A flowerlike sponge coated with carbon black nanoparticles for enhanced solar vapor generation

Efficient solar water vapor generation enabled by water-absorbing polypyrrole coated cotton fabric with enhanced heat localization

Synergistic Tandem Solar Electricity-Water Generators

Recent progress of nanostructured interfacial solar vapor generators

Trapping waste metal ions in a hydrogel/coal powder composite for boosting sewage purification via solar-driven interfacial water evaporation with long-term durability

Sandwich-structured evaporator with multilayer confined heating interface for boosting solar vapor generation

Round-the-clock interfacial solar vapor generator enabled by form-stable phase change materials with enhanced photothermal conversion capacity

Solar vapor generation represents a promising approach to alleviate water shortage for producing fresh water from undrinkable water resources. Although Cu-based plasmonics have attracted tremendous interest due to efficient light-to-heat conversion, their application faces great challenges in the oxidation resistance of Cu and low evaporation rate. Herein, a hybrid of three-dimensional carbonized loofah sponges and graphene layers encapsulated Cu nanoparticles is successfully synthesized via a facile pyrolysis method. In addition to effective light harvesting, the localized heating effect of stabilized Cu nanoparticles remarkably elevated the surface temperature of Cu@C/CLS to 72 °C, and a vapor generation rate as high as 1.54 kg m-2 h-1 with solar thermal efficiency reaching 90.2% under 1 Sun illumination was achieved. A study in the purification of sewage and muddy water with Cu@C/CLS demonstrates a promising perspective in a practical application. These results may offer a new inspiration for the design of efficient nonprecious Cu-based photothermal materials.

Solar vapor generation is considered a green and practical approach to take advantage of solar energy as a renewable source and provide pure water. However, developing suitable materials with high efficiency and long-term stability under one sun illumination is challenging. Consequently, in this paper, we manifested two-dimensional Zn/Co zeolitic imidazolate framework (ZIF)-L as a sacrificial template to prepare carbon nanotube (CNT) through carbonization of the ZIF-L (Z-CNT). This porous Z-CNT as the solar absorber was deposited on a low-cost fiber paper, as a carrier for water transport by the capillary effect. A polystyrene foam was placed under the provided film, which prevents the heat loss to bulk water. By utilizing this solar vapor generator, a high water evaporation rate of 1.44 kg m2 h−1 and a photothermal conversion efficiency of 84% was achieved under one sun. Beside the porosity, high light adsorption of carbon nano tubes (CNT) due to having black colour and low thermal conductivity of this material incorporate the high achieved efficiency.

Plasmonic wooden flower for highly efficient solar vapor generation

Solar vapor generation is emerging as a promising technology using solar energy for various applications including desalination and freshwater production. However, from the viewpoints of industrial and academic research, it remains challenging to prepare low-cost and high-efficiency photothermal materials. In this work, we report the controlled carbonization of polypropylene (PP) using NiO and poly(ionic liquid) (PIL) as combined catalysts to prepare a Ni/carbon nanomaterial (Ni/CNM). The morphology and textural property of Ni/CNM are modulated by adding a trace amount of PIL. Ni/CNM consists of cup-stacked carbon nanotubes (CS-CNTs) and pear-shaped metallic Ni nanoparticles. Due to the synergistic effect of Ni and CS-CNTs in solar absorption, Ni/CNM possesses an excellent property of photothermal conversion. Meanwhile, Ni/CNM with a high specific surface area and rich micro-/meso-/macropores constructs a three-dimensional (3D) porous network for efficient water supply and vapor channels. Thanks to high solar absorption, fast water transport, and low thermal conductivity, Ni/CNM exhibits a high water evaporation rate of 1.67 kg m−2 h−1, a solar-to-vapor conversion efficiency of 94.9%, and an excellent stability for 10 cycles. It also works well when converting dye-containing water, seawater, and oil/water emulsion into healthy drinkable water. The metallic ion removal efficiency of seawater is 99.99%, and the dye removal efficiency is >99.9%. More importantly, it prevails over the-state-of-art carbon-based photothermal materials in solar energy-driven vapor generation. This work not only proposes a new sustainable approach to convert waste polymers into advanced metal/carbon hybrids, but also contributes to the fields of solar energy utilization and seawater desalination.

Solar vapor generator: A natural all-in-one 3D system derived from cattail

Biomass-derived photothermal conversion materials are considered to be promising evaporator choices for cost-effective, sustainable, and environmentally friendly solar vapor generation. Herein we demonstrate a double-layer flamed straw, which is a typical solar-driven interfacial evaporator that can directly convert solar energy into heat and then localize heat at interface for vapor generation. Benefiting from the unique structure of a natural corn straw, the flamed straw exhibits a high solar absorbance of 91%, ultralow thermal conductivity (0.042 W m-1 K-1), and a sufficient water supply. Notably, the flamed-straw evaporator achieves a fast evaporation rate of 1.497 kg m-2 h-1 and a high photothermal efficiency of 86% under 1 sun illumination, showing comparable efficiency with the reported studies. Our work highlights the promise of using the low-cost biomass-derived materials as highly effective solar vapor generators in the realm of seawater desalination and wastewater treatment.

PBAT/MXene monolithic solar vapor generator with high efficiency on seawater evaporation and swage purification

With the ever-growing demand in fresh water supply, great efforts have been devoted to developing sustainable systems which could generate fresh water continuously. Solar vapor generation is one of the promising strategies which comprise an unlimited energy source and efficient solar-to-heat generators for overcoming fresh water scarcity. However, current solar vapor generation systems suffer either from inefficient utilization of solar energy or an expensive fabrication process. In this paper, we introduced a nano-plasmonic approach, i.e., a floatable nanocompoiste where copper sulfide nanorods (Cu2-xS NRs) are embedded in a polyvinyl alcohol (PVA) matrix, for solar-to-vapor generation. A high solar vapor generation efficiency of ~87% and water evaporation rate of 1.270 kg m−2 h−1 were achieved under simulated solar irradiation of 1 sun. With the illumination of natural daylight, seawater was purified using Cu2-xS NRs-PVA gel, with high purity, as distilled drinking water. The plasmonic nanocomposites demonstrated here are easy to fabricate and highly efficient for solar vapor generation, illustrating a potential solution for future seawater desalination.

Vapor generation using solar energy is emerging as an efficient technology for wastewater purification and seawater desalination to relieve global water crisis. However, salt deposition on the evaporation surface seriously impairs the long-term steady water evaporation performance. Herein, the flexible salt-rejecting photothermal paper comprising reduced graphene oxide (rGO) and ultralong hydroxyapatite nanowires (HNs) has been developed for high-performance solar energy-driven water evaporation and stable desalination of seawater. The rGO/HN photothermal paper has advantages such as the hierarchical porous structure, interconnected channels, high mechanical strength, high efficiencies of solar light absorption and photothermal conversion, fast water transportation, and good heat insulation and salt-rejecting properties. Furthermore, the hydrophilicity and hydrophobicity of the rGO/HN photothermal paper can be adjusted by regulating the thermal treatment time. The water evaporation rate and energy efficiency of the hydrophilic rGO/HN photothermal paper are 1.48 kg m-2 h-1 and 89.2%, respectively, under 1 sun illumination (1 kW m-2). The hydrophobic rGO/HN photothermal paper shows a long-time stable water evaporation and salt-rejecting performance in the process of seawater desalination. The flexible salt-rejecting rGO/HN photothermal paper can produce clean water from wastewater and seawater with high rejection rates of organic dyes, metal ions, and salt ions, and it is promising for applications in water purification and seawater desalination.