Fresh water generation inspired by the natural solar-driven evaporation has been widely utilized to relieve the fresh water scarcity. To accelerate the water evaporation to the maximum, variety of photothermal materials have been introduced into the evaporation process with rationally designed structure and surface property.

Recently, the research team led by Prof. JIANG Heqing from Qingdao Key Laboratory of Functional Membrane Material and Membrane Technology, Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences (CAS), reported a facile nanocomposite strategy to fabricate the carbon based photothermal membrane with controllable microstructure and high solar-driven evaporation efficiency, which has been published as  Journal of Materials Chemistry A. Lately, bio-inspired by the auricle with concave surface for efficient sound collection, we designed a series of macro-scaled 3D photothermal cones to further improve the water evaporation performance.

Thanks to the rational 3D morphology, the net energy efficiency can reach up to 93.8%, while the apparent efficiency has broken through the limitation of 2D membrane. In the desalination evaluation with the water sample from Jiaozhou Bay (China), the 3D photothermal cone showed high evaporation rate, about 350 % higher than that of natural evaporation.

Fortunately, the precipitated salt from seawater doesn’t cover the whole cone surface, which is not only beneficial for the salt enrichment and recovery but stable performance on photothermal desalination. Scientists believe that the rationally designed 3D photothermal cone has high potential to be used in solar-driven fresh water generation. The macroscopic morphology design can be a successful attempt to exhibit a novel strategy for the development of high-efficiency photothermal materials.