Co‐Modified MoS2 Hybrids as Superior Bifunctional Electrocatalysts for Water Splitting Reactions: Integrating Multiple Active Components in One

Abstract The development of highly active, stable, low‐cost, and earth‐abundant electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) remains a great challenge. Herein, the cobalt (Co)‐modified MoS 2 hybrid catalysts grown on nickel foam (NF) are successfully synthesized by a facile solvothermal method. The optimized catalyst (denoted as Co‐Mo‐S‐2/NF) shows excellent HER activity with low overpotentials of 77 and 96 mV at a current density of 10 mA cm −2 , as well as excellent stability with negligible loss of the cathodic current after 3000 cycles in 1.0 M KOH and 1.0 M phosphate‐buffered saline (pH = 7), respectively. Significantly, when used as OER catalyst, the Co‐Mo‐S‐2/NF hybrid also displays outstanding OER activity with a low overpotential of 294 mV at a current density of 10 mA cm −2 and good long‐term stability for 120 h at 10 mA cm −2 without observable fading under alkaline condition. The excellent electrocatalytic activity of the generated catalyst is mainly due to abundant active site, large active area, improved conductivity, and synergistic effect within MoS 2 , Co 9 S 8 , and CoMoS 3.13 . This work provides a unique strategy to design the high‐performance and stable electrocatalysts for HER and OER.