Hierarchical construction of 3D binder-free NiMoO/CoFeO/NF arrays to enhance water splitting and charge-storage efficiency.

Developing inexpensive, highly active, robust bi-functional electrocatalysts for energy conversion and storage technology remains a vital challenge. Herein, we hierarchically constructed 3D binder-free NiMoO/CoFeO/NF heterostructure material via an effective and facile two-step hydrothermal process. The strong electronic coupling among NiMoO and CoFeO counterparts alternates the charge environment at the NiMoO/CoFeO interface, which builds the highway for a rapid and continuous charge transfer process.