A photothermal-photocatalytic layered aerogel for harvesting water and hydrogen from seawater

Abstract

Photocatalytic hydrogen production from seawater holds potential to decrease the use of fresh or pre-treated water. However, direct photocatalytic splitting of seawater currently encounters challenges such as corrosion of catalyst and unsatisfied stability. To address these issues, we have integrated seawater desalination with photocatalytic water vapor splitting for in-situ hydrogen production, while also obtaining freshwater. This approach avoids direct contact between photocatalytic materials and seawater solution, effectively mitigating corrosion and enhancing hydrogen production performance. Based on this design, we constructed a layered structure of photothermal-photocatalytic aerogel material via in-situ synthesis method and designed corresponding device for freshwater-hydrogen coproduction, demonstrating notable hydrogen production rate of 17.94 mmol m⁻² h⁻¹ with solar-to-hydrogen efficiency of 0.12 ± 0.02 % and freshwater production rate of 0.92 kg m⁻² h⁻¹. This work demonstrates significant practical value in photothermal-photocatalysis field, potentially addressing the problem of energy and water scarcity in off-grid region.