CoSe2 nanocrystals embedded into carbon framework as efficient bifunctional catalyst for alkaline seawater splitting

Abstract

Herein, CoSe 2 nanocrystals embedded into carbon framework grown on carbon cloth is developed to catalyze the overall seawater splitting. • CoSe 2 nanocrystals embedded into carbon framework is synthesized as bifunctional catalyst for overall seawater splitting. • The catalyst shows overpotentials of 245 and 134 mV for OER and HER to reach 10 mA cm –2 , respectively. • The catalyst can operate at 1.842 V with a current density of 500 mA cm -2 in a two-electrode electrolyzer and work for 50 h. Direct seawater splitting is more attractive and feasible in realizing hydrogen economy, but the key challenge lies in the development of efficient and stable bifunctional electrocatalysts toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, CoSe 2 nanocrystals embedded into carbon framework grown on carbon cloth are successfully designed, featuring cooperative effect of CoSe 2 and nitrogen-doped carbon framework, which endow the excellent performance toward overall seawater splitting. The catalyst requires overpotentials of 245 and 134 mV for OER and HER to reach 10 mA cm –2 , respectively. Meantime, this catalyst also maintains robust electrocatalytic activity during over 50 h. Further, in the two-electrode alkaline seawater splitting electrolyzer, the catalyst shows a working voltage of 1.842 V to deliver 500 mA cm –2 at 80 o C, suggesting promising applications in sustainable hydrogen production. Our work may shed light on developing advanced and cost-effective electrocatalysts toward seawater splitting.