Rational design of graphene oxide and its hollow CoO composite for superior oxygen reduction reaction - Carbon4Energy

Graphene oxide (GO) is one important derivative of graphene, fascinating the whole world with its dazzling properties and versatile performance. Yet the chemical routes often show limited control on the density of functionalities and their distribution, forging a barrier in spreading GO’s applications. We modified Hummers’ method and aimed at controlling the oxygen functionality of GO. The modified synthetic GO (MdGO) finds their most oxygen content on edge regions and configuring the overwhelming presence of carboxyl groups which can be easily removed upon annealing. The excellence of high conductivity of intrinsic graphene can be thus recovered after the removal of the main functional groups. Resulted MdGO was reduced and doped by NH3, and reduced MdGO (rMdGO) was tested to be one excellent support for oxygen reduction reaction (ORR) electrocatalyst. As a demonstration, composite of CoO and N-rMdGO was fabricated and exhibiting highly comparable ORR performance in alkaline relative to 20 wt% Pt/C.