One-pot hydrothermal synthesis of Zinc ferrite/reduced graphene oxide as an efficient electrocatalyst for oxygen reduction reaction.

Abstract Fabrication of low-cost and efficient electrocatalyst for oxygen reduction reaction (ORR) is highly desirable. Herein, Zinc ferrite/reduced graphene oxide (ZnFe 2 O 4 /rGO) is prepared by a quite simple and environmentally benign approach and applied as a high performance ORR electrocatalyst for the first time. The surface morphology and chemical composition of ZnFe 2 O 4 /rGO are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis and Fourier transform infrared spectroscopy. Cyclic voltammetry, linear sweep voltammetry and chronoamperometry are used to evaluate the electrochemical activities and stabilities of ZnFe 2 O 4 /rGO catalysts in alkaline media. Among ZnFe 2 O 4 /rGO with different mass ratios, the catalyst with 69.8 wt% ZnFe 2 O 4 (called ZnFe 2 O 4 /rGO (3)) has the best catalytic activities and it shows much superior methanol tolerance and better durability than the commercial Pt/C catalyst. Due to the synergistic effect, the ZnFe 2 O 4 /rGO (3) nanohybrid exhibits high ORR catalytic performance and durability, which follows a desirable four electron transfer mechanism in alkaline media. Therefore, it may be a highly competitive catalyst for fuel cells and metal-air batteries.