In Situ Synthesis of Ultrathin Graphene‐Like Nanosheets as a Highly Effective Oxygen Catalyst for Zinc−Air Batteries

Abstract

Two‐dimensional materials have large specific area, high electron transfer capability and abundant exposed active sites, which are beneficial to improve their catalytic properties. Here, we used a simple salt‐template method to construct ultrathin graphene‐like Fe/N−C nanosheets (named as Fe/GNS‐1.5). During the synthesis process, NaCl crystallite serves as a rigid template of two‐dimensional mesoscopic structure. Iron nitrate acts as a gas‐foaming agent, which plays pivotal part in the morphology and structure of catalysts. The obtained Fe/GNS‐1.5 nanosheets with a thickness of 3 nm have a large specific surface area (705 m2 g−1). Benefiting from the structure advantages, Fe/GNS‐1.5 exhibits a great bifunctional catalytic performance. The Fe/GNS‐1.5 catalyst is employed as air cathode of zinc−air battery to examine its practical application, which presents excellent power density (156 mW cm−2) and favorable cyclic stability for more than 600 cycles.

Metal–Nitrogen–Carbon Catalysts of Specifically Coordinated Configurations toward Typical Electrochemical Redox Reactions

“…Among them, transition metal-nitrogen-carbon (M-N-C) materials have gained the most intensive attention, attributable to its unique electronic structure and promising electrocatalytic activity. [1][2][3][4][5][6] Since the first report on cobalt phthalocyanine as a highly active catalyst for ORR in 1964 by Jasinski, a large number of studies have been made to construct highly efficient M-N-C catalysts, and significant progress has been achieved. [7][8][9][10][11][12][13][14][15][16][17][18][19][20] A major breakthrough, achieved by Yeager and co-workers, reveals that these costly macrocycles can be substituted by individual precursors of metal and nitrogen.…”

Hollow Mesoporous Carbon Nanospheres Decorated with Metal Oxide Nanoparticles as Efficient Earth‐Abundant Zinc‐Air Battery Catalysts

“…Heteroatom-doped carbon nanomaterials such as Ndoped hollow mesoporous carbon nanospheres (HMC) and Fe/ N-doped graphene nanosheets have shown excellent catalytic activities toward ORR and OER. [18,19] Transition metal oxides, phosphates and sulfides have also exhibited promising performance in Zn-air batteries. [20][21][22][23][24][25] In addition, a variety of metal oxide nanoparticles have been interfaced with HMC with varying degrees of success.…”

“…Of late, a variety of materials have been investigated as alternative catalysts. Heteroatom‐doped carbon nanomaterials such as N‐doped hollow mesoporous carbon nanospheres (HMC) and Fe/N‐doped graphene nanosheets have shown excellent catalytic activities toward ORR and OER [18,19] . Transition metal oxides, phosphates and sulfides have also exhibited promising performance in Zn‐air batteries [20–25] .…”