Three-dimensional Co-MoS2/Ni3S2/Ni assembly with interfacial engineering and electronic modulation for efficient hydrogen evolution reaction

To maximize the active sites and accelerate the electron transfer are of significant importance for developing efficient MoS2-based catalysts towards hydrogen evolution reaction (HER). Herein, we report a facile one-step construction of three-dimensional assembly in which Co doped MoS2 nanoflowers are attached on partially sulfided nickel foam (Co-MoS2/Ni3S2/Ni). The three-dimensional structure enables maximum exposure of the active sites. Besides, interfacial interaction between MoS2 and Ni3S2 accelerates the electron transfer kinetics and increases the electrochemically active surface area. Additionally, electronic synergy effect of Co to MoS2 promotes the formation of 1T-MoS2 phase. Consequently, the optimized Co-MoS2/Ni3S2/Ni catalyst shows a superior HER performance with low overpotentials of 43 mV and 201 mV to achieve the current densities of 10 mA/cm(2) and 100 mA/cm(2), as well as an excellent stability of 11 h. Besides, Co-MoS2/Ni3S2/Ni has a small Tafel slope of 53 mV dec(-1) which indicates a combined Volmer-Heyrovsky mechanism during the HER process. This work provides a novel insight for designing excellent MoS2-based HER catalysts through electronic modulation and interfacial engineering.