Facile preparation of polydimethylsiloxane/carbon nanotubes modified melamine solar evaporators for efficient steam generation and desalination.

Solar driven interfacial evaporation has received extensive attention as a very promising desalination technique to solve the fresh water shortage crisis. However, salt-fouling and poor stability during long-term solar desalination seriously hinder applications of solar evaporators. In addition, most of the reported evaporators rely on expensive materials and complex preparation processes. Here, we report facile preparation of polydimethylsiloxane/carbon nanotubes (PDMS/CNTs) modified melamine solar evaporators for efficient steam generation and desalination. The elastic solar evaporators feature (i) macroporous network with rough skeleton owing to phase separation of PDMS, high solar absorbance (99%) and excellent photothermal performance, low thermal conductivity (0.032 W m-1 K-1), and (iii) unique wettability (hydrophobic upper surface and hydrophilic lower part). Consequently, the evaporators have an evaporation rate of 1.44 kg m-2 h-1 and a solar-to-vapor conversion efficiency of 84% for solar evaporation of deionized water under 1 sun illumination. Interestingly, the evaporators show similar solar evaporation performance for saline water compared to deionized water. Moreover, the evaporators show excellent salt-resistance and stability during long-term continuous solar desalination owing to rapid water replenishment in the evaporators. The evaporators may find practical applications in solar desalination because of the merits of the evaporators and the simple preparation method.

Li Q ，Zhao X ，Li L ，Hu T ，Yang Y ，Zhang J ... -  《-》

Melamine/Silicone Hybrid Sponges with Controllable Microstructure and Wettability for Efficient Solar-Driven Interfacial Desalination.

Li L ，Li Q ，Feng Y ，Chen K ，Zhang J ... -  《-》

Highly Salt-Resistant interfacial solar evaporators based on Melamine@Silicone nanoparticles for stable Long-Term desalination and water harvesting.

Interfacial solar-driven evaporation (ISE) is one of the most promising solutions for collecting fresh water, however, poor salt-resistance severely limits the long-term stability of solar evaporators. Here, highly salt-resistant solar evaporators for stable long-term desalination and water harvesting were fabricated by depositing silicone nanoparticles onto melamine sponge, and then modifying the hybrid sponge sequentially with polypyrrole and Au nanoparticles. The solar evaporators have a superhydrophilic hull for water transport and solar desalination, and a superhydrophobic nucleus for reducing heat loss. Spontaneous rapid salt exchange and reduction in salt concentration gradient were achieved due to ultrafast water transport and replenishment in the superhydrophilic hull with a hierachical micro-/nanostructure, which effectively prevents salt deposition during ISE. Consequently, the solar evaporators have long-term stable evaporation performance of 1.65 kg m-2h-1 for 3.5 wt% NaCl solution under 1 sun illumination. Moreover, 12.87 kg m-2 fresh water was collected during consecutive 10 h ISE of 20 wt% brine under 1 sun without any salt precipitation. We believe that this strategy will shed a new light on the design of long-term stable solar evaporators for fresh water harvesting.

Huang X ，Li L ，Zhao X ，Zhang J ... -  《-》

Scalable Superhydrophilic Solar Evaporators for Long-Term Stable Desalination, Fresh Water Collection and Salt Collection by Vertical Salt Deposition.

Solar-driven interfacial evaporation (SIE) is very promising to solve the issue of fresh water shortage, however, poor salt resistance severely hinders long-term stable SIE and fresh water collection. Here, we report design of superhydrophilic solar evaporators for long-term stable desalination, fresh water collection and salt collection by vertical salt deposition. The evaporators are prepared by sequentially deposition of silicone nanofilaments, polypyrrole and Au nanoparticles on a polyester fabric composed of microfibers. The evaporators feature excellent photothermal effect and ultrafast water transport, due to their unique micro-/nanostructure and superhydrophilicity. As a result, during SIE the salt gradually deposits vertically rather than occupies larger area on the evaporators. Consequently, long-term stable SIE with high evaporation rates of 2.4-2.1 kg m-2 h-1 for 3.5-20 wt % brine in continuous 10 h is achieved under 1 sun illumination. Meanwhile, the loosely deposited salt can be easily collected, realizing zero brine discharge. Moreover, scalable preparation of the evaporator is achieved, which exhibits efficient collection of high quality fresh water (10.08 kg m-2 in 8 h) via SIE desalination under weak natural sunlight (0.46~0.66 sun). This strategy sheds a new light on the design of high-performance solar evaporators and their real-world fresh water collection.

Huang XP ，Li LX ，Chen K ，Zhang JP ... -  《-》

Flexible and Mildew-Resistant Wood-Derived Aerogel for Stable and Efficient Solar Desalination.

Zhang Q ，Li L ，Jiang B ，Zhang H ，He N ，Yang S ，Tang D ，Song Y ... -  《-》