Preparation of Porous Graphene@Mn₃O₄ and Its Application in the Oxygen Reduction Reaction and Supercapacitor

Abstract

Porous graphene has been recognized as a promising material for applications in electrochemical applications. Engineering the porous graphene-based hierarchical and hybrid structures is a promising way to further improve the electrochemical performances. Here, we reported a rational design of the porous graphene@Mn3O4 (PGM) structure for the applications in both the oxygen reduction reaction (ORR) and supercapacitor. Thanks to the efficient porous graphene substrate and rational decoration of Mn3O4, the catalytic performance of as-prepared PGM is comparative to that of Pt/C when used as electrocatalysts for the ORR, showing a relatively positive onset and half-wave potential (0.89 and 0.81 V) and a large diffusion-limiting current density (5.85 mA cm–2). In addition, PGM also shows good specific capacitance (208.3 F g–1), cycle stability, and rate performance when used in the supercapacitor electrodes and asymmetric device (maximum energy density of 30.1 Wh kg–1 and power density of 9500 W kg–1).

In situ self‐template synthesis of cobalt/nitrogen‐doped nanocarbons with controllable shapes for oxygen reduction reaction and supercapacitors

“…This is due to the short diffusion distance and the fast mass transfer rate of oxygen. Moreover, the good parallel linearity of the Koutecky‐Levich (K‐L) plots indicates first‐order reaction kinetics with respect to the concentration of dissolved O 2 . The electron transfer number (n) and hydrogen peroxide yield were analysed by producing a K‐L plot (Figure F).…”

“…Moreover, the good parallel linearity of the Koutecky-Levich (K-L) plots indicates first-order reaction kinetics with respect to the concentration of dissolved O 2 . 47 The electron transfer number (n) and hydrogen peroxide yield were analysed by producing a K-L plot ( Figure 6F). The values of n were 3.7, 3.9, and 4.3 for Co/N-CMS, Co/N-CLPC, and N-CMS, respectively, at 0.7 V. The values for Co/N-CLPC and Co/N-CMS are close to the theoretical values.…”

Facile Synthesis of MOF‐derived Mn3O4@N‐doped Carbon with Efficient Oxygen Reduction

“…Cai and co‐authors have presented nano‐engineered directed growth of Mn 3 O 4 quasinanocubes on N‐doped polyhedrons derived from ZIF‐8, which exhibits good oxygen reduction activity . Huang and co‐authors have described the preparation of porous graphene@Mn 3 O 4 hybrid materials with great potential in catalyzing oxygen reduction and supercapacitors . Hu's research group has reported highly efficient Mn 3 O 4 ‐decorated N‐doped carbon electrocatalysts towards oxygen reduction, which were constructed by pyrolyzing mixture of carbon black, MnCl 2 , cyanamide, and dopamine …”

Top-down synthesis of sponge-like Mn3O4at low temperature

“…Considerable interest has been paid to synthesizing Mn 3 O 4 nanostructures, 11,12 for instance, nanoparticles, [13][14][15][16] nanorods, 17,18 nanowires or nanobers, 19,20 nanoplates, 21 superlattices 22 and hierarchical nanostructures. [23][24][25][26][27][28] Among these, hierarchical Mn 3 O 4 nanostructures take advantage of both nanometer-sized building blocks and micro-sized assemblies. Hierarchical Mn 3 O 4 nanostructures with remarkably increased surface areas are expected to display better performance in applications as rechargeable lithium ion batteries, supercapacitors and active catalysts.…”

“…The bottom-up approach, which has been extensively researched over the past decade, assembles the nanometersized building blocks to hierarchical structures with the help of structural directing agents. 23,25,26 However, the bottom-up approach may be quite complex and the controlled-synthesis of hierarchical structures may be difficult. On the other hand, top-down fabrication offers a greater exibility and controllability, and it is much more suitable for the production of hierarchical structures.…”