| 초록 |
Five types of C3N4 structures including alpha-, beta-, cubic-, pseudocubic- and graphitic-C3N4 have been known so far. Among them, the graphitic carbon nitride (g-C3N4) has attracted significant research interest due to its huge potential as photocatalysts for hydrogen production from water. In contrast to this, the potential of g-C3N4 as active materials for electrochemical energy storage and conversion has not been significantly considered due to its poor electronic conductivity. We have studied on electrochemical properties of carbon nitrides by engineering chemical composition and core structure. Although stabilizing high content of nitrogen in a carbon nitride framework is not favourable in terms of thermodynamics, we were successful in synthesizing nitrogen-rich carbon nitrides with triazole-based frameworks by adopting a novel precursor of 5-amino-1H-tetrazole. Interestingly, the electrochemical performances of the triazole-based carbon nitrides in both lithium-ion batteries and oxygen reduction reactions are improved as nitrogen content in the carbon nitrides increases. DFT calculations prove that the triazole moiety in the nitrogen-rich carbon nitrides plays critical roles in electrochemical reactions of lithium-ion batteries and ORR. We believe that the triazole-based carbon nitrides would be emerging materials for not only electrochemical applications but also diverse applications of photocatalysis, sensing, and biotechnology. |
