Coral-Like 3D-Co Nanoflowers Anchored on Reduced Graphene Oxide for Enhancing Hydrogen Generation of NaBH4

Abstract

Sodium borohydride (NaBH₄) is recognized as an important material for hydrogen storage and transportation because of its extremely significant hydrogen storage capacity. However, achieving large-scale hydrogen generation via the hydrolysis of NaBH₄ requires efficient catalysts to enhance hydrogen evolution efficiency. In this study, a simple one-pot synthesis method was proposed to prepare 3D hierarchical flower-like materials composed of ultrathin cobalt based nanosheets（Co-3DHFLM） anchored on graphene oxide (GO), improving the dispersion of active cobalt sites. The yielded 3D-Co catalysts anchored on reduced graphene oxide (rGO) by high-temperature hydrogen reduction, can promote the structural rearrangement of active sites from planar nanoflowers to a more porous coral-like structure, thereby enhancing the stability and catalytic activity of the catalyst. Additionally, the effects of GO addition amounts and reduction temperatures on catalyst performance were systematically investigated. At a reduction temperature of 773 K, 3D-Co@rGO₁₅ catalyst achieved the hydrogen generation rate of 4251.1 mL·min^-1·g_Co^-1 at 303 K with an activation energy of 28.1 kJ·mol^-1. The results demonstrate that significant improvements in catalytic efficiency can be achieved by modulating the morphology and structure of the catalyst, providing new insights for the design of efficient composite catalysts.