Toward heterostructured transition metal hybrids with highly promoted electrochemical hydrogen evolution.

It is essential to precisely develop low-cost and sustainable electrocatalysts for the hydrogen evolution reaction. Herein, we explore a robust and controllable hydrothermal approach to synthesize defect-rich MoS 2 nanoflakes on exfoliated MoS 2 and WS 2 . Such well-designed hetero-structural hybrids of MoS 2 /exfoliated MoS 2 and MoS 2 /exfoliated WS 2 exhibit dramatically promoted electrochemical activity and high stability. The as-grown MoS 2 nanoflakes hybridized on exfoliated MoS 2 and WS 2 generate abundant active edge sites (rich in basal defects) and unsaturated sulfur atoms, resulting in highly enhanced electrocatalytic performance. This is expected to pave the way towards a significant improvement in transition metal dichalcogenide heterostructures as electrocatalysts.