Interfacial engineering of Co-doped 1T-MoS2 coupled with V2C MXene for efficient electrocatalytic hydrogen evolution

Abstract

Earth-abundant MoS2 has attracted great attentions as a promising hydrogen evolution reaction (HER) electrocatalyst, but it is limited by sluggish water dissociation and strong adsorption of the oxygen-containing intermediates in alkaline media. Herein, an interfacial engineering strategy to fabricate Co-doped 1T-MoS2 coupling with V2C MXene was reported to improve the HER kinetics of MoS2. DFT calculations predict that the construction of heterogeneous interfaces between V2C MXene and Co-doped 1T-MoS2 can effectively reduce the energy barrier of water dissociation and optimize the free energy of hydrogen adsorption. As a result, the synthesized Co-MoS2/V2C@CC nanohybrid exhibits excellent HER performance with small overpotentials of 70.1, 263.2 and 296 mV to achieve current densities of 10, 500 and 1000 mA cm−2, respectively, and outstanding stability for 50 h HER test without degradation. Additionally, the overall hydrazine-assisted water splitting (OHzS) system catalyzed by Co-MoS2/V2C@CC in both anode and cathode requires only 0.33 V to achieve a current density of 10 mA cm−2 with significant long-term durability.