Unlocking efficient urea oxidation via Built-in field modulation in NiFe2O4/CeO2 Mott–Schottky heterojunction

Interface engineering via the construction of heterojunctions to accelerate electron transfer is an effective strategy for enhancing electrocatalytic activity. This study designed and synthesized a NiFe 2 O 4 /CeO 2 Mott–Schottky (M–S) heterojunction for efficient urea oxidation reaction (UOR), which exhibits exceptional activity with a current density of 50 mA cm −2 at 1.40 V (vs. RHE). Spectroscopic analyses validate the formation of the M–S heterojunction, where a significant work function difference drives spontaneous electron transfer from NiFe 2 O 4 to CeO 2 through Ni–O–Ce bridge, thereby establishing a strong built-in electric field. This interfacial charge rearrangement precisely modulates the electronic structure of the Ni sites, enhancing initial urea adsorption and lowering the d -band center. ​​Such modulation weakens intermediate binding and reduces the energy barrier for the rate-determining CO 2 desorption step. The utility of NiFe 2 O 4 /CeO 2 is demonstrated through reduced energy consumption in hybrid water electrolysis ​​along with improved efficiency and longevity in urea-assisted zinc–air batteries. This study ​​elucidates​​ the effectiveness of M–S heterojunction engineering for developing highly efficient catalysts for advanced energy conversion and storage.