Hydrophilic Photothermal Fiber Solar Evaporators For Solar Desalination

The accelerated utilization of fresh water resources caused by contemporary industry and population expansion has pushed the globe into a deeper fresh water crisis.Solar desalination has been considered a sustainable method to obtain fresh water.The notion of interfacial evaporation has been proven in recent years to be the most effective strategy for completely using solar energy and reducing heat loss as much as possible.Currently,the scientists have developed many excellent solar steam generation devices based on metal-based materials,carbon-based materials,organic materials,biomass-based materials and other photothermal nanomaterials as the solar heater,but most of them possess the complicated preparation processes and photobleaching problems.The photothermal material of the solar evaporation device,after a lengthy solar radiation,will be polluted by salt crystals that precipitate on its surface,thus limiting sunlight absorption and drastically decreasing evaporation rate,thus severely hindering the widespread use and utilization of solar seawater desalination technology.In practical application,it is necessary to further improve the salt resistance to maintain the high solar evaporation efficiency of the evaporator device for a long time.Under the simulated solar radiation of 1.0 k W·m^-2,the evaporation rate of solar evaporate is 1.39 kg·m^-2·h^-1,and the efficiency is 95.1%.In addition,20 days of outdoor evaporation test showed that water evaporation plant is still running effectively,has the good salt resistance.The ion concentration of purified water meets the drinking water standard of the World Health Organization（WHO）.The design strategy for high efficiency salt cycle solar evaporators is summarized and suggested in this article.The strategy is based on the following fundamental ideas:（i）photothermal nanoparticles are evenly dispersed into the fibers to improve the solar-thermal conversion efficiency;（ii）the surface of the fiber is functionalized to possess hydrophilic property;（iii）three dimensional arched evaporation device is constructed to improve water transportation rate,reduce the heat loss and enlarge the evaporation area.Using the hydrophilic oxidized carbon fiber as the photothermal material to build the hydrophilic oxidized carbon fiber solar evaporator was the final step in validating the design strategy.The implementation and validation of this technique will offer a fresh perspective on the future study and application of photothermal materials as well as the creation and design of general desalination technology.