02832nas a2200265   4500008004100000022001400041245012000055210006900175260000900244300001400253490000600267520190400273653002502177653001802202653001702220653003102237653003002268653002102298100002102319700002302340700003002363700001702393700002402410856013202434       2021                        eng d  a2574-096200aZinc-air batteries catalyzed using Co3O4 nanorod-supported N-doped entangled graphene for oxygen reduction reaction0 aZincair batteries catalyzed using Co3O4 nanorodsupported Ndoped   cMAY   a4570-45800 v43 a<p>The work reported here deals with the development of an efficient non-platinum electrocatalyst for electrochemical oxygen reduction reaction (ORR) through a sequential pathway involving hydrothermal treatment followed by freeze-drying to build the desired structural architecture of the catalyst. The designed catalyst (Co3O4/nitrogen-doped entangled porous 3D graphene (NEGF)), which contains Co3O4 nanorods anchored on the surface of three-dimensional (3D)-structured N-doped graphene, was found to display higher ORR activity during single-electrode testing and demonstrate a Zn-air battery (ZAB) system. Under the hydrothermal treatment at 180 degrees C, in the presence of ammonia, nitrogen was doped into the carbon framework of graphene, which subsequently formed a self-assembled entangled 3D structure of graphene after freeze-drying. The hydrothermal treatment and freeze-drying processes were found to play vital roles in tuning the morphological and structural features of the catalyst. The doped nitrogen, apart from its favorable contribution toward ORR, helped facilitate efficient dispersion of oxide nanorods on graphene. Co3O4/NEGF displayed remarkable ORR activity in 0.1 M KOH solution, as evident from the 60 mV onset potential shift compared to the state-of-the-art Pt/C catalyst and the Tafel slope value of 74 mV dec(-1) vs 68 mV dec(-1) for Pt/C. The ZAB fabricated by employing Co3O4/NEGF as the cathode catalyst was found to be an efficient competitor for the system based on the Pt/C cathode. This high performance has been credited to the controlled interplay of the governing factors such as the interfacial interactions leading to the efficient dispersion of metal oxide nanorods, increased catalyst surface area, the cooperative effect arising from the defects present in the N-doped porous 3D graphene, and the synergetic interactions operating in the system.</p>10acobalt-oxide nanorod10afreeze-drying10ahydrothermal10aN-doped entangled graphene10aoxygen reduction reaction10azinc-air battery1 aManna, Narugopal1 aSingh, Santosh, K.1 aKharabe, Geeta, Pandurang1 aTorris, Arun1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/zinc-air-batteries-catalyzed-using-co3o4-nanorod-supported-n-doped-entangled-graphene-oxygen