3D Nitrogen-Doped Graphene Aerogel-Supported Fe₃O₄ Nanoparticles as Efficient Electrocatalysts for the Oxygen Reduction Reaction

Abstract

Three-dimensional (3D) N-doped graphene aerogel (N-GA)-supported Fe(3)O(4) nanoparticles (Fe(3)O(4)/N-GAs) as efficient cathode catalysts for the oxygen reduction reaction (ORR) are reported. The graphene hybrids exhibit an interconnected macroporous framework of graphene sheets with uniform dispersion of Fe(3)O(4) nanoparticles (NPs). In studying the effects of the carbon support on the Fe(3)O(4) NPs for the ORR, we found that Fe(3)O(4)/N-GAs show a more positive onset potential, higher cathodic density, lower H(2)O(2) yield, and higher electron transfer number for the ORR in alkaline media than Fe(3)O(4) NPs supported on N-doped carbon black or N-doped graphene sheets, highlighting the importance of the 3D macropores and high specific surface area of the GA support for improving the ORR performance. Furthermore, Fe(3)O(4)/N-GAs show better durability than the commercial Pt/C catalyst.

Graphene-based transition metal oxide nanocomposites for the oxygen reduction reaction

“…The synergetic promotion of chemical coupling effects between graphene sheets and metal oxides has great influence on the electrocatalytic activities of ORR. [40][41][42] The synthesis of 3D Fe 3 O 4 /N-doped graphene (N-graphene) hybrids through hydrothermal self-assembly, freeze-drying and pyrolysis exhibited excellent electrocatalytic activity for the ORR in alkaline electrolytes 43 such as a lower onset potential, higher current density, lower H 2 O 2 generation with electron transfer number (∼4), and better durability. Fig.…”

“…Co 3 O 4 /graphene, 55 MnCo 2 O 4 /N-rGO, 56 FeO x /graphene 15,41,43,45,48 CuO/N-rGO, 74 and TiO 2 -FGSs 77 nanocomposites were proven to have comparable ORR activity, long catalytic stability, and better tolerance to methanol crossover and CO poisoning compared with commercial Pt/C. The strong and intimate electrical and chemical couplings between transition metal oxide nanoparticles and graphene can promote the charge transfer between interfaces and molecules.…”

Promotion of oxygen reduction by a bio-inspired tethered iron phthalocyanine carbon nanotube-based catalyst

“…Although Pt and its alloys are known as the most efficient catalysts for activation of the strong oxygenoxygen double bond [3][4][5] , their application is limited by high costs and scarce reserves. To overcome this problem, low-cost, nonprecious metal catalysts have attracted much attention in the search for an alternative catalyst for a new generation of fuel cells and metal-air batteries [6][7][8][9][10][11][12] . Among the non-precious catalysts studied, Fe-N-C catalysts have attracted the most interest owing to their low-cost and facile preparation methods 13,14 .…”

Two-dimensional NiCo2O4nanosheet-coated three-dimensional graphene networks for high-rate, long-cycle-life supercapacitors

“…Although high-capacitance pseudocapacitors have been achieved using pseudocapacitive materials as electrodes, they normally suffer from low power density and unstable cycling performance because of their intrinsically low electrical conductivity. [20][21][22] Due to their high porosity, large internal surface area, and outstanding electrical and mechanical properties, 23,24 three-dimensional graphene networks (3DGNs) serve as a striking platform for construction of composite electrodes with enhanced properties for wide applications, such as supercapacitors, 20,[24][25][26][27][28] Li-ion batteries, [29][30][31][32] catalysis, [33][34][35] and sensors. 26,36 Particularly, supercapacitors constructed from 3DGN based-materials have been studied to achieve enhanced electrochemical performances including higher specific capacitance, better rate capability and longer cycle life.…”