Structural characterization and electrochemical performance of macroporous graphite-like C3N3 prepared by the Wurtz reaction and heat treatment

Abstract

Macroporous graphite-like C₃N₃ (g-C₃N₃) with s-triazine rings as building blocks was synthesized by the Wurtz reaction of C₃N₃Cl₃ with sodium in autoclaves. The structure and electrochemical performance as a lithium ion battery anode of the obtained samples were then investigated. Structural characterization results reveal that the as-prepared samples show characteristic 002 basal plane diffractions and s-triazine rings structures with an N/C atomic ratio of about 1 : 1, indicating that the theoretical g-C₃N₃ has been successfully prepared. It was found that the heat treatment can help improve the initial coulombic efficiency and reversible capacity due to the decrease of the nitrogen content and the partial degradation and rearrangement of triazine rings. When used as an anode for Li-ion batteries, the g-C₃N₃ formed by heat treatment up to 600 °C exhibits a relatively good reversible capability and cycling stability (197.8 mA h g⁻¹ at 100 mA g⁻¹), with measurements superior to those of reported bulk g-C₃N₄ and other graphite-like carbon nitride analogues.