Tuning Confined Nanospace for Preparation of N-doped Hollow Carbon Spheres for High Performance Supercapacitors.

Abstract

The structural parameters and surface functionalities of hollow carbon spheres are critical for their electrochemical performance. Herein, preparation of N-doped-hollow carbon spheres (N-HCS) with tunable structural parameters and surface properties is reported by using a confined pyrolysis strategy. Polystyrene/polyaniline (PSPAN) was pyrolyzed in a silica shell, which provided a confined nanospace. PSPAN functioned as both the core and a source of carbon and nitrogen. The surface properties and structural parameters of the obtained N-HCS could be optimized by regulating the pore size of the silica shell. The silica shell coating also prevented agglomeration of the N-HCS, leading to a regular and well-distributed spherical morphology. The N-HCS synthesized in relatively porous conditions had thinner shell, larger mesopore size, higher surface area, and higher nitrogen content and showed excellent electrochemical performance as a supercapacitor with a specific capacitance of 436.5 F g-1 at 0.5 A g-1 .