Heterostructures Composed of N-Doped Carbon Nanotubes Encapsulating Cobalt and β-Mo2 C Nanoparticles as Bifunctional Electrodes for Water Splitting.

Herein, we demonstrate the use of heterostructures comprised of Co/β-Mo2 C@N-CNT hybrids for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in an alkaline electrolyte. The Co can not only create a well-defined heterointerface with β-Mo2 C but also overcomes the poor OER activity of β-Mo2 C, thus leading to enhanced electrocatalytic activity for HER and OER. DFT calculations further proved that cooperation between the N-CNTs, Co, and β-Mo2 C results in lower energy barriers of intermediates and thus greatly enhances the HER and OER performance. This study not only provides a simple strategy for the construction of heterostructures with nonprecious metals, but also provides in-depth insight into the HER and OER mechanism in alkaline solution.