Ultralight porous carbon loaded Co-doped MoS2 as an efficient electrocatalyst for hydrogen evolution reaction in acidic and alkaline media

Molybdenum disulfide (MoS 2 ) has a Gibbs free energy comparable to platinum (Pt), suggesting it can replace Pt as a hydrogen evolution reaction (HER) catalyst. However, the shortcomings of the restricted number of MoS 2 active sites and poor intrinsic electrical conductivity have resulted in impeding its widespread application. In this work, Co/MoS 2 @NPC electrocatalyst was prepared by using nitrogen-doped porous carbon (NPC) as a substrate material, and then hydrothermally anchoring cobalt-doped molybdenum disulfide (Co-doped MoS 2 ) on the substrate. Co/MoS 2 @NPC was subsequently applied to hydrogen evolution reaction in acidic and alkaline media. It was found that the overpotential of 0.2Co/MoS 2 @NPC was only 139 mV for HER at 10 mA cm −2 with a Tafel slope of 69 mV dec −1 in acidic medium; while in alkaline medium, its overpotential was 163 mV with a Tafel slope of 106 mV dec −1 , and it operated stably over 10 h. The superior HER performance may be related to the point that NPC as a substrate can uniformly disperse MoS 2 , exposing more active sites and ensuring high electronic conductivity of MoS 2 . In addition, the introduction of Co into MoS 2 changed the intrinsic activity of MoS 2 and interacted with CoS x and pyridine nitrogen in NPC, constituting a ternary catalytic interaction. Therefore, this study provides a novel strategy for optimizing the HER activity of MoS 2 .