A facile and green route to prepare reduced graphene oxide (RGO) is reported. The graphite oxide is firstly pretreated by detonating exfoliation in muffle furnace at low temperature and then is completely reduced to RGO in hydrogen atmosphere at high temperature, namely two-step method. Extensive characterisations show that the as-prepared RGO with high ratio of C/O and surface area consists of crumpled and few-layer thick graphitic sheets. The RGO is used to electrocatalyse nitrobenzene (NB) to P-aminophenol (PAP). High catalytic activity and stability obtained in the electrochemical measurement indicate that the RGO could be a promising alternative catalyst toward the electroreduction of NB to PAP.