Graphene-supported iron-based nanoparticles encapsulated in nitrogen-doped carbon as a synergistic catalyst for hydrogen evolution and oxygen reduction reactions

Abstract

Electrolyzers and fuel cells have been extensively investigated as promising solutions for renewable energy storage and conversion. Hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) are important electrocatalytic processes in electrolyzers and fuel cells. Exploring efficient non-precious metal catalysts for HER and ORR in acidic medium remains a great challenge. Herein, we report that graphene-supported iron-based nanoparticles encapsulated in a nitrogen-doped carbon (Fe@N-C) hybrid material acts as an efficient HER and ORR catalyst. The hybrid material was synthesized by pyrolysis of graphene oxide and ammonia ferric citrate followed by acid-leaching. During the pyrolysis, nitrogen was doped into a graphene lattice, and the carbon nanoshell grown on graphene effectively suppressed the stacking of graphene sheets, exposing more active sites to reactants. The hybrid material showed higher electrocatalytic activities than graphene sheets or Fe@N-C alone, which is probably attributed to the synergetic role of nitrogen-doped graphene and Fe@N-C towards the electrocatalytic reactions.

Morphological Studies on the Agglomeration of FeCo Supported Nitrogen-doped Reduced Graphene Oxide Catalyst Prepared at Varying Annealing Temperature

“…Carbon materials as support have gained great interest with various modifications in order to prepare support with the higher specific surface area thus enhance the fuel cell performance. The most popular approach recently is to develop Fe-and Co-based nitrogen (N)-containing complexes supported on carbon materials through annealing method (Chen et al 2015;Fu et al 2013;Ghanbarlou et al 2015;Jiang et al 2013;Peng et al 2013;Wang et al 2015;Wu et al 2011;Xie et al 2014).…”

High‐Performance Hydrogen Evolution from MoS2(1–x)Px Solid Solution

“…The HER activity of the solid solution can be further improved by increasing the surface area, such as employing MoS 2 nanoparticles as precursor, or adding carbon black as a substrate. We note that there is still room for additional enhancement of the solid solution, such as manipulating with smaller sizes of MoS 2 precursor and using high‐surface‐area heteroatom‐alloyed carbon support . The formation of a solid solution leads to an increase in surface roughness and ECSA of the materials.…”

Graphene-Based Catalysts for Hydrogen Evolution Reaction

“…encapsulated CoNi and RuCo nanoalloys have been reported to have a high HER activity due to the thin nitrogen-doped graphene layer protecting the alloy from corrosion and simultaneously promoting the electron penetration of the transition metals to the carbon surface [19,23]. A similar synergistic effect has been shown for iron nanoparticles [24].…”