Construction of Fe₂O₃@CuO Heterojunction Nanotubes for Enhanced Oxygen Evolution Reaction

Delicate design and controllable fabrication of efficient oxygen evolution reaction (OER) electrocatalysts based on earth-abundant elements is a highly desired yet challenging task. Herein, Fe2O3@CuO core–shell nanotube heterostructure in situ grown from copper foam (denoted as Fe2O3@CuO NTs/CF) was first synthesized as an efficient OER electrocatalyst. It has been demonstrated that the unique nanotube morphology provided large electrochemical surface area. Moreover, the electron transfer between Fe2O3 and CuO (electronic interaction) within the heterojunction tuned the electronic structure of Cu and Fe sites which not only improved the electron transfer efficiency but also changed the rate-determining step of OER compared with Fe2O3 or CuO, leading to an enhanced OER kinetics (Tafel slope of 41.07 mV dec–1). Benefiting from the structure engineering and electronic modulation, Fe2O3@CuO NTs/CF exhibits an improved activity with 398 mV overpotential at 100 mA cm–2. This work supplies an efficient strategy for fabricating heterostructure catalyst with tubular morphology and modified electronic structure for OER and other electrochemical applications.