As population demands for freshwater increase, existing natural freshwater resources face significant strains. Currently, over 2.5 billion people live in localities that are subject to severe water scarcity at least 1 month of the year.1 Scarcity affects all types of localities, such as urban, rural, coastal areas, landlocked areas, and off-grid locations. Increasingly, active water purification technologies are being used to boost and secure freshwater supplies. A widely used desalination technology is seawater reverse osmosis (SWRO), in which pumps pressurize the feedwater to well above its osmotic pressure to pump water molecules through a membrane largely impermeable to salt ions (posmotic∼25 bar).2 City-scale SWRO plants are operational in several countries, delivering on the order of 106 m3 of treated water per day (<0.1% of the total global daily water consumption). However, as the need for water purification increases and the requirements for each locality becomes more diverse, SWRO plants alone cannot meet the growing demand for a technological solution. Barriers toward increased penetration of SWRO include the enormous investment required to develop such plants, poor downscalability of the technology, the geographical limitation to coastal areas and near urban environments, and high energy requirements (typically about 4 kWh/m3).2