Designing rational nanostructures of metal-organic frameworks based carbon materials to promote the bifunctional catalytic activity of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is highly desired but still remains a great challenge. Herein, an in situ growth method to achieve 1D structure-controllable zeolitic imidazolate frameworks (ZIFs)/polyacrylonitrile (PAN) core/shell fiber (PAN@ZIFs) is developed. Subsequent pyrolysis of this precursor can obtain a heteroatom-doped carbon nanofiber network as an efficient bifunctional oxygen electrocatalyst. The electrocatalytic performance of derived carbon nanofiber is dominated by the structures of PAN@ZIFs fiber, which is facilely regulated by efficiently controlling the nucleation and growth process of ZIFs on the surface of polymer fiber as well as optimizing the components of ZIFs. Benefiting from the core-shell structures with appropriate dopants and porosity, as-prepared catalysts show brilliant bifunctional ORR/OER catalytic activity and durability. Finally, the rechargeable Zn-air battery assembled from the optimized catalyst (CNF@Zn/CoNC) displays a peak power density of 140.1 mW cm , energy density of 878.9 Wh kg , and excellent cyclic stability over 150 h, giving a promising performance in realistic application.

Atomically thin borophene has recently been synthesized experimentally, significantly enriching the boron chemistry and broadening the family of two-dimensional (2D) materials. Recently, oxides of 2D materials have been widely investigated for next-generation electronic devices. Based on the first-principles calculations, we predict the existence of the superconductivity in honeycomb borophene oxide (B2O), which possesses a high stability and could be potentially prepared by intrinsically incorporating oxygen into the recently synthesized borophene. The mechanical, electronic, phonon properties, as well as electron–phonon coupling of metallic B2O monolayer, have been systematically scrutinized. Within the framework of the Bardeen–Cooper–Schrieffer theory framework, the B2O monolayer exhibits an intrinsic superconducting feature with a superconducting transition temperature (Tc) of ~10.3 K, higher than many 2D borides (0.2–7.8 K). Further, strain can be utilized to tune the superconductivity with the optimal Tc of 14.7 K under a tensile strain of 1%. The superconducting trait mainly originates from the out-of-plane soft-mode vibrations of the system, which are significantly enhanced via the light O atoms’ incorporation compared to other 2D metal-boride superconductors. This strategy would open a door to design 2D superconducting structures via the participation of light elements. We believe our findings greatly bloom the 2D superconducting family and pave the way for future nanoelectronics.

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The optimized Fe–N–NDC-1-900 exhibits robust anchoring ability to immobilize atomic Fe species with abundant Fe–N4 sites, demonstrating excellent electrocatalytic activity in both the ORR and OER.

Two dimensional superconductors are demonstrated in our predicted rect-, hex-GaB6, rect- and hex-InB6 systems, with superconducting transition temperatures of 1.67, 14.02, 7.77 and 4.83 K, respectively.

We demonstrate that the recent experimentally synthesized Cu2Si monolayer is a BCS-type two-dimensional superconductor with Tc being ∼ 4.1 K.

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