Patch Clamp for MoS₂ Layer‐Dependent Hydrogen Evolution Reaction

Conventional electrochemical experiments can only obtain the average contribution of all active sites in the catalyst. Hence, it is meaningful to distinguish the electrochemical contribution of the local active sites in single‐crystal catalysts. Here, a double‐hole patch clamp is designed to achieve a localized electrochemical measurement in a model catalyst, MoS 2 . The double‐hole patch clamp is further applied to measure the hydrogen evolution reaction of MoS 2 . By increasing the MoS 2 thickness from monolayer to bilayer, the onset potential increases from 156 to 238 mV. There is no obvious electrocatalytic reaction by further increasing the MoS 2 thickness to the trilayer. This could contribute to the ≈2.1 eV out‐of‐plane bandgap and corresponding high vertical resistance of MoS 2 . This double‐hole patch clamp provides a new tool to understand the electrocatalysis activities of the local active sites.