Solar‐Driven Atmospheric Water Production Through Hierarchically Ordered Porous Carbon for Self‐Sustaining Green Hydrogen Production

Abstract

Abstract Green hydrogen production by proton exchange membrane water electrolysis (PEMWE) powered by clean energy is a promising and environmentally friendly technology. However, it relies on a high‐purity water source, which is limited in regions facing water scarcity. Here, a coupled self‐sustaining solar‐enabled system is reported that couples atmospheric water harvesting with PEM water electrolysis (AWH‐PEMWE), offering a novel pathway for clean water generation and green hydrogen production. The atmospheric water harvester (AWH) component utilizes N and O co‐doped hydrophilic ordered porous carbon, engineered with an interconnected hierarchical porous structure with prosperous channels for efficient mass transport. It enables effective interfacial solar evaporation for water release, achieving a record‐high water harvesting capacity of 0.49 L kg −1 h −1 at 40% relative humidity (RH). During outdoor tests, the AWH‐PEMWE system reaches a peak green hydrogen production rate of 204 mL h −1 at midday using only atmospheric water as feedstock. Remarkably, the system remains operational under ultra‐low humidity conditions down to 20% RH, addressing the challenge of water availability in arid environments. Importantly, the system operates without the need for carrier gases or external energy input accessories, enabling a fully solar‐driven process with zero carbon emission throughout the hydrogen production cycle.