Biomimetic flow guiding electrode design for high-efficiency seawater electrolysis: Overcoming salt precipitation challenges

Seawater electrolysis is a promising route for sustainable hydrogen production, yet its efficiency is limited by slow cathodic bubble detachment and Mg²⁺/Ca²⁺ precipitation that block active sites. Inspired by desert beetles and cactus spines, we developed a superhydrophilic/superhydrophobic wedge-shaped microstructure array electrode. This design accelerates bubble removal via high-speed gas channels and prevents salt buildup, keeping active sites exposed for hydrogen production. The electrode-based alkaline anion exchange membrane electrolyzer achieves 0.5 A·cm⁻² at 1.57 V in seawater and operates stably for 500 h at 2 A·cm⁻², reducing hydrogen cost to $1.7/kg of H₂ (below the US Department of Energy’s $2/kg of H₂ target). This work aims to advance hydrogen production and offers insights into developing efficient electrodes for seawater electrolysis.