Boosting hydrogen evolution and triiodide reduction via electronic coupling on (1T, 2H) MoS2/N-doped carbon dodecahedron

Designing a noble-metal-free catalyst with desired composition and structure is highly significance for accelerating catalytic kinetics of the hydrogen evolution reaction (HER) and triiodide reduction reaction (IRR), which is essential for advancing green hydrogen production from water electrolysis and improving the power convention efficiency (PCE) of dye-sensitized solar cells (DSSCs). Herein, the small-sized (1T, 2H) phase MoS2 nanosheets were uniformly wrapped around N-doped C dodecahedron (MoS2@NC) through a continuous synthesis strategy with ZIF-8 serving as the original template. When MoS2@NC is used as a catalyst for HER, it only requires a low overpotential of 93 mV to reach 10 mA cm−2, surpassing most reported MoS2-based catalyst. Furthermore, a device fabricated with MoS2@NC achieves a PCE of 8.20%, which is comparable to that of Pt-based ones (8.59%). Theoretical calculation revealed that the enhanced HER activity of MoS2@NC is mainly attributed to the enhanced water adsorption energy and a reduced energy barrier for overcoming the rate-determining step during HER process. Additionally, the interfacial S sites in MoS2@NC are responsible for the excellent catalytic activity in IRR. The experimental and theoretical results collectively confirm that the as-designed MoS2@NC is a promising bifunctional catalyst.