A space-sacrificed pyrolysis strategy for boron-doped carbon spheres with high supercapacitor performance

[Display omitted] •B-doped carbon spheres are prepared by a space-sacrificed pyrolysis strategy.•The surface area and boron content can been regulated by triphenyl borate.•High boron content with uniform boron atomic distribution are achieved.•The B-doped carbon spheres show high thermal oxidation stability.•The B-doped carbon spheres exhibit high supercapacitor performance. Targeting the potential application of morphological carbon in electrode materials, a space-sacrificed pyrolysis strategy was applied for the preparation of boron-doped carbon spheres (B-CSs), using commercial triphenyl borate (TPB) as carbon and boron co-source. The unique structure of TPB play an important role in the sacrificed space, and has notable effect on the surface area of B-CSs. The as prepared B-CSs possess a high surface area and boron content with uniform boron atoms distribution and high surface polarity, which contributes to the improvement of pseudo-capacitance. The sizes, specific surface areas, and boron contents of B-CSs can be easily regulated by varying the experimental parameters. The optimal sample has a boron content of 1.38 at%, surface area of 560 m2 g−1 and specific capacitance of 235F g−1. We can believe that this work would provide a flexible and extensible preparation technique of B-CSs for electrochemical applications.