High‐Efficiency Water Collection of Superhydrophobic Condensation Absorber

The atmosphere contains ≈1.3 billion tons vapor that can be condensed to obtain water, which has the promise of alleviating the water crisis. However, condensed droplets are difficult to shed from the condensation surface that means a low surface refreshing frequency, showing the low water collection rate and efficiency. Here, this limitation is successfully overcome by proposing a novel superhydrophobic condensation absorber (SCA). All surfaces of the SCA are superhydrophobic but covered with a series of superhydrophilic through pores and superhydrophilic points which enabled the SCA with a rapid droplet nucleation capability. The whole condensation processes exhibit that the SCA has the extremely small droplet shedding volume and the highly frequent surface refreshing, which are 0.00003 and 1.1× 106 times that of the existing water collection method, respectively. The water collection rate of SCA is superior than that of the existing water collection methods, reaching to 80 mg cm-2 h-1 at the subcooling temperature of only 10 °C. In addition, the collected water by this SCA is clean without any contaminant. This high-efficiency and eco-friendly water collection method will maximize the acquisition of clean water from atmosphere, which has a strong implication for the people suffering from the freshwater crisis.