Efficient Unassisted Overall Photocatalytic Seawater Splitting on GaN-Based Nanowire Arrays

Large-scale, clean, efficient, and sustainable hydrogen production from water is one of the major goals in solar-to-fuel conversion as the sun and water represent the two most abundant and geographically balanced free resources available on earth. Considering that most of the liquid water available on the earth's surface is present in the form of seawater, H₂ generation from seawater splitting is highly desirable for large-scale practical and economical application. Herein, we report on the first demonstration of direct efficient overall solar-driven seawater splitting on p-GaN-based nanowire arrays without any external bias or sacrificial agents from various types of simulated seawater solutions. A stable solar-to-hydrogen (STH) conversion efficiency of 1.9% was obtained under concentrated irradiation, demonstrating its possible utilization for the large-scale, environmentally friendly, sustainable generation of clean solar fuel.