One-step construction of hollow hybrid carbon spheres embedded with ultrafine Nb2O5

Abstract

Rational construction of well-dispersed nanoparticles embedded in hollow carbons is of great significance for maximizing the active site utilization while maintaining durability. However, typical synthetic approaches mainly depend on template-assisted-etching strategies, which are tedious with multistep procedures and inadequate to control the spatial distribution, impeding their widespread applications. Herein, an elaborate one-step aqueous assembling strategy is proposed to integrate the hollow cavity formation and nanoparticle embedding, in which the copolymerization of aniline and pyrrole at micelle interfaces creates the hollow cavity, while the concurrent ammonium niobate oxalate chelating with aniline allows for orientated-anchoring within the shell. Hollow hybrid carbon spheres with around 5 nm Nb2O5 nanoparticles embedded in the shell and controlled porosity are fabricated upon manipulated pyrolysis process. As a proof-of-concept application, the lithium-sulfur batteries performance using these materials as sulfur host are preliminarily investigated. The present protocol opens up new avenues for the design and preparation of multiple-discrete materials.