Scalable sulfonated activated carbons as high-capacity sorbents for atmospheric water harvesting

This is the authors' abstract. We don't add key points for this paper.

We report the synthesis of sulfonated activated carbons capable of direct capture of water from air at relative humidities as low as 10% and temperatures of up to 45 °C. Sulfonated activated carbons are produced via solvent-free sulfonation using only activated carbon and neat sulfuric acid, two abundant and widespread industrial materials. The resulting materials are rapidly accessible, easily scaled, and exhibit excellent water sorption, achieving a total uptake capacity of >1.4 g·g -1 and 0.28 g·g -1 at just 30% relative humidity, placing them among the best-performing materials to date. Water sorption experiments reveal rapid water adsorption and desorption, enabling numerous cycles in a single day. We scale up production of a sulfonated activated carbon to 1.6 kg and demonstrate long-term cycling stability in a water harvesting device, offering excellent potential for real-world implementation.