Cactus-like amorphous MoS2-CoFeLDO heterostructures for alkaline hydrogen evolution reaction

Abstract

Designing efficient and stable non-precious metal catalysts with heterogeneous structures for electrolytic hydrogen evolution in alkaline media is a challenging topic. Cactus-like amorphous MoS2-CoFeLDO heterostructures derived from calcination of MoS2-CoFeLDH in argon markedly reduced overpotential of hydrogen evolution reaction (HER). The HER overpotential of MoS2-CoFeLDO@400 °C in 1 M KOH solution required only 36 mV to reach a current density of 10 mA/cm2 and remained highly active for ≥24 h. Finite element simulations showed that cactus-like tip generated higher charge intensity, then aggregated electrons induced a higher electric field for local H+ enrichment. XRD and TEM analyses confirmed amorphous MoS2 with abundant hydrogen evolution sites in MoS2-CoFeLDO@400 °C. DFT calculations demonstrated that MoS2-CoO had a 0.5 eV lower reaction energy barrier than MoS2-CoFeLDH in the Tafel step, indicating superior reaction kinetics to promote HER.