Facile synthesis of three-dimensional platinum nanoflowers decorated reduced graphene oxide: An ultra-high performance electro-catalyst for direct methanol fuel cells

In this work, we demonstrate platinum (Pt) nanoflowers-reduced graphene oxide (rGO) composite as an efficient electrocatalyst for methanol oxidation reaction (MOR) in acidic medium. rGO was prepared by low-cost, eco-friendly hydrothermal method and electro-deposition of Pt yielded three-dimensional large area Pt nanoflowers distributed over and among thin rGO nanosheets, thereby preventing restacking of rGO sheets. The composite exhibited outstanding electro-catalytic activity (15.3 mA cm(-2)), stability with CO tolerance ability (I-f/l(b) = 6.99) which is, to the best of our knowledge, similar to 2.2 folds greater than other previously reported carbon nanomaterials based catalysts. Values of I-f, I-b, and I-f/l(b) ratio of Pt-rGO based electrode were 13.2, 5.2 and 2.55 folds higher than only Pt respectively, which are ascribed to higher surface area of Pt nanoflowers that offers multidimensional pathways for easy diffusion of methanol to Pt, more catalytic active sites and excellent utilization of Pt for MOR. The composite shows huge potential to be used as binder free, cost-effective and durable electrocatalyst for electrochemical sensing and DMFCs applications.