Solar-driven MXene aerogels with high water vapor harvesting capacity for atmospheric water harvesting

The vast reservoirs of atmospheric freshwater have been investigated for their potential to provide a sustainable water supply with the right water sorbent material to satisfy water requirements in dry regions. Here, this study offers a technique for creating a solar-powered polymer hygroscopic aerogel for atmospheric water harvesting (AWH) with an MXene solar absorber. This preparation technique combines solution exchange and lyophilization. The results show that the porous aerogel can achieve high performance with high vapor capture (up to 5.86 g·g−1 at 90% RH and 25 °C), rapid photothermal conversion efficiency (up to 37.4 °C within 10 min under 0.5 kW·m−2 light at 25 °C), a low desorption temperature (lower than 40 °C), and an effective water release rate. Under real-world outdoor conditions (0.11–1.01 kW·m−2), the water collection capacity reaches 1.125 L·kg−1, sufficient for an adult's daily minimum water intake. Even under extreme environmental circumstances, our approach provides a simple, effective, and practical solution.