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

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.