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We demonstrate in this paper a super-hydrophilic and oleophobic green porous photothermal material based on wood fiber as a novel oil-repellent photothermal material for efficient solar vapor generation (WF-SP). WF-SP is an excellent light-absorbing material with the advantages of a porous nanostructure, super-hydrophilic, low thermal conductivity, high-temperature resistance, and oleophobicity. Based on these advantages, WF-SP exhibits good solar photothermal conversion performance with solar vapor generation efficiencies of 85.4%, 75.3%, and 70.2% at 1 kW m−2, 2 kW m−2, and 3 kW m−2 radiation intensities, respectively. The results provide new possibilities for the design and preparation of low-cost, green, and pollution-free photothermal materials with high solar thermal conversion efficiency for solar photothermal conversion vapor generation. [ABSTRACT FROM AUTHOR]

Solar steam generation (SSG) has become a cutting‐edge technology to solve fresh water shortage. Herein, a neotype photothermal conversion material (CAEP‐PFO) was designed and prepared by using expanded perlite as raw material and sodium alginate as crosslinking agent, through directional freezing, surface carbonization and oil‐phobic modification. Through characterization analysis, the results showed that the prepared CAEP‐PFO has a porosity of 92 %, a light absorption of more than 88 %, and a low thermal conductivity of 0.06834 W m−1 K−1. In addition, CAEP‐PFO exhibits excellent salt resistance and oil repellency, and possess an evaporation efficiency of 78.6 % in 10 % brine and 80.2 % in oil‐bearing wastewater under the irradiation of 1 kW m−2, respectively. After 8 cycles of test, the evaporation efficiency in pure water is relatively stable, and the average evaporation efficiency can reach 84.28 %. The research may lay a foundation for the future preparation of photothermal materials and the practical application in seawater and oil‐bearing wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] Solar steam generation (SSG) is one of the promising technologies for seawater desalination and contaminated water purification. However, SSG devices are always restricted by poor insulation performance, insufficient solar spectrum absorption and serious salt-fouling. Here, a double-layered novel SSG system was fabricated by using poly(ionicliquid)s gels with hollow SiO 2 microspheres in-situ doping to enhance the thermal insulation of lower layer, and co-modified the top surface by polypyrrole (PPy) and silver particles to strengthen the solar absorption capability. Benefiting from the low thermal conductivity (0.082 W m−1 k−1), strong light absorption (ca. 96%) and adequate water transport capability of poly(ionic liquid)s gels. As SSG device, a superb photothermal conversion efficiency of 90.5% is achieved under 1 sun illumination. Moreover, the poly(ionic liquid)s gels based SSG system also shows good desalination performance in artificial sea water and high concentration brine, and the purified water from artificial seawater can achieve the WHO's standard for drinking water. Therefore, this work combined attractive in-situ doping and co-modified strategies for fabricating high performance and thus shows significant potential for real applications. [ABSTRACT FROM AUTHOR]

Solar steam generation (SSG) has emerged as one of renewable and environmentally friendly technologies for production of fresh water. Here, we demonstrate the preparation of a novel oil-repellent photothermal materials based on copper foam (CF) for efficient SSG. Only by a simple chemical oxidation treatment on CF (named as R–CF), the smooth CF skeleton changes to be rough, leading to an enhanced light absorption of up to 90% which is far higher than that of untreated CF (10–70%). By combination of its high porosity (89.6%) and high specific surface area (230 m2 g−1), the R–CF shows superior ability on SSG as well as salt-resistance, i.e., its evaporation efficiency in water and high saline solution reaches 85.25% and 70.19% under 1 kW m−2 irradiation, respectively. In addition, R–CF was further treated by a surface chemical modification to achieve hydrophilicity while oil-repellent wettability (named as OR-R-CF), enabling it solar vaporization even in oily water, e.g., an evaporation efficiency of 77.0% was obtained in oily water, which is great advantageous to those existing photothermal materials usually suffer the drawbacks of poor oil-repellent or anti-fouling property and thus shows significant potentials for practical SSG applications in both seawater and oily water. We propose a facile method of surface-modified foamed copper to prepare oil-repellent photothermal materials (OR-R-CF). Taking advantage of its excellent light absorption, macroporous structure and connected water channels, OR-R-CF material exhibits excellent solar evaporation performance and oil-repellent. This work provides great potential for practical applications in seawater and oily wastewater. [Display omitted] • R–CF has high light absorption, good thermal stability and an open pore structure. • Evaporation efficiency of R–CF in water and high saline solution reaches 85.25% and 70.19% under 1 kW m−2 irradiation, respectively. • OR-R-CF has unique oil-repellent characteristics, and its evaporation efficiencyof 77.0% was obtained in oily water. [ABSTRACT FROM AUTHOR]

Solar steam generation (SSG) with efficient interface-evaporation manner has recently emerged as one of the promising approaches to produce fresh water. In this work, halloysite-based SSG (H1) with aligned channels was prepared from halloysite (Hal) and chitosan (CS) by directional freezing and simple carbonization. Then modified the sides and lower surface of H1 to obtain oleophobic generator H2. The as-prepared H1 possess high light absorption (Ca.97.4), excellent thermal insulation (0.086 W m−1 K−1 in dry state), and abundant porosity (75.6%). Furthermore, the halloysite based evaporator H1 with unique aligned channels can ensure timely water transportation. As a result, leading to a high evaporation rate of 1.58 kg m−2 h−1 with an excellent photothermal conversion efficiency of 95.5% under 1 kW m−2 illumination. In addition, the hydrogel-based evaporation H1 also exhibits superior salt-resistant performance for solar desalination in high concentration brine, and the purified water from artificial seawater can achieve the WHO's standard for ion concentration of drinking water. Moreover, after modification the oleophobic H2 exhibit an excellent evaporation performance in oily water, and can reach to a high conversion efficiency of 86.0%. The halloysite-based evaporation devices have promise to be ideal candidates for efficient SSG and may further expanding the scope of their practical applications. [Display omitted] • H-SSGs has high light absorption, rich porosity and unique aligned channels. • The unique channels make H-SSGS promising in different water environments. • H-SSGs effectively expand the practical application range of SSG. [ABSTRACT FROM AUTHOR]