure, photothermal-enhanced photocatalysis and thermoelectricity generation applications are evaluated, while these new functionalities are integrated into solar-driven desalination system. The outdoor device exhibits daily water yield of 10.89 kg m⁻², synergy with maximum 200.7 mV output voltage and high dye degradation efficiency, demonstrating flexible applications in multi-functional interfacial evaporation systems according to various requirements.     

Janus Nano-Micro Structure-Enabled Coupling of Photothermal Conversion,Heat Localization and Water Supply for High-Efficiency Solar-Driven Interfacial Evaporation

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.     

Synergistic Effect of Photothermal Conversion in MXene/Au@Cu2−xS Hybrids for Efficient Solar Water Evaporation

A three-plasmon hybrid, in which core–shell Au@Cu_2−xS hybrids are bonded with ultrathin Ti₃C₂T_x MXene, is prepared for high-efficiency photothermal conversion and membrane-based solar water evaporation for the first time. The MXene/Au nanorod@Cu_2−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@Cu_2−xS and Au nanorod@Cu_2−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.     

A Lotus-Petiole-Inspired Hierarchical Design with Hydrophilic/Hydrophobic Management for Enhanced Solar Water Purification

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.     

Solar-Powered High-Performance Lignin-Wood Evaporator for Solar Steam Generation

Recent research on wood-based solar evaporators has made great progress and significant breakthroughs have been made in using lignin as a photothermal material; however, the intensity change mechanism regarding the conjugate structure of lignin is almost never mentioned. This study innovatively proposes a mechanism to explain the changes in conjugate intensity that occur before and after lignin dissolution and fabricates a lignin/wood-based solar evaporator (LWE) using an all-wood-based material that is salt-tolerant and has long-term serviceability. Lignin in the evaporator serves not only as a photothermal material for converting light energy into heat energy but also as a reinforcement for the evaporator's structural strength. Adding lignin changes the original structure of balsa wood, increasing the proportion of intermediate water in the LWE, thereby lowering the enthalpy of water evaporation. The optimized LWE with an enhanced desalination capability, dye removal property, and high stability exhibits full-spectrum solar absorption of about 83.6%, a photothermal conversion efficiency of 91.74%, and an evaporation efficiency of 1.93 kg m⁻² h⁻¹, which surpasses most wood-based evaporators. This study demonstrates that all-wood-based materials can be used to prepare evaporators with excellent performance, providing a new approach to address freshwater depletion.     

Bioinspired,Sustainable, High-Efficiency Solar Evaporators for Sewage Purification

To alleviate the severe water crisis, an interfacial solar evaporator provides a promising method to produce freshwater. Although many superior solar evaporators present high evaporation rates by reducing the water evaporation enthalpy, adapting sustainable materials to construct high-efficiency solar evaporators remains challenging. Herein, inspired by the corncob pith's structure and functional groups, interconnected porous cellulose hydrogel is proposed by crosslinking sustainable hydroxypropyl cellulose. Benefiting from the porous structure and abundant hydroxy group, the corncob pith/carbon nanotubes (CNTs) and cellulose hydrogel/CNTs evaporators show a low evaporation enthalpy of 880.5 ± 42.1 and 1280.7 ± 57.8 J g⁻¹ due to the reduced hydrogen bond numbers between water molecules and enable evaporation rates of 3.06 and 2.56 kg m⁻² h⁻¹, respectively. Moreover, the evaporators present superior purification performance for seawater and sewage, and show excellent anti-biological fouling properties under light irradiation. It is anticipated that the bionic strategy would provide an in-depth understanding of designing next-generation sustainable solar evaporators in the framework of the dual-carbon concept.     

Quasi-Ordered Nanoforests with Hybrid Plasmon Resonances for Broadband Absorption and Photodetection

With the continuing development of green energy technology, solar energy is the most widely distributed and easily utilized form of energy in nature. High-absorption absorbers over a wide spectrum range are beneficial for solar energy harvest. Herein, a fast and efficient method is developed to fabricate a broadband absorber consisting of quasi-ordered nanoforests and metal nanoparticles using a simple plasma bombardment process on a 4-inch silicon wafer, offering high throughputs that can meet practical application demands. The absorber exhibits high absorption exceeding 90% from 300 to 2500 nm, good absorption stability with negligible disturbance from the polarization and the incident angle of light. This effective absorption behavior can be ascribed to multilevel hybridization of the plasmon resonances in the hybrid structures and cavity mode resonances inside the nanoforests. Furthermore, the absorber is integrated onto a thermopile for photodetection with largely enhanced photoresponse from 532 to 2200 nm. The photoinduced voltage of the devices shows a large increment of 433% at 100 mW cm⁻² light power density, in comparison with a contrast pristine thermopile. It is expected that such a broadband absorber holds great potential for multiple applications, including solar steam generation, photodetection, and solar cells.     

Topographic Manipulation of Graphene Oxide by Polyaniline Nanocone Arrays Enables High-Performance Solar-Driven Water Evaporation

Tuning the surface topography of solar evaporators is of significance for boosting light absorption and enhancing solar-to-vapor efficiency. Herein, a novel strategy to manipulate the surface topography of graphene oxide (GO) via electrostatic assembly coupled with in situ polymerizations of aniline is reported. The GO surface is fully hybridized with the polyaniline (PANI) nanocone arrays, manifesting periodic structures with highly foldable configurations. Additionally, the PANI arrays tune the surface chemistry of GO and retard the redispersion of GO into water, thus enabling corresponding composite (PG) robust structural durability. Featuring these intriguing attributes, when applied as an evaporator in pure water, the PG delivers an improved evaporation performance of 1.42 kg m⁻² h⁻¹ and a high evaporation efficiency of 96.6% under one sun illumination. Further investigations reveal that the periodically conical structures of PANI over GO surface strengthen light absorption via multiple reflections and facilitate heat localization. Desalination test substantiates the reliability of PG for practical freshwater production. The numerical simulations and optical microscopy observation exhibit the surface topography-strengthened vapor generation effect. This study sheds new light on the rational manipulation of surface topography of photothermal materials for high-efficiency solar evaporation.     

A Diode-like Scalable Asymmetric Solar Evaporator with Ultra-high Salt Resistance

Passive solar-driven interfacial evaporation is an environmental-friendly approach for seawater desalination. However, non-volatile salts usually precipitate on the evaporator surface during evaporation, significantly reducing the evaporation rate and blocking the evaporator. Although several strategies have been proposed for this issue, they are usually only effective under low salinity conditions and natural solar irradiation. In this study, a scalable solar evaporator is proposed, which is expediently fabricated by carbonizing the commercially available coconut fiber cloth, through designing and optimizing an asymmetric bi-layer structure with a trapezoidal evaporation surface and a wide leg-strengthened water supply pathway. Both experimental and simulation results indicate that the evaporator presents ultra-high salt tolerance, which keeps running steadily for consecutive 14 days under the high salinity of 14 wt% NaCl and high irradiation of 4 suns. This excellent salt resistance arises from a diode-like ion migration introduced by its asymmetric structure. Meanwhile, a remarkable evaporation rate of 7.28 kg m⁻² h⁻¹ is also achieved under the harsh condition, resulting from the high solar absorbance and the reduced evaporation enthalpy of the evaporator. Such an evaporator is confirmed as a simple, low-cost, scalable, efficient, and long-term stable device for producing freshwater under harsh desalination conditions.     

Donor–Acceptor-Type Organic-Small-Molecule-Based Solar-Energy-Absorbing Material for Highly Efficient Water Evaporation and Thermoelectric Power Generation

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.     

Mutual Reinforcement of Evaporation and Catalysis for Efficient Freshwater–Salt–Chemical Production

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.     

A Floating Integrated Solar Micro-Evaporator for Self-Cleaning Desalination and Organic Degradation

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.     

Dual-Zone Photothermal Evaporator for Antisalt Accumulation and Highly Efficient Solar Steam Generation

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.     

Phase-Separated Polyzwitterionic Hydrogels with Tunable Sponge-Like Structures for Stable Solar Steam Generation

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.     

An Easy-to-Fabricate 2.5D Evaporator for Efficient Solar Desalination

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.     

Ionic Dye Based Covalent Organic Frameworks for Photothermal Water Evaporation

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.     

Bioinspired Fractal Design of Waste Biomass-Derived Solar–Thermal Materials for Highly Efficient Solar Evaporation

Solar evaporation is considered a promising technology to address the issue of fresh water scarcity. Although many efforts have been directed towards increasing the solar–thermal conversion efficiency, there remain challenges to develop efficient and cost-effective solar–thermal materials from readily available raw materials. Furthermore, further structural modification of the original biomass structure, particularly at multiple length scales, are seldom reported, which may further improve the solar–thermal performance of these material systems. Herein, a novel low-cost system is developed based on a common bio-waste, pomelo peels (PPs), through a bioinspired fractal structural design strategy, fractal carbonized pomelo peels (FCPP). This FCPP system shows an extremely high solar spectrum absorption of ≈98%, and marvelous evaporation rate of 1.95 kg m⁻² h⁻¹ with a solar–thermal efficiency of 92.4%. In addition, the mechanisms of the evaporation enhancement by fractal structural design are identified by numerical and experimental methods. Moreover, using FCPP in solar desalination shows great superiority in terms of cost and its potential in sewage treatment is also studied. The present work is an insightful attempt on providing a novel proposal to develop bio-waste-derived solar–thermal materials and construct biomimetic structures for efficient solar evaporation and applications.     

Highly Salt-Resistant 3D Hydrogel Evaporator for Continuous Solar Desalination via Localized Crystallization

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.     

Plasmon Based Double‐Layer Hydrogel Device for a Highly Efficient Solar Vapor Generation

Solar vapor generation is a facile and an efficient way for solar energy harvesting, which is applied to address the issue of fresh water extraction from sewage or brine. Several solar vapor generation devices have been developed in the past few years, but the low evaporation rate still remains as a challenge. In this work, a novel double‐layer solar vapor generation device, named as Ag‐PSS‐AG/AG device, is reported. This device is based on the hierarchical composition of silver nanoparticles (Ag NPs) and poly (sodium‐p‐styrenesulfonate) (PSS) decorated agarose gel (AG). The device reveals a synergetic effect of the two layers with high light‐harvesting and water‐transfer performance, respectively, leading to an ultrahigh vapor generation rate of 2.10 kg m^?2 h^?1 with a solar thermal efficiency of 92.8% under 1 sun illumination. This high evaporation rate is mainly owing to the powerful light‐thermal conversion of Ag NPs as well as the outstanding water transfer capability of agarose hydrogel. Consequently, this device can be directly used for the purification of sewage and muddy water. It is also promising for applications in separation, humidity management, and others.