Facile One-Pot Synthesis of α–MnO2/CeO2 Nanowires for Mg-Air Batteries

In this work, we synthesized MnO 2 /CeO 2 electrocatalysts by in situ decoration of α –MnO 2 with CeO 2 particles during a one-step hydrothermal process. The morphology, composition, and electrochemical properties were studied in the context of application to the oxygen reduction reaction (ORR) and Mg-air battery. According to the results, α –MnO 2 /CeO 2 microfibres exhibited better ORR performance than α –MnO 2 microfibres due to the synergistic result between the introduction of Ce 3+ in CeO 2 lattice and the enhancement of Mn 3+ content in MnO 2 lattice. α –MnO 2 /CeO 2 microfibres provided a higher surface area and more catalytic active sites than α –MnO 2 microfibres by controlling the molar ratio of Ce 3+ /Mn 7+ for the precursor. When the mole ratio of Ce 3+ and Mn 7+ in the precursors was 10%, the four-electron transfer process of the MnO 2 /CeO 2 microfibres (MC-140-12-10) was found to be similar to that of the 20 wt% Pt/C commercial catalysts. MC-140-12-10 microfibres also showed the excellent long-term stability after 25,000 s and superior Mg–air battery performances than α –MnO 2 . Hence, the work paves the way for developing Mg-air batteries through a simple synthesis and cost-effective ORR catalyst.