The selective formation of graphene ranging from two-dimensional sheets to three-dimensional mesoporous nanospheres

This research presents a template-free solvothermal method which offers selective preparation of graphene ranging from two-dimensional sheets to 3-dimensional nanospheres. The thus prepared nanospheres have size-defined mesopores with a huge surface area and, after doping with nitrogen, exhibited stronger electrocatalytic activity toward oxygen reduction than commercial Pt/C catalysts.