Two birds with one stone: facile fabrication of an iron-cobalt bimetallic sulfide nanosheet-assembled nanosphere for efficient energy storage and hydrogen evolution.

Transition metal sulfides are widely regarded as the most promising electrode materials for supercapacitors. Herein, we utilized a straightforward electrodeposition method to prepare an iron-cobalt bimetallic sulfide nanosheet-assembled nanosphere on nickel foam (FeCo 2 S 4 /NF). The synergistic effect between bimetals and the unique three-dimensional structure significantly improved its capacitive performance. As a result, it demonstrated a remarkable specific capacitance, brilliant long-term stability and acceptable rate capability. Moreover, FeCo 2 S 4 /NF and active carbon (AC) were used to assemble an asymmetric supercapacitor (ASC), and FeCo 2 S 4 //AC displays a maximum energy density of 29.4 W h kg -1 at 800 W kg -1 . Moreover, when adopted as an electrocatalyst for the hydrogen evolution reaction (HER), FeCo 2 S 4 /NF exhibited excellent catalytic properties ( η 10 = 165 mV). Our research provides a valuable insight into the multidisciplinary integration of high-performance energy materials.