Graphene-Loaded Bimetallic Oxide Nanoparticle Oxygen Electrode Materials for Rechargeable Zinc–Air Batteries

Currently, precious metal catalysts Pt/C and RuO2/IrO2 are considered efficient catalysts for oxygen reduction reaction (ORR). However, their high cost, scarcity, and poor stability hinder their wide application. Therefore, a simple method to prepare bimetallic oxide nanoparticles as electrodes instead of precious metals is of significant importance for electrocatalysis at present. Here, we use graphene nanosheets as carbon precursors, which can exhibit excellent ORR performance by taking advantage of the empty orbitals of the samarium f-layer, which will result in a high specific surface area due to the use of templates. Therefore, in the preparation process, samarium oxide- and iron oxide-encapsulated nanosheets are formed from samarium and iron coordination polymers, respectively. Moreover, the specific Brunauer–Emmett–Teller effective active sites and the synergistic interaction between samarium oxide and iron oxide also promote ORR kinetics This novel rare earth transition-metal nanoparticle-encapsulated ORR catalyst with a conductive carbon matrix (SmFeOx@CN-5) is attractive for zinc–air battery applications.