NiCo-Se nanoparticles encapsulated N-doped CNTs derived from prussian blue analogues for high performance supercapacitors

Abstract

Herein, N-doped carbon nanotubes (CNTs) encapsulating NiCo-Se nanoparticles (NPs) are assembled to spheres (NCNTs/NiCo-Se), which are successfully synthesized by using Ni-Co prussian blue analogues (PBAs) as templates and precursors. It is rare to derive CNTs from PBAs by means of C3H6 among the reported work and the structure evolution of NCNTs spheres derived from PBAs is exhibited. The high flow rate of N2 and C3H6 tend to cause short CNTs and large diameter of CNTs, respectively, owing to the dual-effect of diffusion and deposition of C atoms. Due to the advantage superposition of CNTs with high length-diameter ratio and NiCo-Se NPs, NCNTs/NiCo-Se gets excellent capabilities of charge transfer, diffusion efficiency, and electrochemical reactions. When the C3H6/N2 is 0.2/0.3 L min−1, the as-fabricated NCNTs/NiCo-Se deliver a substantially appreciable specific capacitance of 171.1 mAh g−1 (current density of 1 A g−1). The asymmetric supercapacitor (ASC) yields a maximum energy density of 55 Wh kg−1 at a power density of 801 W kg−1. In general, this work offers an attractive route to synthesize CNTs composites from PBAs.