Understanding the synergetic interaction within α-MoC/β-Mo2C heterostructured electrocatalyst

Constructing heterostructure is an important strategy to design efficient electrocatalysts. The synergetic interaction between dissimilar materials has been considered as the origin of the activity enhancement, however, the interfacial interaction is challenging to probe, thus, the underlying mechanism remains obscure. Here, we reported a heterostructured α-MoC/β-Mo2C electrocatalyst for hydrogen evolution in alkaline media, which shows a significant electrocatalytic activity improvement as compared to the single component. Based on extensive characterizations including high-resolution transmission electron microscopy and X-ray absorption fine structure (XAFS) spectroscopy, together with density functional theory, we unraveled the synergetic interaction between α-MoC and β-Mo2C, implying that α-MoC sites are beneficial for water dissociation and hydrogen prefers to release on β-Mo2C sites.