Interface engineering of Co3O4—SmMn2O5 nanosheets for efficient oxygen reduction electrocatalysis

Interface engineering is an efficient strategy to modify electronic structure and further improve electrocatalytic activity. Herein, crystalline/amorphous heterostructured Co 3 O 4 -SmMn 2 O 5 nanosheets (Co 3 O 4 -SMO NSs) have been synthesized by coupling of SMO (electron acceptor) with higher Fermi-level Co 3 O 4 (electron donor), via a one-step hydrothermal method followed by calcination. The resulting Co 3 O 4 -SMO NSs display higher half-wave potential and specific activity than those of pure SMO or Co 3 O 4 . In addition, Co 3 O 4 -SMO NSs exhibit superior stability and methanol tolerance. The crystalline/amorphous heterostructure and the electron interaction between SMO and Co 3 O 4 result in interfacial charge transfer. This leads to more active valence states and more oxygen vacancies, optimizing the adsorption energy of O species and expediting electron migration, thus boosting oxygen reduction reaction (ORR) catalytic performance. This study provides a promising strategy to design efficient ORR electrocatalysts by interfacial engineering.