Efficient functionalization of reduced graphene oxide by 3-(pyridin-2-yl)-1,2,4,5-tetrazine and design of hybrids with silver nanoparticles for electrocatalysis

The efficiency of graphene functionalization by 3-(pyridin-2-yl)-1,2,4,5-tetrazine using inverse demand Diels-Alder reaction was investigated in comparison with the symmetrical 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine. Elemental compositions on the surface of functionalized graphene were analyzed by X-ray photoelectron spectroscopy (XPS), evidencing the higher amount of nitrogen when using the H-substituted tetrazine derivative. In a second step, silver nanoparticles were electrodeposited on these functionalized graphene sheets to enhance the electrocatalytic properties of graphene. The amount of silver determined by XPS increases with the amount of nitrogen introduced on graphene as it was intended for. The electrocatalytic properties have been assessed on the Oxygen Reduction Reaction (ORR), showing good performances in terms of ORR potential even with very small amounts of silver compared to previously reported data.