Water connects every aspect of life. Only 4% of the world's water is fresh water, where most of water sources have different degrees of salinity. As a result, billions of people around the globe face water scarcity which is a global challenge. Desalination technologies which separate the fresh water from the solvated salts ions in saline water are attracting major attention. However, conventional desalination processes including thermally and pressure driven processes are highly energy intensive. To address this issue, here we report that the atmospheric-pressure plasma (APP) treatment of saline water can be a new potential alternative low-energy and green desalination route. Meanwhile, valuable salts are recovered by direct salt crystal precipitation within a short plasma processing time. During desalination and salt precipitation, plasma activated desalinated water (PADW) is generated and can be used for clean energy generation by water splitting and sustainable agriculture by enhanced plant seed germination. In turn, functional nanomaterials can be extracted from the precipitated salt. The PADW exhibited low salinity of 5.6 ms/cm with low pH value of 2.1. The unique intrinsic PADW chemistries further enhanced the electrochemical water splitting in both hydrogen evolution reaction (HER) at a Pt electrode and oxygen evolution reaction (OER) at a RuO 2 electrode compared with the conventional acidic solution of similar pH. Moreover, the feasibility of using PADW in sustainable agriculture was demonstrated by enhancing mungbean seed germination using tap water mixed with PADW. At optimum mix concentration, both seed germination rates and germination percentages increased. Finally, we demonstrated the feasibility of synthesis of high-value 2D nanomaterials exemplified by Mg(OH) 2 nanosheets via single step thermal process using the salt precipitated from the seawater by the plasma process. Combined with straightforward use of renewable electricity to generate APPs, this study reveals the plasma potential for sustainable recovery of clean water, clean energy generation, sustainable agriculture, and manufacturing of advanced functional nanomaterials -all from the greatest treasure of our blue planet -seawater.

Enhanced catalytic activity of Ag/BN nanohybrids is ascribed to the formation of a thin intermediate Ag–O–B layer.