Graphene aerogel with multidimensional surface grafting: confined thermal localization and rapid water delivery for efficient solar evaporation

Efficient 3D Solar Evaporator for water-cleaning/seawater-desalination made with Loofah coated with graphite recycled from alkaline/spent batteries

Magnetic field-enhanced interfacial photo-thermal evaporation within the liquid organic hydrogen carrier

High-efficiency evaporation and concentration with exceptional salt resistance via a chitosan annular hydrogel evaporator.

Hybrid solar-driven interfacial evaporation systems for water-energy nexus: recent advances in freshwater and energy sustainability

ABSTRACT Interfacial solar steam evaporation (ISSE) technology has attracted significant attention due to its remarkable potential for producing clean water using solar energy. Although substantial progress has been made in photothermal materials and evaporator design, a critical bottleneck persists in translating this technology from laboratory research to real‐world application: the pronounced disconnect between advanced material development and practical system engineering. Current research efforts remain predominantly focused on the “performance competition” of front‐end materials, while the corresponding design of efficient and reliable back‐end systems has not kept pace. To bridge this gap, this review adopts a back‐end engineering perspective to systematically evaluate the full‐chain development of ISSE technology, encompassing advanced material design, structural engineering, and evaporation efficiency enhancement strategies tailored to diverse application environments. We further summarized unified back‐end solution frameworks for characteristic scenarios for cross‐medium synergistic evaporation systems (CMSES). Ultimately, this review aims to clarify scientifically grounded and engineering‐relevant pathways for translating theoretical advances into practical deployment, thereby supporting the development of ISSE from laboratory studies toward real‐world applications.

Solar-driven interfacial evaporation (SDIE) technology demonstrates significant potential in seawater desalination, yet its evaporation efficiency and durability remain constrained by bottlenecks such as insufficient solar-to-thermal conversion efficiency, impeded water transport, and salt contamination accumulation. This study proposes a three-step strategy of "electrostatic self-assembly photoreduction-winding" to construct a coaxial rolled evaporator (CRE) comprising reduced rGO/Cu2O-OHNMs@MF. Based on nanomacro-scale codesign, this structure employs a p-n heterojunction array to drive photogenerated carrier separation and localized heat release, thereby reducing water vaporization enthalpy. Radial spiral slits form a gradient capillary network enabling rapid water supply and reverse diffusion of salt ions. The outer rGO pleated photothermal layer enhances solar energy capture while inhibiting salt crystallization. Under 1 kW m-2 irradiation, the CRE system achieves an evaporation rate of 2.58 kg m-2 h-1 with 97.19% efficiency, maintaining structural integrity under extreme conditions including pH = 1-14, 90 °C temperatures, ultrasonic agitation, and mechanical compression. After 20 consecutive cycles of operation in real seawater, the performance retention rate reaches 94.87%. The desalinated water meets WHO drinking water standards and supports normal wheat growth. Overall, this study provides innovative insights and practical solutions for highly efficient, salt-tolerant, antimicrobial, and scalable solar seawater desalination as well as agricultural irrigation technology.

Interfacial evaporation is recognized as a promising sustainable desalination technology, yet its energy efficiency remains bottlenecked by the intrinsically high enthalpy of water evaporation. Here, we engineer a covalent organic framework (COF)-based membrane with a hierarchical micrometer-to-angstrom architecture to precisely regulate water behavior for efficient activation and evaporation. With competitive interface/solution nucleation kinetics, confined interfacial growth of COF on vertical microchannels drives a re-entrant crystallinity transition, yielding uniform COF lattices with ordered water-binding sites. Critically, experimental and theoretical investigations reveal that angstrom-scale hydrophobic/hydrophilic motifs within the COF synergistically promote activated water states featuring weak hydration and rapid diffusion behavior, thereby maximizing intermediate water domains and reducing the evaporation enthalpy to only 30% of that of bulk water. Consequently, the engineered membrane achieves a high rate of 2.98 kg m-2 h-1 under a moderate thermal gradient (45 °C/25 °C) and maintains stable performance over 240 h of continuous operation. This work establishes a paradigm for manipulating water activation via angstrom-scale texturing in porous materials, paving the way for energy-efficient desalination and beyond.

Canal-mounted photovoltaic (CM-PV) panel solutions minimize canal evaporation and panel operating temperature to improve performance. This research examines how flow rate affects CM-PV panel energy output and water savings. No experimental investigations have examined the flow rate impact in CM-PV systems under real operating conditions. In the experimental study conducted in this direction, two canal structures were simulated with different flow velocities, and two separate scenarios were created. The first scenario employed one pump in one canal and two pumps in the other to produce a flow differential. In the second scenario, one pump was utilized in one canal and three in the other canal to increase the flow differential. The experimental data obtained indicate a direct proportional relationship between the number of pumps and the amount of evaporation; indeed, in the first scenario, there was a difference of 2 L in evaporation between the canals, whereas in the second scenario, this difference was 4 L. These results confirm the assumption that the amount of evaporation increases as the flow rate increases. An increase in the amount of evaporation indirectly increased the panel efficiency. In the case of electricity generation, the maximum and average power differences between the panels were 16.6 W and 9.16 W, respectively. For the second scenario in the power parameters, a maximum difference of 22.9 W and an average difference of 14 W were determined. Efficiency differences varied between scenarios; in the first scenario, the maximum efficiency was 0.9% and the average efficiency was 0.6%, while in the second scenario, these values were 1.3% and 0.8%, respectively.

Multifunctional Aerogels as Efficient Solar Evaporators for Seawater Desalination and Wastewater Treatment

Landfill leachate membrane concentrate (LLMC) is a high-salinity and high-organic wastewater stream that poses significant treatment challenges to conventional evaporation technologies. This study investigated the treatment performance and operating costs of a low-temperature atmospheric evaporation (LTAE) system for LLMC treatment under mild operating conditions. The effects of key operational parameters—including evaporation temperature (60–95 °C), pH (5–11), air–liquid mass ratio (A/L = 0.5–10), and concentration factor (CF = 5–20)—were systematically evaluated based on condensate quality parameters (UV254, CODCr, and NH3–N). Results demonstrated that the LTAE system achieved a higher concentration ratio (CF = 20) compared to the on-site mechanical vapor compression (MVC) system (CF ≈ 10). The optimal operating conditions for meeting effluent discharge standards were determined to be 70 °C, pH: 5, A/L = 5 and CF = 20. Under these conditions, the condensate contained ~5.6 mg/L NH3–N and ~91.6 mg/L CODCr, while the concentrate reached ~4200 mg/L NH3–N and ~38,000 mg/L CODCr, indicating that some organic matter and ammonia nitrogen escaped from the system and a gas scrubbing unit is recommended to minimize secondary pollution. Within the experimental range, the system achieved the highest KcA = 22,871.25 kW/(m3·°C) and the highest KdA reached 6.52 kg/m3·s. Economic analysis revealed a specific energy consumption of 110.5 kWh/t of freshwater produced. Despite the relatively high energy consumption, the LTAE system demonstrates considerable potential for the advanced treatment of high-organic wastewater, offering enhanced freshwater recovery under mild thermal conditions. This study provides theoretical and data support for the application of LTAE technology in LLMC treatment and similar challenging organic wastewater.

Freshwater scarcity is a global challenge, and solar-driven interfacial evaporation (SDIE) technology has received widespread interest for its sustainability. However, vapor accumulation and salt deposition significantly reduce its performance. This study describes a solar evaporator with a Janus wettability grooved structure. This design not only allows for efficient double-sided evaporation but also provides a localized heat environment that greatly improves natural convection, effectively enhancing vapor diffusion. Under 1 sun irradiation, the optimized evaporator (JGE-60°) had an evaporation rate of 2.27 kg m-2 h-1. Under forced convection (4 m/s) conditions, its surface temperature dropped below ambient, reversing heat loss and increasing the evaporation rate to 5.96 kg m-2 h-1. Owing to the asymmetric wettability of its dual-sided structure, salt is selectively directed and deposited on the shaded side. This enables stable operation for 30 h in a 20 wt % brine while achieving a salt collection rate of 193.9 g m-2 h-1. This work simultaneously addresses two critical bottlenecks─vapor diffusion suppression and salt accumulation─through a simplified structural design, providing an important scientific and applied paradigm for evaporator design.

Freshwater scarcity and waterborne diseases are among the most pressing global challenges resulting from climate change and industrial expansion. Solar-driven interfacial evaporation systems (SDIEs) present a new approach that enables higher solar-to-heat and heat-to-vapor conversion efficiencies for higher evaporation rates of freshwater generation. However, sustainable evaporation also faces challenges associated with salt accumulation and heat losses to the environment and bulk water. Herein, a new class of photothermal nanocomposites (spinel CoMn2O4/Ti3C2 MXene nanosheets) is synthesized that exhibits enhanced photothermal conversion behavior. The 3D photothermal hydrogel is constructed by integrating the CoMn2O4@MXene nanocomposite into a polyvinyl alcohol (PVA) matrix, where a 3D porous architecture facilitates rapid water transport (hygroscopic value), localized heat confinement (39.7 °C), and salt rejection (3.5 wt%). The cross-linked hydrogel matrix prevents nanocomposite leaching during continuous evaporation (1.45 kg m−2 h−1) under one sun solar intensity. Evaporation performance under different salinities (3.5–15 wt%) confirmed the sustainability of the evaporator and reduced variability in evaporation rates, and effective desalination of seawater (salinity reduction: 99.98%) is demonstrated. This work provides a scalable, multifunctional platform for sustainable clean water generation.

Solar-driven water purification presents an environmentally sustainable approach to tackle the critical issue of freshwater scarcity. However, developing advanced hydrogel systems that simultaneously achieve efficient solar-thermal conversion and comprehensive pollutant removal remains challenging. This work reports the synthesis of three novel conjugated polymers through molecular engineering of diketopyrrolopyrrole with modified benzo[1,2-c:4,5-c']bis[1,2,5]thiadiazole derivatives to enhance electron-withdrawing characteristics. The optimized molecular structures exhibit extended light absorption and minimized radiative decay through synergistic intramolecular charge transfer and controlled molecular motion in the aggregated state. Among them, PDPP-SeQ achieves a remarkable photothermal conversion efficiency of 26.71% under standard solar illumination. By incorporating PDPP-SeQ micelles into a polyethylenimine/polyvinyl alcohol matrix, we fabricated a multifunctional solar-absorbing hydrogel (SAG-Se). The composite demonstrates exceptional performance, including a record water production rate of 10.18kg/m2·h with excellent cycling stability, representing the highest reported value among organic photothermal systems. Notably, the design enables concurrent freshwater and electricity generation (55mV output) without sacrificing evaporation efficiency. The resulting SAG-Se purification platform combines portability with robust treatment capabilities, effectively eliminating contaminants. This study provides fundamental insights into molecular design principles for high-efficiency photothermal materials while demonstrating their practical application in integrated water-energy systems for remote regions.

Dual-functional NiCo2O4 nanofibers/chitosan aerogel for efficient solar evaporation and bacterial removal

CuS/biomass carbon-hydrogel photothermal materials for efficient solar-driven interfacial evaporation

Repurposing spent battery waste into plasmonic photothermal membrane for efficient solar-driven evaporation and freshwater production.

γ-Fe2O3:Co3O4 coated cellulose sponges as interfacial solar absorbers for efficient photothermal evaporation and desalination

ABSTRACT Solar evaporation has received considerable attention in recent years due to the abundance of solar energy, widely available water sources, and facile facilities, in combination with improvements in conversion efficiency enabled by improved photothermal materials, interfacial heating system designs, and thermal management. In this process, cellulose demonstrates tremendous potential for constructing novel and highly efficient solar evaporators due to its renewability, tunable nanostructure, low thermal conductivity, and strong hydrophilicity. Therefore, in this review, we take the general structure and photothermal conversion mechanism of solar evaporators as our starting point, delving into breakthrough advances in cellulose‐mediated solar evaporators concerning the selection of photothermal materials and substrates. In particular, we also explored the structural design, key features (e.g., thermal management, broadband light absorption, efficient water transport, and salt resistance design), and corresponding construction strategies of cellulose‐mediated solar evaporation. In addition, we have demonstrated the most advanced and innovative applications of cellulose‐mediated solar evaporators in seawater desalination, wastewater treatment, and thermoelectric conversion. The current challenges and future research opportunities for cellulose‐mediated evaporators are also discussed. We sincerely hope this review can provide a fresh roadmap for the future development of solar evaporation technology and further stimulate research enthusiasm for novel high‐performance cellulose‐mediated evaporators.

ABSTRACT An innovative strategy of aggregation‐induced stabilization is presented to achieve highly stable boron‐containing organic diradicaliods by forming different π–π stacking aggregates through cooperative π bridge and hydrogen bond regulation. Herein, three D‐π‐A‐π‐D crossover shaped molecules (PPCy‐Ph, PPCy‐Th, and PPCy‐Fu) are synthesized with π‐bridge engineering from phenyl‐, thienyl‐to furyl for precisely modulating molecular conformation and aggregation state. As the most stable boron‐containing π‐radicals to date, they all display unprecedentedly stable ESR signals at harsh conditions (300°C in air for 2 h and boiling water for 2 h) and superior photo‐, chemical‐ and thermal stability due to synergistic effect of hydrogen bonding interactions. In particular, PPCy‐Th exhibited best photothermal conversion efficiency, reaching 275°C under 808 nm laser irradiation (1.0 W cm 2 ), superior solar‐driven water evaporation rate of 1.42 kg m −2 h −1 and evaporation efficiencies (η) of 98.37%, thermoelectric power generation (256 mV) under 1 sun illumination. The multiple applications in cogeneration of water and electricity, seawater desalination, sewage treatment, laser ignition, and driving electric fan are demonstrated. Moreover, PPCy‐Fu NPs display efficient photothermal & photodynamic synergistic cancer cell killing under hypoxia. This study highlights a novel strategy for developing stable boron‐containing diradicaloids with excellent photo‐thermal conversion efficiency.