S1 | Page Layer-separated distribution of nitrogen doped graphene by wrapping on carbon nitride tetrapods for enhanced oxygen reduction reaction in acid medium Sreekuttan M. Unni a,b , Rajith Illathvalappil a , Pranav K. Gangadharan, a Siddheswar N. Bhange a and Sreekumar Kurungot a,b *. Experimental Graphene oxide (GO) synthesis: In a typical synthesis, a mixture of graphite flakes and potassium permanganate (KMnO 4 ) was slowly added to the 9:1 mixture of con. sulphuric acid (H 2 SO 4 ) and phosphoric acid (H 3 PO 4 ). The mixture was stirred for 12 h at 60 o C. After cooling to room temperature, deionised water (DI water) was added to dilute the mixture followed by the addition of 30% hydrogen peroxide (H 2 O 2 ) to remove unreacted manganese oxide. While adding the peroxide into the acid mixture, the original pink colour of the mixture turned to yellow. The resulting solution was washed several times with nitric acid (HNO 3 ), hydrochloric acid (HCl) and ethanol. pH of the solution was reduced using continuous washing with DI water till the pH reaches above 4. The resulting reddish brown viscous solution was washed with diethyl ether and kept for drying at a temperature of 60 o C in vacuum oven. Preparation of CN x wrapped nitrogen doped graphene (CNG): CNG with different NG loading was synthesised using a simple scalable approach. In a typical synthesis, washed melamine foam was dipped in the GO solution (4 mg/ml) followed by drying using an IR lamp. For different loading of GO in the melamine foam, the number of dipping was changed. Dried GO-melamine foam was annealed at 900 o C for 3 h in argon atmosphere. The Electronic Supplementary Material (ESI) for ChemComm. This journal is © The Royal Society of Chemistry 2014