Facile preparation and properties of cubic TiN@CN nanocapsules as electrode materials for supercapacitors and as microwave absorbers

We adopted a facile method consisting of the arc discharge method combined with the in situ self-polymerization process to synthesize the cubic TiN@CN nanocapsules in this work, and we also investigated the electrochemical performance and microwave absorption properties of the TiN@CN nanocapsules in detail. The results show that the TiN@CN nanocapsules exhibit excellent electrochemical performance. The specific capacitance of the TiN@CN nanocapsules is 119 F g⁻¹ at 1 A g⁻¹, and their capacitance retention rate is 92% after 5000 cycles at the current density of 2 A g ⁻¹. Besides, the cubic TiN@CN nanocapsules also exhibit powerful microwave absorption capacity. The reflection loss (RL) below − 20 dB is achieved in a wide frequency range of 7.2–15.5 GHz with a thickness range of 1.1–2.3 mm, and the optimal RL value is − 40.6 dB at 10.6 GHz with a relatively thin thickness of 1.6 mm. Therefore, TiN@CN nanocapsules are promising and applicable as electrode materials for supercapacitors and as microwave absorbers.