“…23 Based on their availability in nature and affordable cost, TMOs such as zinc, cobalt, iron, tin, nickel, manganese, and chromium oxide have been employed as alternative materials. [24][25][26] Many researchers have analyzed TMO-based GO composites such as ZnOÁrGO, 27 NiCoMnO 2 /N-rGO, 28 Cu 0.31 NiO 0.69 /rGO, 29 TiO 2 /rGO, 30 Ni-CeO 2 /rGO, 31 CoMoO 4 /rGO, 32 and CuO-NiO/ rGO 33 as electrocatalysts in ORR applications. As a result, the starting potential and current density of the composite materials increased due to the synergistic effect of TMO incorporation with rGO.…”