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Interfacial solar steam generation (ISSG) offers a sustainable and environmentally friendly strategy for addressing the energy and water crises. In this study, we fabricated a highly efficient and cost-effective plasmonic photoabsorber for ISSG of seawater by coating silver nanoparticles (Ag NPs) on pinecone (PC). The PC with low thermal conductivity and numerous aligned microchannels for fast water transport, provides sufficient water supply and reduces the bulk heat loss. In addition, Ag NPs strongly absorb solar radiation through the surface plasmon resonance effect. Using Ag/PC under 1 sun (1 kW m–2), we achieved an evaporation flux and efficiency of 1.82 kg m–2 h–1 and 100%, respectively. Moreover, Ag/PC removed more than 99% of Na+, K+, Mg2+, and Ca2+ ions from seawater. The plasmonic PC also exhibited excellent cycling during 10 cycles efficiency of ISSG. Furthermore, treatment of paper industry wastewater with Ag/PC resulted in a significant decrease in the concentration of ions. [ABSTRACT FROM AUTHOR]

Aiming to achieve the goals of high evaporation rate, eco-friendly and facile preparation with low-cost raw materials, a type of photothermal hydrogel which use tannic acid-iron ion complexes as photothermal material and gelator was successfully synthesized by a facile blending method. The photothermal hydrogel can achieve a high rate of 1.897±0.11 kg·m−2·h−1 and an energy efficiency of 89.7±2.73% under 1 sun irradiation and has been proven to realize efficient sewage treatment and desalination in outdoor condition. [Display omitted] • The tannic acid-Fe3+ complex is used as photothermal material and gelators. • A photothermal hydrogel evaporator is prepared by a blending method. • All the raw materials are eco-friendly and low-cost. • A high evaporation rate of 1.897 ± 0.11 kg·m−2·h−1 under 1 sun irradiation is achieved. The field of solar vapor generation has developed rapidly in recent years, but achieving the goals of a high evaporation rate, eco-friendliness and rapid preparation with low-cost raw materials is still a challenge. In this work, a type of photothermal hydrogel evaporator was prepared by blending eco-friendly poly(vinyl alcohol), agarose, Fe3+ and tannic acid (TA) together, in which the tannic acid-ferric ion (TA*Fe3+) complexes served as photothermal materials and effective gelators. The results indicate that the TA*Fe3+ complex exhibits excellent gelatinization ability and light-absorption performance, which leads to a compressive stress of 0.98 MPa at 80% strain and up to 85% light absorption ratio in the photothermal hydrogel. For interfacial evaporation, a high rate of 1.897 ± 0.11 kg·m−2·h−1 corresponding to an energy efficiency of 89.7 ± 2.73% under 1 sun irradiation is achieved. Moreover, the hydrogel evaporator exhibits high stability in a 12-hour test and a 20-cycle test without a decline in evaporation performance. The outdoor testing results show that the hydrogel evaporator can achieve an evaporation rate of > 0.70 kg/m2 and effectively purify wastewater treatment and seawater desalination. [ABSTRACT FROM AUTHOR]

Interfacial solar steam generation (ISSG) is a sustainable and environmental‐friendly technology for seawater desalination and wastewater purification using green and sustainable solar energy. Herein, a robust and efficient interfacial solar steam generation device or photoabsorber for ISSG of seawater and wastewater treatment was designed by coating wood with trace amount of Pd nanoparticles (NPs) and reduced graphene oxide (RGO). High evaporation flux of 5.25 kg m−2 h−1 was achieved by Pd20/RGO80/wood (a piece of wood was coated with 80 and 20 mg L−1 of Pd NPs and RGO as a top and bottom layer, respectively) under 3 kW m−2. The value of electrical conductivity of seawater decreased from 6000.0 to 5.8 μS cm−1 after desalination. The durability test showed the photoabsorber was stable for 30 cycles. The total cost to evaporation rate of the device was calculated as 0.29± ${\pm }$ 0.003 USD/(cm3 h−1). The photoabsorber also showed excellent performance in wastewater treatment in removal of dyes of methylene blue and Reactive blue 5. Also, the concentration of heavy metals of Zn2+, Cd2+, Pb2+, Fe2+, Ni2+, and Cr6+ reduced from 1000 ppm to near zero in the presence of photoabsorber. [ABSTRACT FROM AUTHOR]

Solar steam generation (SSG) utilizes green, widespread solar energy as an energy source, making it a promising technology for seawater desalination and wastewater purification. Interfacial SSGs (ISSGs) localize the heat converted from solar energy at the air-water interface to enhance interfacial temperature and decrease heat loss to bulk water, leading to a significant increase of solar-to-vapor conversion efficiency. However, ISSGs still face significant limitations in fabrication cost, overall efficiency, and biodegradability. Bio-based ISSGs have attracted much attention for their sustainability and low cost. A large number of high-efficiency bio-based ISSGs have been developed in the past decade. Reviews on bio-based ISSGs are still rare. This review first introduces the state-of-art development of the key processes and general principles of ISSG devices, including energy sources, photothermal conversion, thermal management, water supply, evaporation enthalpy, and durability. All these processes are crucial to the final performance of ISSGs, requiring careful design and tuning to achieve high efficiency. Then a variety of bio-based ISSGs are elaborated upon, such as those made from wood, bamboo, lotus, rice, pomelo peel, sunflower, cuttlefish ink, mushroom, and algae. Bio-based ISSGs excel in sustainability and low cost but still suffer from low efficiency and short durability. The use of biological materials with water collection abilities is also discussed for designing water collectors. Finally, the challenges and promising prospects of bio-based ISSGs are discussed, including efficiency, extraction of bio-based materials, stability, durability, and condensation rates. This review aims to facilitate and inspire the rapid development of bio-based ISSGs. [Display omitted] • ISSG is a promising method for desalination and waste treatment. • ISSG enhances efficiency by localizing heat at the air-water interface. • Bio-based ISSG attracts much attention due to its sustainability and low cost. • Key processes and general principles of ISSG are introduced. • A variety of bio-based ISSGs reported in recent years are elaborated. [ABSTRACT FROM AUTHOR]

• Heat pipes are used to separate light-absorbing and evaporation surfaces due to their efficient heat transfer. • Salt accumulation and steam obstruction issues on the light-absorbing surface are overcome. • A hydrophobic copper plate is used as the condensation surface for efficient water collection. • Evaporation rate of 1.17 kg m−2h−1 and water production rate of 0.45 kg m−2h−1 under 1 sun irradiation are achieved. Interfacial solar steam generation (ISSG) holds great potential for seawater desalination, and wastewater treatment. However, salt accumulation on the evaporation surface and low condensation rate notoriously degrade the performance of traditional interfacial evaporators during prolonged operation. To tackle the issues, this study introduces a general absorption-evaporation decoupled device enabled by a heat pipe assembly. Black acetate fabric is tightly attached on one side of the heat pipe surface as a photothermal layer, while a hydrophilic cellulose film is integrated on the other side with a siphon architecture, serving as an evaporation surface. The heat pipes enable efficient heat transfer from the light-absorbing side to the evaporation side of the device, thereby achieving a significant evaporation rate of 1.17 kg m−2h−1 under one-sun irradiation intensity. In addition, the device demonstrates excellent evaporation performance under different saline concentrations and maintains long-term stable operation. Furthermore, a hydrophobic copper plate is adopted as the condensation surface, leading to an improved water yield as high as 0.45 kg m−2h−1 with a steam-to-water efficiency of 38.5 %. The produced freshwater has also been proven suitable for agricultural use. Overall, the proposed decoupled design paves the way toward durable and efficient ISSG devices. [ABSTRACT FROM AUTHOR]

Utilizing solar energy for interfacial solar steam generation and wastewater remediation is regarded as one of the sustainable approaches for alleviating clean water shortage. However, it is still a great challenge to comprehend all the requirements of efficient evaporation, salt resistance and wastewater treatment as well as low cost in one evaporator, thus hindering its large-scale practical application. Herein, in this work, an environmentally friendly and low-cost hierarchical porous architecture (APC@TMF) was prepared by assembling potassium citrate activated poplar catkin derived porous carbon (APC) into the porous structure of thermalized melamine formaldehyde resin sponge (TMF) by a simple dipping method. The APC@TMF integrates the advantages of APC and TMF, thus leading to good light absorption, low thermal conductivity, high hydrophilicity and fast water transport. As expected, APC@TMF exhibits a high evaporation flux of 2.28 kg m−2 h−1 with energy conversion efficiency of 96.3 % in seawater, which outperforms TMF, PVA/TMF, PVA/APC and recently reported evaporators. Beyond that, it demonstrates good performance for seawater desalination and wastewater remediation as well as high cost-effectiveness. APC@TMF hierarchical porous architecture, assembled by filling poplar catkin (APC) derived carbon into the porous structure of thermalized melamine formaldehyde resin sponge (TMF), is successfully prepared by a simple dipping method, exhibits outstanding solar-driven interfacial seawater evaporation and wastewater purification performance. [Display omitted] • APC@TMF was prepared by assembling biomass-derived carbon into thermalized sponge. • APC@TMF shows good performance in seawater desalination and wastewater remediation. • The hierarchical porous structure of APC@TMF helps reduce the evaporation enthalpy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Facile design of the photothermal membrane for solar steam generation. • PDA-modified ZIF-L enhances solar absorption and photothermal properties. • Sodium alginate-based membrane effectively prevents salt deposition. • Stable freshwater generation from high-salinity brines is achieved. • The S-ZIF-L/PDA sponge has excellent water treatment capabilities. Interfacial solar steam generation (ISSG) technology is considered to be one of the most promising approaches to alleviating the global shortage of clean water due to its high solar thermal conversion efficiency. However, achieving stable evaporation in high salinity solutions and preventing the occurrence of salt deposition phenomena remains a challenge. Here, an efficient and stable photothermal membrane-based evaporator has been developed, which consists of polydopamine (PDA) modified leaf-like zeolitic imidazolate framework (ZIF-L) implanted in sodium alginate (SA) membrane supported on a melamine sponge (S-ZIF-L/PDA sponge), providing more advantages for boosting the photothermal conversion performance and preventing salt deposition. This S-ZIF-L/PDA sponge displays an excellent light absorption (>95 %), and remarkable evaporation rate of 1.66 kg·m−2·h−1 with a solar-thermal efficiency of 91.06 % under 1.0 sun (1 kW·m−2) illumination. Benefiting from the super hydrophilic feature of the melamine sponge and the rejection properties of the SA membrane structure, the obtained sponge effectively prevents salt and contaminants from depositing on the surface. Particularly, the S-ZIF-L/PDA sponge achieves an evaporation efficiency of 86.17 % in 20 wt% NaCl solution, along with excellent resistance to salt deposition and marvelous stability in cycling tests. The salt ion concentration of the obtained fresh water is much lower than the World Health Organization (WHO) drinking water standard, and the organic removal rate exceeds 99 %. This work provides a competitive solution for high-salinity desalination and wastewater treatment. [ABSTRACT FROM AUTHOR]