Electrochemical imaging correlated to hydrogen evolution reaction on transition metal dichalcogenide, WS2

Abstract

The ability of two-dimensional, layered transition-metal dichalcogenides (TMDs) to promote hydrogen evolution reaction (HER) has attracted much attention for hydrogen-generation applications. Their electrocatalytic active sites originally come from unique electronic properties at the edges. Here, we use scanning electrochemical cell microscopy (SECCM) to visualize and quantify the electrochemical HER activities of tungsten disulfide (WS2) islands. We show that the HER correlated current distribution is affected by the number of WS2 layers. SECCM imaging provides a direction for future designs in TMD-based electrocatalysts.