ZnCo2S4 nanosheet array anchored on nickel foam as electrocatalyst for electrochemical water splitting

Exploring transition metal-based, highly efficient and bifunctional catalysts for electrochemical water splitting remains a challenging task. Herein, ZnCo 2 S 4 nanosheet array supported on nickel foam (ZnCo 2 S 4 /NF) is fabricated and demonstrated to be efficacious electrocatalyst for both oxygen evolution and hydrogen evolution reactions. The resulting catalyst affords overpotentials of only 278 mV to achieve 10 mA cm − 2 towards oxygen evolution and 185 mV to reach 10 mA cm − 2 towards hydrogen evolution with superior stability in alkaline solution. The assembled two-electrode water electrolyzer using ZnCo 2 S 4 /NF can reach a current density of 10 mA cm − 2 by 1.66 V cell voltage.