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The boron doped carbon nanomaterials that include in-plane B–C bonds at the local structure are considered as an efficient electrocatalyst for oxygen reduction reaction (ORR). However, a fundamental understanding about the electrocatalytic activity of out-of-plane B–C bonds remains unclear. Herein, we synthesize a boron nanosheet/reduced graphene oxide (B@rGO) heterostructure, where out-of-plane B–C chemical bonds are formed at the heterointerfaces, greatly improving the ORR activity. As verified by the combined experimental analyses and theoretical calculations, the ORR activity is boosted because the out-of-plane B–C chemical bonds contribute to the cleavage of O–O bond of O 2 * intermediate. The B@rGO heterostructure composite exhibits much higher ORR activity than those of respective boron and rGO nanosheets as demonstrated by half-wave potential, Tafel slope, electron transfer number, and electrochemical active area, achieving better durability and methanol tolerance than the commercial 20 wt% Pt/C catalyst. In this context, primary Zn–air battery, using the as-synthesized B@rGO heterostructure composite as metal-free electrocatalyst, delivers high peak power density of 131 mW cm−2 and specific capacity of 639.3 mAh g Zn −1. • Boron nanosheet/reduced graphene oxide heterostructure is constructed. • The out-of-plane B–C chemical bonds are formed at the heterointerfaces. • The ORR activity is boosted by the out-of-plane B–C bonds. • B@rGO heterostructure achieves high ORR activity and durability. • The Zn–air battery delivers a high power density of 131 mW cm−2. [ABSTRACT FROM AUTHOR]

Density functional theory calculations were carried out to study how the position of single-atom doping affects the electronic properties of three graphyne models. We found that the position of the dopant (B, N, or O) plays an important role in tuning the electronic structure of graphynes. For α-graphyne, the electronic structure is significantly different for different positions of B and O doping. For β-graphyne, the electronic structure depends remarkably on the doping position for O doping, but not much for B and N doping, whereas for γ-graphyne, it depends on the position for B and O doping, but not for N doping. [ABSTRACT FROM AUTHOR]