Corresponding Author

Yao Zhou(zhouy@xmu.edu.cn)


Oxygen reduction reaction (ORR) plays a profound role in determining cathode performance in metal-air batteries and fuel cells. Owing to its inherently sluggish kinetics, high-performance ORR catalysts which favors the scissoring of O-O bond and formation of O-H bond are a requisite. In this regard, Pt has been explored as the most efficient ORR electrocatalysts. Nevertheless, due to its expensiveness, the usage of Pt catalysts represents one of the major sources of cost in those energy conversion devices. Thus, the development of alternative ORR electrocatalysts with minimized Pt utilization has been widely pursued over the past few decades. Metal-nitrogen-carbon catalysts are expected to replace traditional commercial Pt-C and become a new generation of ORR electrocatalyst. In this paper, using a commercial chain hollow carbon nanosphere (ECP-600JD) with high specific surface area and high conductivity as carbon source and template, Fe2O3@Fe-N-C nanocomposite was prepared by a straightforward one-step pyrolysis method as a high-performance ORR electrocatalysts in alkaline media, and its structural characteristics and catalytic performance have been systematically studied. Such a nanocomposite was characterized with large external surface area (467.8 m2·g-1), high electronic conductivity, as well as the co-existence of Fe-Nx active sites and Fe2O3 nanoparticles. Owing to its compositional and structural merits, the optimal Fe2O3@Fe-N-C catalyst showed good ORR activity in 0.1 mol·L-1 KOH solution, with its half-wave potential being 0.84 V. When used in zinc-air batteries, the open circuit voltages of the battery assembled by Fe2O3@Fe-NC-1000 and Pt-C were 1.51 V and 1.42 V, respectively. It also demonstrates better rate performance than Pt-C, which can be attributed to the large specific surface area that can provide excellent mass transfer ability under high current density, and its own excellent electrical conductivity was also extremely important. According to the mass of zinc consumed, the specific capacity of the zinc-air battery was calculated, and the specific capacity of the battery assembled with Fe2O3@Fe-NC-1000 could reach 776.8 mAh·gZn-1, while the specific capacity of Pt-C under the same conditions was 691.9 mAh·gZn-1. The polarization curve and power density of the catalyst were also obtained. The peak power density of zinc-air battery with Fe2O3@Fe-NC-1000 as the cathode reached 88.3 mW·cm-2, while the peak power density of the battery with Pt-C as the cathode was 76.8 mW·cm-2. Our research provides a straightforward and easily scalable approach towards the pursuit of high-performance ORR electrocatalysts.

Graphical Abstract


hollow carbon nanosphere, Fe-N-C, Fe2O3, oxygen reduction reaction, zinc-air battery

Publication Date


Online Available Date


Revised Date


Received Date



[1] Debe M K. Electrocatalyst approaches and challenges for automotive fuel cells[J]. Nature, 2012, 486(7401): 43-51.
doi: 10.1038/nature11115 URL

[2] Zhao Z Q, Fan X Y, Ding J, Hu W B, Zhong C, Lu J. Challenges in zinc electrodes for alkaline zinc-air batteries: obstacles to commercialization[J]. ACS Energy Lett., 2019, 4(9): 2259-2270.
doi: 10.1021/acsenergylett.9b01541 URL

[3] Jiang M, Fu C P, Yang J, Liu Q, Zhang J, Sun B D. Defect-engineered MnO2 enhancing oxygen reduction reaction for high performance Al-air batteries[J]. Energy Storage Mater., 2019, 18: 34-42.

[4] Wang Z L, Xu D, Xu J J, Zhang X B. Oxygen electrocatalysts in metal-air batteries: from aqueous to nonaqueous electrolytes[J]. Chem. Soc. Rev., 2014, 43(22): 7746-7486.
doi: 10.1039/C3CS60248F URL

[5] Parvez K, Yang S B, Hernandez Y, Winter A, Turchanin A, Feng X L, Mullen K. Nitrogen-doped graphene and its iron-based composite as efficient electrocatalysts for oxygen reduction reaction[J]. ACS Nano, 2012, 6(11): 9541-9550.
doi: 10.1021/nn302674k URL

[6] Xiao J W, Xu Y Y, Xia Y T, Xi J B, Wang S. Ultra-small Fe2N nanocrystals embedded into mesoporous nitrogen-doped graphitic carbon spheres as a highly active, stable, and methanol-tolerant electrocatalyst for the oxygen reduction reaction[J]. Nano Energy, 2016, 24: 121-129.
doi: 10.1016/j.nanoen.2016.04.026 URL

[7] Zhong G Y, Wang H J, Yu H, Peng F. Nitrogen doped carbon nanotubes with encapsulated ferric carbide as excellent electrocatalyst for oxygen reduction reaction in acid and alkaline media[J]. J. Power Sources, 2015, 286(15): 495-503.
doi: 10.1016/j.jpowsour.2015.04.021 URL

[8] Li Z L, Li G L, Jiang L H, Li J L, Sun G Q, Xia C G, Li F W. Ionic liquids as precursors for efficient mesoporous iron-nitrogen-doped oxygen reduction electrocatalysts[J]. Angew Chem. Int. Ed., 2015, 54(5): 1494-1498.
doi: 10.1002/anie.201409579 URL

[9] Dhavale V M, Singh S K, Nadeema A, Gaikwad S S, Kurungot S. Nanocrystalline Fe-Fe2O3 particle-deposited N-doped graphene as an activity-modulated Pt-free electrocatalyst for oxygen reduction reaction[J]. Nanoscale, 2015, 7(47): 20117-20125.
doi: 10.1039/C5NR04929F URL

[10] Niu W H, Li L G, Liu X J, Wang N, Liu J, Zhou W J, Tang Z H, Chen S W. Mesoporous N-doped carbons prepared with thermally removable nanoparticle templates: an efficient electrocatalyst for oxygen reduction reaction[J]. J. Am. Chem. Soc., 2015, 137(16): 5555-5562.
doi: 10.1021/jacs.5b02027 URL

[11] Zang Y P, Zhang H M, Zhang X, Liu R R, Liu S W, Wang G Z, Zhang Y X, Zhao H J. Fe/Fe2O3 nanoparticles anchored on Fe-N-doped carbon nanosheets as bifunctional oxygen electrocatalysts for rechargeable zinc-air batteries[J]. Nano Res., 2016, 9(7): 2123-2137.
doi: 10.1007/s12274-016-1102-1 URL

[12] Sun M, Dong Y Z, Zhang G, Qu J H, Li J H. α-Fe2O3 spherical nanocrystals supported on CNTs as efficient non-noble electrocatalysts for the oxygen reduction reaction[J]. J. Mater. Chem. A, 2014, 2(33): 13635-13640.
doi: 10.1039/C4TA02172J URL

[13] Schaefer Z L, Gross M L, Hickner M A, Schaak R E. Uniform hollow carbon shells: nanostructured graphitic supports for improved oxygen-reduction catalysis[J]. Angew Chem. Int. Ed., 122(39): 7199-7202.
doi: 10.1002/ange.201003213 URL

[14] Shen H J, Gracia-Espino E, Ma J Y, Zang K T, Luo J, Wang L, Gao S S, Mamat X, Hu G Z, Wagberg T, Guo S J. Synergistic effects between atomically dispersed Fe-N-C and C-S-C for the oxygen reduction reaction in acidic media[J]. Angew Chem. Int. Edit., 2017, 56(44): 13800-13804.
doi: 10.1002/anie.201706602 URL

[15] Jiang W J, Gu L, Li L, Zhang Y, Zhang X, Zhang L J, Wang J Q, Hu J S, Wei Z, Wan L J. Understanding the high activity of Fe-N-C electrocatalysts in oxygen reduction: Fe/Fe3C nanoparticles boost the activity of Fe-Nx[J]. J. Am. Chem. Soc., 2016, 138(10): 3570-3578.
doi: 10.1021/jacs.6b00757 URL

[16] Guo D H, Shibuya R, Akiba C, Saji S, Kondo T, Nakamura J. Active sites of nitrogen-doped carbon materials for oxygen reduction reaction clarified using model catalysts[J]. Science, 2016, 351(6271): 361-365.
doi: 10.1126/science.aad0832 URL

[17] Masa J, Xia W, Muhler M, Schuhmann W. On the role of metals in nitrogen-doped carbon electrocatalysts for oxygen reduction[J]. Angew Chem. Int. Ed., 2015, 54(35): 10102-10120.
doi: 10.1002/anie.201500569 URL

[18] Liu Y L, Xu X Y, Sun P C, Chen T H. N-doped porous carbon nanosheets with embedded iron carbide nanoparticles for oxygen reduction reaction in acidic media[J]. Int. J. Hydrogen Energ., 2015, 40(13): 4531-4539.
doi: 10.1016/j.ijhydene.2015.02.018 URL

[19] Hu Y, Jensen J O, Zhang W, Cleemann L N, Xing W, Bjerrum N J, Li Q F. Hollow spheres of iron carbide nanoparticles encased in graphitic layers as oxygen reduction catalysts[J]. Angew Chem. Int. Ed., 2014, 126(14): 3749-3753.
doi: 10.1002/ange.v126.14 URL

[20] Liang Y Y, Li Y G, Wang H L, Zhou J G, Wang J, Regier T, Dai H J. Co3O4 nanocrystals on graphene as a synergistic catalyst for oxygen reduction reaction[J]. Nat. Mater., 2011, 10(10): 780-786.
doi: 10.1038/nmat3087 URL



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.