A brush-like Cu 2 O-CoO core-shell nanoarray: an efficient bifunctional electrocatalyst for overall seawater splitting.

Herein, a brush-like Cu 2 O-CoO core-shell nanoarray on copper foam (Cu 2 O-CoO/CF) can achieve efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance in alkaline seawater electrolyte. This Cu 2 O-CoO/CF shows overpotentials as low as 315 and 295 mV at 100 mA cm -2 for the OER and HER, respectively. Moreover, it could also be operated at 1.82 V with 100 mA cm -2 in a two-electrode electrolyzer and exhibits strong stability for at least 50 hours of electrolysis. The excellent performance and hierarchical structure advantages of Cu 2 O-CoO/CF provide new ideas for designing efficient seawater splitting electrocatalysts.