Ni(OH)2 nanoparticles decorated on 1T phase MoS2 basal plane for efficient water splitting

1T phase molybdenum disulfide (1T-MoS2) with metallic conductivity and excellent catalytic activity at edge sites towards hydrogen evolution reaction (HER) has been recognized as one of the most promising candidates for HER catalysis. However, the basal plane sites which account for the vast majority of sites are less active, resulting in limited activity of 1T-MoS2. In this case, improving the activity of basal planes appears to be a promising way to enhance overall HER activity. Herein, we report a hierarchical self-supported electrode composed of nanowire arrays of 1T-MoS2 nanosheets decorated with Ni(OH)2 nanoparticles (Ni(OH)2@1T-MoS2 NWAs) for alkaline water electrolysis. The activity toward HER is significantly improved by promoting water dissociation and hydrogen adsorption capability on the 1T-MoS2 basal plane by constructing a heterogeneous structure with Ni(OH)2. Furthermore, Ni(OH)2 endows the electrode with catalytic activity for the oxygen evolution reaction (OER). Benefiting from these advantages, the resulting electrode achieved extraordinary activity with a small overpotential of 56.9 mV and 1.51 V to reach 10 mA cm−2 for alkaline HER and overall water electrolysis. Furthermore, the density functional theory (DFT) calculations revealed the reaction mechanism.