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Exploring an efficient strategy to enhance the catalytic oxygen reduction performance of carbon‐based catalysts is of great significance in the field of electrocatalysis. In this work, through a facile polymerization‐carbonization approach under the regulation of melamine, N,S‐codoped hierarchically porous carbon nanosheets with controllable morphology are fabricated by using polyaniline as the precursor. The resultant catalysts have favorable features of the synergetic effect of N,S co‐doping and the advanced structural property with high specific surface area and hierarchical pore structure, contributing to an encouraging onset potential (Eonset = 0.94 V) in alkaline media, comparable to that of Pt/C catalysts, as well as excellent electrochemical stability and methanol tolerance. By rationally adjusting the experimental parameters, the mechanism of melamine on the formation of final porous nanosheet structure during high‐temperature pyrolysis is clarified, and the optimal experimental conditions for the superior catalysts are also discussed. Furthermore, a rechargeable Zn‐air battery constructed with the resulting materials exhibits desirable performance with low charge‐discharge gap and impressive life‐span. This contribution would supply some novel inspiration to design carbon‐based materials with desired features for energy‐related technologies. [ABSTRACT FROM AUTHOR]

A "gas-breathing" integrated air diffusion electrode based on BN-C catalysts was prepared with improved oxygen utilization and transfer efficiency, achieving high-performance for Zn-air batteries even without external O 2 -pumping equipment. [Display omitted] • A "gas-breathing" integrated air diffusion electrode is designed for rechargeable Zn-air batteries. • B,N-codoped carbon catalysts exhibit efficient ORR and OER bifunctional activity. • The hydrophobic diffusion layer in air diffusion electrode assists high oxygen transfer and utilization efficiency. • Air diffusion electrode endows the constructed ZABs with high-current and long-cycle battery applications. • All solid-state ZABs based on BN/C-ADE with commendable flexibility and efficient charge–discharge property. Rechargeable Zn-air batteries (ZABs) are promising candidates for next-generation sustainable energy storage due to high theoretical energy density and inherent safety. For further practical applications, in addition to developing bifunctional cathode catalysts, there is still a significant performance bottleneck of poor oxygen utilization efficiency in conventional air cathodes, which is often overlooked. To address this problem, a novel "gas-breathing" integrated air diffusion electrode based on B,N-codoped carbon (BN-C/ADE) is designed, which combines gas-diffusion layers and catalyst layers into a single architecture. The hydrophobic diffusion layer with substantial channels promotes active diffusion of oxygen from air atmosphere to reaction interface without the need for an air pump. Consequently, compared with the conventional cathode, a reduced overpotential, higher power density (118.5 mW cm−2) and long lifespan (over 170 h) are obtained for liquid ZABs based on BN-C/ADE, even without external oxygen-pumping equipment, profiting from higher oxygen utilization and transfer efficiency. [ABSTRACT FROM AUTHOR]

The high-efficient and low-cost oxygen electrocatalysts are of significant importance but challenge in energy storage and conversion devices. The oxygen electrocatalysis involves triple-phase interfaces of solid catalyst, liquid electrolyte and gaseous oxygen. The reaction microenvironment in which the ample transmission pathway sufficiently feeds the highly active sites and expulses product rapidly is typically desired. Herein, the reaction interface microenvironment of hollow spherical bimetallic electrocatalyst (CoFe-SNC) is regulated via structural architecture engineering, achieving the ample triple-phase contact points of O 2 (gas), electrolyte (liquid) and electrocatalyst (solid). Sufficient O 2 supply and unimpeded mass transfer afforded by triple-phase interface flourish catalytic efficiency and enhance oxygen electrocatalysis. Simultaneously the incorporation of sulfur dopant improves the intrinsic catalytic activity, giving rise to highly active sites in reaction interface of CoFe-SNC. With such well-constructed triple-phase interface microenvironment, the CoFe-SNC shows outstanding oxygen reduction reaction activity (E 1/2 = 0.86 V vs RHE) and stability in basic media, and a low charging–discharging voltage gap (1.19 V) with excellent durability is realized in rechargeable Zn–air batteries. [Display omitted] • The hollow spherical architecture is manipulated to deliver ample solid-liquid-gas reaction interface. • The incorporation of sulfur dopant gives rise to highly active sites on reaction interface. • The CoFe-SNC with desirable interface microenvironment shows outstanding performance in Zn–air battery. [ABSTRACT FROM AUTHOR]