Functionalization of Graphite with the Diels–Alder Reaction to Fabricate Metal‐Free Electrocatalysts for Highly Efficient Hydrogen Evolution Reaction
A facile method was reported to produce a modified graphene via Diels‐Alder cycloaddition reaction with malemide and graphite precursors. Two procedures were used for the embedding of malemide functional groups on surface or edge of graphene; MI‐EGnPs (maleimide edge‐functionalized graphene nanoparticles) with the more edges functional groups and MI‐GnPs (maleimide functionalized graphene nanoparticles) with the more surface functional groups. In order to investigate the influence of functionalization on the electrochemical behavior of the modified graphene structures, the prepared materials were used as the metal‐free electrocatalysts for hydrogen evolution reaction (HER) in alkaline media. MI‐ EGnPs showed a Tafel slope of −110 mV dec−1 compared to −168 mV dec−1 for MI‐GnPs. The observed difference in the electrochemical performances of the samples were interpreted due to the connection places of functional groups.