Metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) as the novel porous materials have the merits of diverse, adjustable functionality, high porosity and surface area, which have great application prospects in the gas storage, separation and catalysis. In addition, their derivates make up for the insufficient of electronic conductivity and chemical stability of MOFs and COFs, and provide a new ideal for accurate control of material structure. Up to now, many efficient electrocatalysts have been designed based on MOFs, COFs and their derivates for O₂ reduction/evolution reactions (ORR/OER) and CO₂ reduction/evolution reactions (CO₂RR/CO₂ER) in the metal-air batteries. In this review, the latest development of MOFs, COFs and their derivates in the metal-air batteries is summarized, and we discuss the structural characteristics of these materials and their corresponding mechanisms of action. By comprehensively reviewing the advantages, challenges and prospects of MOFs and COFs, we hope that the organic framework materials will shed more profound insights into the development of electrocatalysis and energy storage in the future.

Realizing the reduction of N₂ to NH₃ at low temperature and pressure is always the unremitting pursuit of scientists and then electrochemical nitrogen reduction reaction offers an intriguing alternative. Here, we develop a feasible way, gamma irradiation, for constructing defective structure on the surface of WO₃ nanosheets, which is clearly observed at the atomic scale by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The abundant oxygen vacancies ensure WO₃ nanosheets with a Faradaic efficiency of 23% at -0.3 V vs. RHE. Moreover, we start from the regulation of the surface state to suppress proton availability towards hydrogen evolution reaction (HER) on the active site and thus boost the selectivity of nitrogen reduction.

The urgent expectation of the next-generation energy storage devices for electric vehicles has driven researchers' attention to the lithium-oxygen (Li-O₂) batteries due to the satisfied specific energy density. Herein, spatially-controlled Co₃O₄ nanoflake arrays with three-dimensional- networked morphology are adopted as flexible and self-standing oxygen cathodes in Li-O₂ batteries. The spinel-phase Co₃O₄ nanoflakes were converted from two-dimension metal-organic frameworks with abundant available channels and large specific surface area. The open-structure nanoflake arrays possess sufficient Li₂O₂/cathode contact interface, great bifunctional catalytic performance and adequate Li₂O₂ accommodation, leading to the enhanced electrochemical performance of the Li-O₂ batteries. As expected, the binder-free porous Co₃O₄/CT cathode delivers a high capacity of 6, 509 mAh·g^-1 (200 mA·g^-1) and enhanced stability over 100 cycles (limited by 1, 000 mAh·g^-1). In addition, pouch-type Li-O₂ batteries were successfully designed and cycled with Co₃O₄/CT cathode as oxygen electrodes, demonstrating its potential application for flexible electronics and wearable energy storage devices.