Turning on electrocatalytic oxygen reduction by creating robust Fe-Nx species in hollow carbon frameworks via in-situ growth of Fe doped ZIFs on g-C3N4
Iron-nitrogen-carbon (Fe-N-C) electrocatalysts have been demonstrated as hopeful candidates to substitute for conventional Pt/C electrocatalysts in oxygen reduction reaction (ORR) due to the benefits of high-efficiency and affordable-price. Unfortunately, Fe is prone to aggregate at high-temperature treatment, which may cover up the Fe-Nx species active sites and further affect ORR performance. Thus, the key issue is to avoid the Fe aggregation and keep it uniformly dispersed as much as possible. In this work, Fe-N-C catalysts with robust Fe-Nx species in hollow carbon frameworks were created via in-situ growth of Fe doped Zn based zeolitic imidazolate frameworks (ZIFs) on g-C3N4 with the subsequent pyrolysis treatment. The developed catalysts demonstrates superb ORR activity, high resistance to methanol and ultralong stability as compared with traditional Pt/C catalysts in alkaline solution. The talented performance is profiting from the firm connection and robust structure of best Fe-Nx species homogeneously dispersed in the hollow carbon frameworks. This work presents a facile and reasonable strategy for the development of excellent ORR electrocatalysts.