Electrochemical Grafting of a Pyridinium-Conjugated Assembly on Graphite for H2O2 Electrochemical Production

Carbon materials have shown great promise as cost-effective electrocatalysts for H2O2 electrochemical production. In this work, we prepare a series of well-defined pyridinium-conjugated graphite sheets via nucleophilic substitution reaction of graphite with pyridine derivatives in anodic oxidation process. A combination of experimental and computational investigations confirm that the pyridine derivatives are electrochemically grafted onto the armchair-type edges of graphitic layers, where the adjacent carbon atoms show the positively charged state by the intramolecular charge transfer. The strong charge delocalization on pyridinium-conjugated graphite sheets leads to the enhanced electrocatalytic performance for oxygen reduction in terms of both activity and selectivity (above 97 %) for H2O2 production. Moreover, we find that the yield of H2O2 is also affected by the H2O2 decomposing capabilities of functional groups on pyridinium. As one kind of pyrolysis-free strategies, the proposed electrochemical grafting can serve as a molecularly precise regulation to develop nitrogen doped carbon materials for more applications.

Automated summary

In this work, well-defined pyridinium-conjugated graphite sheets were synthesized via electrochemical grafting, exhibiting enhanced electrocatalytic performance for oxygen reduction and high selectivity for H2O2 production. The positive charge on the adjacent carbon atoms, induced by intramolecular charge transfer, leads to the improved catalytic activity. The functional groups on pyridinium also affect the yield of H2O2. The proposed electrochemical grafting provides a pyrolysis-free strategy for precise regulation of nitrogen-doped carbon materials and has great potential for various applications.