Abstract Designing and developing highly active and stable non‐precious metal electrocatalysts for the acidic oxygen evolution reaction (OER) is a key issue in realizing the widespread application of proton exchange membrane water electrolyzers (PEMWEs). Spinel‐type Co 3 O 4 has been considered a potential candidate due to its competitive activity for acidic OER; however, its inferior stability hinders its practical deployment. On the other hand, MnO 2 has garnered significant attention due to its excellent resistance to dissolution and self‐healing properties in acidic electrolytes. Therefore, we herein report to enhance the activity and stability of acidic OER by interfacial engineering to construct a heterostructure between Co 3 O 4 and MnO 2 (Co 3 O 4 /MnO 2 ). As a result, Co 3 O 4 /MnO 2 exhibits efficient activity with a current density of 100 mA cm −2 at an overpotential of 460 mV and fast kinetics (with a Tafel slope of 62.8 mV dec −1 ) for acidic OER. Meanwhile, the as‐prepared heterostructure displays high stability toward acidic OER with maintaining the current density of 10 mA cm −2 for over 60 h. Detailed characterizations as well as electrochemical in situ spectroscopies reveal that the transfer of electrons across the heterointerfaces enhances the faster lattice‐oxygen‐mediated mechanism (LOM) pathway, ultimately facilitating the acidic OER process.
Wang et al. (Sun,) studied this question.